Journal articles: 'Too Wear'

1

Goldman, Howard H. "Today I Wear a Blue Hat, Too." Psychiatric Services 64, no. 12 (2013): 1183. http://dx.doi.org/10.1176/appi.ps.640124.

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Jiang, Ya Nan, Wei Hua Zhang, and Dong Li Song. "Study on the Law of Wheel Wear Based on Copula." Applied Mechanics and Materials 427-429 (September 2013): 246–51. http://dx.doi.org/10.4028/www.scientific.net/amm.427-429.246.

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The law of wheel wear is the basis for making turning repair cycle, and is one of the most important guarantees for the safe and stable running of train. A statistical analysis of individual wheel wear parameter was carried out based on wheel profile data of CRH2. The change law of individual wear parameter with mileage showed that wear process of wheel could be divided into two periods: the run-in period and the stable wear period. The paper has realized to research on the correlation between nominal wheel diameter abrasion value and wheel flange thickness variation based on Copula, too. Frank Copula was selected to describe correlation of the two wear parameters, the correlation index (α) of Frank Copula was estimated and the joint distribution function considering dependence was given. The value of α indicated that there was a weak positive correlation between the two wears, which can be ignored for calculating the accumulative failure rate of wheel wear. So the two wear parameters can be regarded as independent random variables during failure analysis of wheel wear.

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Wu, Na, and Jing Zeng. "Parameter Studies for Wheel Wear Using a Flexible Wheelset." Advanced Materials Research 712-715 (June 2013): 1230–34. http://dx.doi.org/10.4028/www.scientific.net/amr.712-715.1230.

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In order to reduce wheel profile wear of high-speed train and extend the service life of wheels, a high-speed vehicle multi-body dynamic model and wheel profile wear model are established, in which the wheelset is considered as flexible. The influence of wheel profile, track gauge, and rail cant is extensively studied. The simulation results show that the type XP55 wheel has smallest cumulative wear depth, and type LM wheel has largest wear depth. It is known that the equivalent conicity of the wheel should not be too large or too small. The track gauge with 1435-1438mm and rail cant with 1:35-1:40 can have better wheel wear performance.

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Liu, Sheng Rong, Jian Li Wang, Hong Feng Wang, Xiao Le Ge, and Jia Fei Pu. "Analysis of Friction and Wear Properties of 7075 Aluminum Alloy Modified by FSP." Key Engineering Materials 866 (October 2020): 135–42. http://dx.doi.org/10.4028/www.scientific.net/kem.866.135.

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In this paper, the wear resistance of the different parameter (the tool rotation speed and feed speed) modified layer of the hot rolled 7075 aluminum alloy by the friction stir processing (FSP) were studied. The wear mechanism was explored by analyzing the surface morphologies of the modified layer after wear. The results showed that the wear resistance of 7075 aluminum alloy modified by FSP was superior to that of the base metal at different temperatures. The comprehensive wear resistance was better when the tool rotation speed and the feed speed were 500 rpm and 60 mm/min under different temperatures. Furthermore, the FSP parameters had a significant influence on the wear resistance of the modified layer. When the FSP parameters were too high or too low, the wear resistance would be reduced and the adhesive wear would appear. In addition, the modified layers obtained by different parameters received poor wear resistance when the temperature at high values.

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Goralka, Chris, Jake Bridges, Muhammad Jahan, et al. "Friction and Wear Reduction of Tungsten Carbide and Titanium Alloy Contacts via Graphene Nanolubricant." Lubricants 10, no. 10 (2022): 272. http://dx.doi.org/10.3390/lubricants10100272.

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The tribological behavior of graphene as an additive in a water-based nanofluid lubricant was investigated using pin-on-disk tests on titanium alloy (Ti-6Al-4V) and cemented tungsten carbide (WC–Co) contacts. The effect of graphene concentration and surface roughness was investigated. A non-monotonic trend of friction and wear with increasing concentration was observed. An optimal graphene concentration of 0.10 wt.% was found to provide the lowest friction and wear at different surface roughnesses, with the friction, specific wear rate of the sample surface, and tip wear reduced by 29%, 37%, and 95%, respectively. The friction reduction and anti-wear performance of the nanofluids increased as the sample surface roughness increased. The non-monotonic friction and wear trends can be explained by the agglomeration of graphene around the contact zone, where too small a graphene concentration does not provide enough lubrication and too high a concentration prevents sliding owing to a large amount of agglomeration particles at the contact. The superior friction and wear performance of the graphene nanolubricants demonstrate its potential in minimum quantity lubrication (MQL) and other applications.

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Milan, Brožek. "Abrasive wear resistance of selected woods." Research in Agricultural Engineering 63, No. 2 (2017): 91–97. http://dx.doi.org/10.17221/74/2015-rae.

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In this contribution, the results of the wear resistance study of 10 sorts of wood (apple, aspen, beech, hornbeam, horse-chestnut, London plane, mahogany, silver fir, sour cherry and sweet cherry) are published. The laboratory tests were carried out using the pin-on-disk machine when the abrasive clothes of three different grits (240, 120 and 60) were used. The wear intensity was assessed by the volume, weight and length losses of the tested samples. From the results of the carried out tests it follows that the wear resistance of different woods is different. It was proved that the wear resistance of different woods depends on the abrasive particles size, too. Also the technical-economical evaluation was part of the carried out tests. It was univocally proved that at the intensive abrasive wear using the abrasive cloth the best results were shown by hard woods, e.g. apple, beech or mahogany. Soft woods, e.g. horse-chestnut, silver fir or sweet cherry, are cheap, but their wear is bigger compared to hard woods.

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Wang, Yaohui, Yingkai Feng, Xiaohu Sun, Shaoquan Liu, and Guoqiang Chen. "Effect of Process Parameters on the Microstructure and Wear Resistance of Fe3Al/Cr3C2 Composites." Coatings 14, no. 4 (2024): 384. http://dx.doi.org/10.3390/coatings14040384.

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In this paper, a brake cylinder coating comprising a composite material of an Fe3Al and Cr3C2 mixed powder was prepared by adding laser cladding onto carbon structural steel. We studied the influence of process parameters on the microstructure and tribological properties of the cladding materials using scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS), and 3D white light interferometer and wear tests. The influence of different processes on the morphology of the carbide strengthening phase was found to be relatively small with a Cr3C2 content of 15 wt.%. The carbides mainly exhibited a network structure in each group of cladding layers. The area of the network strengthening phase varied under different processes. Of the cladding layers formed with different processes, the scanning speed of the 0.003 m/s cladding layer had the lowest wear rate. When the laser power was too low or the powder feed rate was too high, unmelted Cr3C2 particles could be found in the cladding layer. During the wear process, the particles peeled off, causing severe abrasive wear. When the powder feeding rate was too low, more materials in the base material entered the cladding layer. This made the composition of the cladding layer similar to that of the grinding material, resulting in severe adhesive wear.

