The Problem of Copper Softening During Cold Gas Dynamic Spraying

The effect of the gas-dynamic (cold) spraying of the Cu-Al2O3-Zn powder mixture on the microstructure and strength of the copper substrate is investigated. A copper cold drawn contact wire was used as a substrate. We propose using gas-dynamic cold spraying to restore the local wear of the contact wire. The study of the microstructure using the electron backscattered diffraction (EBSD) method showed the presence of grain orientation characteristics of the cold drawing of copper. Recrystallization of the surface layers of the contact wire during spraying does not occur. Using the microhardness measurement, the absence of softening of the layers of the contact wire with a depth of up to 2 mm is shown. The results of mechanical tests show that spraying does not lead to a decrease in the tensile strength of the contact wire. The results of creep tests show that spraying does not lead to a decrease in the heat resistance of the contact wire.