Production and Characterization of Niobium Toughened Ti-TiAl3 Metallic-Intermetallic Composite

Abstract

Ti-TiAl3 in situ composites with 10 wt.% Nb were successfully prepared from Ti, Al, and Nb metallic powders by powder metallurgy processing technique of electric current activated/assisted sintering. The current and process time used for producing metallic-intermetallic composites were 2000 A and 90 s, respectively. In terms of fracture toughness, effects of addition of ductile niobium phase to Ti-TiAl3 composites were investigated. According to SEM-EDS and XRD results, the synthesized composites mainly consisted of TiAl3 matrix and dispersive Nb reinforcing phases, as well as ductile Ti phases. Hardness and fracture toughness values of the samples were measured by Vickers hardness tester under loads of 100 g and 10 kg, respectively. Fracture toughness value of TiAl3 intermetallic composites was increased with Nb ductile phase addititon from 1.69 +/- 0.05 MPam(1/2) to 5.23 +/- 0.3 MPam(1/2).