Micro-structures and tensile properties of copper-wire-reinforced Sn–Bi alloy micro-composite fabricated by micro-ultrasonic powder moulding

The goal of this study was to propose a new method to fabricate metal/alloy micro-composites and investigate the properties of the micro-composites. A micro-ultrasonic powder moulding method was proposed for the fabrication of copper wires/Sn–Bi eutectic alloy micro-composite ( x -Cu w /Sn–Bi, where x refers to the number of copper wires). Micro-structures and tensile properties of the micro-composite were investigated by scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction and tensile tests. Micro-structures indicated that the interface bonding of the copper wires and Sn–Bi alloy matrix was fairly good. During the tensile tests, the micro-composite’s tensile strength increased significantly with increasing the number of copper wires; however, the elongation first improved and then decreased. The reinforced copper wires failed by two mechanisms during the tensile tests. In one mechanism, the copper wire fractured in the middle position, while in the other, it pulled out from the Sn–Bi alloy matrix.