The interface morphology of thixo-joined cold work tool steel

Abstract

Cold-work tool steel is considered to be a nonweldable metal due to its high percentage content of carbon and alloying elements. The application of a new process of the semi-solid joining of two parts of AISI D2 cold-work tool steel is proposed using a partial remelting method. Samples were heated in an argon atmosphere up to 1275??C which corresponded to about 20% of liquid fraction and held for 10 minutes. Metallographic analyses along the joint interface showed a smooth transition from one to the other and neither oxides nor micro-cracking was observed. The current work successfully confirmed that avoidance of a dendritic microstructure in the semi-solid joined zone and high bonding quality components can be achieved without the need for force or complex equipment when compared to conventional welding processes.