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Hrabě, P., R. Chotěborský, and R. Medlín. "Influence of overlay layers on the abrasive wear." Research in Agricultural Engineering 52, No. 3 (2012): 115–22. http://dx.doi.org/10.17221/4887-rae.

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A problem of machine parts wear decrease and in this way of the economical effectiveness of rapid wearable parts interferes with majority of manufacturing processes. Service life and operating reliability of a great number of machine parts is largely influenced by friction and wear, which take a significant part in the power and material losses. Wear affects significantly the maintenance, repair and renewal costs of machine parts, too. Today we can use a row of overlay materials. They differ above all by chemical composition, which determinates the conditions of use. Next conditions are the solidification of the welded-on material and the diffusion ability of main alloying elements, which determine the resultant structure of an overlay. The paper intents on multilayer overlays problem and on the number of overlay layers influence on abrasive wear.

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9

Yan, Jingang, Zhenming Yang, Limin Zhang, and Jianxin Wang. "Research on the Microstructure and Properties of Arc-Sprayed Austenitic Stainless Steel and Nickel-Based Alloy Composite Coatings with Different Spraying Distances." Crystals 15, no. 2 (2025): 142. https://doi.org/10.3390/cryst15020142.

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1Cr18Ni9Ti and Monel composite metal coatings with five different spraying distances were prepared by arc spraying technology. The density, hardness, friction, and wear properties and acid corrosion rate of the coatings with different spraying distances were studied by X-ray diffraction, scanning electron microscopy, Rockwell hardness test, and friction and wear test. Research shows that the spraying distance has a significant effect on the density, hardness, porosity, friction, and wear properties and corrosion rate of the coating. When the spraying distance is 250 mm, the coating has the maximum density and hardness, the minimum porosity and corrosion rate, and the minimum friction coefficient and wear volume. Cu3.8ni and cr0.19fe0.7ni0.11 compounds in the coating have significant effects on the friction, wear, and hardness of the coating. The results show that too-high or too-low spraying distance will lead to pores and large particle agglomeration in the coating, which will affect the surface physical properties of the coating.

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10

Xu, Liu Jie, Shi Zhong Wei, Ying Ping Ji, Guo Shang Zhang, Ji Wen Li, and Rui Long. "Effect of Carbon on Frictional Wear Behaviours of High Vanadium High Speed Steel under Dry Sliding Condition." Materials Science Forum 654-656 (June 2010): 370–73. http://dx.doi.org/10.4028/www.scientific.net/msf.654-656.370.

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The high vanadium high-speed steel (HVHSS) with about 9wt% vanadium and different carbon contents were prepared using casting process. The effects of carbon on wear properties of HVHSS were studied using pin-on-ring tester, and the failure behaviors were investigated via SEM. Results show the optimal wear resistance is obtained when HVHSS possesses moderate carbon content (2.58wt.%). The cause is that the matrix microstructure of moderate carbon HVHSS is mainly low-carbon lath martensite with good toughness and high hardness, and it can effectively resist micro-cutting and figure wear at the same time, so the role of high-hardness vanadium carbides (VC) can be played enough because of the strong support of matrix. If carbon content is too low, the wear failure of HVHSS is mainly caused by severe micro-cutting and adhesive wear on contact surface because the matrix microstructure of high speed steel is ferrite with very low hardness, which leads to poor wear resistance. While, the matrix microstructure is mainly composed of high carbon martensite with poor toughness when carbon content is too high, therefore, it possesses very poor resistance to cycle fatigue and thermal fatigue, resulting in decrease of wear resistance.

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11

Li, Hulin, and Jingshu Cao. "The tribological properties of bearing alloys under oil lubrication." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 234, no. 10 (2020): 2042–52. http://dx.doi.org/10.1177/0954406220902168.

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In this article, the tribological behaviors of CuPb24Sn under different load and oil lubrication conditions were studied. The worn surface, material transfer, and debris of the material were analyzed by the scanning electron microscopy and energy-dispersive X-ray spectrometer. In addition, the wear rate of CuPb24Sn was measured by means of a laser microscopic 3D and profile measurement apparatus. The results show that the soft phase lead wears preferentially from the sample surface under both light and heavy load conditions. Under the light load condition, the wear rate of the soft phase lead is low. Therefore, in this condition the samples are lubricated by oil and surface residual lead, and the wear mechanism is mainly abrasive wear. However, under heavy load conditions, the soft phase lead is quickly consumed. The lubricating oil film is thinner and the asperities contact is increased. And then the surface temperature and oxidation of samples are increased too. In this case, the main wear mechanisms of samples are adhesive wear and oxidation wear. At the same time, with the depletion of lead, cracks begin to form and propagate at the interface between lead and copper, and then peel off from the matrix to form wear debris, which further accelerates the wear of the sample.

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12

Miller, Joshua. "‘We wear too many caps’: role conflict among ambulance service managers." British Paramedic Journal 3, no. 4 (2019): 44. http://dx.doi.org/10.29045/14784726.2019.03.3.4.44.

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13

Hamdy, R. C., J. V. Lewis, A. Kinser, et al. "Too Many Choices Confuse Patients With Dementia." Gerontology and Geriatric Medicine 3 (January 1, 2017): 233372141772058. http://dx.doi.org/10.1177/2333721417720585.

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Choices are often difficult to make by patients with Alzheimer Dementia. They often become acutely confused when faced with too many options because they are not able to retain in their working memory enough information about the various individual choices available. In this case study, we describe how an essentially simple benign task (choosing a dress to wear) can rapidly escalate and result in a catastrophic outcome. We examine what went wrong in the patient/caregiver interaction and how that potentially catastrophic situation could have been avoided or defused.

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14

Li, Zhu Jun. "Study on Fretting Wear Behavior of 40CrNiMoA Steel." Advanced Materials Research 139-141 (October 2010): 447–51. http://dx.doi.org/10.4028/www.scientific.net/amr.139-141.447.

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This study deals with fretting wear behavior of 40CrNiMoA steel on a SRVⅣoscillating friction and wear tester. The results indicate that with the frequency and load increasing, both the friction coefficient and fretting wear volume increase. With the amplitude increasing, the fretting wear volume increased too, but the effect of amplitude on friction coefficient was not simple positive correlation according to the experimental results. Meanwhile, the fretting wear mechanism is directly related to test frequency, load and amplitude. When they are small, the main fretting wear mechanism is abrasive wear, with these test parameters increasing, the main fretting wear mechanism turns to a combination of abrasive wear and adhesion wear. Based on the experimental results, the anti-fretting wear measures of steel worm gear pairs used in mechanical tracked regulator of tracked vehicle are discussed.

