Dynamic mechanical properties of SnAgCu solder

The split Hopkinson bar technique and the material test system were applied to explore experimentally the mechanical properties of SnAgCu solder at room temperature. The stress-strain curves obtained at different strain rates indicate that SnAgCu solder exhibits a strong strain-rate effect and its plastic hardening moduli have great difference under quasi-static and impact loads. Metallographic analysis shows that the plastic deformation in SnAgCu solder under quasi-static compression is governed by the rotation and deformation of crystal grains, and the dendrite deformation has directivity. While under dynamic compression, the deformation mechanism is distinctly different from that under quasi-static compression, the dendrite as the original phase is no directivity and the primary dendrite arms are broken into secondary dendrite.