Flow behavior of TiB₂ reinforced aluminum matrix composite in FSW

Objective The flow state of various regions of TiB₂/7050 aluminum matrix composite material during steady-state friction stir welding (FSW) was investigated in order to explore the influence of welding parameters on the material flow state and weld formation. Methods A finite element model was established by using numerical simulation, and actual welding experiments were conducted for verification. Results The material flow velocity was highest at the edge of shaft shoulder, and gradually decreased with increasing depth in the vertical direction. The material was unevenly distributed on the advancing side (AS) and retreating side (RS) of the stirring tool. The rational speed of the stirring tool had a greater impact on flow velocity than the welding speed, but the welding speed had a more significant impact on the flow trajectory. Conclusion The excellent welded joints could be obtained under a stirring head rotating speed of 800 r/min and a welding speed between 200～300 mm/min.