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15

Zhang, Lian Yong, Fang Hong Sun, and Yan Hua Jiang. "Research on the Structure and Wear Properties of Grind-Hardened 42CrMo." Advanced Materials Research 619 (December 2012): 561–66. http://dx.doi.org/10.4028/www.scientific.net/amr.619.561.

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grind-hardening test was performed on 42CrMo steel in the paper. Microstructure of the hardened layer was observed and the wear-resistance of hardened specimens was done too. The results showed that microstructure of the fully hardened layer was mainly composed by lath martensite; microhardness of the hardened layer was above 700HV and the abrasive wear and the adhesive wear properties of hardened layer were 2~9 times than that of the base.

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16

Jin, Yong, Wu Ouyang, Zihao Liu, and Jianhui Zhou. "Simulation and Experiment Research on Abrasive Wear of the Ship Mechanical Seal." Journal of Physics: Conference Series 2419, no. 1 (2023): 012056. http://dx.doi.org/10.1088/1742-6596/2419/1/012056.

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Abstract The wear of friction pair resulting from seawater particles will inevitably bring marine tail shaft mechanical seal in the process of work, and abrasive wear will increase the static ring wear, resulting in the leakage of the mechanical seal. In this paper, through finite element simulation analysis of abrasive wear with different particle sizes and abrasive wear tests under different static ring materials, it is concluded that larger abrasive particle sizes will increase the deformation and residual stress on the surface of static ring materials, thus increasing the amount of wear, and the surface of softer static ring materials will be more serious. Also, if the particle size is too large, the particle concentration of the friction surface will decrease, and the wear will decrease.

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17

Leiss, Dan. "Paying the Price: Pressure Washers." CoatingsPro 10, no. 5 (2010): 26–27. https://doi.org/10.5006/cp2010_10_5-26.

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18

Lee, Kwon Yong, Hwan Kim, D. W. Kim, Dae Joon Kim, Myung Hyun Lee, and Won Seon Seo. "Wear Characteristics of Low Temperature Degradation-Free Zirconia/Alumina Composites in a Point Contact Condition." Key Engineering Materials 342-343 (July 2007): 557–60. http://dx.doi.org/10.4028/www.scientific.net/kem.342-343.557.

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The sliding wear of four different compositions of novel low temperature degradation-free zirconia/alumina (LTD-free Z/A) composites were characterized in a ceramicceramic point contact pair. The wear tests were performed by a pin-on-disk type wear tester in a linear reciprocal sliding motion with a point contact in both dry and bovine serum lubricated conditions at room temperature. For the dry sliding wear tests, AZ-2 (20 vol% (Y,Nb,Ce)-TZP/ 80 vol% Al2O3) showed the best wear resistance among four kinds of LTD-free Z/A composites. For the bovine serum lubricated sliding wear tests, wear was too little to be measured for all kinds of Z/A composites. These novel LTD-free Z/A composites having excellent wear resistance demonstrated a potential as the alternative materials for the ceramic- ceramic contact pairs of femoral head and acetabular liner in total hip replacement.

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Lee, Kwon Yong, Hwan Kim, Dae Joon Kim, Myung Hyun Lee, and Won Seon Seo. "Wear of Low Temperature Degradation-Free Zirconia/Alumina Composites in a Ceramic-Ceramic Contact Pair." Key Engineering Materials 309-311 (May 2006): 1265–68. http://dx.doi.org/10.4028/www.scientific.net/kem.309-311.1265.

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The sliding wear behaviors of three different compositions of novel low temperature degradation-free zirconia/alumina (LTD-free Z/A) composites were examined in a ceramicceramic contact pair. The wear tests were performed by using a pin-on-disk type wear tester in a linear reciprocal sliding motion with a line contact in both dry and bovine serum lubricated conditions at room temperature. From the results of dry sliding wear tests, Z/A#1 ((5.3Y,4.6Nb)-TZP/80 vol% Al2O3) showed the best wear resistance among three kinds of LTD-free Z/A composites. For the bovine serum lubricated sliding wear tests, wear was too little to be measured for all kinds of Z/A composites. These novel LTD-free Z/A composites having excellent wear resistance demonstrated a potential as the alternative materials for the ceramicceramic contact pairs of femoral head and acetabular liner in total hip replacement.

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20

Seo, Jung Won, Hyun Kyu Jun, Seok Jin Kwon, and Dong Hyeong Lee. "Rolling Contact Fatigue and Wear Behavior of Rail Steel under Dry Rolling-Sliding Contact Condition." Advanced Materials Research 891-892 (March 2014): 1545–50. http://dx.doi.org/10.4028/www.scientific.net/amr.891-892.1545.

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Rolling contact fatigue and wear of rails are inevitable problems for railway system due to wheel and rail contact. Increased rail wear and increased fatigue damage such as shelling, head check, etc. require more frequent rail exchanges and more maintenance cost. The fatigue crack growth and wear forming on the contact surface are affected by a variety of parameters, such as vertical and traction load, friction coefficient on the surface. Also, wear and crack growth are not independent, but interact on each other. Surface cracks are removed by wear, which can be beneficial for rail, however too much wear shortens the life of rail. Therfore, it is important to understand contact fatigue and wear mechanism in rail steels according to a variety of parameters. In this study, we have investigated fatigue and wear characteriscs of rail steel using twin disc testing. Also the comparative wear behavior of KS60 and UIC 60 rail steel under dry rolling-sliding contact was performed.

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Viňáš, Ján, Janette Brezinová, and Miroslav Greš. "Resistance of Cladding Layers Made by FCAW Method to Erosive Wear." Materials Science Forum 862 (August 2016): 33–40. http://dx.doi.org/10.4028/www.scientific.net/msf.862.33.

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The paper deals with the tribological properties of investigated types of hard-faced materials at erosive wear process. Influence of inclination angle of elements on friction resistance and microhardness changes of hard-faced layer were investigated too. From quantitative aspect were hard-faced layers evaluated on the base of weight loses. From achieved results follow that inclination angle is one from determining factors on to material’s wear measure.

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22

Wang, You, Mufu Yan, Xiaodong Li, and Tingqun Lei. "Frictional Temperature Field and Wear Behavior of Steel 52100 With Different Microstructures." Journal of Tribology 116, no. 2 (1994): 255–59. http://dx.doi.org/10.1115/1.2927206.

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In this paper, the frictional temperature fields and the wear resistance of steel 52100 with different microstructures during dry sliding were studied by wear testing and computer simulation for thermometric data, which were real-time recorded by a thermal video system, using a mathematical model of frictional temperature field. The results show that the wear resistances of different microstructures are in close relationship with the temperature fields in surface layers during sliding. It is suggested that, because the different microstructures possess different thermal conductivities, the different microstructures will exhibit different frictional temperature fields, which will affect the wear resistances themselves. The less the thermal conductivity, the higher is the surface temperature during sliding, the lower is the wear resistance too.

