Research Article
Volume 1 Issue 1
Shakib Alsowidy* and Belqees Alasry
September 12, 2022
Abstract
This work aims to study a new lead-free solder alloy as a substitute for lead-tin alloys in order to solve the problem of protecting human health. The effect of thermal aging on the electrical resistivity of a eutectic Sn-3.5wt%Ag lead-free solder alloy has been investigated. The samples have been aged at the temperature range of 100°C - 160°C. During aging, the precipitation behavior has been followed by the electrical resistivity measurements. The resistivity change of Sn-3.5wt%Ag eutectic alloy rises to a maximum value and then decreases to a constant value at each aging temperature. The maximum value increases as aging temperature increased. The little reduction in resistivity after the maximum value is due to the coalescence and growth of precipitates and then decreasing in the scattering effect to the electrons. Microstructural characterizations using scanning electron microscope (SEM) were conducted to follow in detail the precipitation behavior. The SEM results cleared that the precipitation process increases with increasing thermal aging time and the coarsening of fine precipitates occurs in the samples aged at a long time.
Keywords; Electrical resistivity; thermal aging; scattering centers; conduction electrons; precipitation process