The researching of physical-mechanical properties of intermetallic catalysts obtained in shs conditions

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 200-300^oС 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.