Journal articles: 'Powders characterization'

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Condruz, Mihaela Raluca, Gheorghe Matache, and Alexandru Paraschiv. "Characterization of IN 625 recycled metal powder used for selective laser melting." Manufacturing Review 7 (2020): 5. http://dx.doi.org/10.1051/mfreview/2020002.

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Additive manufacturing of high-quality materials by Selective Laser Melting depends not only on establishing appropriate process parameters, but also on the characteristics of the metal powders used and their stability over time or after recycling. The aim of the research was to characterize the IN 625 powder used over multiple manufacturing cycles with a Lasertec 30 SLM machine. In order to achieve the research's goal, virgin and recirculated powder's physical and technological characteristics were investigated. A decrease in all D-values (D10, D50, D90) of the powder size distribution was observed after multiple recirculation cycles showing a decrease of the powder dimensional range over time. Both virgin and recirculated powders are composed of mainly spherical particles, but elongated particles and satellite particles were observed as well. The dimensional evolution analysis showed a deviation from the powder ideal roundness, deviation that is more pronounced over multiple recirculation cycles. It was experimentally determined that the powders present a good flowability based on the flow rate value obtained for both virgin and recirculated powders, confirmed also by the Hausner ratio and angle of repose.

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Sheng, Yan Wei, Zhi Meng Guo, and Jun Jie Hao. "Characterization of Spherical Molybdenum Powders Prepared by RF Plasma Processing." Advanced Materials Research 482-484 (February 2012): 2563–67. http://dx.doi.org/10.4028/www.scientific.net/amr.482-484.2563.

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Spherical molybdenum powders were synthesized by (RF) plasma with irregular molybdenum powders. The powder characteristics and spheroidization efficiency of the feeding rate for obtain the spherical molybdenum powders were studied. The phase composition and morphological properties of the powders were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM). As a result, the fine spherical powders composed of pure molybdenum with favorable dispersity and its surface became smooth. The spheroidization efficiency of synthesized powders was almost 100 % at feeding rate of 5g/min. LMS analysis indicated that the as-prepared powder had narrow particle size distribution and the spheroidization efficiency of the sample decreases gradually as increasing of the feeding rate. The RF plasma spheroidization of molybdenum powder is an ideal route synthesis of well- spherical molybdenum powders used as near net-shape technology and powder metallurgy.

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Li, Hui Qin, Ji Xian Gong, and Yi Zhang. "Characterization of Protein Powder from Waste Rabbit Hair." Advanced Materials Research 194-196 (February 2011): 407–10. http://dx.doi.org/10.4028/www.scientific.net/amr.194-196.407.

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Rabbit hair is an important animal fiber in China, making up 90% of the total output in the world. Fuds is one of familiar problems in the processing of rabbit hair, which lead to plenty of waste fibers. Recently, there has been interest in converting protein fibers into powder to develop their new uses. This provides great opportunities for waste rabbit hair. In this study, rabbit hair powders have been produced and the structure and properties were characterized at multi-level. Surface morphology of rabbit hair powders was observed by scanning electron microscopy (SEM) and the majority of rabbit hair powders appear to be small fibrous particles. The FTIR spectrum of rabbit hair and rabbit hair powders was detected. Although no new chemical bonds were produced in the rabbit hair powders, the result showed that some absorbing peaks of rabbit hair powder become stronger than that of rabbit hair. Absorption of rabbit hair powders was also investigated. The result showed that rabbit hair powder had higher moisture retention rate than that of rabbit hair, wool fiber and cotton fiber. Moreover, rabbit hair powder showed remarkable sorption ability for metal ions. The characterization of rabbit hair powder will provide useful basal data for the further application of rabbit hair in novel areas.

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Yang, Lian Wei, Rui Jie Wang, and Guo Sheng Gai. "Preparation and Characterization of Honghua Powders by Ultrafine Pulverization." Advanced Materials Research 454 (January 2012): 55–58. http://dx.doi.org/10.4028/www.scientific.net/amr.454.55.

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Honghua has been demonstrated useful for promoting blood circulation and stopping pain. The physicochemical characterization of Honghua powders was greatly influenced by ultrafine pulverization. To study the physicochemical characterization of Honghua, the raw plant material of Honghua was ground to powders by high speed centrifugal sheering (HSCS) pulverizer. The micron powders were characterized by laser scattering granulometric analyzer and scanning electron microscope (SEM). Hydroxysafflor yellow A is one of active ingredients of Honghua, and its dissolution speed was determined to evaluate the chemical characterization of Honghua powder. The results showed that after ultrafine pulverization, dissolution speed of hydroxysafflor yellow A was increased by 28.6% compared with the normal powders

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Young, Benjamin, Joseph Heelan, Sean Langan, Matthew Siopis, Caitlin Walde, and Aaron Birt. "Novel Characterization Techniques for Additive Manufacturing Powder Feedstock." Metals 11, no. 5 (April 27, 2021): 720. http://dx.doi.org/10.3390/met11050720.

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Additive manufacturing is a rapidly expanding field, encompassing many methods to manufacture parts and coatings with a wide variety of feedstock. Metal powders are one such feedstock, with a range of compositions and morphologies. Understanding subtle changes in the feedstock is critical to ensure successful consolidation and quality control of both the feedstock and manufactured part. Current standards lack the ability to finely distinguish almost acceptable powders from barely acceptable ones. Here, novel means of powder feedstock characterization for quality control are demonstrated for the solid-state AM process of cold spray, though similar methods may be extrapolated to other additive methods as well. These characterization methods aim to capture the physics of the process, which in cold spray consists of high strain rate deformation of solid-state feedstock. To capture this, in this effort powder compaction was evaluated via rapidly applied loads, flowability of otherwise non-flowable powders was evaluated with the addition of vibration, and powder electrical resistivity was evaluated through compaction between two electrodes. Several powders, including aluminum alloys, chromium, and cermet composites, were evaluated in this effort, with each case study demonstrating the need for non-traditional characterization metrics as a means of quality control and classification of these materials.

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Li, Zai Yuan, Myongil Pang, and Yu Chun Zhai. "Preparation and Characterization of Fe90Ni6Cu4 Alloy Powders." Advanced Materials Research 233-235 (May 2011): 930–33. http://dx.doi.org/10.4028/www.scientific.net/amr.233-235.930.

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The Fe90Ni6Cu4 precursor powder was prepared by chemical co-precipitation taken FeSO4·7H2O, NiSO4·6H2O, CuSO4·5H2O and NaOH as raw materials. The Fe90Ni6Cu4 precursor powder shape was majority stick, its diameter was about 10nm, length was about 100nm. The reaction conditions were that concentration of Fe2+, Ni2+and Cu2+mix solution was 0.1mol·L-1, NaOH solution concentration was 4 mol·L-1, the dropping rate of NaOH solution was 50 ml·min-1, the reaction temperature was 30°C, the pH value of the reaction end was 11, the stirring rate was 1200 r·min-1. The Fe90Ni6Cu4 alloy powders were obtained through hydrogen reduction of the Fe90Ni6Cu4 precursor powders. When the hydrogen reduction temperatures lower, it’s the reaction speed slower. When the reduction temperature was 800°C, the restore time needed to the 1200sec. The Fe90Ni6Cu4 alloy powder particle’ size was 200-500 nm.

