Decomposition of Supersaturated Solid Solution during Non-isothermal Aging and Its Effect on the Physical Properties and Microstructure of the Ag-Cu7.5 Alloy

The aim of the study was to examine the effect of supersaturated solid solution decomposition during non-isothermal aging on the microstructure and selected physical and mechanical properties of the Ag-7.5 wt.% Cu alloy. The decomposition mechanism was determined by complex research methods, i.e., physical properties testing, microstructure examinations, as well as hardness measurement. Decomposition of Ag-Cu7.5 supersaturated solid solution during heating has two stages. The first stage involves a significant increase in hardness and has no effect on electrical conductivity. During the second stage, growth of discontinuous precipitates and an increase in hardness and electrical conductivity are observed. Discontinuous precipitation cells consist of βCu rods and plates surrounded by αAg phase. Obtained activation energy of this microstructural evolution is lower than its values presented in the literature.