Microstructure and mechanical properties of TiC nanoparticles reinforced 7075 aluminium alloy fabricated by oscillating laser-arc hybrid additive manufacturing

In this work, TiC nanoparticles (TiC_ps) reinforced 7075 aluminium alloy was fabricated via an oscillating laser-arc hybrid additive manufacturing process. To show the beneficial effect of TiC_ps addition on microstructure and mechanical properties, a conventional 7075 aluminium alloy was also manufactured for comparison. Upon the addition of TiC_ps, remarkable grain refinement was achieved with a decrease in average grain size from 111.8 to 12.5 µm, and grain boundary segregation was alleviated. It was also found that many secondary phases precipitated at the grain interior in the deposit with TiC_ps. Owing to the refined microstructure and favourable precipitation, as-deposited 7075 aluminium alloy with TiC_ps showed enhanced tensile properties of ultimate tensile strengths of 346 and 355 MPa along scanning and build directions.