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Lee, Sang Jin, and Choong Hwan Jung. "Characterization of Nano Scaled Mullite Powders Prepared by Organic-Inorganic Solution Technique." Solid State Phenomena 119 (January 2007): 43–46. http://dx.doi.org/10.4028/www.scientific.net/ssp.119.43.

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Nano scaled mullite (3Al2O3·2SiO2) powders had been fabricated by an organic-inorganic solution technique using a polyvinyl alcohol (PVA) as an organic carrier. PVA polymer contributed to a soft and porous powder microstructure, and ball milling with the porous powder was effective in making nano-sized mullite powders. In addition, the degree of polymerization of PVA affected the crystallization behavior. The fully crystallized and ball-milled mullite powders had an average particle size of 120 nm with a specific surface area of 67.0 m2/g. In this paper, the simple solution technique and milling process for the fabrication of nano scaled mullite powders are introduced. And the effects of PVA on the crystallization behavior and powder specific surface area are also studied. The characteristics of the synthesized powders are examined by using XRD, TEM, particle size analyzer and nitrogen gas adsorption.

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Gromov, Nalivaiko, Ambaryan, Vlaskin, Buryakovskaya, Kislenko, Zhuk, et al. "Aluminum–Alumina Composites: Part Ⅰ: Obtaining and Characterization of Powders." Materials 12, no. 19 (September 27, 2019): 3180. http://dx.doi.org/10.3390/ma12193180.

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The process of advanced aluminum-alumina powders production for selective laser melting was studied. The economically effective method of obtaining aluminum–alumina powdery composites for further selective laser melting was comprehensively studied. The aluminum powders with 10–20 wt. % alumina content were obtained by oxidation of aluminum in water. Aluminum oxidation was carried out at ≤200 °C. The oxidized powders were further dried at 120 °C and calcined at 600 °C. Four oxidation modes with different process temperatures (120–200 °C) and pressures (0.15–1.80 MPa) were investigated. Parameters of aluminum powders oxidation to obtain composites with 10.0, 14.5, 17.4, and 20.0 wt. % alumina have been determined. The alumina content, particle morphology, and particle size distribution for the obtained aluminum–alumina powdery composites were studied by XRD, SEM, laser diffraction, and volumetric methods. According to the obtained characteristics of aluminum–alumina powdery composites, they are suitable for the SLM process.

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Stefan, I., and G. C. Benga. "Elaboration and Characterization of the Nanometric Titanium Diboride Powders by Mechanical Milling Method." Annals of Dunarea de Jos University of Galati Fascicle XII Welding Equipment and Technology 31 (December 28, 2020): 55–58. http://dx.doi.org/10.35219/awet.2020.08.

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The research activities are oriented towards elaborating and characterizing nano-sized powders by powder metallurgy technologies based on wet milling in a planetary mill. For the elaboration of the TiB2 powders, a wet milling regime of initial powders was used up to nano size with the following parameters: milling technology by collision, milling times, rotational speed. The characterization of the TiB2 material will include particle size distribution analysis. EDXS and SEM analysis were used to study the structural evolution of the powder after ball milling. The mechanical milling technology, by its milling regimes, proved to be very efficient, obtaining a reduction of the titanium diboride powders particle size up to 50% compared to the initial unmilled powders.

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Haušild, Petr, Jaroslav Čech, Miroslav Karlík, Filip Průša, Pavel Novák, and Jaromír Kopeček. "Nanoindentation Characterization of Mechanically Alloyed Fe-Al-Si Powders." Key Engineering Materials 784 (October 2018): 15–20. http://dx.doi.org/10.4028/www.scientific.net/kem.784.15.

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The effect of processing conditions on microstructure and mechanical properties of Fe-Al-Si powders was studied by means of scanning electron microscopy, X-ray diffraction and nanoindentation. Fe-Al-Si alloy powder was prepared from pure elemental powders by mechanical alloying. Microstructure and mechanical properties of powders were characterized after various durations of mechanical alloying. Special sample preparation technique was developed allowing to characterize the properties of individual powder particles after each step of processing in a planetary ball mill. This step-by-step characterization allowed to find the optimum conditions for subsequent spark plasma sintering.

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Tomasi, Roberto, Adriano A. Rabelo, Adriana S. A. Chinelatto, Laudo Reis, and Walter J. Botta Fo. "Characterization of high-energy milled alumina powders." Cerâmica 44, no. 289 (October 1998): 166–70. http://dx.doi.org/10.1590/s0366-69131998000500003.

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The utilization of reactive high-energy milling has been reported for the synthesis of ceramic powders namely, metal oxides, carbides, borides, nitrides or mixtures of ceramics or ceramic and metal compounds. In this work, high-energy milling was used for reduction of alumina powders to nanometric particle size. The ceramic characteristics of the powders were analyzed in terms of the behavior during deagglomeration, compaction curves, sintering and microstructure characterization. It was observed that the high energy milling has strong effect in producing agglomeration of the nanosized powders. This effect is explained by the high-energy impact of the balls, which may fracture particles or just cause the particles compacting. In this case, strong agglomerates are produced. As the powder surface area increases, stronger agglomerates are produced.

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12

Hunt, Emily M., and Matt Jackson. "Coating and Characterization of Mock and Explosive Materials." Advances in Materials Science and Engineering 2012 (2012): 1–5. http://dx.doi.org/10.1155/2012/468032.

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This project develops a method of manufacturing plastic-bonded explosives by using use precision control of agglomeration and coating of energetic powders. The energetic material coating process entails suspending either wet or dry energetic powders in a stream of inert gas and contacting the energetic powder with atomized droplets of a lacquer composed of binder and organic solvent. By using a high-velocity air stream to pneumatically convey the energetic powders and droplets of lacquer, the energetic powders are efficiently wetted while agglomerate drying begins almost immediately. The result is an energetic powder uniformly coated with binder, that is, a PBX, with a high bulk density suitable for pressing. Experiments have been conducted using mock explosive materials to examine coating effectiveness and density. Energetic materials are now being coated and will be tested both mechanically and thermally. This allows for a comprehensive comparison of the morphology and reactivity of the newly coated materials to previously manufactured materials.

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Pavlovic, M. G., B. M. Jovic, V. D. Jovic, U. Lacnjevac, and V. M. Maksimovic. "Electrochemical deposition and characterization of Ni-Mo alloy powders." Processing and Application of Ceramics 1, no. 1-2 (2007): 11–17. http://dx.doi.org/10.2298/pac0702011p.

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Electrodeposition of Ni-Mo alloy powders from ammonium sulfate and ammonium chloride containing electrolytes of different Ni/Mo ions concentration ratios was investigated by polarization measurements. The morphology, chemical composition and phase composition of electrodeposited Ni-Mo alloy powders were investigated using DSC, TGA, SEM, EDS and XRD analysis. EDS results showed that powder composition depends on Ni/Mo ions concentration ratio, as well as on the position where the EDS analysis was performed. As-deposited alloy powders were nanocrystalline showing no XRD peaks with undefined morphology (SEM). After recrystallization for 2 h in N2 atmosphere at 600?C the presence of NiMoO4 phase was identified in the powder electrodeposited from chloride electrolyte at the Ni/Mo ions concentration ratio 1/3, with well defined crystalline powder particles.