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23

Yan, Lan Lan, Xiang Yang Bian, and Ming Yang Feng. "On the Contemporary Cognition of Qipao’ Design." Advanced Materials Research 1048 (October 2014): 201–6. http://dx.doi.org/10.4028/www.scientific.net/amr.1048.201.

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This paper analyzes the contemporary cognition of Qipao’ design in the context of a Qipao exhibition. Social psychology methods, EXCEL and SPSS are used in the experiment, including questionnaires and interviewing. The data analysis shows six mainly cognitions of Qipao: 1) more than 70% participants loved Qipao, but over 80% of them never wore it; 2) nearly all the participants cared of Qipao’s design when they purchased it; 3) Chinese women didn’t wear Qipao because it was too Chinese and the practicability was too weak; 4) more than 70% participants knew Qipao’s typical design elements; 5) the side slits was the most beautiful elements, and the participants wanted it be used on their daily clothes; 6) red was the most common color of Qipao. It also gives corresponding reasons for the cognitions.

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24

Ashurst, Adrian. "How to … safely wear personal protective equipment in a care home setting." Nursing and Residential Care 22, no. 8 (2020): 1–3. http://dx.doi.org/10.12968/nrec.2020.22.8.6.

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Revised COVID-19 guidance for care staff means that, going forward, wearing full personal protective equipment will be the new normal. Residents, too, will have to adjust to this change. Adrian Ashurst offers tips for proper wear and increased uptake

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Qureshi, Waqar, Francesca Cura, and Andrea Mura. "Characterization of fretting wear experiments on spline couplings by principal component analysis." Proceedings of the Institution of Mechanical Engineers, Part J: Journal of Engineering Tribology 231, no. 7 (2016): 860–68. http://dx.doi.org/10.1177/1350650116682162.

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Fretting wear is a quasi-static process in which repeated relative surface movement of components results in wear and fatigue. Fretting wear is quite significant in the case of spline couplings which are frequently used in the aircraft industry to transfer torque and power. Fretting wear depends on materials, pressure distribution, torque, rotational speeds, lubrication, surface finish, misalignment between spline shafts, etc. The presence of so many factors makes it difficult to conduct experiments for better models of fretting wear and it is the case whenever a mathematical model is sought from experimental data which is prone to noisy measurements, outliers and redundant variables. This work develops a principal component analysis based method, using a criterion which is insensitive to outliers, to realize a better design and interpret experiments on fretting wear. The proposed method can be extended to other cases too.

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Galantu, Jiri. "The Wear Analysis of Chisel-Edge Ruling Tool for Diffraction Gratings." Advanced Materials Research 772 (September 2013): 389–93. http://dx.doi.org/10.4028/www.scientific.net/amr.772.389.

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The wear analysis of chisel-edge ruling tool for diffraction gratings is very complex because of following two reasons that one is the wear distribution on edge after grating ruling is too minute so that hard to find and measured by conventional equipment like microscope, and the other is the effect of wear on the groove depth, pitch, ridge, blaze angle, non-blaze angle, groove bottom angle and diffraction efficiency of gratings. In order to determine what extent of wear is can be ignored, this paper had go on brief approximate test study on wear analysis of chisel-edge ruling tool for diffraction gratings which ruling echelle gratings groove density of 79 gr/mm, and analyzed the variation of groove depth, pitch, ridge, blaze angle, non-blaze angle, groove bottom angle and diffraction efficiency along with ruling distance, and found the microscale tool wear on chisel-edge ruling tool, finally determined this extent of tool wear cannot effect ruling echelle gratings groove density of 79 gr/mm .

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Wang, Guo De, Zhi Sheng Jing, Guo Wei Qin, and Shan Chao Tu. "Wear Particles Recognition Based on Improved LBP." Applied Mechanics and Materials 427-429 (September 2013): 1874–78. http://dx.doi.org/10.4028/www.scientific.net/amm.427-429.1874.

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Wear particles recognition is a key link in the process of Ferrography analysis. Different kinds of wear particles vary greatly in texture, texture feature is one of the most important feature in wear particles recognition. Local Binary Pattern (LBP) is an efficient operator for texture description. The binary sequence of traditional LBP operator is obtained by the comparison between the gray value of the neighborhood and the gray value of the center pixel of the neighborhood, the comparison is too simple to cause the loss of the texture. In this paper, an improved LBP operator is presented for texture feature extraction and it is applied to the recognition of severe sliding particles, fatigue spall particles and laminar particles. The experimental results show that our method is an effective feature extraction method and obtains better recognition accuracy compared with other methods.

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Han, Feng Qi, Guang Jun Li, Xiang Sheng Pang, Zhi Zun Li, and De Yuan Zhang. "Research of Mechanism of Chipping in Step Tapping of Superalloy Based on Wavelet Analysis." Materials Science Forum 532-533 (December 2006): 153–56. http://dx.doi.org/10.4028/www.scientific.net/msf.532-533.153.

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Stepping tapping is a new tapping mode for Nickel-based superalloy GH4169. Longer life of tap and higher machining efficiency can be obtained. But chipping of tap is very prevalent. In this paper, the mechanism of chipping in step tapping is investigated. Based on the wavelet analysis of the signals of tapping torque, the load applied to the tap in every stage of the period of motion is studied. It is found that chipping is prone to occur at the moment when the rotating direction of tap shifts from forward to backward, which is caused by the too large and rapidly changed tensile stress on cutting edge. The excessive wear of cutting edge results in the too large tensile stress. To reduce the wear, the backward rotating angle of tap should be selected to be smaller than 100°.

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Lee, Sang Hyeop, Man Ho Kim, Suk Lee, and Kyung Chang Lee. "Automatic Lubrication System for Minimizing Friction of Driving Parts for Large-Sized Commercial Vehicle." Advanced Materials Research 909 (March 2014): 198–203. http://dx.doi.org/10.4028/www.scientific.net/amr.909.198.

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One of the causes of malfunction of commercial vehicle is corrosion or wear. In order to prevent corrosion and wear, lubricants have to be supplied periodically. However, the period of lubrication usually depends on operator's judgment. If the period is too short, excess lubricant will cause pollution and unnecessary expenses, whereas long periodic supply of lubricant might cause wear, damage and eventual breakdown. Therefore, an automatic lubrication system with predetermined interval will reduce the excessive supply of lubricating oil and prevent wear and damage. This thesis presents an automatic lubrication system which consists of a lubricant pump and an embedded controller. An automatic lubrication operating algorithm is used to operate the lubricant pump and feedback the pressure status of the system using pressure sensors. The developed system shows an efficient periodic supply of lubricant.

