PURPOSE: To join efficiently a titanium alloy at a low cost without laborious atmosphere conditioning in a frictional press welding method of the titanium alloy by specifying a friction time and subjecting the alloy to a brake type frictional press welding under the conditions satisfying a specific equation.
CONSTITUTION: A round bar or steel of an α+β type titanium alloy is subjected to brake type frictional press welding for 3W7sec friction time under the conditions satisfying the following equation: P2≥660(ndP1)-0.44 where n: a difference in revolving speed rpm, d: the diameter of the round bar or pipe mm, P1: friction pressure kgf/mm2, P2: upset pressure kgf/mm2. The joint part having a good mechanical property virtually equal to the mechanical property of the base material is thus obtd. stably and surely.
SUZUKI SHIYUUJIROU
TAKADA FUMIHIRO
