Influence of temperature gradient and growth rate on the mechanical properties of directionally solidified Sn-3.5 wt% Ag eutectic solder

摘要

The Sn-3.5 wt% Ag eutectic alloy was direction-ally solidified upward with a constant growth rate (V = 16.5 μm/s) at different temperature gradients (G = 1.43-4.28 K/mm) and with a constant temperature gradient (G = 3.93 K/mm) at different growth rates (V = 8.3-500 μm/s)in a Bridgman-type directional solidification furnace. The rod spacings (longitudinal section, λ_L and transverse section, λ_T) and mechanical properties (microhardness, HV and ultimate tensile strength, σ_(UTS) of Sn-3.5 wt% Ag eutectic alloy were measured. The dependency of the microhardness, ultimate tensile strength on the temperature gradient, growth rate and rod spacings were determined. According to experimental results, the microhardness and ultimate tensile strength of the solidified samples increase with increasing G and V, but decrease with the increasing the rod spacing.