Liquid-phase impact diffusion welding of SiCp/6061Al and its mechanism

• Published in: Materials science & engineering. A, Structural materials : properties, microstructure and processing Structural materials : properties, microstructure and processing, 2008-08, Vol.490 (1-2), p.427-437
• Main Authors: WEI GUO, MENG HUA, HANG WAI LAW, HO, John Kin Lim
• Format: Article
• Language: English
• Subjects: Applied sciences; Dispersion hardening metals; Elasticity. Plasticity; Exact sciences and technology; Joining, thermal cutting: metallurgical aspects; Mechanical properties and methods of testing. Rheology. Fracture mechanics. Tribology; Metals. Metallurgy; Powder metallurgy. Composite materials; Production techniques; Welding
• ISSN: 0921-5093; 1873-4936
• DOI: 10.1016/j.msea.2008.01.058

Liquid-phase impact diffusion welding (LPIDW) technique was used to join the aluminum matrix composite SiCp/6061Al. The composite joints welded successfully, gave tensile strength up to 260 MPa and radial deformation below 3%. Analysis of the microstructure and tensile strength of the welded joints showed: (i) the achievement of prominent joint interface between SiC particles and the matrix; (ii) the change of pernicious contact-state from reinforcement (SiC)/reinforcement (SiC) to reinforcement (SiC)/matrix/reinforcement (SiC) of the reinforcement particles; (iii) the disappearance of the harmful microstructure/brittle phase of Al4C3 from the welded joint; (iv) the density of dislocation in the matrix next to the interface being higher; (v) the sign of intensively mutual entwisting of dislocation; and (vi) the deformation mainly taking place in the matrix grain. Furthermore, the rapid thermal pressing offered a denser nucleus area for matrix crystal and their deforming matrices around SiC particles engendered intensive aberration, which was favorable for forming nano-grains and for improving the properties of the welded composite joints.