Microstructures and mechanical properties during sinter-forging of a novel TiAl alloy

AbstractA novel TiAl alloy was prepared by sintering and forging, and the microstructure and compression properties of the sintered and forged alloys were investigated. The results show that the alloy consists of γ-TiAl and α2-Ti3Al; the microstructure of the alloy in both sintered and forged states is divided into fine-crystal regions and coarse-crystal regions, and the fine-crystal regions in the sintered state consist of slate-like γ grains with a small amount of α2 grains, while the coarse-crystal regions consist of equiaxed γ grains. The fine-crystal regions in the forged state consist of equiaxed γ grains with a few α2 grains, and the coarse-crystal regions consist of equiaxed γ grains. The alloy has lower porosity and a more homogeneous microstructure. The compressive properties of the forged alloy were improved, the compressive strength increased from 1172 to 2349 MPa, and the engineering strain increased from 32% to 42%.Keywords: Powder metallurgysinter-forgingmicrostructuremechanical properties Additional informationFundingThe authors gratefully acknowledge the financial support of the National Natural Science Foundation of China (No. 51704088) and the Natural Science Foundation of Heilongjiang Province of China (No. YQ2020E030).