Influence of high-melting particle implantation on microstructure of Al alloy thin-wall components fabricated by droplet plus arc additive manufacturing

In this paper, a novel droplet + arc additive manufacturing has been proposed for fabricating particle-reinforced Al matrix composites parts with high efficiency and low cost. The tilted arc was used as heat source, Al-2219 was used as matrix, and the microscale spherical WC and Ti particles were used as reinforced phases respectively. Thin-wall parts of 8.0 vol% WCP/Al and 7.5 vol% TiP/Al were successfully fabricated. The results showed that the interface pore defects were significantly affected by the wettability between particle and liquid Al matrix. Obvious pore defects were found at WC-Al interface, but no pore defects were observed at Ti-Al interface. It is also found that the complete transition from coarse columnar grains to fine equiaxed grains can be realized by particle implantation. Compared with the Al-2219 part, the average grain size of the 7.5 vol% TiP/Al part is reduced from about 100 mu m to 20.7 mu m.

Automated summary

In this paper, a novel droplet + arc additive manufacturing technique is proposed for fabricating particle-reinforced Al matrix composites parts. Experimental results show that the interface pore defects are affected by the wettability between particle and liquid Al matrix. Additionally, the transition of grain size can be achieved by particle implantation.