Research on arc additive manufacture forming of TiB₂ reinforced aluminum matrix composite wire

Objective Arc additive manufacturing process of TiB₂ particle reinforced aluminum matrix composite wire was explored in this paper. TiB₂/6056 aluminum matrix composite wire was used as welding material, and cold metal transition with addition of pulse (CMT+P) was employed as heating method. Methods The temperature field distribution of single-layer and multi-bead additive part was simulated by Simufact welding software. The single-layer and multi-pass additive part was produced, and the microstructures were observed and analyzed. Results The results of process test showed that when the current was 140 A, wire feeding speed was 8 m/min, welding speed was 5 mm/s, and the forming performance of additive part was the best. The overlapping width was 0.736 times that of the bead width, which was suitable for the inter pass lap forming of single-layer and multi-bead additive with smooth and uniform surface. Conclusion The simulation and experiment results both testified that during single-layer and multi-pass additive manufacturing, the welding beads were greatly affected by the heat of the welded beads and the following beads, which led to form the coarse-grained microstructures. Porosities were mostly distributed at fusion zone between of adjacent beads. TiB₂ particulates were aggregated at the grain boundary of α-Al.