Effects of Rotation Speed on Microstructure and Mechanical Properties in Ti/Cu Dissimilar Friction Stir Welding

The dissimilar welding of titanium and copper by fusion is very difficult because the melting points materials are highly different strong brittle intermetallic compounds (IMCs) can be easily produced in welded zone heat-affected zone, etc. Friction stir was employed as a type solid-state for Ti/Cu to obtain sound reduce total process cost. This study investigated how metal flow changes according variation rotational speed tool, from 450 rpm 600 rpm. When too high, plastic softened material increased such TiCu, Ti2Cu3, Ti2Cu, were generated Cu region zone. microstructural evolution AS (Advancing Side) RS (Retreating soundness its mechanical properties evaluated through evolution. A high hardness value 200 Hv or more exhibited some points, due formation (Cu) region. friction at 50 mm/min an appropriate rotation 500 showed good properties.