Microstructural evolution and mechanical properties of Sn-Bi-Cu ternary eutectic alloy produced by directional solidification

Abstract

Sn-36Bi-22Cu (wt.%) ternary eutectic alloy was prepared using vacuum melting furnace and casting furnace. The samples were directionally solidified upwards solidification rate varying from 8.3 to 166 µm/s and at a constant temperature gradient (4.2 K/mm) in a Bridgman-type directional solidification furnace. The composition analysis of the phases and the intermetallics (Cu 3 Sn and Cu 6 Sn 5 ) were determined from EDX and XRD analysis respectively. The variation of the lamellar spacing (Bi-rich phase) and the Cu 3 Sn phase spacing with the solidification rate were investigated. The dependence of microhardness, ultimate compressive strength and compressive yield strength on solidification rate were determined. The spacing and microhardness were measured from both longitudinal and transverse sections of the samples. The dependence of microhardness on the lamellar spacing and the Cu 3 Sn phase spacing were also determined. The relationships between phase spacings, solidification rate and mechanical properties were determined from linear regression analysis.

Effect of Temperature Gradient and Growth Velocity on Microstructure and Mechanical Properties on Zn–7Al–3Cu Ternary Eutectic Alloy

“…The exponent value of V (0.02) obtained from this study as a function of HV ( Figure 10) is slightly lower than the values of 0.06, 0.06, 0.07 and 0.09 values reported by Ç adırlı et al 34 for Sn-23Bi-5Zn alloy, by Hu et al 35 for Sn-58Bi eutectic alloy, by Vnuk et al 36 for Sn-Zn eutectic alloy, and by Böyük and Maraşlı 31 for Sn-3.5Ag-0.9Cu eutectic alloy, respectively. The exponent values of k (0.04 and 0.06) obtained in this study as a function of the HV (Figure 11) is close to the value of 0.07 reported by Ş ahin et al 37 for Sn-36Bi-22Cu eutectic alloy. There are small differences in these exponential values obtained by different researchers.…”

On the derivation of unsteady closed-form analytical solution for the solidification of pure and eutectic materials with boundary conditions of the third kind

“…These methods generally lead to greater agreement with the results observed in practice. On the other hand, a large number of experimental studies have also been performed to fulfil the same objective [31][32][33][34][35][36][37][38][39][40][41][42][43][44][45][46][47][48][49][50]. Another interesting technique that has been widely used to determine the unsteady thermal variables acting during solid-liquid phase change is the inverse heat conduction problem (IHCP), which is based on a mathematical description of the physical mechanisms of the process supplemented with experimentally obtained temperature measurements in metals and/or molds.…”

Microstructural and Creep Characterization of Sn-0.7Cu and Sn-0.7Cu-xBi Lead-free Solders for Low Cost Electronic Applications

“…Mevlüt Şahin et. al [14] are determined the relationships among phase spacings, solidification rate, and mechanical properties from linear regression analysis for the Sn-36Bi-22Cu (wt.%) ternary eutectic alloy. The influence of Ag and In additions on tensile creep behavior and thermal properties of bulk eutectic Sn-Cu solder alloy is reported by El-Daly et.…”