Fabrication of functionally graded injection molds using friction stir molding process of AA5083/brass-laminated composite

This paper presents a multi-material hybrid additive manufacturing process based on friction stir molding (FSM) for injection mold manufacturing. While a single material was utilized in FSM, herein functionally graded injection molds (FG molds) using FSM and multi-materials are manufactured. Two materials, brass 60/40 and AA5083 were used to demonstrate the process feasibility. A series of friction stir spot welding experiments were performed to identify suitable process settings. This included different combinations of rotational speeds and plunge rate of friction stir spot welding (FSSW) tool. The quality of testing coupons was examined by their shear loads and hardness profiles. ANOVA showed that only the plunge rate affects the quality of coupons and that the higher the plunge rate gives better quality. Two simple FG injection molds were manufactured and used to produce plastic parts based on the proper process settings. The FG molds produced parts with better quality compared to conventional steel molds which demonstrate the feasibility of the proposed process.