2015 Volume 56 Issue 2 Pages 212-217
The microstructure and shear strength of active-transient liquid phase (A-TLP) bonded joints of high volume fraction (70 vol%) SiC particle reinforced A356 composite using an active interlayer of quaternary Al-33Cu-6Mg-1Ti (mass%) were compared with TLP bonded joints using Ti-free Al-33Cu-6Mg interlayer to establish suitable interlayer composition design route. For the developed Ti-containing active filler metal, void free dense interface between SiC particle and bond seam with C-Al-Si(-Mg) or C-Al-Si-Ti product was readily obtained, and the joint shear strength increased with increasing joining temperature from 550°C to 580°C and 600°C. While for the Ti-free interlayer, gaps between most SiC and metallic bond seam and between some matrix/bond interfaces remained, even at 600°C. The maximum shear strength of the joints using Al-33Cu-6Mg-1Ti and Al-33Cu-6Mg were 62 MPa (with small fracture unit and partial fracture path within A356 matrix) at 600°C and 31 MPa (with too large fracture unit and initial interface fracture path) at 580°C, respectively. Thus, the beneficial effects of Ti addition into interlayer on improving (i) wettability between SiC particle and metallic bond seam and (ii) joint shear strength were demonstrated.
