Vacuum diffusion brazing of SiCp/Al composites

Vacuum diffusion brazing of SiC particle reinforced aluminum matrix was performed with Al/Cu/Al composite foils. The microstructure of the joint was investigated by SEM, EDS and XRD. The formation mechanism of the joints was analyzed according to Al-Cu binary phase diagram. The effects of brazing temperature on the interfacial microstructure and shear strength were studied. The results shows that as the brazing temperature rise from 590℃ to 640℃, the interfacial products change from Al₂Cu+αAl eutectic structure to discontinuous Al₂Cu intermetallic compound. The diffusion distance of liquid into base materials increase and the shear strength of joints increases and then decreases with brazing parameters. When the brazing temperature is 620℃, the holding time is 10 min and the bonding pressure is 1 MPa, the shear strength of the joints is up to the maximum value of 69 MPa.