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

Abstract

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 distributed in 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.