Effect of rapid solidification and small additions of Zn and Bi on the structure and properties of Sn-Cu eutectic alloy

The Sn-Cu eutectic alloy has been produced by rapid solidification using the melt-spinning technique, and both Zn and Bi have been added individually to it, in the ratio 0.5 wt.%. X-ray diffraction (XRD) analysis and differential thermal analysis (DTA) have been carried out. Resistivity, Vickers microhardness (HV), and yield stress (sigma(y)) have been measured. Also a new method for measuring creep has been described using a HV tester. The creep measured by this method is termed "microcreep." It is a quick, nondestructive method and requires a small sample, about 1 cm(2), with thickness 1 mm or less. The results show that formation Of CU39Sn11 occurs due to the addition of both Zn and Bi. The addition of Zn increases HV and sigma(y), but slightly lowers the creep resistance; however, the addition of Bi deteriorates the creep resistance. Also, it is found that the creep rate of as-quenched melt-spun alloys is high.