Effect of Ti–Si–Mg-Al wire on microstructure and mechanical properties of plasma arc in-situ welded joint of SiCp/Al composites

Abstract

The influence of Ti–Si–Mg–Al wire on microstructure and mechanical properties of SiCp/Al metal matrix composite joints produced by plasma arc in-situ weld-alloying was investigated. Argon-nitrogen mixture was used as plasma gas and Ti–Si–Mg–Al flux-cored wires as filled composites. Weldments were submitted to tensile test. Meanwhile, the macro morphology and microstructure of the joints were examined. The result shows that the formation of needle-like harmful phase Al4C3 is effectively inhibited and the wettability of molten pool is improved by adding Ti–Si–Mg–Al flux-cored wires. With 15Ti-5Si-5Mg-Al flux-cored wire as filled composite, the maximum tensile strength of the welded joint is 267 MPa, which is up to 83% that of the matrix composites under annealed condition.