THE INFLUENCE OF CU ON THE THERMAL AND MECHANICAL PROPERTIES AND MICROSTRUCTURE OF LEAD-FREE SN–5SB SOLDER ALLOY

Abstract

In this study, we investigated the effect of Cu addition on the thermal and mechanical behavior of a lead-free Sn-Sb5 solder alloy. The specific heat of the samples was studied with differential thermal analysis (DTA). The wettability of the prepared molten alloys was measured by evaluating the contact angle on various smooth surfaced substrates (glass, pure Al, pure Cu, and CuZn30 alloy). Contact angles were recorded photographically at 550K using (colophonic acid) as flux. Microhardness tests were performed as a function of temperature to calculate the effective activation energy of Sn-Sb and Sn-Sb-Cu solder alloys. The isothermal creep curves of the alloy samples were obtained by applying various constant stresses at a constant temperature of 480 K and then annealing the samples at a pre-threshold temperature (Tm/2). Microstructural studies of as-cast alloys after annealing treatment are reported, with the influence of cold working and creep testing on the structural changes and properties of Sn-Sb and Sn-Sb-Cu alloys.