Characterization of bismuth–tin–lead and bismuth–tin–lead–cadmium fusible alloys

Abstract

Microstructure, electrical, mechanical and thermal properties of quenched bismuth–tin eutectic, Rose (Bi50Sn22.9Pb27.1) and Wood’s (Bi50Sn12.5Pb25Cd12.5) alloys have been investigated using scanning electron microscopy, X-ray diffraction analysis, the double bridge method, the dynamic resonance method, Vickers hardness measurement and thermal analysis. Wood’s alloy (Bi–Pb–Sn–Cd) has low electrical resistivity and melting point but a high elastic modulus and internal friction when compared with the Rose (Bi–Pb–Sn) alloy. The presence of cadmium in Wood’s alloy decreases its melting point and electrical resistivity with an increase in its elastic modulus, which improves the mechanical properties. Wood’s alloy (Bi–Pb–Sn–Cd) has better properties, which make it useful in various applications such as in protection shields for radiotherapy, locking of mechanical devices and welding at low temperature.