Nanoindentation and Structural Analysis of Sintered TiAl((100−x))-(x)TaN Composites at Room Temperature

The nanohardness, elastic modulus, anti-wear, and deformability characteristics of TiAl((100−x))-(x)TaN composites containing 0, 2, 4, 6, 8, and 10 wt.% of TaN were investigated via nanoindentation technique in the present study. The TiAl((100−x))-(x)TaN composites were successfully fabricated via the spark plasma sintering technique (SPS). The microstructure and phase formation of the TiAl sample constitute a duplex structure of γ and lamellar colonies, and TiAl(2), α-Ti, and TiAl phases, respectively. The addition of TaN results in a complex phase formation and pseudo duplex structure. The depth-sensing indentation evaluation of properties was carried out at an ambient temperature through a Berkovich indenter at a prescribed load of 100 mN and a holding time of 10 s. The nanoindentation result showed that the nanohardness and elastic modulus characteristics increased as the TaN addition increased but exhibited a slight drop when the reinforcement was beyond 8 wt.%. At increasing TaN addition, the yield strain ([Formula: see text]), yield pressure ([Formula: see text]), and elastic recovery index ([Formula: see text]) increased, while the plasticity index ([Formula: see text]) and the ratio of plastic and elastic work (RPE) reduced. The best mechanical properties were attained at the 8 wt.%TaN addition.