This study investigates the microstructure, thermal conductivity, hardness, and strength of Cu-Cr-Zr coatings produced by cold gas spraying. The elements in the powders were found to have a significant influence on microstructure, particle morphology, and strengthening mechanisms. The strengthening mechanisms of copper alloy coatings include fine crystal reinforcing, solution strengthening, work hardening, and dispersal reinforcing. Different mechanisms are shown to be more or less effective depending on powder composition and the presence of impurities. By filtering impurities before gas atomization, the thermal conductivity of as-sprayed Cu-Cr-Zr coatings can be improved by a factor of two.