Influence of processing conditions on joint strength in backward extrusion forged bonding

The aim of this study is the development of a forge bonding technology in which Al alloy and steel billet are formed and bonded to each other in one cold forging process. A result of the good bond between the metals in backward extrusion is acquired now. The bonding strength on the bonding boundary was measured by microtensile test for the purpose of confirmation of its reliability. In the test, microtensile test specimens were cut off at the bonding boundary by using a wire cutting machine. The specimens were split on the boundary and the fractured surfaces were observed with a scanning electron microscope. Surface area ratio of adhesion metal which comes from the other side of specimen also was measured in the observation.