Vacuum-Free Stirring Brazing of SiCP/A356 Composites and Aluminum Alloy Using Semisolid Filler Metal with Low Solid Fraction
This paper explores the brazing process of SiCp/A356 composites and aluminum alloy using semisolid metal. The two substrates were heated up to the semisolid temperature range of Zn-Al filler metal in the joint region by a resistance heating plate. In order to mix the filler metal with the base metal of both sides to be a single uniform joint, a stirrer was introduced into the weld seam. After stirring, specimens were sectioned for analysis of macro- and micro-structures along the weld region. The research shows that SiCp/A356 composites and aluminum can be local joined with semi-solid filler metal. It can be found that part of the oxide film on the interface of the base metal was disrupted and removed through the observation by SEM. The metallurgical bonds can be formed between the filler metal and the base materials. Moreover, the oxide film of surface of aluminum alloy disrupted and removed was easier than that of surface of composites with existing of Sic particle. The joint microstructure with globular α-Al grain enclosed by rich-Zn phase can be obtained after stirring brazing.
Shiquan Liu and Min Zuo
H. B. Xu et al., "Vacuum-Free Stirring Brazing of SiCP/A356 Composites and Aluminum Alloy Using Semisolid Filler Metal with Low Solid Fraction", Advanced Materials Research, Vols. 306-307, pp. 738-741, 2011