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Lu, Liang Liang, Shao Ming Zhang, Jun Xu, Yan Wei Sheng, Shan Shan Wang, Wen Dong Zhao, Jin Hui Zhang, and Xin Ming Zhao. "Solidification Characterization of K418 Alloy Powders Fabricated by Argon Gas Atomization." Materials Science Forum 849 (March 2016): 788–93. http://dx.doi.org/10.4028/www.scientific.net/msf.849.788.

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The solidification characterization of K418 alloy powders prepared by argon atomization was studied, and thermal parameters of the alloy powder during solidification process were calculated. The results show that powder morphology is spherical shape, the average diameter of the powder is 55μm, the amount of less 100μm powder is about 90 percent, the solidification microstructure of powders particle surface are dentrite and cellular structure. Decreasing the particle size, the microstructures of particle interior change from dentrite in major to cellular structures, and the structure is more uniformed. The length of secondary dentritic arm and the cooling rate as a function of K418 alloy powders size is established, the cooling rate increases with a decrease of the powder particle size, the cooling rate is in the range of 104K.S-1-106K.S-1.

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Palomares-Sánchez, S., S. Ponce-Castañeda, F. Ruiz, M. Mirabal-García, J. R. Martínez, and S. Díaz-Castañón. "Structural and magnetic characterization of (Ba,Sr)-hexaferrite Powders." Revista de Metalurgia 35, no. 3 (June 30, 1999): 143–47. http://dx.doi.org/10.3989/revmetalm.1999.v35.i3.617.

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Nogueira, M. V., G. M. M. M. Lustosa, Y. Kobayakawa, W. Kogler, M. Ruiz, E. S. Monteiro Filho, M. A. Zaghete, and L. A. Perazolli. "Nb-Doped TiO2 Photocatalysts Used to Reduction of CO2 to Methanol." Advances in Materials Science and Engineering 2018 (2018): 1–8. http://dx.doi.org/10.1155/2018/7326240.

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In pursuit of higher photoactivity, Nb-doped TiO2 powders were evaluated in the reduction of CO2. The replacement of Ti by Nb in the crystalline structure of TiO2 promoted methanol formation. Nb-doped TiO2 powders were successfully synthesized in Nb concentrations of 0.0, 0.5, 1.0, and 2.5% (w/w = weight/weight) using the Pechini method. The materials were calcined at 500°C for two hours to promote the formation of the anatase crystalline phase. After characterization, the powders were modified through an Nb0 magnetron sputtering deposition using a metallic target in vacuum conditions of 2 × 10−3 torr, with a deposition time of 10 minutes, and calcination again at 500°C for two hours. The resulting powders showed a surface area up to 30 m2/g. The Pechini method promoted the substitution of Ti4+ for Nb4+ as observed using XRD and XPS techniques at the crystalline structure and at the surface of the powder. Furthermore, the presence of Nb0 was also observed at the powder’s surface. The presence of Nb in the crystalline structure increased the photoactivity of powders when compared to nonmodified TiO2 powders, while the Nb0 deposition at the powder’s surface decreased the photoactivity for all the investigated compositions.

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Gan, Linli, Heng Guo, Zhiheng Xiao, Zhiwei Jia, Han Yang, Dan Sheng, Heng Pan, Weilin Xu, and Yunli Wang. "Dyeing and Characterization of Cellulose Powder Developed from Waste Cotton." Polymers 11, no. 12 (December 2, 2019): 1982. http://dx.doi.org/10.3390/polym11121982.

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In this study, waste cotton fibers were environmentally reused. First, they were milled into fine powders with particle sizes of around 30 µm and dyed for use as pigments. Dyeing properties of the cellulose powder were explored by determining the dye uptake, K/S value, and bath ratio. Among the various samples, powders with owf (on weight of fabric) of 0% dye (pristine cellulose powder), and 10% and 50% dyed powders were selected; and these powders were characterized by several methods to compare the properties of dyed and undyed cellulose. The surface morphologies of the powders were observed with a scanning electron microscope (SEM). Combining the SEM images with the Brunauer–Emmet–Teller (BET) data, it was found that the smaller the particle size, the larger is the surface area. In addition, the X-ray photoelectron spectroscopy (XPS) results revealed that with increasing dye concentration, the intensity of the C peak reduced, while those of O and S increased. Moreover, the main components of the dyed and undyed cellulose powders were found to be almost the same from the Fourier-transform infrared spectroscopy (FTIR) results. Finally, the dynamic mechanical analysis (DMA) data revealed that the loss modulus was significantly larger than the storage modulus, demonstrating that the material mainly undergoes viscous deformation.

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Liu, Z., C. Huang, C. Gao, R. Liu, J. Chen, and Z. Xiao. "Characterization of Ti6Al4V powders produced by different methods for selective electron beam melting." Journal of Mining and Metallurgy, Section B: Metallurgy 55, no. 1 (2019): 121–28. http://dx.doi.org/10.2298/jmmb181025008l.

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Three different types of Ti6Al4V powders produced by electrode induction melting gas atomization (EIGA), plasma rotating electrode process (PREP), and plasma atomization (PA) were compared from these aspects: particle size distribution, particle shape, and microstructure. Theywere characterized by particle size and shape analyzer, scanning electron microscope, and X-ray diffraction. The results show some benefits of using PA Ti6Al4V powder in selective electron beam melting. The particle size distribution of these Ti6Al4V powders were bimodal, and the PA Ti6Al4V powder had the narrowest particle size span. The roundness and elongation, the bluntness index of the most analyzed Ti6Al4V powders were greater than 80%. There were 52%, 81%, and 93% Ti6Al4V powders without satellite, respectively. These particle shape results indicate that EIGA, PRER, and PA Ti6Al4V powders have good sphericity and low content of satellites. The flowability of PA (20.55 s/50 g) is better than that of EIGA (24.80 s/50 g) and PREP (25.76 s/50 g). The microstructure of Ti6Al4V powders was composed of martensite ??.

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Plummer, H. K., W. T. Donlon, J. E. Allison, and S. Shinozaki. "The characterization of rapidly solidified Al-8Fe-2Mo powder." Proceedings, annual meeting, Electron Microscopy Society of America 44 (August 1986): 546–47. http://dx.doi.org/10.1017/s0424820100144206.

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A centrifugally atomized rapidly solidified Al-8Fe-2Mo powder was characterized by Light Microscopy (LM), Scanning Electron Microscopy (SEM) and Analytical Electron Microscopy (AEM). The powder sample was studied in an as-solidified state and after annealing in 1 at. argon for 6 hr at 400°C. Further studies have characterized the consolidated bars produced by compaction and extrusion of these powders.The 30 to 150 μm powders are spherical as seen in the SEM (Fig.1) with small (5 to 15 μm) satellite powders sometimes attached in external (A,B Fig.1) and internal (A Fig.2C) locations. A comparison of powders (epoxy mounted and polished) by both the LM (Fig. 2A) and the SEM (Figs. 2B and 2C) reveals a two component microstructure with occasional voids.

