Journal articles on the topic 'Broaching machine'

Predicting machine tool performance at the design stage is one way to resolve the time issue and achieve cost savings. The objective of this paper was to develop a new non-hydraulic broaching machine using a servo motor, ball screw, and roll element linear guide using virtual prototyping technology. First, we developed a multi-body simulation model (MBS) of a servo-based broaching machine to investigate its dynamic behaviour. Then, an adaptive sliding mode proportional-integral-derivative (PID)-based controller (ASMPID) was proposed to conduct the broaching process. We then performed a co-simulation between the mechanical structure and virtual controller to investigate the ram body trajectory and identify the optimal control parameters. Finally, we manufactured a prototype machine to evaluate the simulation results and determine the benefits of the new system. Our results indicated that the proposed model, which includes a mechanical structure and intelligent controller, effectively improved broaching machine design. Therefore, this work is expected to improve the prototyping efficiency of new broaching machines.

Modal parameters for LG51SH broaching machine from operational responses are studied to examine the dynamic properties of mechanical structure. The operational modal is analyzed using PolyMAX method with responsive data of key point in broaching machine, which is excited in practical broaching operation and tested by LMS SCADAIII-105 system. The identified steady state modal, representative modal shape, modal damping ratio and natural frequency in broaching are presented. The test and analysis result shows that there are natural frequency of 38Hz and 192Hz, which are close to multiple of the fundamental frequency of cutting force in broaching, 6Hz, therefore, reasonable cutting velocity should be adopted to void producing fundamental frequency of cutting force in broaching.

Broaching is a type of machining that uses a toothed tool similar to a saw. There are several types of broaching machines includes linear broaching machines and hydraulic machines. Early linear broaching machines were driven mechanically by screws. However, hydraulic machines are faster, smoother in operation, and allow for high-speed steel broaches to be used. The purpose of this study is to an analysis of the vertical moving table type in the broaching machine. In this study, finite element analysis was carried out to examine the structural characteristics of broaching machine design. A model was created in CATIA software and analyzed with ANSYS to find the structural characteristics. The friction characteristic of PBT-40 material was also investigated. This material is recommended for guide rail surface lamination to reduce the friction coefficient and ram body wear. The simulation results provide information for the next step of development before physical prototype will be made. The maximum deformation of the workpiece table was 0.0517 mm on the positive Z-axis, and the maximum deformation on the pulling head device was 0.0598 mm on the negative Z-axis. The friction coefficients were between 0.013 and 0.047 in the sliding speed range of 0.06 to 0.34 m/s. The PBT-40 material has a wear coefficient of 1.604x10-13 m3/Nm according to the test. From the ANSYS friction simulation, it can be concluded that the PBT-40 material would not easily wear out during operation of the machine. It can be seen that small frictional stress occurred on the surface ranging from 8.273x10-5 to 8.381x10-5 MPa.

In view of the disadvantages on working vibration or even cannot work of broaching machine derived by broaching-load’s uncertainty, a testing system of broaching-load is designed. The testing system uses an industrial computer, a high-precision data-acquisition-card, two pressure-sensors, a displacement-sensor and Borland C++ to test the broaching-load on the base of broaching machine’s electronic control system. The factual application in hydraulic broaching machine shows that the proposed system has a good performance on testing-accuracy. The proposed system gives an effective solution to broaching-load testing.

Dynamic properties of the whole broaching machine structure greatly contribute to the broaching quality and efficiency. However, it is hard to measure the dynamic parameters because they will change during operation compared with the static results from classic experimental modal analysis. This study is to examine the dynamic parameters of broaching machine LG7120KT using both the numerical finite element (FE) method and the experimental operational modal analysis (OMA). Firstly, FE analysis model of the broaching machine with the real dimension is constructed and calculated. Second, experimental results are obtained from OMA in practical broaching process, which can be used to identify steady-state modes. Modal parameters including mode shapes, damping ratio, and natural frequencies are examined, using both LMS SCADAS III-305 system and PolyMAX method in OMA. The numerical and experimental results show high agreement in their calculated natural frequencies. From the modal analysis results, it is also found the vibration normal to cutting direction can be greatly reduced by adjusting broaching speed. From the topology optimization result based on the already correlated FE model, we redesigned a lightweight machine structure with a better dynamic performance, due to its lower displacement of broaching machine at force point and its higher first-order natural frequency. The experimental and numerical results in this paper help to design the structural parameters of broaching machine and propose a better broaching process.

The 3D geometric model was established based on working principle of a new keyway broaching machine. The horizontal deformation of drawing knife blade in working stroke is analyzed by the finite element software ABAQUS. The research which effect law of the feed, structural sizes of cutter rod and sizes of cutter guiding rod on position deformation of broaching blade in working stroke given quantitative relationship between parameters of processing craft and structure and cutting precision. The selection method and way of processing parameters and structural parameters to improve broaching precision of keyway broaching machine are obtained. The research work provides relevant technological basis for the design of high precision keyway broaching machine.

This paper takes the CNC broaching machine as the research object. The dynamic models for the various components of the broaching machine are established. The theories of the modal analysis and the dynamic performance are studied respectively. According to the analysis results, the improvement schemes on the partial structures or geometries are put forward. At the same time, the paper also studied preliminarily the dynamic characteristics of the CNC broaching machine. During the analysis process, the models of the parts and the whole model are established using the finite element method to optimize the structures of the parts and the whole. That has undoubtedly a very important significance for improving the dynamic performance of the new machines structure, improving the processing accuracy, shortening the development cycle and reducing the development costs.

For the general broaching machines problems of structure bulkiness, poor cylinder synchronization, lack of optimization design, low-grade control system, low efficiency and operational reliability, the paper studied the structural optimization technology of the large-scale high-performance CNC vertical broaching machine, designed the new 360-degree high-load lateral rotary table, the axial-rotary multi-pass joint of the anti-leakage and the elastic-contact, and the modular slider rails, so as to improve the mechanical performance, the working stability and reliability. The remote network intelligent monitoring system and the multi-function data acquisition processor for the developed CNC broaching machine, realize the enterprise management information, the enterprise resource optimization, and the automation and intelligence of the manufacturing process.

With respect to the conventional hydraulic broaching machine, the all-electric CNC broaching machine has many advantages. This paper combines the digital servo control system, the double ball screw and the linear motion rail to realize broaching for the two workpieces internal threads of the different rotations and lead distances. The DSP-based full-AC drive control system was developed. The observer is used to observe the speed instead of measuring the speed using the velocity sensor such as the encoder. It solves the drive control problems for the speed-sensorless servo-motors. That is in line with the trend of the CNC broaching machine technology toward the electronization, high-speed and preciseness.