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"Monitoring Wear-and-Tear in Helicopters, and Also in Hips, Knees and Ankles, Too." Asian Journal of Applied Sciences 4, no. 3 (2011): 321. http://dx.doi.org/10.3923/ajaps.2011.321.321.

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31

Wei, Xin, Hui Yuan, Rui Wei Huang, and Shao Hui Lai. "Wear Characteristics of ID Saw Blade in Silicon Ingot Slicing Process." Materials Science Forum 532-533 (December 2006): 157–60. http://dx.doi.org/10.4028/www.scientific.net/msf.532-533.157.

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In this paper, the wear behavior of the ID (inner diameter) saw blade in the cutting process of silicon ingot was observed with SEM. Its wear mechanism was discussed and the relation between the blade wear and vibration, deflection was analyzed. The results show that the blade worn manners include flatted diamond, micro-fractured diamond, macro-fractured diamond, pulled-out hole, tortoise-fractured bond, and polished bond. In the abnormal working stage of a blade, however, the working surface of the blade is displayed mainly with pulled out diamond, flatted diamond, macro-fractured diamond grains. Abnormal initial tension condition will induce severe vibration and deflection, and so then lots of diamond grits fractured or pulled out too early.

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Zhang, Li, Li Hua Dong, D. S. Wang, C. H. Fan, and Y. Zhou. "A Survey on Electrode Materials for Electrical Discharge Machining." Materials Science Forum 697-698 (September 2011): 495–99. http://dx.doi.org/10.4028/www.scientific.net/msf.697-698.495.

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This work screens electrode materials used in EDM and proposes some potential electrodes for future industrial applications. Traditional graphite, W, and Mo EDM electrodes have low TWR due to their high melting points; while, Zn, brass, and Cu often experience too much tool wear. As to some newly developed alloy and composite materials, their machining performances depend on not only their melting points but also their microstructures. Cu-W alloy has high wear resistance but it is susceptible to shape loss due to its internal porosity. By contrast, Cu-graphite, Cu-ZrB2 and Cu-TiB2 composites show good capabilities of removing material with little wear loss and therefore could be promising for future usages.

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Wu, BW, QF Qiao, GX Chen, et al. "Effect of the unstable vibration of the disc brake system of high-speed trains on wheel polygonalization." Proceedings of the Institution of Mechanical Engineers, Part F: Journal of Rail and Rapid Transit 234, no. 1 (2019): 80–95. http://dx.doi.org/10.1177/0954409719833787.

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This paper conducts a detailed investigation into the formation mechanism of wheel polygonalization in high-speed trains and its influence factors through numerical simulation. A finite element model including two rails, one wheelset, and three disc brake units is set up to study the formation mechanism of wheel polygonalization in high-speed trains based on the point of view of frictional self-excited vibration. Using the finite element complex analysis, the dynamic stability of the wheelset–track–disc brake system is studied. In addition, the influence factors on the wheel polygonalization are investigated. Results show that when the longitudinal creep force is unsaturated, the 21-order polygonal wear of wheels occurs easily due to the self-excited vibration of the disc brake unit. When the longitudinal creep force is saturated, the 12-order polygonal wear of wheels probably occurs due to the self-excited vibration of the disc brake unit. The bigger the friction coefficient between the brake disc and pad, the greater the occurrence propensity of the polygonal wear of wheels. Vertical fastener damping that is too large or too small is disadvantageous for suppressing wheel corrugation. However, increasing the lateral fastener damping is beneficial for reducing the polygonal wear of wheels. When the vertical fastener stiffness is 25 MN/m, 7-order, 9-order, and 14-order wheel polygonalization can easily occur. A higher lateral fastener stiffness is beneficial for the suppression of wheel polygonalization.

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Komanduri, R., and M. Lee. "The Ledge Tool: A New Cutting Tool Insert." Journal of Engineering for Industry 107, no. 2 (1985): 99–106. http://dx.doi.org/10.1115/1.3185990.

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The salient features of a simple, wear-tolerant cemented carbide tool are described. Results are presented for high-speed machining (3 to 5 times the conventional speeds) of titanium alloys in turning and face milling. This tool, termed the ledge cutting tool, has a thin (0.015 to 0.050 in.) ledge which overhangs a small distance (0.015 to 0.060 in.) equal to the depth of cut desired. Such a design permits only a limited amount of flank wear (determined by the thickness of the ledge) but continues to perform for a long period of time as a result of wear-back of the ledge. Under optimum conditions, the wear-back occurs predominantly by microchipping. Because of geometric restrictions, the ledge tool is applicable only to straight cuts in turning, facing, and boring, and to face milling and some peripheral milling. Also, the maximum depth of cut is somewhat limited by the ledge configuration. In turning, cutting time on titanium alloys can be as long as ≈ 30 min. or more, and metal removal of ≈ 60 in.3 can be achieved on a single edge. Wear-back rates in face milling are about 2 to 3 times higher than in straight turning. The higher rates are attributed here to the interrupted nature of cutting in milling. Use of a grade of cemented carbide (e.g., C1 Grade) which is too tough or has too thick a ledge for a given application leads to excessive forces which can cause gross chipping of the ledge (rapid wear) and/or excessive deflection of the cutting tool with reduced depth of cut. Selection of a proper grade of carbide (e.g., Grades C2, C3, C4) for a given application results in uniform, low wear-back caused by microchipping. Because of the end cutting edge angle (though small, ≈ 1 deg) used, the ledge tool can generate a slight taper on very long parts; hence an N.C. tool offset may be necessary to compensate for wear-back. The ledge tool is found to give excellent finish (1 to 3 μm) in both turning and face milling. In general, conventional tooling with slight modifications can be used for ledge machining. The ledge tool can also be used for machining cast iron at very high speeds.

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Zhang, Dan Dan, Zai Ji Zhan, Chang Hong Guo, and Gong Min Tang. "Preparation and Properties of Cu Matrix Reinforced with Ti₂AlN Ceramic Particles." Key Engineering Materials 602-603 (March 2014): 523–26. http://dx.doi.org/10.4028/www.scientific.net/kem.602-603.523.

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Cu matrix composites with various contents of Ti2AlN were fabricated by powder metallurgy using spark plasma sintering (SPS) method. Ti2AlN ceramic particles were pre-treated by electroless copper plating, the result showed that Ti2AlN reinforcement and Cu matrix were strongly bonded. The effects of Ti2AlN content on microstructure, electrical resistivity and mechanical properties were systematically investigated. With the addition of low fraction of Ti2AlN, the hardness and tensile strength of matrix were improved without losing the fracture toughness too much. Tensile strength of Ti2AlN/Cu composites were about 380 MPa with the content of 7 wt. % reinforcing phase, and the conductivity of the composites remained about 61.5 % IACS. Moreover, the wear tests illustrated that the loads were effectively born by the Ti2AlN reinforcement, the main tribological mechanism changed from adhesive wear to abrasive wear compared with Cu, thus the friction and wear resistance was also obviously improved.

