2007 Volume 25 Issue 2 Pages 353-361
This paper describes about the autocompleting friction welding method that was developed by the authors. The autocompleting friction welding method was produced by using a center insert drive friction welding machine, and it was carried out with a circumferential share fracture at the disk type insert specimen by the friction torque generated during friction process. The material joined was low carbon steel (same material) with the weld faying surface diameter of 10mm, and the effect of an insert thickness of a disk type specimen (insert thickness) on joining phenomena were investigated. The following conclusions are provided.
(1) When an insert thickness was 3.2mm at a friction pressure of 36MPa with a friction speed of 27.5s-1, the peripheral portion of an insert specimen at the welded interfaces had provided circumferential share fracture by the initial torque that was produced during friction process. The joint had a crack at the adjacent region of the welded interfaces although it had the same tensile strength as the base metal.
(2) The joint made by using a disk type insert specimen that had the groove on the peripheral portion had the same tensile strength as the base metal and it fractured at the base metal. This joint had also 90 degrees bend ductility with no crack. In this case, the optimum groove thickness was 1.2mm at a groove inner diameter of 11mm with the insert thickness of 4.0mm at a friction pressure of 36MPa with a friction speed of 27.5s-1.
(3) The joint was automatically welded by using the disk type insert specimen, that insert thickness and the groove thickness was determined with the material, the diameter of the weld faying surface, and the friction welding condition. That is, the sound friction welded joint was made by the autocompleting friction welding method.