Cutting forces generated in broaching have a direct influence on the generation of heat, tool wear or failure, quality of machined surface and accuracy of the work piece. In this paper not only a cutting forces test scheme has been proposed but also a cutting forces measurement equipment has been designed with PCB 740B02 dynamical strain sensor and LMS SCADA III test system, respectively. Dynamical strain sensor was pasted on the cylinder type sensitive elements with which table and workpiece was connected. Experimental investigation on the dynamic cutting forces in the broaching direction of a hydraulic broaching machine had been carried out. Cutting forces measurement tests on Q235 steel workpiece material during broaching had been performed. Broaching in a variety of velocities, namely, 3.3m/min, 5m/min and 8m/min and in a variety of cutting depth, namely, 0.03mm, 0.04mm, 0.05mm and 0.07mm, were investigated. Output signal was analyzed both in time and frequency domains and the key characteristics of the cutting forces signal was obtained. Correlation between the frequency of broaching forces and the broaching velocity was also studied.

In order to improve the keyway broaching process and verify the feasibility of vibration-assisted broaching process, an experimental study on a novel hydraulic vibration assisted broaching (HVAB) system with double-valve electro-hydraulic exciter (DVEHE) is proposed in this paper. The performances of HVAB at different excitation frequencies were compared from three aspects: (a) the cutting force under the different vibration frequencies, (b) the surface roughness of the workpiece, and (c) the flank face wear of the tool. For precision on-line measurement of larger broaching forces, four piezoelectric sensors were fixed on the broaching machine. The experimental results show that HVAB can effectively improve the performance of the broaching process, approximately reduce the broaching force by as much as 9.7% compared to conventional broaching (CB) and improve the surface quality of workpiece. Some explanations are offered to support the observations.

Fir tree groove broaching is prone to deformation, which affects the machining precision of rear wheel groove. The numerical broaching force is calculated to improve deformation of the processed round tank .This paper uses the planer to make cutting tests that are carried out in shaping machine to simulate the wheel broaching process and measures the cutting force in the experiment. After analyzing the unit numerical cutting force of GH4698 broaching is finally obtained. It provides a simple method to calculate the cutting force of wheel groove machining.

Reasonable tool condition has crucial importance to prevent tool malfunction such as abnormal wear, chipping and cutting teech breakage when broaching expensive components i.e. gas turbine engines disks. This paper proposes a broaching simulation test method of using customized single tooth groove tools with a variety of rake angle and clearance angle to simulate broaching processing at shaper machine under different cutting depth. The effects of tool condition and cutting depth on cutting forces, surface roughness analyzed by Response Surface Methodology and surface morphology of machined surface were discussed, which revealed that the changes of cutting depth play a dominate role in processing quality, followed by tool rake angle, and tool clearance is subordinate. Good tool edge strength should be assured from prevent shock and vibration during the selection of tool condition.

Aiming at the lower performance, accuracy and efficiency of the existing motion control process for the traditional broaching machine, the paper studies the high-performance dual-hydraulic synchronous servo drive control technology. The synchronous electro-hydraulic servo system forms the closed loop control by the detection and feedback of the output quantity. It eliminates and restrains largely the influence of the adverse factors to obtain the high-precision synchronous driving performance. The numerical control system based on the real-time error compensation and the intelligent control to the auxiliary machinery is developed. It is used for the CNC broaching machine to make the steady-state synchronous displacement error of the double cylinders be ≤ 0.5mm.

The two-cylinder drive is one of many commonly used mechanical drive forms. Its synchronous control accuracy determines the movement accuracy of the working machinery. The paper established the mathematical model for the two-cylinder electro-hydraulic servo synchronous drive system, and revealed that the two-cylinder horizontal electro-hydraulic synchronous drive system has the cascade form of the linear system with the nonlinear system. Taking the band sawing machine and the broaching machine as the application object, the paper analyzed their compositions and synchronization CNC systems. Aiming at the dual-cylinder drive form for the broaching machine, the IPSO-PID synchronous controller of the two-cylinder system was designed. Through the digital simulation and actual testing, the results show that the IPSO-PID synchronous controller is faster in the tracking response speed and better in the synchronization performance than the conventional PID synchronization controller.

Broaching operations require stiff machine tools that have to withstand high cutting forces. This work aims to develop a methodology to predict the macroscopic cutting forces on a real, internal broaching operation comprising a large number of teeth. The macroscopic forces are estimated, based on the addition of local forces that are applied to each section and are simultaneously in contact with the broach. These local forces are calculated using a model of specific cutting pressure, depending on the rise per tooth. This study uses two methods to identify this specific cutting pressure model, that is, a direct approach based on orthogonal cutting tests and an inverse approach based on an instrumented broaching operation. It is shown that the direct method is effective in identifying a specific cutting pressure model and enables the prediction of macroscopic forces. Moreover, the direct approach provides more comprehensive results in terms of radial forces.

The 3D model of a horizontal broaching machine is built in inventor, and the first ten natural frequencies and mode of vibration are obtained by the software of ANSYS. Dynamic response of the whole machine is also calculated in ANSYS, the weak link of the dynamic performance of the whole machine is found combined with the result of modal analyses, consequently, settings of the cutting speed and the improvement for the structure are provided.

Broaching is a precision multipoint metal removal operation normally employed for manufacturing variety of complex parts having either internal or external features. Broaching can produce high precision and good surface finish at a high metal removal rate. The unique feature of a broach tool is that the feed/depth of cut for the teeth is built into the broach unlike other cutting tools. The tool design (e.g., rise per tooth and tooth geometry) play a vital role in the broach performance. A specially adapted machine tool modified to investigate a single broach tooth has been used. Cutting forces and material removal rate have been measured during experimental work for different combination of broaching parameters and broach tool geometry. The effect of the parameters on the surface quality produced has been established. The characteristics of chips formed have also been defined. Finally, optimum tooth geometry and rise per tooth have been recommended for tool performance, broached surface quality and efficient chip formation. The information provided in this paper will be beneficial for broach tool designers and manufacturing engineers.

