Effect of Milling on Sintering Behaviour of γ-TiAl by Spark Plasma Sintering

Abstract

In this study, densification behavior of mechanically alloyed TiAl powders by spark plasma sintering has been analyzed. TiAl alloy with a composition of TiAl-xNb-1Cr-0.4Mo-0.1B (x ¼ 0, 3.5, 6, 8.5) was prepared by mechanical milling for 20 hrs and was consolidated by spark plasma sintering. Average particle size of 20 hrs milled powders was 5 mm and morphology of these milled powders was flaky. Density of these sintered samples varied from 99.1% to 99.8% of the theoretical density. The addition of Nb increases the densification of TiAl intermetallic compounds. The increase in densification of these milled TiAl powders has been related to the effects of milling such as decrease in particle size and morphological changes.