Development of lead-free solder composites containing nanosized hybrid (ZrO2 + 8 mol.% y2O3) particulates

Abstract

In this study, lead-free composite solders were successfully synthesized, with varying amount of nanosized ZrO2 + 8 mol.% Y2O 3 particulates incorporated into 95.8 Sn - 3.5 Ag - 0.7 Cu solder. These composite materials were fabricated using the powder metallurgy technique involving blending, compaction, sintering and extrusion. The extruded materials were then characterized in terms of their physical properties, microstructural development, thermal and mechanical properties. Experimental results revealed that with the addition of increasing amount of reinforcements, the density values of the composite solders decreased, but there was no influence on the melting point of the composite solders. Thermomechanical analysis of the solder nanocomposites showed that the use of reinforcements lowered the average coefficient of thermal expansion of the solder material. Moreover, the results of mechanical property characterizations revealed that the addition of reinforcements aids in improving the overall strength of the nanocomposite solder. An attempt is made in the present study to correlate the variation in volume percentages of the hybrid reinforcements with the properties of the resultant nanocomposite materials.