scholarly journals Research of mechanical properties of the sintered samples from electro-erosion cobalt-chromium powder

2018 ◽  
Vol 7 (2.2) ◽  
pp. 28
Author(s):  
E V. Ageev ◽  
A Yu. Altukhov ◽  
S V. Pikalov ◽  
V I. Serebrovskii ◽  
R I. Safronov

The main requirement for powders for additive 3d technologies is the spherical shape of the particles. Such particles are most compactly packed into a certain volume and ensure the "fluidity" of the powder composition in the supply systems of the material with minimal resistance. Proceeding from the peculiarities of the methods for the production of spherical powders with the aim of obtaining spherical granules of regulated granularity, the technology of electroerosive dispersion is proposed, which is characterized by relatively low energy costs and ecological purity of the process. Based on the results of the studies aimed at investigating the mechanical properties of sintered samples from cobalt-chrome powders obtained for additive technologies by electroerosive dispersion, it was established that the average Vickers hardness of sintered samples is 14,63 Gpa; the porosity of the sintered samples is 6,15%.

2020 ◽  
Vol 299 ◽  
pp. 611-616
Author(s):  
Evgeniy V. Ageev ◽  
A.Y. Altukhov ◽  
M. S. Korolyov

The main requirement for powders for additive 3d technologies is the spherical shape of the particles. Such particles are most compactly packed into a certain volume and ensure the "fluidity" of the powder composition in the supply systems of the material with minimal resistance. The wide use of the EED method for processing metal waste into powders for the purpose of their reuse and application in additive technologies is hampered by the lack in the scientific and technical literature of full-fledged information on the effect of the initial composition, regimes and media on the properties of powders and technologies of practical application. Therefore, in order to develop technologies for the reuse of electroerosive powders and to evaluate the effectiveness of their use, complex theoretical and experimental studies are required. The aim of the work was to conduct a phase analysis of additive products from electroerosive cobalt-chrome powders. The phase composition of the samples was studied by X-ray diffraction on a Rigaku Ultima IV diffractometer in Cu-Kα radiation (wavelength λ = 0.154178 nm) using Soller slits. Based on the results of the X-ray diffraction analysis of additive articles from electroerosion cobalt-chrome powders, it has been experimentally established that the main phases in the sintered samples are Co, Cr and Co3C.


2019 ◽  
Vol 9 (7) ◽  
pp. 1308 ◽  
Author(s):  
Rob Kleijnen ◽  
Manfred Schmid ◽  
Konrad Wegener

This work describes the production of a spherical polybutylene terephthalate (PBT) powder and its processing with selective laser sintering (SLS). The powder was produced via melt emulsification, a continuous extrusion-based process. PBT was melt blended with polyethylene glycol (PEG), creating an emulsion of spherical PBT droplets in a PEG matrix. Powder could be extracted after dissolving the PEG matrix phase in water. The extrusion settings were adjusted to optimize the size and yield of PBT particles. After classification, 79 vol. % of particles fell within a range of 10–100 µm. Owing to its spherical shape, the powder exhibited excellent flowability and packing properties. After powder production, the width of the thermal processing (sintering) window was reduced by 7.6 °C. Processing of the powder on a laser sintering machine was only possible with difficulties. The parts exhibited mechanical properties inferior to injection-molded specimens. The main reason lied in the PBT being prone to thermal degradation and hydrolysis during the powder production process. Melt emulsification in general is a process well suited to produce a large variety of SLS powders with exceptional flowability.


2015 ◽  
Vol 817 ◽  
pp. 307-311 ◽  
Author(s):  
Peng Chao Zhang ◽  
Jin Chuan Jie ◽  
Yuan Gao ◽  
Tong Min Wang ◽  
Ting Ju Li

The Cu-Cr and Cu-Cr-Ti alloy plates were prepared by vacuum melting and plastic deformation. The effect of slight Ti element on microstructure and mechanical properties of Cu-Cr alloy was discussed. The result shows that Cr particles with spherical shape precipitated from Cu matrix after aging. Plenty Ti atoms dissolved in the vicinity of Cr particles and there were still parts of solid solution Ti atoms in other regions. Improvements in peak hardness and softening resistance were achieved with the addition of Ti element in Cu-Cr alloy. The addition of 0.1 wt.% Ti element makes Cu-Cr alloy possess tensile strength of 565 MPa and hardness of 185.9 HV after aging at 450 °C for 120 min, which can be attributed to multiple strengthening mechanisms, i.e. work hardening, solid solution strengthening and precipitation strengthening.