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Li, Zhaoyang, Guanyu Zhou, Chihuan Yao, et al. "Development and Application of Asynchronous Roll Shifting Strategy of Double Attenuation Work Roll in Hot Rolling." Metals 12, no. 8 (2022): 1265. http://dx.doi.org/10.3390/met12081265.

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In view of the problems of the violent crown fluctuation and unstable shape control in the endless rolling production line, the field measurement results show that the abnormal crown fluctuation is related to the shifting limit position of the work roll after the uneven wear occurs. For this reason, the asynchronous roll shifting strategy is developed, which has double attenuation of roll shifting amplitude and roll shifting step. By coupling the roll wear contour model, the roll thermal contour model and the rolls-strip integrated model, the strip crown calculation model of the whole rolling unit is established, and the causes of abnormal crown fluctuation are revealed theoretically. In addition, the simulation analysis of the important parameters of asynchronous roll shifting strategy of double attenuation working roll is made by using this model. The number of strips in a roll shifting cycle is found to be too large or too small, which is not benefited by the control of the strip crown stability due to the influence of roll wear and roll thermal crown. A rolling unit has many shifting cycles. When the roll shifting amplitude at the end of a rolling unit is smaller, which can make the amplitude difference between adjacent roll shifting cycles greater, it is easier to avoid the uneven edge wear area and to control the strip crown stability. The industrial test shows that the maximum crown fluctuation in a rolling unit decreases by 21.05%, and the maximum crown fluctuation of adjacent strips decreases by 28.57%, which significantly improves the stability of crown control.

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Cheng, Shiya, Yuankai Zhou, and Xue Zuo. "Current-Carrying Wear Behavior of Cu–TiC Coatings Obtained Through High-Speed Laser Cladding on Conductive Slip Rings of 7075 Aluminum Alloy." Metals 15, no. 7 (2025): 688. https://doi.org/10.3390/met15070688.

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Cu-5wt%TiC coatings were fabricated by high-speed laser cladding on the 7075 aluminum alloy substrate using various scanning speeds to improve its current-carrying wear resistance. The effects of scanning speed on the microstructure, phase, hardness, and current-carrying tribological properties of the coating were investigated using a scanning electron microscope, an X-ray diffractometer, a hardness tester, and a wear tester, respectively. The results show that the increase in scanning speed accelerates the coating’s solidification rate. Among the samples, the coating comprised of equiaxed crystals prepared at 149.7 mm/s presents the best quality, but solidification speeds that are too rapid lead to elemental segregation. The hardness of the coating also decreases with the increase in scanning speed. The coating prepared at 149.7 mm/s exhibits the best wear resistance and electrical conductivity. The wear rate of the coating prepared at 149.7 mm/s at 25 A was 4 × 10−3 mg·m−1, respectively. During the current-carrying friction process, the presence of thermal effects and arc erosion cause the worn track to be prone to oxidation, adhesion, and plastic deformation, so the current-carrying wear mechanisms of coatings at 25 A include adhesive wear, oxidation wear, and electrical damage.

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Zhang, Zheng Mei, Jin Sheng Zhang, Zhi Wang, and Chun Ying Zheng. "Experimental Study on High Efficiency Grinding Technology for Irregular Surface of Q.L. Red Granite." Key Engineering Materials 416 (September 2009): 40–44. http://dx.doi.org/10.4028/www.scientific.net/kem.416.40.

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Based on orthogonal experiment design the study about the irregular surface of Qilu Red granite was performed, the tend charts of technologic parameters were established. The relations of factor primary and secondary between cutting speed, feed rate and depth of cut on two performance measures, machining efficiency and wear of cutter were investigated by range analysis, and the optimal cutting parameters for each performance measure were obtained too. Mathematic models of machining efficiency and wear of cutter were deduced by analysis of regression about experimental results. The theoretic foundation was offered to reasonably select technologic parameters of grinding for irregular surface of granite.

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Braun, Kerstin. "How Much Veil Is Too Much Veil: On the Constitutionality and Advisability of Face Veil Bans for German Public School Students." German Law Journal 18, no. 6 (2017): 1331–58. http://dx.doi.org/10.1017/s2071832200022367.

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With increasing cultural and religious diversity in Germany, a debate has emerged over the extent and limits of religious freedom in day-to-day life. While much controversy arose over whether public school teachers have the right to wear Islamic head coverings, students as private individuals are free to wear a headscarf at school if they wish. Yet, recent school and administrative court decisions suggest that the situation is different for students who wear niqab and Islamic face veils rather than just head veils. This Article contemplates whether niqab-wearing students can be expelled from public school under current German law. In addition, this Article addresses the constitutionality of law reform in this area especially considering the European Court of Human Rights' jurisprudence in the French context. The Article subsequently contemplates the advisability of such law reform while also drawing on the experiences of countries which have already enacted so-called burqa bans. As many countries are currently in the process of considering face veil bans, this Article may have relevance beyond the German context.

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Prasad, S. V., S. D. Walck, and P. F. Lloyd. "TEM examination of wear debris from a self-lubricating metal-matrix composite prepared by ultramicrotomy." Proceedings, annual meeting, Electron Microscopy Society of America 53 (August 13, 1995): 560–61. http://dx.doi.org/10.1017/s0424820100139172.

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Self-lubricating materials are usually multi-phase composites comprising of a solid lubricant dispersed in a matrix of a metal or a polymer. During sliding contact, chemical reactions among the constituent phases of the composite, the counterface and the gases in the surrounding environment are inevitable. The wear debris is a product of such chemical (or tribochemical) reactions. Determination of the chemistry and the crystal structure of the wear debris is therefore crucial to the understanding of the wear mechanisms. In self-lubricating composites, the quantity of the debris generated is often too small to perform x-ray diffraction.It has been previously demonstrated that self-lubricating aluminum metal-matrix composites can be synthesized by dispersing silicon carbide and tungsten disulfide particles in commercial aluminum alloy matrices. A typical microstructure of an Al-0.10SiC-0.05WS2 MMC is shown in Fig. 1. The friction and wear test was performed, in a ball-on-disk configuration, on a polished disk of the aluminum MMC against a 440C steel ball.

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Liu, Yu, Tian Hao Xu, Ying Liu, Hai Cheng Zhang, Xing Xing Li, and Guang Bin Chen. "Research on Microstructure and Wear Property of 45 Steel Quenched with Different Laser Power." Key Engineering Materials 861 (September 2020): 35–40. http://dx.doi.org/10.4028/www.scientific.net/kem.861.35.

