Experimental Production of Cu–Cr–N Composite Alloys and Thermodynamic Modeling of Their Phase Composition

Abstract

Composite Cu–Cr–N alloys were obtained in situ under vibration of “copper melt–chromium powder” compositions before their crystallization. Two types of alloys were prepared, where chromium powder was freely dispersed or compacted into a tablet. Atmospheric nitrogen was used as a source of chromium nitrides in the alloys. The microstructure of the alloys is represented by a copper matrix hardened with chromium particles and numerous inclusions of nonstoichiometric chromium nitrides Cr₂N_1 – x. Thermodynamic modeling showed that the composition and quantities of chromium nitrides in the Cu–Cr–N alloy depend on the partial pressure of nitrogen above the melt.