Abstract
This paper described the joining phenomena and joint strength of friction welded joint between Ti-6Al-4V and low carbon steel (S15CK) . When the joint was made with a friction pressure of 30MPa, the adjacent region of the weld interface reached to about 1,075 ℃ at a friction time of 8.0s or longer. This joint had the intermetallic compound layer (IMC interlayer) at the weld interface, and the joint efficiency of 100% was not achieved. It was demonstrated that the joint inhibited the generating of the IMC interlayer on the weld interface by increasing friction pressure, because the temperature at the weld interface was able to estimate a propensity to decrease with increasing friction pressure. Then, the joint, which was made with a friction pressure of 120MPa, a friction time of 7.0s or longer, and a forge pressure of 330MPa, had the 100% joint efficiency and it fractured from the S 15CK base metal with no cracking at the weld interface. This joint did not have the IMC interlayer on the weld interface. In conclusion, the joint should be made with the opportune high friction pressure and opportune long friction time for it without IMC interlayer with the high forge pressure for completely joining of the weld interface.