Knowledge of temperature fields and heat flow evolving during metal cutting processes is of significant importance for ensuring and predicting the product`s quality. Furthermore, this knowledge enables an improved usage of resources, such as machine tools and tool deployment. The strength of the heat sources as a result of the process and the distribution of the temperature in the material directly influence the tool wear mechanisms, wear rate, thermo-elastic deflection of the tool centre point and the amount of heat flowing into the newly generated work piece surface. Especially the latter effect is of crucial importance when it comes to safety critical components as they are employed in aero-engines. In aviation industry, the surface integrity is used as a complex quality measure summarising several aspects at the machined surface and sub-surface out of which many issues are predominantly thermal issues (e.g. temperature driven hardening of the work piece material, re-cast and white etching layers as well as residual stress profiles).

Higher productivity and improved part quality requirements are increasingly being demanded of material removal processes. While these demands impose significant challenges, in some cases they also present opportunities to consider grinding as a viable alternative to processes such as turning, milling, and broaching. This has been made possible through advances in various aspects of grinding technology including abrasives, wheel design, coolant, and its application as well as machine tool technology. The current paper discusses grinding of a nodular cast iron transmission yoke component on a dual spindle grinder as opposed to the current processes of milling and broaching. High contact length in this application presented significant problems to supply coolant to the grinding zone and had an adverse effect on wheel life. An electroplated cubic boron nitride wheel was designed with special arrangements to supply coolant to the grinding zone. This design facilitated grinding the yokes at a specific removal rate of 200mm3/mms and a cutting speed of 80 m/s while maintaining yoke parallelism of less than 5 μm. Grinding tests were conducted using water-soluble oil coolant. Both grinding power and part parallelism were monitored in a pilot run to evaluate the wheel life. The approach was demonstrated to provide lower total operating cost while providing superior part quality.

The paper presents effect of burnishing broaching process on the geometric structure of the steel tubes. Burnishing is a plastic surface treatment. Processing tools are hard and smooth surface. Burnishing elements of are ball, roll and disk. Burnishing be flat surfaces, and cylindrical shape. Burnished surfaces are cylindrical outer and inner. Because of the type of the force can be divided into static and dynamic burnishing. Due to the kinematics can be divided into sliding and roller burnishing. Occurrence of moving parts in direct contact with the material qualifies for the group process of burnishing rolling. The sliding burnishing design element property is part of the work surface burnished permanently attached to the handle. Burnishing is used as a finishing strengthens and smoothness, can be realized on the universal machine tools and machining centers, effectively replaces the machining operations such as grinding, reaming, honing and lapping.

This paper deals with developments of Wire-EDM technologies for fir tree slot production. The aim of these developments is to substitute certain conventional processes within turbine manufacturing that have been identified as non-optimal like the critical broaching process. Thereby the negative characteristics like inflexible manufacturing processes, high machine tool investment costs and huge energy consumption can be abolished. The objective targets of the conducted research are to meet all safety requirements of the critical components and get an economic manufacturing process. In the first step a special brass wire technology for cutting Ni-based super alloys was developed. Main focus was to meet the requirements of fir tree production concerning aspects of surface integrity and geometry. To measure these aspects on the one hand non-destructive analyses have been performed to guarantee surface roughness and accuracy. On the other hand destructive analyses in terms of cross section polishing for showing thermal influenced rim zones have been prepared. A capable Wire-EDM process is presented.

During a manufacturing process, it is essential to quickly identify whether a tool needs to be replaced or adjusted, to ensure that production quality is not compromised. Therefore, the re-inspection of the product or first article inspection is an important process. Reducing the inspection time can reduce the time spent waiting for a product in the production line. This research aimed to design a system that can automatically and rapidly measure the dimensions of irregular tooth contours in the broaching process, to ensure cutting tools are replaced when necessary. This study developed an automatic machine for measuring the irregular tooth contours of large ring parts; the tooth root, tooth height, and tooth thickness of the workpiece are measured. The measurement diameter is approximately 200 mm, and the radial inspection accuracy is within ±20 μm; we aimed to reduce the detection time considerably. An optical micrometer and an automatic rotating platform were used in the measurement system. The workpieces to be measured were easy to install, and the eccentricity was automatically corrected by the system, thus saving time that would be taken to correct Abbe errors. This research successfully developed a rapid optical measurement system that can reduce the inspection time from 30 min to 60 s. Moreover, the maximum radial measurement error is −0.02 mm, which means that the measurement accuracy is within ±20 μm (total: 40 μm).

The Industry 4.0 revolution envisions fully interconnected scenarios in the manufacturing industry to improve the efficiency, quality, and performance of the manufacturing processes. In parallel, the consolidation of 5G technology is providing substantial advances in the world of communication and information technologies. Furthermore, 5G also presents itself as a key enabler to fulfill Industry 4.0 requirements. In this article, the authors first propose a 5G-enabled architecture for Industry 4.0. Smart Networks for Industry (SN4I) is introduced, an experimental facility based on two 5G key-enabling technologies—Network Functions Virtualization (NFV) and Software-Defined Networking (SDN)—which connects the University of the Basque Country’s Aeronautics Advanced Manufacturing Center and Faculty of Engineering in Bilbao. Then, the authors present the deployment of a Wireless Sensor Network (WSN) with strong access control mechanisms into such architecture, enabling secure and flexible Industrial Internet of Things (IIoT) applications. Additionally, the authors demonstrate the implementation of a use case consisting in the monitoring of a broaching process that makes use of machine tools located in the manufacturing center, and of services from the proposed architecture. The authors finally highlight the benefits achieved regarding flexibility, efficiency, and security within the presented scenario and to the manufacturing industry overall.

The restoration cost for agricultural machinery parts systematically influences on that of agricultural production. Hence the need to find the most effective and less expensive methods for repairing these parts. The bushes of the connecting rods of internal combustion engines are among the parts that wear out quickly and are made with expensive and deficient bronzes. The technical equipment used consists a worn out bushes of bronze treated by various methods, a vibro-rolling device, deformation software, a profilograph-profilometer, a microscope, and a machine of friction. In order to analyze the performance of the bushes of the connecting rods of internal combustion engines resulting from various treatments, the following parameters were determined: the height of the micro-relief elements, the absorption and the surface oil retention force, the optimum support surface, the wear and the wear intensity, the temperature of the friction area and the duration of the running-in period. The vibro-rolling followed by the deformation by broaching increases oil retention force from 1.8 to 2 times, and the wear resistance from 1.86 to 3.45 times as compared with the traditional technology. This new technology can be used for the restoration of the bushes of the connecting rods of internal combustion engines.

