The combustion synthesis of Ni–Ti intermetallic compounds

Abstract

Combustion synthesis is a novel method which has been successfully used for the production of numerous refractory compounds. In the present study, this process was used to synthesise porous Ni–Ti intermetallic compounds. Two different nickel particle sizes (10 and 63 μm) were used to make compacts with different Ni + Ti:Ti + C ratios of 100:0, 90:10 and 80:20. The use of fine nickel particle size resulted in an intense reaction and the products were deformed as a result of melting. In the samples with larger nickel particle size, melting did not occur and the products only underwent an expansion because of an increase in the pore fraction. The reaction between Ti and C increased the exothermicity of the total process, and yielded products with a better distribution of pores. The products were characterised by SEM and XRD analyses. The main phases detected in the products were NiTi and NiTi2. TiC particles were also dispersed within the matrix.