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FATHI, M. H., and M. KHARAZIHA. "MECHANOCHEMICAL SYNTHESIS AND CHARACTERIZATION OF NANOSTRUCTURE FORSTERITE BIOCERAMICS." International Journal of Modern Physics B 22, no. 18n19 (July 30, 2008): 3082–91. http://dx.doi.org/10.1142/s0217979208047948.

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Recent investigations suggest that forsterite ceramics possess good biocompatibility and mechanical properties and might be suitable for potential application like bone implant material. In this study, nanocrystalline forsterite ( Mg 2 SiO 4) powder was prepared by mechanochemical method and subsequent heat treatment and the effect of fluorine ion as catalyst was studied. Mechanochemical process and heat treatment were done on the MgCO 3, SiO 2 and ( NH 4)2 SiF 6 powders. The synthesized powders were characterized by X-ray diffraction (XRD), thermogravimetric (TG) analyses and scanning electron microscopy (SEM). The synthesized nano-powder had particle size smaller than 100 nm. The crystallite size of powders after 5 hours mechanical activation was 18 nm. Mechanical activation in the presence of fluorine ion affects the mechanism of forsterite formation and increase the rate of decomposition of MgO and fabrication of forsterite.

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Tshabalala, Lerato Criselda, Ntombizodwa Mathe, and Hilda Chikwanda. "Characterization of Gas Atomized Ti-6Al-4V Powders for Additive Manufacturing." Key Engineering Materials 770 (May 2018): 3–8. http://dx.doi.org/10.4028/www.scientific.net/kem.770.3.

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In this paper, titanium powders from various sources were characterized to compare powder intergrity for additive manufacturing by selective laser melting process. Selective laser melting by powder-bed based Additive Manufacturing (AM) is an advanced manufacturing process that bonds successive layers of powder by laser melting to facilitate the creation of engineering components. This manufacturing approach facilitates the production of components with high geometrical complexity that would otherwise be impossible to create through conventional manufacturing processes. Although the use of powder in AM is quite common, powder production and optimization of powder properties to yield desired performance characteristics has posed a serious challenge to researchers. It is therefore critical that powder properties be studied and controlled to ensure reliability and repeatability of the components that are produced. Typically, the desired feature of high quality titanium metal powders for AM are a combination of high sphericity, density and flowability. Scanning electron microscopy, EDS, particle size distribution and powder rheology were extensively performed to investigate the properties of gas-atomized Ti-6Al-4V powders.

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Vajpei, A. J., and Gopal S. Upadhyaya. "Characterization of Oxide Powders." Key Engineering Materials 75-76 (January 1992): 91–118. http://dx.doi.org/10.4028/www.scientific.net/kem.75-76.91.

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Sheppard, Laurel, and D. R. Johnson. "Characterization of Ceramic Powders." Materials and Processing Report 2, no. 11 (February 1988): 1. http://dx.doi.org/10.1080/08871949.1988.11752131.

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Petzow, G., and R. Sersale. "Characterization of Si3N4 powders." Pure and Applied Chemistry 59, no. 12 (January 1, 1987): 1673–80. http://dx.doi.org/10.1351/pac198759121673.

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CHENG, JIN-BO, AI-DONG LI, QI-YUE SHAO, YUE-FENG TANG, and DI WU. "SYNTHESIS AND CHARACTERIZATION OF FERROELECTRIC NANOCRYSTAL POWDERS OF SrBi2Ta2O9 BY A POLYMERIZABLE COMPLEX METHOD." International Journal of Modern Physics B 19, no. 15n17 (July 10, 2005): 2514–19. http://dx.doi.org/10.1142/s0217979205031249.

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Ferroelectric nanocrystal powders of SrBi2Ta2O9 (SBT) have been first prepared by a polymerizable complex (PC) route. The bismuth powder, strontium carbonate, and water-soluble tantalum oxalate solution were used as starting materials. Thermal analyses (TGA and DSC), x-ray diffraction (XRD), transmission electron microscopy (TEM), and conventional BET method were explored to characterize the structure, morphology, and specific surface area of PC-derived SBT powders calcined at 500-850 °C. As control samples, SBT powders were also fabricated by metalorganic decomposition (MOD) method. The XRD and TEM results indicate that high pure and well crystalline powders can be obtained at 650 °C with a average size of 50 nm. The PC-derived powder has much larger surface area than MOD-derived powder. The BET value of PC and MOD powder at 750 °C for 2h is 6.7 and 1.5m2/g, respectively. The specific surface area of powder prepared by conventional solid-state reaction is quite low, typically less than 1.5m2/g. Therefore, the feasibility of the polymerizable complex route is demonstrated in the powder synthesis of SBT with large surface area.

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Basosidik, Suraida, Piyapong Pankaew, Ekachai Hoonnivathana, Pichet Limsuwan, and Kittisakchai Naemchanthara. "Characterization of Chitin Extracted from Waste Sources via XRD, FTIR, and TGA Techniques." Advanced Materials Research 488-489 (March 2012): 1404–8. http://dx.doi.org/10.4028/www.scientific.net/amr.488-489.1404.

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This work presents the chitin preparation from waste sources, the chitin powders were successfully extracted from shrimp shell, crab shell and squid pen. To prepare chitin powders, all raw materials were washed and grounded using agate mortar, which the particle size of powder is 212–250 μm. Then, the powdered materials were immersed into solution of chloroform and methanol (with 2:1 ratio) at room temperature for removing fat. The deprotienation and decarbonation, the samples were immersed in 50 wt% of NaOH solution for 24 h and in 4 wt% of HCl for 1 h, respectively. The XRD, FT-IR and TGA techniques were used to indicate the different characteristic between α-chitin and β-chitin prepare.

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Vähä-Nissi, Mika. "Characterization of filled powders for powder coating of paper." Powder Technology 279 (July 2015): 127–33. http://dx.doi.org/10.1016/j.powtec.2015.04.008.

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Yeh, Tze Yang, and Kuo Yuan Peng. "Characterization of Simultaneously Gas Atomized Ti/TiC Composite Powders." Key Engineering Materials 704 (August 2016): 302–7. http://dx.doi.org/10.4028/www.scientific.net/kem.704.302.

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Metallic composite materials are mainly manufactured by powder metallurgy (PM) or casting, with reinforced ceramic particulates dispersed in a metal matrix. The current study presents an investigation with respect to simultaneously gas-atomized spherical Ti/TiC composite powders. Various analytical methods are used to characterize the gas-atomized Ti/TiC composite powders, including XRD, laser particle size analysis, flow rate tests, apparent density and tap density tests, SEM, and alike. The spherical Ti/TiC composite powders will be further laser sintered at the next stage to utilize mechanical properties testing.

