Abstract
Semisolid compression brazing of Al50Si alloy using Zn-Al-Cu filler metal assisted by SiC particles coating has been developed. The effects of the size and concentration of SiC particles on the microstructure and mechanical properties of the joints were studied. By using 1 μm SiC particles and the concentration of SiC particles increased to 3 g/m2, oxide film on the surface of base metal was completely disrupted and a good bonding strength was obtained. As SiC concentration further increased to 4 g/m2, colonies of SiC particle with nonwetting areas of filler metal formed at the interface, resulting in a decrease in the bonding strength. By using 5 μm SiC particles, the bonding strength was enhanced as SiC concentration increased from 1 g/m2 to 3 g/m2 due to the removal of the oxide film. By further increasing SiC concentration to 16 g/m2, the strength was constantly improved because of the dislocation strengthening effect generated at the SiC particle layer/filler metal interface. When SiC concentration increased to 32 g/m2, nonwetting area appeared inside the SiC particles layer, causing a decrease in the bonding strength.
Highlights
IntroductionAl50Si alloys with high thermal conductivity and low expansion have high potential in electronic packaging fields
Al50Si alloys with high thermal conductivity and low expansion have high potential in electronic packaging fields.e associated joining technologies for these materials have been increasingly investigated
When SiC concentration further increases to 32 g/m2, the fracture occurs in the SiC particles layer (Figure 8(e)), and a large number of SiC particles with less filler metal between them are observed at the fracture surface (Figure 8(f )), indicating that the large nonwetting area in the SiC particle layer is responsible for the fracture of the joint and the low bond strength
Summary
Al50Si alloys with high thermal conductivity and low expansion have high potential in electronic packaging fields. E associated joining technologies for these materials have been increasingly investigated. Brazing is a fast, reliable joining technology for aluminum alloys. The oxide film on substrate surface is one of the major barriers in achieving reliable joints. Removal of the oxide film is usually necessary before brazing aluminum alloys. Previous brazing approaches require vacuum environment or flux to remove the oxides, adding the cost and impacting the environment. Flux-less brazing methods, such as removing the oxide film via pretreatments of magnetron sputtering [1], electroless plating [2], and ultrasonic cladding [3], have limited application because of the sophisticated equipment and/or extreme conditions before bonding
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