In this study, cold reduction process of the tubular metal is applied to manufacture the drive shaft for the rear wheel drive system. With this method during forming process, chip forming such as hobbing and broaching method is not involved. The manufacturing process is as follows; the tube which the sheet is formed and welded to by roll forming machine, is mounted on a suitable mandrel. This mandrel has an external toothing which corresponds to internal toothing of the final product. During axial moving and rotating of the workpiece, forming operation is carried out in lengthwise direction of the toothing. This forming rolls is positioned on the roll head and have a rolling axis vertical with the one of a mandrel. The total forming load needed in the cold reduction process is separated into numerous forming steps along the entire cylindrical length of the zone to be formed. In the process of cold forming on the profiled mandrel during the impact forming operation, material is pushed into depression of toothing of a mandrel mainly in a radial direction. Finally splines can be generated on the surface of components and overall elongated. If the process parameter such as the length of forming per 1rotation of 1roll is not optimized, the impact force from the rolls of the forming process causes geometrical defects. So the optimal parameters such as feeding and rotating speed of workpiece and the forming length should be properly determined. And the effects of the weld line positioning on the formability of the forming process is analyzed to minimize the generation of the defects such as crack on the surface of splined zone.

The present work analyzes the influence of an orthogonal machining process on the generation of nanocrystalline surface layers. Thereby, AISI 4140 is used as work piece material. Metallic parts with a severe nanocrystalline grain refinement in the near-surface area show many beneficial properties. Such surface layers considerably influence the friction and wear characteristics of the work piece in a subsequent usage as design elements working under tribological loads. The focus of this paper is an experimental analysis of a finishing orthogonal cutting operation, carried out with a broaching machine, to generate nanocrystalline surface layers. The influence of process and geometry parameters on the generation of nanocrystalline surfaces is investigated with the aim to massively decrease the grain size in the work piece surface layer. Parameters that are studied and taken into account in the manufacturing process are cutting edge radius rβ, depth of cut h and cutting velocity vc. The cutting edge radius rβ is modified by a drag finishing process. The generation of nanocrystalline surface layers is especially influenced by the design of the uncoated carbide cutting tools. Additionally, cutting force Fc and passive force Fp are determined by a 3-component dynamometer to calculate the relationship between specific cutting force kc and specific passive force kp. The temperature beneath the clearance face is detected by a fiber optic pyrometer. These measurement methods and devices are applied to detect the impact of the most relevant measurement values occurring during machining and causing a drastic reduction of grain size in the surface layer. The evaluation of the manufacturing process is carried out by detailed analyses of the microstructural conditions in the surface layer after processing using a Focused Ion Beam (FIB) system. These material characterizations provide information about the surface engineering concerning the microstructural changes in the surface layer of the work piece due to finishing orthogonal cutting processes.

Broaching is an important technique for creating tooth structures in mechanical components. In the present work, the effects of the broaching process on the material state in the near surface region at the root of the tooth was analyzed. The studies were carried out on broached plates made from case hardening steel SAE 5120. The cutting speed and machining condition (cooling lubricant, dry machining) were varied. During broaching with a TiAlN coated tool the cutting forces were monitored. Subsequently, the local residual stresses at the root of the tooth were determined using X-ray diffraction. Further, surface roughness and micro hardness measurements as well as microstructure analysis complement the results. The results indicate that cutting forces have a high influence on the development of the residual stress state at the machined surface whereas no significant effect on changes in surface hardness and microstructure could be observed. Dry cutting with relatively high cutting speeds (≥ 30m/min) result in low cutting forces and hence in high tensile residual stresses in broaching direction.

A process for grinding deep profiled slots in a nickel-based alloy with electroplated cubic boron nitride (CBN) wheels and straight oil is presented. These slots were prepared by this process for further grinding with electroplated CBN quills to generate the final fir-tree slots in gas turbine disks. Fir-tree slots are usually machined using broaching. The application of broaching, however, is limited in the case of nickel-based powder metal alloys due to short life of broaching tools and the effect on machined surface integrity. Grinding tests were first conducted on rectangular blocks to grind slots without inclinations at a fixed wheel speed vs = 60 m/s to identify the combinations of depths of cut, workspeed, and up/down grinding satisfying the requirements of ground surface quality and material removal rate. Inclined slots were then ground with the identified condition on a block representing a segment of an actual turbine disk to validate the condition. The wheel life was finally tested by grinding all the slots on the actual disk. Grinding power was measured, and the ground surfaces were inspected for any sign of burning. Preset target material removal rate and wheel life were obtained. It was found that electroplated CBN wheels are capable of grinding deep profiled slots on the difficult-to-cut nickel-based alloy.

The effect of starting notch machining methods on fracture splitting of connecting rod was studied by axial tensile tests with single edge notch. The axial tensile specimens were made of the high carbon microalloyed steel (C70S6) which is now most widely used by the connecting rod of fracture splitting. The single edge notch of axial tensile specimens were respectively machined by laser notch、wire cut electrical discharge and broaching. The notch tip plastic deformation of specimens was compared by the fractography. The experimental results indicate that the specimens with laser notch can be fractured by the smallest axial tensile load which is respectively about 20% and 30% smaller than the fracture load of the specimens by wire cut electrical discharge and broaching. Considering the rich micro-local crack transformation hardened zones around the notch by laser the paper present the equivalent critical stress intensity factor KIcL which can be used to calculate the fracture load with laser notch.

Based on the theoretical principle of tapping formation and simulation with modified-tooth tap, the relationship among the different geometric parameters of the tap was further analyzed. A series of modified-tooth taps and standard ones with a cutting cone angle of 7°30´and a outer diameter of M6, which were made from high-speed steel W9, were taken to do the comparative tapping test on nickel-based high-temperature alloy GH4169, titanium alloy TC4 and 45 steel. The test results indicated that the leading cause of difficult tapping in GH4169 and TC4 was the largeness of their friction torques which were about 35 % and 62 % of tapping torque respectively, where the frictional wear was a fundamental reason for tough tapping GH4169 and the spring back of machined surface for TC4.The obvious decreases of friction torque with the modified-tooth tap approximately 70% and 50% respectively for GH4169 and TC4 were attributed to its unique tapping formation principle of generating broaching but no remarkable effects on 45 steel in comparison with standard tap.

