Title of article :
Age-Hardening Behavior and the Related Changes in a Silver-Copper-Palladium Alloy
Author/Authors :
Hadi, Morteza Metallurgy and Materials Engineering Department - Golpayegan University of Technology - Golpayegan, Iran , Ebrahimzadeh, Iman Department of Materials Engineering - Najafabad Branch - Islamic Azad University - Najafabad, Iran , Bayat, Omid Department of Metallurgy and Materials Engineering - Hamedan University of Technology - Hamedan, Iran
Abstract :
Age-hardening behavior and related changes were studied to elucidate the hardening mechanism of an Ag–Cu–Pd alloy by Differential Scanning Calorimetry (DSC), hardness test, X-ray diffraction (XRD), scanning electron microscopic (SEM) observations and energy dispersive spectrometer (EDS). The results showed that hardness of the alloy was raised to 90% and 68% of its solution state value by isothermal aging at 300 ◦C and 400 ◦C, respectively. However, aging at 500 ◦C led to a decrease in the hardness of the alloy. Moreover, while age hardening at 300 ◦C occurred due to coherency strains between the (111) plane of Ag-rich and the (111) plane of Cu3Pd phases, the mechanism of aging at 400 ◦C was the formation of Cu3Pd superlattice with the L12-type crystal structure. In contrast, reduction of Cu3Pd phase and formation of Cu solid solution decreased hardness during aging at 500oC.
Keywords :
Ag-Cu-Pd alloys , Age-hardening , Scanning electron microscopy , X-ray diffraction
Journal title :
Journal of Advanced Materials and Processing
