Nanoindentation to microhardness correlation coefficient and Tabor factor determination in relation to microstructure in eutectic SnBi alloy

Abstract

Abstract Determining strength to hardness correlation coefficients from localized hardness measurements in correspondence to microstructure and composition leads the way to inexpensive, non-destructive ways to predict tensile properties of bulk materials which is important for developing preventive maintenance procedures in the semiconductor industry. Nanoindentation and microhardness tests were performed on an in-house prepared eutectic SnBi alloy. Both linear correlation coefficients, C1, between nanoindentation and Vickers microhardness, and k, between Vickers microhardness and ultimate tensile strength, were determined based on experimental measurements. Elemental composition and eutectic morphology were verified by scanning electron microscopy and energy dispersive spectroscopy to emphasize the importance of considering composition, microstructure and strengthening mechanisms when estimating correlations. The correlation coefficients, C1 and k, were found to be ~ 1.7 and ~ 4.0 respectively indicating that composition, microstructure and strengthening play important role in hardness-strength relation. Comparisons to coefficients estimated from data available for SnBi alloy and other alloy systems are discussed.