The researching of physical-mechanical properties of intermetallic catalysts obtained in shs conditions
Journal: Construction, materials science, mechanical engineering (Vol.3, No. 80)Publication Date: 2015-03-24
Authors : B. P. Sereda; Y. A. Belokon; K. V. Belokon; D. V. Sereda;
Page : 297-301
Keywords : SHS; intermetallic; catalysts; porosity; durability; thermal stability;
Abstract
Abstract. Purpose. For nickel aluminides along with traditional methods of casting and powder metallurgy, recently began to use the technology self-propagating high-temperature synthesis (SHS). You must install the regularities of formation porosity and strength intermetallic catalysts when changing the SHS process and the degree of doping. Methodology. As starting components used pure powders of nickel, aluminum, cobalt, copper, and manganese oxide. Dispersible powders was 100-150 m. Scheme batch cooking involved dosing, mixing, mold filling, SHS compaction and heat treatment. The mechanical strength of samples was determined via UG-20 machine. Compression testing was performed according to GOST 25.503-97. Thermal analysis of the test sample was performed on the brand Derivatograph Q1050. The microstructure of the obtained catalysts were tested for light microscope ?Neophot-21? and a scanning electron microscope ?SEM-100?. Findings. Analysis of the results of physical and mechanical properties of intermetallic catalysts showed that they differ depending on the mixture composition and process mode processing. The difference in the physical and mechanical properties of the catalyst is due to differences in the structure, phase composition, the porosity and pore size. The introducing additives porosity manganese catalyst is increased by increasing the volume of large pores and the structure with small capillaries not change due to the localization of manganese oxide in the catalyst pores. However, with the introduction of additives manganese sharply reduced mechanical strength blanks which may be increased if the Ni-Co-Mn catalyst additionally prolegirovat copper. An important advantage of SHS mode, is that the strength of the catalyst is 1,5 times higher than that of the sintered materials at the same porosity. High process temperatures and low content of impurities at the grain boundary (due to self-cleaning) lead to the formation of strong bonds between the grains in the polycrystal. The average value for all of the specific surface of the catalyst is tested samples 112 m2/g. Analysis of the initial sample derivatograms Ni-Co-Mn-Cu gave weight gain of the sample at temperatures ranging from 200-300oС 2% by weight. Originality. New scientific evidence on the effect of mode of SHS process and the degree of doping on the porosity and strength of the intermetallic catalysts. The parameters of the thermal stability ofintermetallic catalysts. Practical value. The parameters of SHS pressing and doping levels to increase the porosity and plasticity of intermetallic catalysts.
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