Effect of cerium on microstructure and mechanical properties of Sn-Ag-Cu system lead-free solder alloys
(School of Materials Science and Engineering, Xi’an University of Technology,
Xi’an 710048, China)
Xi’an 710048, China)
Abstract: The melting point, spreading property, mechanical properties and microstructures of Sn-3.0Ag-2.8Cu solder alloys added with micro-variable-Ce were studied by means of optical microscopy, scanning electron microscopy(SEM) and energy dispersive X-ray(EDX). The results indicate that the melting point of Sn-3.0Ag-2.8Cu solder is enhanced by Ce addition; a small amount of Ce will remarkably prolong the creep-rupture life of Sn-3.0Ag-2.8Cu solder joint at room temperature, especially when the content of Ce is 0.1%, the creep-rupture life will be 9 times or more than that of the solder joint without Ce addition; the elongation of Sn-3.0Ag-2.8Cu solder is also obviously improved even up to 15.7%. In sum, the optimum content of Ce is within 0.05%−0.1 %.
Key words: Sn-Ag-Cu system; lead-free solder alloy; melting point; spreading property; mechanical property