2005 ◽  
Vol 44 (5-6) ◽  
pp. 207-210 ◽  
Author(s):  
A. V. Besov ◽  
V. A. Maslyuk ◽  
A. N. Stepanchuk ◽  
S. G. Napara-Volgina ◽  
L. N. Orlova

BDJ ◽  
1975 ◽  
Vol 138 (8) ◽  
pp. 295-298 ◽  
Author(s):  
M H Reisbick ◽  
A A Caputo

2007 ◽  
Vol 22 (2) ◽  
pp. 326-333 ◽  
Author(s):  
J. Das ◽  
S. Pauly ◽  
C. Duhamel ◽  
B.C. Wei ◽  
J. Eckert

Cu47.5Zr47.5Al5 was prepared by arc melting and solidified in situ by suction casting into 2–5-mm-diameter rods under various cooling rates (200–2000 K/s). The microstructure was investigated along the length of the rods by electron microscopy, differential scanning calorimetry and mechanical properties were investigated under compression. The microstructure of differently prepared specimens consists of macroscopic spherical shape chemically inhomogeneous regions together with a low volume fraction of randomly distributed CuZr B2 phase embedded in a 2–7 nm size clustered “glassy-martensite” matrix. The as-cast specimens show high yield strength (1721 MPa), pronounced work-hardening behavior up to 2116 MPa and large fracture strain up to 12.1–15.1%. The fracture strain decreases with increasing casting diameter. The presence of chemical inhomogenities and nanoscale “glassy-martensite” features are beneficial for improving the inherent ductility of the metallic glass.


2018 ◽  
Vol 14 (2) ◽  
pp. 99-104
Author(s):  
F. Fitriah ◽  
A. Doyan ◽  
S. Susilawati ◽  
S. Wahyuni

One of the renewable energy storage systems that can be used today is the aluminum ion battery. In this study, aluminum foil was used as anode, polyetylene polyprophylene (PE/PP) as separator, electrolyte from AlCl3/[EMIm]Cl and graphite coated corncob, an activated charcoal, as cathode. Coating method of cathode materials was done by mixing both graphite and activated charcoal with varied composition 1:0.5, 1:1, 1:1.5, and 1:3. The coating process began by mixing the graphite and corncob with ethanol as a solvent for six hours, then heating in an oven at 80 °C for three days, gradual drying in a furnace at 350 °C for five hours and sintering at 600 °C for six hours. From this research, SEM results showed that carbon particles were evenly distributed, with spherical particles. The spherical shape was the main requirement of carbon formation in order to produce high energy. Based on the results, battery potential was 2.54 V with average of optimal capacity at a ratio of graphite and corncob activated charcoal 1:1.5 was 83.067 mAh/g. The highest efficiency was also at a ratio of 1:1.5 of 97.20%, because at this ratio, there was an increasing in percentage of element C 91.74%, greater than the percentage of element C on the other three cathode samples.Salah satu sistem penyimpan energi terbarukan yang bisa digunakan saat ini adalah baterai ion aluminium. Pada penelitian ini digunakan aluminium foil sebagai anoda, polyetylene polyprophylene (PE/PP) sebagai separator, elektrolit menggunakan AlCl3/[EMIm]Cl dan grafit terlapisi arang aktif tongkol jagung sebagai bahan katoda. Metode pelapisan bahan katoda dilakukan dengan mencampurkan grafit dan arang aktif dengan variasi komposisi 1:0,5, 1:1,1:1,5 dan 1:3. Proses pelapisan diawali dengan pencampuran grafit dan arang aktif tongkol jagung dengan ethanol sebagai pelarut selama enam jam kemudian pemanasan di oven pada suhu 80oC selama tiga hari, pengeringan bertahap di furnace pada suhu 350oC selama lima jam dan sintering pada suhu 600oC selama enam jam. Dari penelitian ini didapatkan hasil SEM menunjukkan bahwa partikel karbon terdistribusi merata, dengan bentuk partikel bulat (sphare).Sampelberbentuk bulat atau sphere merupakan syarat utama pembentukan karbon supaya dapat menghasilkan energi tinggi. Berdasarkan hasil uji baterai diperoleh potensial sebesar 2,54 Volt dengan rata-rata kapasitas optimal terjadi pada rasio grafit dan arang aktif tongkol jagung 1:1,5 sebesar 83,067 mAh/g. Efisiensi tertinggi juga terjadi pada rasio 1:1,5 sebesar 97,20%. Hal ini karena pada rasio 1:1,5 terjadi peningkatan persentase unsur C yakni 91.74% lebih besar dari persentase unsur C pada tiga sampel katoda yang lainnya.


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