Mechanical properties and microstructure of in situ formed Ti2AlN/TiAl(WMS) composites

The Ti2AlN-reinforced TiAl (WMS) composites with different contents of Ti2AlN were prepared by an in situ method of reactive arc-melting technique. According to the results of X-ray diffraction (XRD) analysis, the Ti2AlN-reinforced WMS composites consist of gamma-TiAl, alpha(2)-Ti3Al, and Ti2AlN phases. Microstructure analysis results indicate that Ti2AlN reinforcements with rod-like in shape form in the WMS matrix with a alpha(2)/gamma lamellar structure containing some bulk gamma phases. With volume fraction of Ti2AlN increasing, the grain size of the composites decreases significantly and the elasticity modulus (E) increases. The compressive strength and compressive fracture strain of the composite with 3 vol% Ti2AlN have a maximum value of 1,654 MPa and 22.5 %, respectively, which are approximately improved by 45.84 % and 29.31 %, respectively, compared with that of the unreinforced WMS alloy.