Effect of Al on the Microstructure and Properties of Cu-15Ni-8Sn Alloy

The Cu-15Ni-8Sn-xAl alloys were prepared by downward continuous casting and homogenized at 850℃ for 4h and 8h. The microstructure and properties of the alloys as cast and homogenized were investigated by means of scanning electron microscopy, metallographic microanalysis, and hardness testing. The results indicate that the macroscopic segregation of Cu-15Ni-8Sn alloy was exacerbated and the homogenization holding time was prolonged by adding the element Al. Further, the hardness of the Cu-15Ni-8Sn-xAl alloy as cast significantly increased with the addition of element Al. However, when the alloy was fully homogenized, the element Al had little effect on the hardness of the Cu-15Ni-8Sn alloy.