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Otmane, Fadhéla, Salim Triaa, A. Maali, and B. Rekioua. "Synthesis and Characterization of Fe-Based Nanocomposites." Diffusion Foundations 22 (May 2019): 39–47. http://dx.doi.org/10.4028/www.scientific.net/df.22.39.

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This study reports on the elaboration and characterization of bulk nanocomposites samples obtained by dispersion of metallic powders at the nanoscale as reinforcements in a polymer matrix. Elemental Fe powders were successfully nanostructured via high-energy ball milling. Structural characterization of the produced powders was conducted using X-Ray Diffraction (XRD) analysis and Scanning Electron Microscopy (SEM). The Halder-Wagner approach was adopted to determine the powder’s average grain size, internal strain, lattice parameters and the mixing factors. Structural parameters evolution and morphological changes according to milling progression are discussed. Bulk nanocomposites samples were shaped in a home moulder by dispersion of coarse Fe and nanostructured Fe powders in a continuous matrix of commercial epoxy resin. The obtained bulk samples match the metallic X-band wave-guide WR-90 dimensions used for electromagnetic characterization. The two-port Sij scattering parameters were measured via an Agilent 8791 ES network analyzer. The measured scattering parameters served to calculate the loss factor of samples and to extract the dielectric permittivity via the Nicholson-Ross-Weir conversion. Spectra evolution of the scattering parameters, the loss factor and the dielectric constant for epoxy resin with coarse Fe and nanostructured Fe reinforcements are commented.

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Käerdi, Helmo, Dmitri Goljandin, Priit Kulu, Heikki Sarjas, and Valdek Mikli. "Characterization of Mechanical Milling Cermet Powders Produced by Disintegrator Technology." Key Engineering Materials 527 (November 2012): 148–53. http://dx.doi.org/10.4028/www.scientific.net/kem.527.148.

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The current paper deals with characterization of TiC−NiMo cermet powders produced by mechanical milling technology. TiC-based cermets scrap was processed by semi-industrial and laboratory disintegrator milling system. Chemical composition, shape and size of produced powders were analyzed. To estimate the properties of recycled cermet powders the sieving analysis, and angularity studies were conducted. The grindability was estimated using specific energy parameter (Es). Considering that viewpoint, the study is focused on angularity studies as the shape of spray powder has considerable influence on spraying efficiency, the quality and reliability of the coating. To describe the angularity of milled powders, spike parameter – quadratic fit (SPQ) was used and experiments for determination of SPQ sensitivity and precision to characterize particles angularity were performed. Uncertainty of measurements demonstrated trustworthiness of results. The standard deviation of SPQ regardless of milling cycles is the same. For use of produced powders as reinforcements in sprayed coatings the technological parameters of powders were studied. Perspective future use of powders as reinforcements in composite coatings as well as abrasives in tooling were demonstrated.

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Giannouli, Christina. "Magnetite: Synthesis and Characterization." Key Engineering Materials 543 (March 2013): 460–63. http://dx.doi.org/10.4028/www.scientific.net/kem.543.460.

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Magnetite nanopowder is a nanostructured magnetic material which is of great importance due to its electric and magnetic properties at room temperature. There are quite enough methods to produce magnetite. In the present work, four samples of magnetite powder were produced, the first three with the alkaline precipitation method from aqueous solution of mixed Fe (II)/Fe (III) salts, without any surfactants and the last one with the micro emulsion method. The prepared powders have been characterized using transmission electron microscopy, Raman and FT-IR spectroscopy and x-ray diffraction in order the structure and the morphology of magnetite to be examined. The produced magnetite powders have a size range of 10-12±2nm and the chemical composition of magnetite.

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Lapčík, Lubomír, Martin Vašina, Barbora Lapčíková, David Hui, Eva Otyepková, Richard W. Greenwood, Kristian E. Waters, and Jakub Vlček. "Materials characterization of advanced fillers for composites engineering applications." Nanotechnology Reviews 8, no. 1 (December 31, 2019): 503–12. http://dx.doi.org/10.1515/ntrev-2019-0045.

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Abstract Four different minerals were investigated; hollow spheres of calcium carbonate, platy mica, needle like wollastonite and glassy perlite and characterized via iGC for surface energy, Freeman powder rheology for flow characterization, cyclic uniaxial die compaction for modulus of elasticity and frequency dependent sound absorption properties. Particle surface energy and particle shape strongly affected the packing density of powder beds. In the case of higher porosity and thus lower bulk density, the powders acoustic absorption was higher in comparison with higher packing density materials. Surface energy profiles and surface energy distributions revealed clear convergence with powder rheology data, where the character of the powder flow at defined consolidation stresses was mirroring either the high cohesion powders properties connected with the high surface energy or powder free flowing characteristics, as reflected in low cohesion of the powder matrix.

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Miyake, Shugo, Taisei Izumi, and Rino Yamamoto. "Effect of the Particle Size of Al/Ni Multilayer Powder on the Exothermic Characterization." Materials 13, no. 19 (October 1, 2020): 4394. http://dx.doi.org/10.3390/ma13194394.

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In this study, the exothermic temperature performance of various Al/Ni multilayer powders with particle sizes ranging from under 75 to over 850 µm, which generate enormous heat during self-propagating exothermic reactions, was determined using a high-speed sampling pyrometer. The Al/Ni multilayer powders were prepared by a cold-rolling and pulverizing method. The multilayer constitution of the Al/Ni multilayer powders was examined by observing the cross-section of the powders using scanning electron microscopy; the results indicate that the powders had similar lamellar structures regardless of the particle size. Exothermic reactions were carried out to measure the temperature changes during the experiment using a pyrometer. We found that the maximum temperature and the duration of the exothermic reaction increased with an increase in the particle size caused by the heat dissipation of the surface area of the Al/Ni multilayer powder. This indicates that the thermal characteristics of the exothermic reaction of the Al/Ni multilayer powder can be controlled by adjusting the particle size of the Al/Ni multilayer powder. Finally, we concluded that this controllability of the exothermic phenomenon can be applied as a local heating source in a wide range of fields.

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Moskal, Grzegorz, Aleksander Iwaniak, and Aleksandra Rozmysłowska-Grund. "Characterization of Thermal Properties of Micro-Sized Ceramic Powders for APS Deposition of Ceramic Layers." Key Engineering Materials 484 (July 2011): 152–57. http://dx.doi.org/10.4028/www.scientific.net/kem.484.152.

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The paper presents test results concerning characteristics of the selected thermal properties of ceramic powders based on rare earth zirconates with a pyrochlore structure of RE2Zr2O7 type, intended for thermal spraying of TBCs. Gadolinium, lanthanum, samarium and neodymium based powders were tested. The scope of the tests encompassed thermal diffusivity analysis of the powders in a compressed pellets form within temperature range 25-1500°C, and also tests of specific heat and thermal expansion coefficient within similar temperature range. Standard powder of 8YSZ type on the basis of zirconium oxide modified with yttrium oxide was used as a reference material. Specific heat measurements of the powders showed that the highest values within the entire test temperature range were obtained for the standard YSZ type powder. In the case of new type of powders, the results obtained are very similar and only slightly lower in comparison with YSZ powder. The lowest values were obtained for the samarium based powder (temperature range corresponding to operating temperature). Character of the curves obtained do not show course of strong reactions connected with phase changes. Dilatometric tests of materials made it possible to determine thermal expansion coefficient. Mean coefficient values are included within the range from 5.5 x 106mm/°C to 10.0 x 106mm/°C. The highest mean value of thermal expansion coefficient was obtained for Nd2Zr2O7 powder and the lowest one for La2Zr2O7 powder. The lowest thermal diffusivity value at room temperature was shown by Nd2Zr2O7 powder, and the highest one by 8YSZ powder (0.215 mm2/s).

