METHOD FOR PRODUCING TiAl BASE ALLOY AUTOMOTIVE ENGINE VALVE

摘要

PROBLEM TO BE SOLVED: To suppress the coarsening of the crystal grains of a sintered body, to suppress the generation of empty holes, to obtain a structure dence over the whole body and to obtain an engine valve in which the cost is reduced and excellent in strength and durability by utilizing the conventional sintering method, moreover controlling the conditions of HIP(hot isothermal pressing method) and executing hot extrusion. ;SOLUTION: In this method for producing a TiAl base alloy automotive engine valve, a powdery mixture or alloy powder in the ratio of Ti1-xAlx (0.39≤x≤0.59, (x): atomic fractional ratio) or powder for sintering essentially consisting of the same is sintered at 950 to 1,100°C, is thereafter subjected to HIP treatment under the conditions of ≥1,100°C and ≥1,000 Kgf/cm2, is moreover heated to ≥1,100°C and is subsequently extrueded.;COPYRIGHT: (C)2001,JPO