Investigation of compounds obtained from Ti-Si-C ternary powder system by mechanical alloying and spark plasma sintering

Abstract

The purpose of this study is to investigate the method of mechanical alloying and its effect on the compounds obtained from the Ti-Si- ternary powder system. At first, a mixture of Ti, Si and C powders with stoichiometric ratio according to Ti 3 SiC 2 chemical composition was milled by high energy planetary ball milling with balls to powder weight ratio of 20: 1 and a rotation speed of 360 rpm. To evaluate the thermal stability of the formed phases and determine the mechanism of reactions, the 40 h milled sample was analyzed by DTA. Then, to test the peaks obtained during DTA analysis, the 20 milled sample thermal treated at 1200°C and 1400°C for 1h. To identify phase development, XRD was used and the microstructural evaluation was obtained by SEM / EDS. The results showed that increasing the milling time not only does not increase the purity of Ti 3 SiC 2 but also causes more impurities mainly TiC and SiC. But heat treatment at 1200 ° C increases the purity of Ti 3 SiC 2 . The mechanism that occurs in the 3Ti-Si-2C system is that first TiC is formed and its heat causes more mixing and the formation of Ti and Si melt. As the TiC process continues, it reacts with the Ti-Si melt to form Ti 3 SiC 2 .