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Simões, Sónia, Filomena Viana, Marcos A. L. Reis, and Manuel F. Vieira. "Microstructural Characterization of Aluminum-Carbon Nanotube Nanocomposites Produced Using Different Dispersion Methods." Microscopy and Microanalysis 22, no. 3 (March 8, 2016): 725–32. http://dx.doi.org/10.1017/s143192761600057x.

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AbstractThis research focuses on characterization of the impact of dispersion methods on aluminum-carbon nanotubes (Al-CNTs) nanocomposite structure. Nanocomposites were produced by a conventional powder metallurgy process after the dispersion of the CNTs on the Al powders, using two approaches: (1) the dispersion of CNTs and mixture with Al powders were performed in a single step by ultrasonication; and (2) the CNTs were previously untangled by ultrasonication and then mixed with Al powders by ball milling. Microstructural characterization of Al-CNT nanocomposites was performed by optical microscopy, scanning and transmission electron microscopy, electron backscatter diffraction, and high-resolution transmission electron microscopy (HRTEM). Microstructural characterization revealed that the use of ball milling for mixing CNTs with Al powders promoted the formation of CNT clusters of reduced size, more uniformly dispersed in the matrix, and a nanocomposite of smaller grain size. However, the results of HRTEM and Raman spectroscopy show that ball milling causes higher damage to the CNT structure. The strengthening effect of the CNT is attested by the increase in hardness and tensile strength of the nanocomposites.

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Delloro, Francesco, Hugo Durand, Laurent Lacourt, Jean-Christophe Teissedre, Alain Thorel, Imène Lahouij, François Lavaud, and Xavier Clausse. "Characterization of mechanical behaviour of aluminum powders under fast dynamic conditions." EPJ Web of Conferences 250 (2021): 01036. http://dx.doi.org/10.1051/epjconf/202125001036.

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Cold spray is a process belonging to the thermal spray family, characterized by relatively low temperatures and high particle velocities. Upon impact, particles undergo large plastic deformation at solid state in dynamic regime up to 109 s-1. The knowledge of powder behaviour in such conditions is essential to catch key phenomena in cold spray and a necessary step for a correct process modelling. However, little is known on mechanical behaviour of feed-stock powders when submitted to cold spray conditions. In this study, an approach focused on single particles combining laser shock induced impact, namely LASHPOL (LAser SHock POwder Launcher), and quasi-static compression was therefore developed. This method was applied in this study on spherical Aluminium powders but can work with any other powder material. The mechanical behaviour of powders was characterized and used to fit the parameters of Johnson-Cook constitutive model, by means of finite element inverse method. The combination of static and dynamic tests resulted in an original characterization of powder, which revealed having a different mechanical behaviour than the corresponding bulk material.

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Tsaknopoulos, Kyle, Caitlin Walde, Derek Tsaknopoulos, Victor Champagne, and Danielle Cote. "Characterization of Thermally Treated Gas-Atomized Al 5056 Powder." Materials 13, no. 18 (September 12, 2020): 4051. http://dx.doi.org/10.3390/ma13184051.

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Aluminum 5056 is a work-hardenable alloy known for its corrosion resistance with new applications in additive manufacturing. A good understanding of the secondary phases in Al 5056 powders is important for understanding the properties of the final parts. In this study, the effects of different thermal treatments on the microstructure of Al 5056 powder were studied. Thermodynamic models were used to guide the interpretation of the microstructure as a function of thermal treatment, providing insight into the stability of different possible phases present in the alloy. Through the use of transmission electron microscopy (TEM) and energy-dispersive X-ray spectroscopy (EDS), combined with thermodynamic modeling, a greater understanding of the internal microstructure of Al 5056 powder has been achieved in both the as-atomized and thermally treated conditions. Evidence of natural aging within these powders was observed, which speaks to the shelf-life of these powders and the importance of proper treatment and storage to maintain consistent results.

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Suhag, Yogita, Gulzar Ahmad Nayik, Ioannis K. Karabagias, and Vikas Nanda. "Development and Characterization of a Nutritionally Rich Spray-Dried Honey Powder." Foods 10, no. 1 (January 14, 2021): 162. http://dx.doi.org/10.3390/foods10010162.

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In the present study, the spray-dried honey powder enriched with aonla (Emblica officinalis Gaertn) and basil (Ocimum sanctum) extract was developed using drying aids—gum arabic (GA), maltodextrin (MD), and whey protein concentrate (WPC), and then characterized based on particle size distribution, colour, glass transition temperature (Tg), X-ray diffraction, and antioxidant and rheological properties. Results showed the highest Tg (86.13 °C) for WPC based honey powder, which, in turn, resulted in least stickiness as compared to GA and MD based honey powders with Tg 74.53 °C and 68.26 °C, respectively. The dried honey powder with all three carrier agents exhibited a metastable amorphous state as proved by the broader peaks of X-ray diffractograms due to the short drying time, whereas, a peak at 1637 cm−1, attributed to the carbonyl (C=O) stretching, established the ascorbic acid in the studied powder on account of aonla extract. The mean particle diameter significantly (p < 0.05) increased, following the order WPC (60.45 μm) > GA (41.24 μm) > MD (20.06 μm) as carrier agents, which were related to the higher feed viscosity. The colour parameter L* (30.74–45.78) and b* (5.82–11.64) values of the nutritionally rich honey powder were higher due to presence of polyphenols in aonla and basil extracts, which resulted in the formation of dark brown complexes. The antioxidant activity of WPC based fortified honey powder was highest (82.73%), followed by GA (78.15%) and MD (74.85%) based honey powders. A significant (p < 0.05) increase was found in powder recovery, solubility, and dispersibility using the drying aids in the following order: WPC < GA < MD. Furthermore, the storage modulus (G′) was higher than loss modulus (G″) in all honey powders, wherein the WPC containing powder demonstrated maximum value of G′, followed by GA and MD. Finally, the three honey powders were microbiologically stable.

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Hsu, Kuo Chin, Jiunn Der Liao, Zheng Zhong Xie, and Yaw Shyan Fu. "Preparation and Characterization of Cubic and Rod-Shaped Indium Tin Oxide Powders Using the Hydrothermal Process." Applied Mechanics and Materials 479-480 (December 2013): 64–68. http://dx.doi.org/10.4028/www.scientific.net/amm.479-480.64.