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The surface of 45 steel is quenched by CO2 laser with scanning speed 1000 mm/min and different laser power 1000W, 1200W, 1400W, 1600W and 1800W. Experiments are carried out to analyze microstructure, friction and wear properties of quenched 45 steel. The results show that the quenching layer thickness increases gradually with the increase of laser power,and the maximum value of quenching layer hardness increases first and then decreases. When the laser power is 1600W, the maximum hardness value is 883HV0.5. But when the laser power is 1800W, the hardness of quenching layer becomes to decrease. The reason is the surface of 45 steel becomes to melt. The wear volume increases first and then decreases too. When laser power is 1600W, the minimum wear volume is 0.08mm3, which is 6.4% to the wear volume of 45 steel matrix without laser quenching. Therefore, better microstructure and properties of 45 steel can be obtained when laser scanning speed is 1000mm/min and laser power is 1600W.

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Suwanpinij, Piyada, Thanaporn Thonondaeng, Parinya Kumma, Bandit Suksawat, and Gobboon Lothongkum. "Control of the bainitic structure for a wear-resisting hard-faced rail track." Materials Testing 64, no. 1 (2022): 1–10. http://dx.doi.org/10.1515/mt-2021-2076.

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Abstract Carbide-free bainite with filmlike retained austenite structure has been reported for its higher wear resistance and toughness compared with conventional bainite and pearlite structure. In order to take advantage from such beneficial structure, this study employs the surface welding method with self-shielded wire electrode containing low carbon (0.15 mass%), high silicon, and nickel on two pearlitic rail steels, R260 and R350HT. The preheating temperature and other welding parameters were carefully selected to avoid too high dilution, which leads to martensite formation. The weld metal, heat-affected zone, and base material were investigated by scanning electron microscopy. Microhardness and wear tests were carried out to ensure improved properties after the surface repair. The results show significant improvements in hardness and wear rate in weld metal compared with the base material.

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Elke, Reinhard, and Claude B. Rieker. "Estimating the osteolysis-free life of a total hip prosthesis depending on the linear wear rate and head size." Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine 232, no. 8 (2018): 753–58. http://dx.doi.org/10.1177/0954411918784982.

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We present a model to estimate the osteolysis-free life of total hip arthroplasty, depending on linear wear rate and femoral head size. An estimate of the radiologic osteolysis threshold was calculated, which was based on volumetric wear. The osteolysis-free life of the cup was estimated from the quotient of the osteolysis threshold and volumetric wear rate, which was calculated from the linear wear rate. The impact of the direction of linear wear was determined by sensitivity analysis. From our review, we calculated a weighted mean polyethylene volume of approximately 670 mm3 as osteolysis threshold. Osteolysis-free life of less than 20 years was estimated for linear wear rates of 50 µm/year for head sizes of 32 mm or more, or for linear wear rates of 100 µm/year for any head size. For head sizes of 36 and 40 mm with a linear wear rate of 50 µm/year, the osteolysis-free period is estimated to be only 14.10 and 11.42 years, respectively. Sensitivity analysis showed reasonably robust results. With the aim of osteolysis-free life of more than 20 years, our study presents a viable model to determine maximum possible head size for articulations. Osteolysis-free period for 36 and 40 mm head sizes are far too low for conventional polyethylenes. As the threshold wear volume for highly crosslinked polyethylene is, as of yet, unknown, more research is warranted before our model can be generalized to XLPE.

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Zhang, Yuan Bin, Hui Luo, and Guo Fan Wang. "The Effect of the Microstructure on the Wear-Resistance in the Welding Deposited Metal." Key Engineering Materials 353-358 (September 2007): 766–69. http://dx.doi.org/10.4028/www.scientific.net/kem.353-358.766.

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The microstructure and wear-resistance of the welding deposited metal of Fe-Ti-Nb-V-C and Fe-Cr-W-Mo-C alloy system (with American MG700 as example) are studyed by using SEM , TEM and MM200 wear testing machine. It is revealed that Ti and Nb promote the formation of dispersed MC type carbide granules, while the carbides of Cr and W or Mo tend to precipitate along grain boundary. The formation of MC carbide granules depletes the carbon content in the matrix, and then low carbon martensite matrix can be achieved. The hard and tough matrix and the granular carbides improve the wear-resistance of the deposited metal. But excessive Ti and Nb induce the formation of bigger granules with sharp corner and result too soft matrix, then the wear-resistance decrease. As to the Fe-Cr-W-Mo-C alloy system, network carbides and high carbon martensite matrix make the deposited metal very brittle. During wearing process, the propagating of microcrack in the matrix induces lots of scraps flake off, which decrease the wear-resistance of the deposited metal. The deposited metal of Fe-0.64Ti-1.18Nb-2.18V-1.43Cr-0.97C alloy system in current study achieve the best wear-resistance.

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Zhu, Yucheng, Jian Li, Chaolei Zhang, Wenjun Wang, and Huan Wang. "High Temperature Dry Tribological Behavior of Nb-Microalloyed Bearing Steel 100Cr6." Materials 14, no. 18 (2021): 5216. http://dx.doi.org/10.3390/ma14185216.

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100Cr6 steel is one of the most widely used bearing steels and a representative of first-generation bearing steel. Many engineering applications require rolling bearings to run at a high temperature. Therefore, it is necessary to improve the high temperature properties of 100Cr6 steel. In this paper, the effect of Nb on high temperature dry tribological behavior, including worn surface and friction coefficient, was analyzed by a wear test when Nb content was 0.018% and 0.040%. The results show that the microstructure is refined gradually, the hardness is improved, and wear volume decreases by 31.8% at most with the increase of Nb content. At 50 °C, the friction coefficient of 100Cr6 steel can be reduced by adding a small amount of Nb, but this effect will be weakened if the content of Nb is too high. In addition, excess Nb increases the hard precipitation of NbC, which aggravates the abrasive wear and leads to the increase in the depth of the worn surface. At 125 °C, the effect of Nb on tribological properties is weaker. With the increase of temperature, the steel substrate softens, and the oxide particles increase, which aggravates the abrasive wear and oxidation wear and makes the wear volume increase significantly.

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Han, Tengfei, Zimin Ding, Wanxi Feng, Xinyu Yao, Fangfang Chen, and Yuesheng Gao. "Effects of Process Parameters on Microstructure and Wear Resistance of Laser Cladding A-100 Ultra-High-Strength Steel Coatings." Coatings 14, no. 6 (2024): 669. http://dx.doi.org/10.3390/coatings14060669.

