DEVELOPMENT OF HEAT RESISTANT MATERIAL BASED ON SILICON NITRIDE WITH INCREASED WEAR RESISTANCE

Abstract

The regularities of sintering under pressure of materials from powder systems Si₃N4–Y₂O3– Al₂O₃, Si₃N₄–Y₂O₃–Al₂O₃–TiH₂ are studied. The peculiarities of the structure formation, phase composition and properties of the obtained materials are investigated. It is determined that the material structure of the Si₃N₄–Y₂O₃– Al₂O₃–TiH₂ system consists of the main matrix phase and the second phase in the form of inclusions in which titanium, nitrogen and silicon are the main elements. It is shown that in addition during sintering there is a significant diffusion to yttrium inclusions. It was found that with increasing alumina content, the crack resistance of the material decreases from 5.3 to 4.8 МPа×М^0,5, and wear resistance – by ~ 8%. It was found that when titanium hydride is introduced into the initial charge up to 15% TiH₂, the crack resistance of the composite increases from 5.3 to 7.1 МPа×М^0,5, and wear resistance – by ~ 22%.