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The cubic and rod-shaped powders of indium tin oxide were synthesized at a stable temperature reaction for 18h using the surfactant aid hydrothermal method under various conditions. The cubic and rod-shaped powder size changes with the concentration of the precursor. The finished products of indium tin oxide can be obtained by calcination at 500°C for 2h in air. Characterization was conducted using scanning electron microscopy (SEM), energy dispersive spectrometry (EDS), X-ray diffractometry (XRD), thermogravimetric analyzer/differential thermal analysis (TG/DTA) and the Brunauer-Emmett-Teller (BET). XRD analysis shows that the conditions of this experiment can produce pure ITO powders. The characterization of cubic and rod-shaped ITO powders is also discussed.

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Hsu, Kuo Chin, Jiunn Der Liao, Zheng Zhong Xie, and Yaw Shyan Fu. "Preparation and Characterization of Cubic and Rod-Shaped Indium Tin Oxide Powders Using the Hydrothermal Process." Applied Mechanics and Materials 311 (February 2013): 430–34. http://dx.doi.org/10.4028/www.scientific.net/amm.311.430.

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The cubic and rod-shaped powders of indium tin oxide were synthesized at a stable temperature reaction for 18h using the surfactant aid hydrothermal method under various conditions. The cubic and rod-shaped powder size changes with the concentration of the precursor. The finished products of indium tin oxide can be obtained by calcination at 500°C for 2h in air. Characterization was conducted using scanning electron microscopy (SEM), energy dispersive spectrometry (EDS), X-ray diffractometry (XRD), thermogravimetric analyzer/differential thermal analysis (TG/DTA) and the Brunauer-Emmett-Teller (BET). XRD analysis shows that the conditions of this experiment can produce pure ITO powders. The characterization of cubic and rod-shaped ITO powders is also discussed.

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Li, B., Xin Long Wang, B. Guo, Yu Mei Xiao, Hong Song Fan, and Xing Dong Zhang. "Preparation and Characterization of Nano Hydroxyapatite." Key Engineering Materials 330-332 (February 2007): 235–38. http://dx.doi.org/10.4028/www.scientific.net/kem.330-332.235.

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The aim of this study is to prepare nano hydroxyapatite powder. Hydroxyapatite powder was prepared via co-precipitated method with the addition of citric acid at pH 9-11 in ambient environment. The precipitates were aged for 24hs, and then milled into powder after washed and dried. The particle morphology and particle size of as prepared HA powders were characterized. The results showed that hydroxyapatite powder with width of 10-30nm and length of 30-100nm was prepared by wet co-precipitation.

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Afonso, Conrado Ramos Moreira, Claudemiro Bolfarini, Walter José Botta Filho, and Claudio Shyinti Kiminami. "Overspray Powder Characterization of Fe-Based Glassy Alloy." Materials Science Forum 727-728 (August 2012): 468–75. http://dx.doi.org/10.4028/www.scientific.net/msf.727-728.468.

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Powder of Fe72Nb4Si10B14 (%at) glassy alloy was obtained by gas atomization in order to investigate the possibilities of amorphous phase formation due to the high cooling rates (103 105 K/s) involved in this process. The ratio between the gas volumetric and the metal mass flow rates used was 1.0, and nitrogen (N2) was used as the atomization gas. The powder, sieved in different granulometric size ranges, was characterized through: X-ray diffratometry (XRD), differential scanning calorimetry (DSC) and scanning electron microscopy (SEM). Fe72Nb4Si10B14 (%at) bulk metallic glass (BMG) showed completely or partially glassy structure depending on the size range. The obtaining of powders with glassy structure that could be applied as shot penning powder particles and thermal spray feeding powder for metallic coatings or would make possible the production of bulk glassy materials by warm consolidation of such powders or even a millimeters thick deposit obtained by spray forming with glassy or metastable microstructure that would be very interesting considering applications as soft ferromagnetic parts.

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Nagata, Kohei, Toshiisa Konishi, Michiyo Honda, and Mamoru Aizawa. "Preparation and Characterization of β-Tricalcium Phosphate Powders with High Solubility for Chelate-Setting Calcium-Phosphate Cements." Key Engineering Materials 758 (November 2017): 194–98. http://dx.doi.org/10.4028/www.scientific.net/kem.758.194.

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We have previously developed a novel chelate-setting β-tricalcium phosphate (β-TCP) cement with non-fragmentation property in vivo. This novel cement has been set on the basis of chelate-setting mechanism of inositol phosphate (IP6). In this study, β-TCP powders were synthesized by mechanochemical method, and the as-prepared powders were heated at 600-1300°C for 1 h. Some properties of the resulting powders were examined. The crystalline phase of the resulting powders in the range of 600-1100°C was of β-TCP single phase. In the cases at 1200°C and 1300°C, the resulting powders were composed of β-TCP and α-TCP. Median particle sizes of the resulting powders increased with heating temperature from 5.35 μm up to 47.7 μm. Dissolution rate of Ca2+ ions from the β-TCP powders was measured by Japanese Industrial Standard T 0330-3. When the heating temperature was at 700°C, the Ca2+ ions solubility was highest among examined ones. The β-TCP powder heated at 700°C for 1 h will be expected as the starting powder for paste-like artificial bone filler with excellent bioresorbability.

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Park, Dae Chul, Toyohiko Yano, Sae Hoon Kim, Won Youl Choi, and Jung Hee Cho. "Surface Characterization of the Milled–Silicon Nitride Nano Powders by XPS and TEM." Key Engineering Materials 326-328 (December 2006): 409–12. http://dx.doi.org/10.4028/www.scientific.net/kem.326-328.409.

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We studied the surface characterization of milled–silicon nitride nano-powders by XPS and TEM. The change of the chemical state and morphology of the oxide layer on the surface of Si3N4 nano-particles before and after a conventional wet–ball–milling process are investigated by X–ray photoelectron spectroscopy for measuring the chemical state of the oxide layer and transmission electron microscopy for observing surface morphology. The native oxide layers of as-received Si3N4 powders confirmed by HREM observation and their chemical states were different each other. As increasing ball–milling time, the chemical composition and the volume of oxide layer in Si3N4 powders were changed. The chemical state of as–received Si3N4 powder was near to SiO2 phase. After ball–milling process for long time, that of the milled Si3N4 powder shifted to Si2N2O phase. As increasing ball-milling time, the oxide layer of Si3N4 powder was also increased.

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Ahmad, M., E. Ahmed, N. R. Khalid, M. J. Jackson, and W. Ahmed. "Synthesis and Characterization of Hexagonal Shaped Nanocrystalline Zinc Oxide Powders." International Journal of Manufacturing, Materials, and Mechanical Engineering 2, no. 2 (April 2012): 61–76. http://dx.doi.org/10.4018/ijmmme.2012040104.

