Thermisch aktivierte verformung von α-Kupfer-Zinn-Legierungen

Abstract

Flow stress changes at the yield point resulting from temperature and strain rate changes during tensile deformation of α-copper-tin alloys agree with theoretical deductions. The estimated activation volumes decrease markedly with increasing alloy concentration, and at the yield point they are determined exclusively by the interaction of tin atoms with slip dislocations. The decrease of activation volumes with the degree of deformation can be interpreted by the additional dislocation intersection processes. Based on experimental data on the deformation of α-CuSn alloys at the yield point, the activation analysis shows that the activation enthalpies are independent of tin concentration and grain size. They are in agreement with the concepts of short-range interaction of tin atoms with slip dislocations and, with ΔG 0 = 0.96 eV, are smaller by a factor of 3 than those observed for pure copper, which have typical values for the dislocation intersection processes.