STRUCTURAL, SURFACE AND TRANSPORT PROPERTIES OF Sn–Ag ALLOYS

Abstract

The structural, surface and transport properties of Sn–Ag alloys were investigated by X-ray diffraction (XRD), radial heat flow, energy-dispersive X-ray (EDX) analysis, scanning electron microscopy (SEM) and four-point probe techniques. We observed that the samples had tetragonal crystal symmetry except for the pure Ag sample which had cubic crystal symmetry, and with the addition of Ag the cell parameters increased slightly. Smooth surfaces with a clear grain boundary for the samples were shown on the SEM micrographs. The grain sizes of pure Ag, [Formula: see text]-Sn and the formed Ag3Sn intermetallic compound phase for Sn–[Formula: see text] wt.% Ag [[Formula: see text], 3.5] binary alloys were determined to be 316[Formula: see text]nm, between 92[Formula: see text]nm and 80[Formula: see text]nm and between 36[Formula: see text]nm and 34[Formula: see text]nm, respectively. The values of electrical resistivity for pure Sn, pure Ag and Sn–[Formula: see text] wt.% Ag [[Formula: see text], 3.5] were obtained to be [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text][Formula: see text][Formula: see text]m at the temperature range of 300–450[Formula: see text]K, respectively. Thermal conductivity values of pure Sn and Sn–[Formula: see text] wt.% Ag [[Formula: see text], 3.5] binary alloys were found to be 60.60[Formula: see text]3.75, 69.00[Formula: see text]4.27 and 84.60[Formula: see text]5.24[Formula: see text]W/Km. These values slightly decreased with increasing temperature and increase with increasing of the Ag composition. Additionally, the temperature coefficients of thermal conductivity and electrical resistivity and the Lorenz numbers were calculated.