An important place among the advantages of cutting tools for broaching, in addition to high efficiency, is held by the high resistance due to the structure in which the forming elements duplicate partially or completely. An important advantage of the broach tool is also its capacity for multiple re-sharpening, allowing recovering the parameters of cutting of a conventionally worn tool up to the characteristics of a new one, within the tolerances range. Due to these qualities, cases where the broach is used for years in plants especially in the case of a small-scale production, are quite common. In these circumstances, its intelligent maintenance, implying regular monitoring of tool condition, proper storage, timely re-sharpening is of great importance. Information support for tool operation with a long service life is impossible without the development and continuous implementation of special organizational methods, which is the most important task of the tool part and engineering technological services of the enterprise. This article describes the experience in the creation, development, practical use of the monitoring system, using the example of angular broaches. This system allowed systematization of all information on machined parts, planning measures for re-sharpening, predicting the remaining life of broaches, determine the economic effect obtained from the operation of each tool item. The introduction of monitoring has become a driving factor in the development of a series of measures for improvement of examination, storage and maintenance of the broach tools. In addition, the monitoring system provided valuable statistical material used for quality management purposes, timely provision of plants with broach tools. All of the above mentioned ultimately allowed us to obtain a significant economic effect, and statistical information became the basis for scientific research conducted at the enterprise.

AbstractWith increasing environmental concerns, the substitution of mineral oil-based cutting fluid has become an urgent issue. Using vegetable soybean oil as base fluid, nanofluid cutting fluids (NFCFs) were prepared by adding different weight concentrations of nanographite particles (NGPs), and their penetration and lubrication performances were studied. A novel simulated tool-chip slit with micrometer-sized geometry was manufactured to evaluate and quantify the penetration rate of the NFCFs by image analysis approach. Moreover, a large number of comparative experiments on the closed-type broaching machine were carried out to compare the performance of the proposed NFCFs and a commercial cutting fluid in terms of cutting force, workpiece surface roughness, and metal chip. It is found that there is an optimal NGP concentration in NFCF for practical cutting applications. When the concentration of NGP is 0.4 wt%, the broaching process lubrication exhibits an ideal mixed lubricate state, resulting in minimal friction resistance, and thus, both the cutting force and chip curling angle reach their corresponding best values. Moreover, the proposed NGP-based vegetable-oil cutting fluid exhibits excellent environment-friendliness and low-cost consumption in the minimal quantity lubrication (MQL) method; this demonstrates its potential for replacing the traditional broaching cutting fluid.

Abstract The demand for higher efficiency in aircraft propulsion engines leads to materials with increasing thermomechanical strengths and new designs inducing filigree geometries of blisks and disks. Because of new designs which induce tighter tolerances, the high mechanical process forces in conventional cutting processes like broaching cause inacceptable geometrical deviations and high tooling costs. Due to the electro-thermal material removal mechanism, electrical discharge machining (EDM) ensures a force free and thus precise machining. The manufacture of fir tree slots in nickel-based alloys by wire EDM has been investigated in the last few years and the process was verified as an alternative technology for broaching. To get a better competitive position, the productivity can be prospectively increased by using an additional indexing rotary axis which ensures a precise and automated production of rotationally symmetric components and reduce production times, e.g., for the manufacture of fir tree slots on a disk. Nevertheless, the application of these axes cause changed flushing conditions and can also affect the electrical contacting as well. Both influence the process performance and demand a technology development or adjustment of standard machining technologies. The influence of these changed machining conditions has not been investigated scientifically to date. In this paper, the surface integrity and process performance of fir tree slots machined by wire EDM on the machine table are compared with the manufacture by using an additional indexing rotary axis.

In this work, the impact of the heat treatment condition of steel AISI 4140 on its frictional contact behavior with coated cemented carbide and cubic boron nitride (CBN) in dry metal cutting is experimentally investigated. Two different kinds of tests were performed. The frictional behavior was investigated under conditions very similar to metal cutting on a frictional test bench, which was installed on a broaching machine. Additionally, orthogonal cutting processes with linear workpiece geometries were conducted on the same machine. The cutting experiments included observations of cutting forces, high-speed filming of chip formation, chip thickness ratio analysis as well as a comprehensive metallographic characterization of the chips and workpiece surfaces. The impacts of the undeformed chip thickness and cutting speed were investigated individually for coated cemented carbide and CBN as cutting materials. The frictional examinations delivered the Coulomb friction coefficients for all four combinations of work and cutting materials as a function of the relative velocity. The identified frictional behaviors explain the dependencies of forces, chip thicknesses, and surface microstructures on the tool and process conditions during the cutting tests.

