Influence of Temperature on Creep Resistance, Structural and Electrical Characteristics of S9Z1 Eutectic Alloys

Abstract

In the present study, the structural and creep resistance properties of S9Z1 alloys with Cu-addition in concentrations (0.1 and 0.3% Wt.) have been investigated using x-ray diffractions (XRD) and Creep testing machine respectively. The three samples were prepared from high purity 99.99% by melting technique in the Pyrex tubs with CaCl<sub>2</sub> to invaded the oxidation. The obtained samples were rolled drawn (cold rolling) into two groups. The first group was as wires for the creep resistance testing. The second group was as small sheets for structural investigations. Patterns of XRD showed that the S9Z1 alloy was primarily composed of two phases; a body centered tetragonal β-Sn matrix phase, and a secondary phase of hexagonal Zn. while with addition Cu (0.1 and 0.3% Wt.) to S9Z1 Alloys the results showed new peaks in the ternary compositions, such as Cu<sub>6</sub>Sn<sub>5</sub>, Cu<sub>5</sub>Zn<sub>8</sub>, phases respectively. The average of particle size (D) of β-Sn matrix was decreased with increasing Cu -adding, whereas the dislocation density (δ) increased with increasing addition. Creep properties of S9Z1, S9Z2 and 3 Alloys were examined at different temperatures (25, 40 and 80°C) under two constant loads (σ= 18.7 and 24.94 MPa). The creep behaviors of ternary alloys were higher than the S9Z1 alloys with all different temperatures under two constant loads. Also, the S9Z3 alloy with all different temperatures and two loads exhibited greatest creep resistance, due to the refinement structure and formation of new IMCs. Values of stress exponent (n) were found to be in the range of 1 to 10.55, for all S9Z2 and 3 alloys respectively. Values of activation energy (Q) of alloys were found to be in the range of 36.48 to 37.49 kJ/mol, for σ = 18.7 Mpa and 27 to 34.8 kJ/mol for σ = 24.94 Mpa for the S9Z1 alloys with Cu addition respectively. At room temperature (25°C), the electrical conductivity of the samples was calculated, and its values increased with Cu additions.