Cavitation resistance of iron-based powder materials

1988 ◽  
Vol 27 (10) ◽  
pp. 805-809
Author(s):  
O. V. Evtushenko ◽  
S. M. Chernega
2021 ◽  
Vol 877 (1) ◽  
pp. 012009
Author(s):  
Mohammed Qasim Kareem ◽  
Vladimir Dorofeyev

Abstract It is possible to expand the applications ranges of powder material products by enhancing the performance properties of these products in addition to their manufacturability and reliability together, it’s possible by materials structures modification. In this paper, the effect of fullerene (C60) additives to iron-based powder material has been studied. All samples produced by Hot-Forging (HF) powder materials technology. Green and HF density of the obtained samples calculated by volume / weight and Archimede’s principle, respectively. The effect of technological parameters on the microstructure of carbon steels’ samples was done by an ALTAMI MET-1M metallographic microscope. Tensile test executed by using of a universal testing machine UMM –5 and the microhardness (HV10) was measured by REICHERT hardness test machine. The results showed that the HF C60 steels’ samples had higher density and strength of 0.81 and 25%, respectively, with a good plasticity in comparison with graphite steels’ samples.


2019 ◽  
Vol 799 ◽  
pp. 252-256
Author(s):  
Simonas Mindaugas Jankus ◽  
Regita Bendikiene

The goal of this work was to investigate microstructure of the selective laser sintering (SLS) produced parts evaluating effect of powder type and fraction size. Studies have shown that printed samples of 316L and GP1 metal powders had a higher defect content compared to printed components from MP1 powder material. From scanning electron microscopy (SEM), it was found that iron-based printed parts melted worse than Co-Cr alloy components. Iron-based 316L and GP1 metal powders did not get enough energy from laser to perform a better microwelding between particles. Surface roughness Ra numerical values for samples 316L, GP1, MP1 respectively are Ra = 13.7 μm; 11.4 μm; 3.0 μm. Stainless steel powder material contains particles which size varies between 20 – 120 μm. The Co-Cr alloy and the maraging steel powder materials are made of 10 – 80 μm particles. The chemical and elemental composition of powder materials were examined using SEM-EDS technology.


2007 ◽  
Vol 534-536 ◽  
pp. 261-264
Author(s):  
Sheng Guan Qu ◽  
Yuan Yuan Li ◽  
Wei Xia ◽  
Wei Ping Chen

An apparatus measuring changes of various forces directly and continuously was developed by a way of direct touch between powders and transmitting force component, which can be used to study forces state of powders during warm compaction. Using the apparatus, warm compaction processes of iron-based powder materials containing different lubricants at different temperatures were studied. Results show that densification of the powder materials can be divided into four stages, in which powder movement changes from robustness to weakness, while its degree of plastic deformation changes from weakness to robustness. The proposed densification mechanism may provide an insight into understanding of warm compaction process.


Author(s):  
V. N. Kokorin ◽  
V. I. Filimonov ◽  
A. V. Kokorin ◽  
A. A. Evstigneev ◽  
B. R. Zinnatov
Keyword(s):  

Author(s):  
V. Yu. Dorofeyev ◽  
D. N. Sviridova ◽  
Kh. S. Kochkarova

Some Yu.G. Dorofeev’s memoirs about joint work and meetings with outstanding materials science expert G.V. Samsonov are given. Meetings in Yugoslavia were of particular importance where G.V. Samsonov and M.M. Ristićtogether with other worldfamous scientists created the International Institute for the Science of Sintering. In the last years of his life, G.V. Samsonov proposed the concept of sintering activation by additives that act as electron acceptors and additionally contribute to the ionic bond in the matrix material. The paper considers the possibility of using this concept in the development of activating additives that reduce the activation energy of the plastic deformation of iron-based powder materials. Sintering activation when forming stable electronic configurations can be accomplished by: 1) accelerating the grain-boundary heterodiffusion of the matrix material in the presence of phase segregations containing an activating microadditive (W–Ni system); 2) intensifying shrinkage durng the plastic flow of matrix material particles facilitated by diffusion porosity formed in the additive particles as a result of predominant additive atom diffusion into base metal particles (Fe–Ni, Fe–Co, Fe–Mn systems); 3) increasing the self-diffusion coefficient of base metal atoms due to the expanded area of a less close-packed crystal lattice (αphase) upon activating additive dissolution (Fe–Mo system). The article reviews the information available on the prospects for using manganese and chromium as compaction activating additives. The compaction activation energy of iron-based powder materials can be reduced by introducing manganese additives. At the same time, the use of diffusion saturation technology is promising. The question of using chromium as an activator does not have an unambiguous answer and suggests the need for further study.


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