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To improve the hardness and wear resistance of mild steel, A-100 ultra-high-strength steel cladding coatings were prepared on the surface of mild steel by laser cladding. In this study, the effects of laser cladding process parameters on the forming quality, phase composition, microstructure, microhardness and wear resistance of the A-100 ultra-high-strength steel cladding coatings were researched. The results show that the main phase of the coating is martensite and a small amount of austenite. The microstructures of the upper part of the cladding coatings are mainly equiaxed grains, while those of the lower part are mainly columnar grains. With an increase in laser specific energy, the microstructures of the cladding coatings become coarse. When the laser specific energy is 70.8 J/mm2, the microhardness of the cladding coating is the highest, and the maximum average microhardness of the cladding coatings is 548.3 HV. When the laser specific energy is low, the wear of the cladding coatings is mainly pitting, while when the laser specific energy is high, the wear type of the cladding coatings is mainly adhesive wear. Moreover, the microhardness and wear resistance of the cladding coatings are reduced if the laser specific energy is too high.

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Shi, Yan, Wendy Yajun Huang, Jane Jie Yu, Sinead Sheridan, Cindy Hui-Ping Sit, and Stephen Heung-Sang Wong. "Compliance and Practical Utility of Continuous Wearing of activPAL™ in Adolescents." Pediatric Exercise Science 31, no. 3 (2019): 363–69. http://dx.doi.org/10.1123/pes.2018-0170.

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Purpose: The aim of this study was to examine the factors that influence compliance and practical utility of a continuous wear protocols for activPAL™ among adolescents. Methods: Seven hundred and fifty-five (11–18 y; 50.6% girls) students wore the waterproof activPAL™ for 7 consecutive days. The effects of factors such as weather and practical strategies on compliance were assessed. Students were asked to note reasons for removing it in a log. After the 7-day period, students anonymously completed a practical utility questionnaire. Results: The final sample used to analyze compliance contained 588 available data points; 72.4% met the validity criteria, which were ≥4 valid days. Rainfall was inversely associated with total wear time, whereas using alcohol pads and cartoon stickers during the application were positively associated with total wear time. Sweating (25.2%) and skin irritation (39.0%) were the most reasons for 290 removal episodes by 235 students. The 131 questionnaires showed that 80.1% regarded the continuous wear period as too long and encountered problems, and 55% would rather not wear it again. Conclusion: Rainy weather affected girls’ compliance with the continuous wear protocol for activPAL™. Skin irritation and sweat-induced inadvertent drops caused removal. Future studies should investigate more user-friendly protocols.

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Fan, Shan, Yi Huang, and Haixia Zeng. "Research on On-line Tool Wear Monitoring Technology Based on GPR." E3S Web of Conferences 252 (2021): 01046. http://dx.doi.org/10.1051/e3sconf/202125201046.

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At present, many kinds of sensors are used for on-line monitoring of cutting process, tool identification and timely replacement. However, most of the original monitoring signals extracted from the cutting process are time series signals, which contain too much process noise. As the signal noise is relatively low, it is difficult to establish a direct relationship with the tool wear. Therefore, how to obtain the effective information from the online monitoring signal and extract the characteristics that can directly reflect the tool wear from the complex original signal, so as to establish an effective and reliable tool wear monitoring system, is the key and difficult problem in the research of the online monitoring technology of tool wear. Firstly, an experimental platform based on the force sensor for on-line monitoring of tool wear was built, and the signal obtained by the force sensor was used to monitor the tool wear, and the feature information was extracted and fused. The innovation of the project lies in the use of Gaussian process regression (GPR) method to predict the tool wear, the use of feature dimensional rise technology, to reduce the impact of noise, on the premise of ensuring the prediction accuracy, improve the confidence interval of GPR prediction results, improve the stability and reliability of the monitoring process.

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Qiu, Ming, Kai-Wen Tian, and Ya-Tao Zhang. "Effect of ambient temperature on the formation mechanism of PTFE liner transfer film of spherical plain bearings." Mechanics & Industry 22 (2021): 11. http://dx.doi.org/10.1051/meca/2021007.

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The relationship between the formation of the transfer film and the tribological properties of the self-lubricating spherical plain bearing was studied at the ambient temperature of 25–145 °C. The results show that the wear, friction coefficient and friction temperature increase of the spherical plain bearings all decreased first and then increased with the increase of the ambient temperature. The general trend is that the bearing has the most excellent anti-friction and wear resistance at 55–85 °C. An increase in ambient temperature will accelerate the formation speed of PTFE transfer film and shorten the running-in period of the bearing, but the ambient temperature above 85 °C will shorten the duration of the PTFE transfer film, thus accelerating the bearing into the degradation period. The transfer film coverage of the liner after wear was characterized, and it was found that the transfer film coverage was the largest when the ambient temperature was 85 °C. The wear form of the bearing is mainly abrasive wear and adhesive wear, and the aramid fiber is more prone to adhesive wear. The anti-friction effect of the bearing is determined by the PTFE transfer film. Elevated ambient temperature can promote the formation of PTFE transfer film and enhance the antifriction effect, but if the ambient temperature is too high, the wear resistance of the PTFE transfer film will be reduced, thus reducing the friction reduction effect.

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Bartkowska, Aneta, Dariusz Bartkowski, Damian Przestacki, Jakub Hajkowski, and Andrzej Miklaszewski. "Microstructural and Mechanical Properties of B-Cr Coatings Formed on 145Cr6 Tool Steel by Laser Remelting of Diffusion Borochromized Layer Using Diode Laser." Coatings 11, no. 5 (2021): 608. http://dx.doi.org/10.3390/coatings11050608.

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The paper presents study results focused on the microstructural, mechanical, and physicochemical properties of B-Cr coatings obtained by means of modification of diffusion borochromized layers by diode laser beam. The studies were conducted on 145Cr6 tool steel. Diffusion borochromized layers were produced at 950 °C in powder mixture containing boron carbides as a source of boron and ferrochrome as a source of chromium. In the next step these layers were remelted using laser beam. Powers: 600, 900, and 1200 W were used during these processes. The microstructure, microhardness, chemical composition, as well as wear and corrosion resistance of newly-formed B-Cr coatings were determined. As a result of laser beam interaction, the diffusion borochromized layer was mixed with the steel substrate. The study showed that too low laser beam power causes cracks in the newly formed B-Cr coating, and on the other hand, too higher laser beam power causes deep remelting resulting in the loss of microhardness. The reduced corrosion resistance in comparison with diffusion borochromized layers was caused by occurrence cracks or deep remelting. For B-Cr coatings produced using laser beam power 600 W, a small decrease in wear resistance was observed, but note that this coating was much thicker than diffusion borochromized layers. On the other hand, laser beam power of 1200 W caused a significant decrease in wear resistance. Newly formed B-Cr coatings had an advantageous microhardness gradient between the layer and the substrate.

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Journal articles on the topic 'Too Wear'

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