A typical Ag-In phase diagram is shown in Figure-1, where seven equilibrium phases exist, out of which two are intermetallic phases i.e. Ag2In and AgIn2 also known as φ and γ phases, respectively [9]. The silver solid solution of Ag-In has solubility of indium up to 21 wt. % with a wide temperature range. Contrarily, the indium rich solid solution has lower solubility of silver i.e. ~1.0 wt. % of silver. At eutectic point of 144 °C, an eutectic reaction occurs at 97 wt. % of indium. At room temperature, alloy with indium composition above 68.1 wt. % is a mixture of indium phase and indium rich intermetallic compound (i.e. φ phase) with a solidus temperature of 144 °C. Above this temperature the alloy converts to a mixture of liquid phase and intermetallic φ phase, which begins to decompose into liquid phase and the γ phase. With increasing temperature, the mixture transforms into liquid and γ phase until 205 °C temperature reaches. At …show more content…
Three alloys were prepared having 2.5, 3.0 and 3.5 weight percent silver designated as hypo-eutectic, eutectic and hyper-eutectic alloys, respectively. To replenish indium losses during alloy making, a 1.5% allowance was added for charge calculations. The alloy making sequence was as follows: first pre-weighed indium shots were placed in an alumina crucible and heated to 165 °C. After complete melting of indium, pre-weighed silver filings were added in the melt and stirred with stainless steel spatula. The temperature of the melt was raised to 185 °C and the melt was kept on stirring for 10 minutes. Subsequently, the alloy was cast into copper mold. To homogenize the alloys, the ingots were cold rolled to >90% reduction in thickness and re-melted at 180 °C for 10 minutes and cast into copper mold. Finally, the ingots were again cold rolled to >70% reduction in thickness and preserved for subsequent characterization and