929 摩擦圧接における摩擦時間と継手強度との関係

Abstract

This report describes relationship between friction time in friction stage and joint strength of friction welding joints. The materials used were mild carbon steels, and a brake type friction welding equipment was used for joining. In actual experiment, the electromagnetic clutch was used in order to exclude the braking deformation at rotation stopping. As experimental method, the relative speed was instantaneously rendering to zero at each friction time. The authors have determined that 100% of joint efficiency in tensile test, i. e. all joints fracture at substrate (not at interface), could be achieved without upsetting stage. That is, the tensile strength of the friction welded joints were dominated by friction welding process until the time that the friction torque reached to the initial peak torque. These joints could be bent in 90 degrees-bend tests, and this result was same as that of the joints welded by conventional welding process, i. e. by using upsetting stage. As a conclusion, the friction joints welded by using no upsetting stage have same mechanical properties as those welded by conventional friction welding process including that. The experimental method without upsetting stage has some advantages, e. g. less burn-off and the burr.