Measurements of mechanical properties of α-phase in Cu–Sn alloys by using instrumented nanoindentation

Instrumented nanoindentation technique is a powerful approach for accurately measuring mechanical properties of materials in micron or even nanoscale. In this article, the effect of tin (Sn) content upon mechanical properties of the α-phase in Cu–Sn alloys was studied by using an instrumented nanoindentation. The experimental results revealed that: (i) the hardness of the α-phase exhibited a linear relationship with Sn content (C) increasing, i.e.,H= 0.0757C + 0.8916, when it was less than the maximum solid solubility (15.8 wt.%), which is in good agreement with the Friedel–Mott–Suzuki theory; (ii) the variation of Young’s modulus in a narrow range of 120–130 GPa is attributed to orientation variation of the α-phase in casting Cu–Sn dendrites.