Effects of chromium and nitrogen contents on microstructural changes in tic particles in (α + β)- and β-titanium matrix composites

Abstract

New composite materials with high strength and toughness are expected to be obtained from titanium alloys by α-titanium precipitation in ceramic particles dispersed in a matrix. In this study, a series of TiCrCN alloys were prepared, and the effects of chromium and nitrogen contents on the microstructural changes in the TiC particles were revealed in (α + β)- or β-titanium alloys. α-Titanium precipitation in the TiC particles was observed when the nitrogen content was more than 2 at% and the chromium content was less than 11 at%. The mechanism of and the conditions for α-titanium precipitation are discussed in terms of the crystallographic relationship between α-titanium and metastable Ti 2C. © 2012 The Japan Institute of Metals.