Effects of titanium addition on the microstructure and mechanical behaviorof iron aluminide Fe3Al

The microstructure. mechanical properties and deformation behavior of four Fe3Al-based alloys containing 0, 5. 10 or 15 at%Ti were investigated With t he addition of Ti. the coarse-grained microstructure of Fe3Al was refined a nd the degree of DO? ordering was decreased. Poor bending ductility and a c hange of fracture mode from cleavage to mixture of intergranular and cleava ge were observed in Ti-added alloys. It was shown that the Ti addition decr eased the room temperature yield strength, but increased the yield strength at elevated temperatures, Anomalous temperature dependence of yield streng th was observed in all the alloys, and the peak strength was shifted to hig her temperatures with increasing Ti content. The Ti addition was also revea led to decrease the strain rate sensitivity and activation energy for high temperature deformation Finally, hot working conditions for the Ti-added Fe 3Al alloys were proposed by taking the stress-strain response, strain rate sensitivity and deformation microstructure into account.