Indentation creep behavior of thermally aged Sn-5wt%Sb-1.5wt%Ag solder integrated with ZnO nanoparticles

In the present study the microstructure changes and their impacts on creep parameters from the indentation creep testing are investigated. For this propose the alloys Sn-5Sb-1.5Ag (SSA) plain solder and SSA reinforced with ZnO nanoparticles composite solder have been fabricated. The specimens were isothermally aged at 125, 175 °C for 24 h, and then quenched in air at 27 °C. The microstructure of the present solders is identified by X-ray diffraction (XRD). A crystalline β-Sn and intermetallic compounds (IMCs) SnSb and Ag₃Sn are detected. Microstructural evolutions revealed refinement of SnSb and Ag₃Sn IMCs as a result of ZnO addition. The reinforcing ZnO nanoparticeles are found to decrease the creep strain. The calculated values of the stress exponent n for the indentation creep process are found to decrease with increasing aging temperature. The value of n of the composite solder was found less than that of the plain solder at the same testing conditions.