Abstract:
A characterization of mechanical and micromechanical properties of
SAC305 solder wire under varied strain rates and temperatures was performed using tensile and nanoindentation tests. The evolution of SAC305
lead-free solder wire grains was compared in samples that were subjected to
various strain rates and temperatures using tensile tests based on ASTM E12
standards. Different behaviours of mechanical properties, micromechanical
properties, and microstructure evolution of SAC305 solder wire were observed
when either temperature or strain rate was held constant and the other
varied. Both tensile and nanoindentation tests produced qualitative results,
such as dynamic recovery and occurrence of pop-in events, that reflected
changes of microstructure. It was observed that some of the mechanical
properties of SAC305 solder wire, namely yield strength (YS), ultimate tensile
strength (UTS) and Young’s modulus, showed the same trends, but with lower
values, compared to micromechanical properties obtained from nanoindentation tests based upon hardness and reduced modulus. Microstructure examination further confirms that the YS, UTS and hardness values increase with
more solder wire grain refinement. SAC305 solder wire also maintained an
equiaxed structure under various strain rates and temperatures.