Do we eat what we are, or are we what we eat? Do we eat or are we eaten? In less cryptic terms, in eating, do we confirm our identities, or are our identities reforged, and refracted by what and how we eat? In posing these questions, I want to shift the terms of current debates about identity. I want to signal that the study of identity may take on new insights when we look at how we are or want to be in terms of what, how, and with whom we eat. If the analysis of identity has by and large been conducted through the optic of sex, it may well be that in western societies we are witnessing a shift away from sex as the sovereign signifier, or to put it more finely, the question of what we are is a constantly morphing one that mixes up bodies, appetites, classes, genders and ethnicities. It must be said that the question of identity and subjectivity has been so well trodden in the last several decades that the possibility of any virgin territory is slim. Bombarded by critiques of identity politics, any cultural critic still interested in why and how individuals fabricate themselves must either cringe before accusations of sociological do-gooding (and defend the importance of the categories of race, class, sex, gender and so forth), or face the endless clichés that seemingly support the investigation of identity. The momentum of my investigation is carried by a weak wager, by which I mean that the areas and examples I study cannot be overdetermined by a sole axis of investigation. My point of departure is basic: what if we were to think identities in another dimension, through the optic of eating and its associated qualities: hunger, greed, shame, disgust, pleasure, etc? While the connections suggested by eating are diverse and illuminating, interrogating identity through this angle brings its own load of assumptions and preconceptions. One of the more onerous aspects of 'writing about food' is the weight of previous studies. The field of food is a well traversed one, staked out by influential authors concerned with proper anthropological, historical and sociological questions. They are by and large attracted to food for its role in securing social categories and classifications. They have left a legacy of truisms, such as Lévi-Strauss's oft-stated maxim that food is good to think with1, or Brillat-Savarin's aphorism, 'tell me what you eat: I will tell you what you are' (13). In turn, scientific idioms meet up with the buzzing clichés that hover about food. These can be primarily grouped around the notion that food is fundamental, that we all eat, and so on. Indeed, buffeted by the winds of postmodernism that have permeated public debates, it seems that there is a popular acceptance of the fact that identities are henceforth difficult, fragmented, temporary, unhinged by massive changes to modes of employment and the economy, re-formations of family, and the changes in the gender and sexual order. Living with and through these changes on a daily basis, it is no wonder that food and eating has been popularly reclaimed as a 'fundamental' issue, as the last bastion of authenticity in our lives. To put it another way, and in the terms that guide me, eating is seen as immediate -- it is something we all have to do; and it is a powerful mode of mediation, of joining us with others. What, how, and where we eat has emerged as a site of considerable social concern: from the fact that most do not eat en famille, that we increasingly eat out and through drive-in fast food outlets (in the US, 50% of the food budget is spent on eating outside the home), to the worries about genetically altered food and horror food -- mad cows, sick chickens, square tomatoes. Eating performs different connections and disconnections. Increasingly the attention to what we eat is seen as immediately connecting us, our bodies, to large social questions. At a broad level, this can be as diffuse as the winds that some argue spread genetically modified seed stock from one region to another. Or it can be as individually focussed as the knowledge that others are starving as we eat. This connection has long haunted children told 'to eat up everything on your plate because little children are starving in Africa', and in more evolved terms has served as a staple of forms of vegetarianism and other ethical forms of eating. From the pictures of starving children staring from magazine pages, the spectre of hunger is now broadcast by the Internet, exemplified in the Hunger Site where 'users are met by a map of the world and every 3.6 seconds, a country flashes black signifying a death due to hunger'. Here eating is the subject of a double articulation: the recognition of hunger is presumed to be a fundamental capacity of individuals, and our feelings are then galvanised into painless action: each time a user clicks on the 'hunger' button one of the sponsors donates a cup and a half of food. As the site explains, 'our sponsors pay for the donations as a form of advertising and public relations'. Here, the logic is that hunger is visceral, that it is a basic human feeling, which is to say that it is understood as immediate, and that it connects us in a basic way to other humans. That advertising companies know that it can also be a profitable form of meditation, transforming 'humans' into consumers is but one example of how eating connects us in complex ways to other people, to products, to new formulations of identity, and in this case altruism (the site has been called 'the altruistic mouse')2. Eating continually interweaves individual needs, desires and aspirations within global economies of identities. Of course the interlocking of the global and the local has been the subject of much debate over the last decade. For instance, in his recent book on globalisation, John Tomlinson uses 'global food and local identity' as a site through which to problematise these terms. It is clear that changes in food processing and transportation technologies have altered our sense of connection to the near and the far away, allowing us to routinely find in our supermarkets and eat products that previously would have been the food stuff of the élite. These institutional and technological changes rework the connections individuals have to their local, to the regions and nations in which they live. As Tomlinson argues, 'globalisation, from its early impact, does clearly undermine a close material relationship between the provenance of food and locality' (123). As he further states, the effects have been good (availability and variety), and bad (disrupting 'the subtle connection between climate, season, locality and cultural practice'). In terms of what we can now eat, Tomlinson points out that 'the very cultural stereotypes that identify food with, say, national culture become weakened' (124). Defusing the whiff of moralism that accompanies so much writing about food, Tomlinson argues that these changes to how we eat are not 'typically experienced as simply cultural loss or estrangement but as a complex and ambiguous blend: of familiarity and difference, expansion of cultural horizons and increased perceptions of vulnerability, access to the "world out there" accompanied by penetration of our own private worlds, new opportunities and new risks' (128). For the sake of my own argument his attention to the increased sense of vulnerability is particularly important. To put it more strongly, I'd argue that eating is of interest for the ways in which it can be a mundane exposition of the visceral nature of our connectedness, or distance from each other, from ourselves, and our social environment: it throws into relief the heartfelt, the painful, playful or pleasurable articulations of identity. To put it more clearly, I want to use eating and its associations in order to think about how the most ordinary of activities can be used to help us reflect on how we are connected to others, and to large and small social issues. This is again to attend to the immediacy of eating, and the ways in which that immediacy is communicated, mediated and can be put to use in thinking about culture. The adjective 'visceral' comes to mind: 'of the viscera', the inner organs. Could something as ordinary as eating contain the seeds of an extraordinary reflection, a visceral reaction to who and what we are becoming? In mining eating and its qualities might we glimpse gut reactions to the histories and present of the cultures within which we live? As Emily Jenkins writes in her account of 'adventures in physical culture', what if we were to go 'into things tongue first. To see how they taste' (5). In this sense, I want to plunder the visceral, gut levels revealed by that most boring and fascinating of topics: food and eating. In turn, I want to think about what bodies are and do when they eat. To take up the terms with which I started, eating both confirms what and who we are, to ourselves and to others, and can reveal new ways of thinking about those relations. To take the most basic of facts: food goes in, and then broken down it comes out of the body, and every time this happens our bodies are affected. While in the usual course of things we may not dwell upon this process, that basic ingestion allows us to think of our bodies as complex assemblages connected to a wide range of other assemblages. In eating, the diverse nature of where and how different parts of ourselves attach to different aspects of the social becomes clear, just as it scrambles preconceptions about alimentary identities. Of course, we eat according to social rules, in fact we ingest them. 