摘要
Hot extrusion was conducted in the α+β phase region for promoting mechanical properties of Ti42Al9V0.3Y. The microstructures and tensile properties before and after hot extrusion were studied. The results show that the microstructure of the as-cast alloy mainly consists of massive γ phase in β matrix and the as-extruded alloy mainly consists of lamellar α2/γ, lamellar β/γ, and strip γ propagating from elongated β phase. In the as-cast alloy, the predominantly observed fracture mode is transgranular cleavage failure at room temperature and intergranular fracture at 650-750 °C. After hot extrusion, it transforms into transgranular cleavage-like failure, including translamellar cleavage and delamination. The excellent tensile properties of the as-extruded material are attributed to the obvious refined microstructure with broken YAl2 particles and the micro-crack shielding action of the TiAl lamellasome.
Hot extrusion was conducted in the α+β phase region for promoting mechanical properties of Ti42Al9V0.3Y. The microstructures and tensile properties before and after hot extrusion were studied. The results show that the microstructure of the as-cast alloy mainly consists of massive γ phase in β matrix and the as-extruded alloy mainly consists of lamellar α2/γ, lamellar β/γ, and strip γ propagating from elongated β phase. In the as-cast alloy, the predominantly observed fracture mode is transgranular cleavage failure at room temperature and intergranular fracture at 650-750 °C. After hot extrusion, it transforms into transgranular cleavage-like failure, including translamellar cleavage and delamination. The excellent tensile properties of the as-extruded material are attributed to the obvious refined microstructure with broken YAl2 particles and the micro-crack shielding action of the TiAl lamellasome.
基金
Project supported by the National Postdoctoral Foundation of China
the Youth Science and Technology Project of Harbin (No 2008RFQXG040),China