EFFECT OF TITANIUM DIBORIDE CONTENT ON BASIC MECHANICAL PROPERTIES OF COMPOSITES SINTERED FROM TiH₂ + TiB₂ POWDER MIXTURE

Abstract

The effect of the titanium diboride content of the starting TiH₂–TiВ₂ powder mixture on the basic mechanical characteristics of the sintered composites is determined in tension and compression tests. The porosity of the compacts sintered at 1250 ºС increases with higher titanium diboride content of the starting mixture, which is associated with the Frenkel effect that occurs in the sintering process. The strength, hardness, and elastic modulus increase in tension when 5% TiВ₂ powder is introduced into the charge, though porosity becomes somewhat higher. These characteristics however decrease when the high-modulus component increases to 10% in the charge. The ductility of the sintered alloys monotonically decreases with higher boride content. The yield point and compressive strength monotonically increase with higher ТіВ₂ content of the charge, though porosity increases. This occurs because porosity has a significantly smaller effect on the strain resistance of the sintered Ті–ТіВ composites in compression than in tension.