SINTERING OF POWDERS IN THE CrSi₂–Ti(Ta)Si₂SYSTEMS DEPENDING ON THE METHODS FOR SYNTHESIS

Abstract

Composite materials on the basis of refractory silicides, in particular their solid solutions, are widely used in many areas of engineering for parts of heating elements and heat resistance protective coatings. This paper presents the findings obtained in the study of peculiarities of solid phase interaction during synthesis of Cr_0.9Ta_0.1Si₂ and Cr_0.5Ti_0.5Si₂ solid solutions depending on the synthesis conditions. The effect of the powder dispersity on compaction of targets from Cr_0.9Ta_0.1Si₂ and Cr_0.5Ti_0.5Si₂powders has been studied, and it has been established that the use of nanosized powders complicates the process of pressing. Also, sintering of targets from nanosized Cr_0.9Ta_0.1Si₂  and Cr_0.5Ti_0.5Si₂  powders was studied. The sintered targets were established to have a small grain size and uniform porosity all over the volume. Thanks to small closed porosity, the targets exhibit high heat resistance under thermal shock.