Abstract:SiC_p/6061Al alloy composite was welded by using TIG and pulsed-TIG welding (P-TIG) without addition of filler metal, or with addition of Al-Si or Al-Mg filler metal. The microstructure and properties of the weld were investigated with XRD, OM, TEM, and MTS-810 testing system was used to observe the effect of different welding procedure and filler metals on the microstructure and properties of the weld. Thermodynamic of SiC-Al reaction was used to analyze the tendency of the reaction between SiC particle and Al matrix during welding. The results showed that the P-TIG tends to produce less plate-like Al₄C₃ precipitates than TIG; when welding with P-TIG, addition of Al-Si filler metal can not only prevent from formation of Al₄C₃, but also decrease hot crack sensitivity of weld; the tensile strength of joint of adding Al-Si filler metal is higher than that of adding Al-Mg filler metal. The SiC_p/6061Al composite can be successfully welded by P-TIG with addition of Al-Si filler metal.

Key words:  SiC_p/6061Al composite; P-TIG; interfacial reaction; filler metal