'Feed the man meat', the ads proclaim following the line of masculinity inwards; while others draw a line outwards from biology and femininity into 'Eat lean beef'. The body that eats has been theorised in ways that seek to draw out the sociological equations about who we are in terms of class and gender. But rather than taking the body as known, as already and always ordered in advance by what and how it eats, we can turn such hypotheses on their head. In the act of ingestion, strict divisions get blurred. The most basic fact of eating reveals some of the strangeness of the body's workings. Consequently it becomes harder to capture the body within categories, to order stable identities. This then forcefully reminds us that we still do not know what a body is capable of, to take up a refrain that has a long heritage (from Spinoza to Deleuze to feminist investigations of the body). As Moira Gatens and Genevieve Lloyd argue in terms of this idea, 'each body exists in relations of interdependence with other bodies and these relations form a "world" in which individuals of all kinds exchange their constitutive parts -- leading to the enrichment of some and the demise of others (e.g. eating involves the destruction of one body at the same time as it involves the enhancement of the other)' (101). I am particularly interested in how individuals replay equations between eating and identity. But that phrase sounds impossibly abstracted from the minute instances I have in mind. From the lofty heights, I follow the injunction to 'look down, look way down', to lead, as it were, with the stomach. In this vein, I begin to note petty details, like the fact of recently discovering breakfast. From a diet of coffee (now with a milk called 'Life') and cigarettes, I dutifully munch on fortified cereal that provides large amounts of folate should I be pregnant (and as I eat it I wonder am I, should I be?3). Spurred on by articles sprinkled with dire warnings about what happens to women in Western societies, I search out soy, linseed and other ingredients that will help me mimic the high phytoestrogen diet of Japanese women. Eating cereal, I am told, will stave off depression, especially with the addition of bananas. Washed down with yoghurt 'enhanced' with acidophilius and bifidus to give me 'friendly' bacteria that will fight against nasty heliobacter pylori, I am assured that I will even lose weight by eating breakfast. It's all a bit much first thing in the morning when the promise of a long life seems like a threat. The myriad of printed promises of the intricate world of alimentary programming serve as an interesting counterpoint to the straightforward statements on cigarette packages. 'Smoking kills' versus the weak promises that eating so much of such and such a cereal 'is a good source of soy phytoestrogenes (isolfavones) that are believed to be very beneficial'. Apart from the unpronounceable ingredients (do you really want to eat something that you can't say?), the terms of the contract between me and the cereal makers is thin: that such and such is 'believed to be beneficial'? While what in fact they may benefit is nebulous, it gets scarier when they specify that 'a diet rich in folate may reduce the risk of birth defects such as spina bifida'. The conditional tense wavers as I ponder the way spina bifida is produced as a real possibility. There is of course a long history to the web of nutritional messages that now surrounds us. In her potted teleology of food messages, Sue Thompson, a consultant dietitian, writes that in the 1960s, the slogan was 'you are what you eat'. Then in the 1970s and 1980s, the idea was that food was bad for you. In her words, 'it became a time of "Don't eat" and "bad foods". Now, happily, 'we are moving into a time of appreciating the health benefits of food' (Promotional release by the Dairy Farmers, 1997). As the new battle ground for extended enhanced life, eating takes on fortified meaning. Awed by the enthusiasm, I am also somewhat shocked by the intimacy of detail. I can handle descriptions of sex, but the idea of discussing the ways in which you 'are reducing the bacterial toxins produced from small bowel overgrowth' (Thompson), is just too much. Gut level intimacy indeed. However, eating is intimate. But strangely enough except for the effusive health gurus, and the gossip about the eating habits of celebrities, normally in terms of not-eating, we tend not to publicly air the fact that we all operate as 'mouth machines' (to take Noëlle Châtelet's term). To be blunt about it, 'to eat, is to connect ... the mouth and the anus' (Châtelet 34). We would, with good reason, rather not think about this; it is an area of conversation reserved for our intimates. For instance, in relationships the moment of broaching the subject of one's gut may mark the beginning of the end. So let us stay for the moment at the level of the mouth machine, and the ways it brings together the physical fact of what goes in, and the symbolic production of what comes out: meanings, statements, ideas. To sanitise it further, I want to think of the mouth machine as a metonym4 for the operations of a term that has been central to cultural studies: 'articulation'. Stuart Hall's now classic definition states that 'articulation refers to the complex set of historical practices by which we struggle to produce identity or structural unity out of, on top of, complexity, difference, contradiction' (qtd. in Grossberg, "History" 64). While the term has tended to be used rather indiscriminately -- theorists wildly 'articulate' this or that -- its precise terms are useful. Basically it refers to how individuals relate themselves to their social contexts and histories. While we are all in some sense the repositories of past practices, through our actions we 'articulate', bridge and connect ourselves to practices and contexts in ways that are new to us. In other terms, we continually shuttle between practices and meanings that are already constituted and 'the real conditions' in which we find ourselves. As Lawrence Grossberg argues, this offers 'a nonessentialist theory of agency ... a fragmented, decentered human agent, an agent who is both "subject-ed" by power and capable of acting against power' ("History" 65). Elsewhere Grossberg elaborates on the term, arguing that 'articulation is the production of identity on top of difference, of unities out of fragments, of structures across practices' (We Gotta Get Out 54). We are then 'articulated' subjects, the product of being integrated into past practices and structures, but we are also always 'articulating' subjects: through our enactment of practices we reforge new meanings, new identities for ourselves. This then reveals a view of the subject as a fluctuating entity, neither totally voluntaristic, nor overdetermined. In more down to earth terms, just because we are informed by practices not of our own making, 'that doesn't mean we swallow our lessons without protest' (Jenkins 5). The mouth machine takes in but it also spits out. In these actions the individual is constantly connecting, disconnecting and reconnecting. Grossberg joins the theory of articulation to Deleuze and Guattari's notion of rhizomes. In real and theoretical terms, a rhizome is a wonderful entity: it is a type of plant, such as a potato plant or an orchid, that instead of having tap roots spreads its shoots outwards, where new roots can sprout off old. Used as a figure to map out social relations, the rhizome allows us to think about other types of connection. Beyond the arboreal, tap root logic of, say, the family tree which ties me in lineage to my forefathers, the rhizome allows me to spread laterally and horizontally: as Deleuze puts it, the rhizome is antigenealogical, 'it always has multiple entryways' compelling us to think of how we are connected diversely, to obvious and sometimes not so obvious entities (35). For Grossberg the appeal of joining a theory of articulation with one inspired by rhizomes is that it