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Nanocrystalline ZnO powders are synthesized using a quick, simple and inexpensive combustion method. Glycine and zinc nitrate, used as fuel and oxidant/cation sources respectively, were mixed together at room temperature to form a slurry or gel. A series of experiments were performed to synthesize nanoparticles for different fuel to oxidant ratios. The rate of heating and stirring greatly influenced the combustion process. The as-synthesized powder was heat treated at elevated temperatures for varying time to remove adsorbed impurities from the surface of the ZnO nanoparticles. Both the as-synthesized and heat treated powders were characterized using a variety of analytical techniques. The hexagonal wurtzite phase of the ZnO powder was revealed from x-ray diffraction measurements. A decrease in the x-ray diffraction density (Dx) and the bulk density (D) resulted in an increase in percentage porosity (%P) of as-synthesized and heat treated ZnO powders. The range of fuel to oxidant ratios used in the present work indicates that they had a strong influence on the grain size of ZnO powders. The average grain size estimated by using the Scherer formula indicated an approximate value of 6-21 nm for the as-synthesized and heat treated samples.

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Adzila, Sharifah, Singh Ramesh, Iis Sopyan, C. Y. Tan, Mohd Hamdi, and W. D. Teng. "Mechanochemical Synthesis of Magnesium Doped Hydroxyapatite: Powder Characterization." Applied Mechanics and Materials 372 (August 2013): 62–65. http://dx.doi.org/10.4028/www.scientific.net/amm.372.62.

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In this study, the mechanochemical method was employed to synthesize hydroxyapatite (HA) and magnesium (Mg) doped hydroxyapatite (HA) powders. The effect of Mg2+ into the synthesized HA powder properties were investigated. Characterization of the synthesized HA and Mg doped HA at various concentrations (1% - 5% MgHA) were accomplished through X-ray diffraction (XRD) and Fourier transform infrared (FTIR) analyses. nanosize of HA and Mg doped HA powders were successfully synthesized through the present method as indicated from the different peaks intensity and adsorption bands obtained in XRD pattern and FTIR respectively.

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Kusunose, Takafumi, Nobuaki Sakayanagi, Tohru Sekino, and Yoichi Ando. "Fabrication and Characterization of Aluminum Nitride/Boron Nitride Nanocomposites by Carbothermal Reduction and Nitridation of Aluminum Borate Powders." Journal of Nanoscience and Nanotechnology 8, no. 11 (November 1, 2008): 5846–53. http://dx.doi.org/10.1166/jnn.2008.261.

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In order to fabricate aluminum nitride/boron nitride (AlN/BN) nanocomposites by pressureless sintering, the present study investigated the synthesis of AlN-BN nanocomposite powders by carbothermal reduction and nitridation of aluminum borate powders. Homogeneous mixtures of alumina (Al2O3), boric acid (H3BO3), and carbon powder were used to synthesize AlN/BN nanocomposite powders containing 10 and 20 vol% BN. Aluminum borate was produced by reacting Al2O3 and B2O3 above 800 °C, and AlN and turbostratic BN (t-BN) were produced by reacting aluminum borate with carbon powder and nitrogen gas at 1500 °C. Carbothermal reduction followed by nitridation yielded an AlN/BN nanocomposite powder composed of nanosized AlN and t-BN. By pressureless sintering nanocomposite AlN/BN powders containing 5 wt% Y2O3, AlN/BN nanocomposites were obtained without compromising the high thermal conductivity and high hardness.

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Eskalen, Hasan, Mikail Aslan, Hakan Yaykaşlı, and Musa Gögebakan. "Synthesis and characterization of Co–B–Fe–Ti nanosized alloyed powders." International Journal of Materials Research 112, no. 1 (January 1, 2021): 35–41. http://dx.doi.org/10.1515/ijmr-2020-7704.

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Abstract In this study, novel Co60Fe18Ti18B4 alloy powders have been synthesized with high compositional homogeneity using a high-energy ball milling technique. The structural, morphological and mechanical properties of the nanosized alloyed powders were examined using different analytical techniques, including scanning electron microscopy, transmission electron microscopy, energy-dispersive X-ray spectrometry and X-ray diffraction. According to the X-ray diffraction analysis for both Co powder and Co60Fe18Ti18B4 alloy powders, with increasing milling time, the content of Co-based (hcp) solid solution decreased and Co-based (fcc) solid solution increased. The mechanical properties of the material were also investigated by Vickers micro-hardness testing. The micro-hardness value of the Co60Fe18Ti18B4 alloy was found as 120.08 HV. After sintering (1 h– 1000 °C), the hardness improved remarkably (536.32 HV). Furthermore, results indicate that the synthesized Co-based alloy powder has both glassy and nanocrystalline phase forms.

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Obradovic, Nina, William Fahrenholtz, Suzana Filipovic, Cole Corlett, Pavle Djordjevic, Jelena Rogan, Predrag Vulic, Vladimir Buljak, and Vladimir Pavlovic. "Characterization of MgAl2O4 sintered ceramics." Science of Sintering 51, no. 4 (2019): 363–76. http://dx.doi.org/10.2298/sos1904363o.

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Single phase MgAl2O4 was made from a one-to-one molar ratio of MgO and Al2O3 powders mixed using ball-milling. Mixtures of MgO and Al2O3 were subsequently treated in planetary ball mill for 30, 60, 90 and 120 minutes in air. The aim of this study was to examine phase composition, microstructure, and densification behavior of sintered specimens. After sintering in dilatometer at 1500?C, the powder was converted to single phase MgAl2O4. The results show that mechanical activation improved the densification behavior of MgAl2O4 sintered specimens, and it reduced the onset temperature for sintering by approx. 100?C. Based on dilatometer data, powders were subsequently densified at 1450?C by hot pressing. Almost ?ll specimens exhibited full density, while sample activated for 30 minutes showed the fastest densification rate.

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Alves, Sérvulo José Ferreira, Marcio Marcelo Sampaio de Sousa, Everthon Rodrigues de Araújo, Francisco Ambrozio Filho, Maurílio José dos Santos, and Oscar Olimpio de Araújo Filho. "Processing of Metal Matrix AA2124 Aluminium Alloy Composites Reinforced by Alumina and Silicon Carbide by Powder Metallurgy Techniques." Materials Science Forum 802 (December 2014): 84–89. http://dx.doi.org/10.4028/www.scientific.net/msf.802.84.

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This work aims the processing of metal matrix AA2124 aluminium alloy composites reinforced by alumina (Al2O3) and silicon carbide (SiC). The composites were manufactured by powder metallurgy techniques, in a grinding using a ball mill spex type (high energy) at a ratio of balls/ powders of 10:1 and grinding time of 30 and 60 minutes using stearic acid (C18H36O2) as lubricant to each one of the samples. The fractions used in both reinforcements were 5, 10 and 15% in mass. The microstructural characterizations of AA2124 alloy powders with the reinforcements of alumina (Al2O3) and silicon carbide (SiC) powders were obtained by scanning electron microscopy (SEM) and the particles sizes and distribuition of the particle sizes in powders produced were obtained by laser diffraction, whereas the sintered characterizations were obtained by scanning electron microscopy (SEM) and mechanical characterization of the sintered tests was achieved by Vickers hardness (HV). The composites were uniaxially cold compacted (room temperature), at a pressure of 7.0 t / cm2, thus forming small pellets that were sintered (at a temperature of 500 °C) in a vacuum furnace at IPEN (SP). There was observed the influence of the respective bulk fractions of reinforcement particles used in mechanical characteristics presented in the resulting composites.

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Journal articles on the topic 'Powders characterization'

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