Effect of micro-alloying element Ti on mechanical properties of Cu-Cr alloy

The mechanical properties and microstructure of Cu-Cr and Cu-Cr-Ti alloys after aging treatment were investigated via hardness measurements, electron backscattered diffraction analysis, and transmission electron microscopy. The results show that the hardness, yield strength, and softening temperature of the Cu-Cr-Ti alloy significantly improved. The interface of the Cu matrix and Cr-rich precipitates was semi-coherent as determined by calculations, and the strengthening mechanism of the Cr precipitates was via the Orowan strengthening relation. A high dislocation density was observed in the matrix, which was because of impediment by fine Cr precipitates in the Cu-Cr-Ti alloy. The effects of dislocation strengthening, solid-solution strengthening, and precipitate strengthening were shown to remarkably enhance the yield strength. (C) 2020 Elsevier B.V. All rights reserved.