combines the 'vertical complexity' of culture and context, with the 'wild realism' of the horizontal possibilities that connect us outward. To use another metaphor dear to Deleuze and Guattari, this is to think about the spread of rhizomatic roots, the 'lines of flight' that break open seemingly closed structures, including those we call ourselves: 'lines of flight disarticulate, open up the assemblage to its exterior, cutting across and dismantling unity, identity, centers and hierarchies' (qtd. in Grossberg, We Gotta Get Out 58). In this way, bodies can be seen as assemblages: bits of past and present practice, openings, attachments to parts of the social, closings and aversion to other parts. The tongue as it ventures out to taste something new may bring back fond memories, or it may cause us to recoil in disgust. As Jenkins writes, this produces a fascinating 'contradiction -- how the body is both a prison and a vehicle for adventure' (4). It highlights the fact that the 'body is not the same from day to day. Not even from minute to minute ... . Sometimes it seems like home, sometimes more like a cheap motel near Pittsburgh' (7). As we ingest we mutate, we expand and contract, we change, sometimes subtly, sometimes violently. The openings and closings of our bodies constantly rearranges our dealings with others, as Jenkins writes, the body's 'distortions, anxieties, ecstasies and discomforts all influence a person's interaction with the people who service it'. In more theoretical terms, this produces the body as 'an articulated plane whose organisation defines its own relations of power and sites of struggle', which 'points to the existence of another politics, a politics of feeling' (Grossberg, "History" 72). These theoretical considerations illuminate the interest and the complexity of bodies that eat. The mouth machine registers experiences, and then articulates them -- utters them. In eating, we may munch into whole chains of previously established connotations, just as we may disrupt them. For instance, an email arrives, leaving traces of its rhizomatic passage zapping from one part of the world to another, and then to me. Unsolicited, it sets out a statement from a Dr. Johannes Van Vugt in San Francisco who on October 11, 1999, National Coming Out Day in the US, began an ongoing 'Fast for Equal Rights for persons who are gay, lesbian and other sexual orientation minorities'. Yoking his fast with the teachings of Ghandi and Martin Luther King, Dr. Van Vugt says he is fasting to 'call on you to choose love, not fear, and to do something about it'. The statement also reveals that he previously fasted 'to raise awareness and funds for African famine relief for which he received a Congressional commendation'. While personally I don't give much for his chances of getting a second commendation, this is an example of how the mouth machine closed still operates to articulate identities and politics to wildly diverging sites. While there is something of an arboreal logic to fasting for awareness of famine, the connection between not eating and anti-homophobic politics is decidedly rhizomatic. Whether or not it succeeds in its aim, and one of the tenets of a rhizomatic logic is that the points of connection cannot be guaranteed in advance, it does join the mouth with sex with the mouth with homophobic statements that it utters. There is then a sort of 'wild realism' at work here that endeavours to set up new assemblages of bodies, mouths and politics. From fasting to writing, what of the body that writes of the body that eats? In Grossberg's argument, the move to a rhizomatic field of analysis promises to return cultural theory to a consideration of 'the real'. He argues that such a theory must be 'concerned with particular configurations of practices, how they produce effects and how such effects are organized and deployed' (We Gotta Get Out 45). However, it is crucial to remember that these practices do not exist in a pure state in culture, divorced from their representations or those of the body that analyses them. The type of 'wild realism' that Grossberg calls for, as in Deleuze's 'new empiricism' is both a way of seeing the world, and offers it anew, illuminates otherly its structures and individuals' interaction with them. Following the line of the rhizome means that we must 'forcibly work both on semiotic flows, material flows, and social flows', Guattari goes on to argue that 'there is no tripartition between a field of reality, the world, a field of representation, the book, and a field of subjectivity, the author. But an arrangement places in connection certain multiplicities taken from each of these orders' (qtd. in Grossberg, We Gotta Get Out 48). In terms of the possibilities offered by eating, these theoretical and conceptual arguments direct us to other ways of thinking about identity as both digestion and as indigestible. Bodies eat into culture. The mouth machine is central to the articulation of different orders, but so too is the tongue that sticks out, that draws in food, objects and people. Analysed along multiple alimentary lines of flight, in eating we constantly take in, chew up and spit out identities. Footnotes 1. As Barbara Santich has recently pointed out, Lévi-Strauss's point was made in relation to taboos on eating totem animals in traditional societies and wasn't a general comment on the connection between eating and thinking (4). 2. The sponsors of the Hunger Site include 0-0.com, a search engine, Proflowers.com, and an assortment of other examples of this new form of altruism (such as GreaterGood.com which advertises itself as a 'shop to benefit your favorite cause'), and 'World-Wide Recipes', which features a 'virtual restaurant'. 3. The pregnant body is of course one of the most policed entities in our culture, and pregnant friends report on the anxieties that are produced about what will go into the future child's body. 4. While Châtelet writes that thinking about the eating body 'throws her into full metaphor ... joining, for example the nutritional mouth and the lover's mouth' (8), I have tried to avoid the tug of metaphor. Of course, the seduction of metaphor is great, and there are copious examples of the metaphorisation of eating in regards to consumption, ingestion, reading and writing. However, as I've argued elsewhere (Probyn, Outside Belongings), I prefer to focus on the 'work' (or as Le Doeuff would say, 'le faire des images') that Deleuze and Guattari's terms accomplish as ways of modelling the social. This is a particularly crucial (if here underdeveloped) point in terms of my present project, where I seek to analyse the ways in which eating may reproduce an awareness of the visceral nature of social relations. That said, and as my valued colleague Melissa Hardie has often pointed out, my text is littered with metaphor. References Brillat-Savarin, Jean-Anthelme. The Physiology of Taste. Trans. Anne Drayton. Penguin, 1974. Châtelet, Noëlle. Le Corps a Corps Culinaire. Paris: Seuil, 1977. Deleuze, Gilles. "Rhizome versus Trees." The Deleuze Reader. Ed. Constantin V. Boundas. New York: Columbia UP, 1993. Foucault, Michel. The Order of Things: An Archaeology of the Human Sciences. New York: Vintage, 1973. Gatens, Moira, and Genevieve Lloyd. Collective Imaginings: Spinoza, Past and Present. New York and London: Routledge, 1999. Grossberg, Lawrence. "History, Politics and Postmodernism: Stuart Hall and Cultural Studies." Journal of Communication Inquiry 10.2 (1986): 61-77. ---. We Gotta Get Out of This Place: Popular Conservatism and Postmodern Culture. New York and London: Routledge,1992. Le Doeuff, Michèle. L'Étude et le Rouet. Paris: Seuil, 1989. Jenkins, Emily. Tongue First: Adventures in Physical Culture. London: Virago, 1999. Probyn, Elspeth. Outside Belongings. New York and London: Routledge, 1996. ---. Sexing the Self. Gendered Positions in Cultural Studies. New York and London: Routledge, 1993. Santich, Barbara. "Research Notes." The Centre for the History of Food and Drink Newsletter. The University of Adelaide, September 1999. Thompson, Sue. Promotional pamphlet for the Dairy Farmers' Association. 1997. Tomlinson, John. Globalization and Culture. Oxford: Polity Press, 1999. Citation reference for this article MLA style: Elspeth Probyn. "The Indigestion of Identities." M/C: A Journal of Media and Culture 2.7 (1999). [your date of access] <http://www.uq.edu.au/mc/9910/indigestion.php>. Chicago style: Elspeth Probyn, "The Indigestion of Identities," M/C: A Journal of Media and Culture 2, no. 7 (1999), <http://www.uq.edu.au/mc/9910/indigestion.php> ([your date of access]). APA style: Elspeth Probyn. (1999) The indigestion of identities. M/C: A Journal of Media and Culture 2(7). <http://www.uq.edu.au/mc/9910/indigestion.php> ([your date of access]).