Study of Brazeability of SiC_P/A356 Composites and Aluminum Alloy Using Semisolid Metal with High Solid Fraction by Stirring

Abstract

The semi-solid brazing process of SiCp/A356 composites and 2024 aluminum alloy using Zn-Al eutectic filler metal at 450 °C has been investigated. The two substrates and Zn-Al filler metal were heated up to the semisolid temperature range of Zn-Al filler metal 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 joining by semisolid metal. It can be found that almost half of the oxide film on the surface of the base metal was disrupted and removed through the observation by SEM. The metallurgical bonds formed between the filler metal and the base materials on the interface of oxide had been disrupted. Moreover, the oxide film of surface of aluminum alloy was more thoroughly disrupted and removed than that of surface of composites with existing of SiC particle.

Trend and Development of Semisolid Metal Joining Processing

“…Recently, there has been increasing interest in developing a vacuum-free SSSJ process, which allows a low joining temperature when applied to a semisolid base metal or semisolid filler metal. Xu et al have carried out extensive experiments by using the SSSJ technique and have shown that the joining of SiCP/A356 composites with similar material or different materials such as 2024-aluminium alloy can be successfully achieved by using a Zn-Al eutectic filler metal in air with the aid of mechanical stirring [29,30]. The two substrates and Zn-Al filler metal were heated up to the semisolid temperature range of the Zn-Al filler metal by a resistance heating plate.…”

“…In addition, this joining process allows surface-tosurface joining rather than the line-to-line joining of conventional welding. Therefore, it prevents corrosion at the interface of the components and confers Tool steel [14] Stainless steel Aluminum alloy [15] Aluminum alloy, cast iron, or stainless steel Particles, balls, short fibers of metallic or nonmetallic materials, such as ceramic, glass, tile, or stone, aluminum alloy, copper alloy, or stainless steel [5,12,17,18] Stainless steel M2 tool steel [20] X210CrW12, 100Cr6, and X5CrNil18-10 9SMn28, CuCo2Be, CuSn12, and GBZ12 [13,21] Sn-15 wt%Pb Sn-15 wt%Pb Sn-5 wt%Pb [10] Pb-15 wt%Sn Pb-15 wt%Sn [25] Zinc AG40A die cast alloy Zinc AG40A die cast alloy [26] A356 A356 [27] SiCP/A356 composites 2024 aluminum alloy Zn-Al [29] SiCP/A356 composites SiCP/A356 composites Zn-Al [43] AZ91 alloy AZ91 alloy Mg-25 wt%Zn [33] A356 aluminum alloy A356 aluminum alloy [34] D2 tool steel D2 tool steel [39] D2 tool steel 304 stainless steel [40] D2 tool steel M2 tool steel [42] a better shape than welding. Furthermore, SSMJ can be used to embed metallic or ceramic materials for use in reinforcement or as bearing systems [12].…”

“…(6) For some material systems, the required bond properties and performance capabilities are difficult or impractical to achieve using conventional joining methods but are possible with SSMJ, which is often used in high-stress, high-temperature applications where brazing, welding, and diffusion brazing cannot be used for various reasons (e.g., low melting temperature joining, insufficient resulting mechanical properties, and unacceptable plastic deformation) [29]. (7) Another advantage is that the SSMJ process often has microstructural and therefore mechanical benefits in that the properties of microstructure of the produced join are often similar to those of the base material.…”