Study of Ni₃Al-Cr₇C₃ composite materials fabricated by self-propagating high-temperature synthesis casting route

Ni₃Al composite materials with 15,25, and 50 wt pct Cr₇C₃ were fabricated by self-propagating high-temperature synthesis (SHS) casting route and analyzed with X-ray diffraction (XRD) and scanning electron microscopy (SEM) with X-ray energy dispersive spectroscopy (EDS). Microhardness and wear property of the materials were measured. The results showed that the materials mainly consisted of Ni₃Al and Cr₇C₃ phases and were dense and pure. The Cr₇C₃ phase was uniformly distribute the Ni₃Al matrix and the adherence of the reinforcement and the matrix was strong. Phases and microstructure of the materials varied with Cr₇C₃ content. There were no cracks in the materials with 15 and 25 wt pct Cr₇C₃, whereas cracks appeared in the material with 50 wt pct Cr₇C₃. Microhardness of the materials was much higher than that of pure Ni₃Al material and increased with Cr₇C₃ content. Wear resistance of the materials was much higher than that of pure Ni₃Al material and the material with 25 wt pct Cr₇C₃ had the best wear resistance.