Effect of Sn3.0Ag0.5Cu3.0Bi on Microstructure and Performance of Soldered Joints of SiCp/6063Al Composite After Electroless Nickel Plating in Vacuum Soldering

SiCp/6063Al composite containing high and low volume fraction SiC after electroless nickel plating were soldered by using Sn3.0Ag0.5Cu3.0Bi solder in vacuum.The vacuum soldered joint microstructure between SiCp/6063Al composite after electroless nickel plating and the effect of holding time on the property of joint were stu-died by means of SEM and shearing test.The results showed that the microstructure of soldering seam was quite com-pact since the lead-free solder could wet SiCp/6063Al composite after electroless nickel plating very well.The shear strength of the soldered joint reached to maximum of 38.3 MPa under soldering temperature of 270 ℃ and holding time for 35 min.The element Sn and Cu from the solder reacted with Ni on the SiCp/6063Al composite,resulting in a metallurgical bonding between the solder and base material.The fracture mode of soldered joint of the SiCp/6063Al composite after electroless nickel plating was mixed ductile mainly of ductile fracture.Fracture occurred in the solder mostly and occurred around the IMC layer rarely.