Study on the Microstructure and Mechanical Properties of Magnetically Controlled Sputtering Supersaturated Solid Cu Cr Alloy Films

Copper chromium(CuCr) alloys are widely used in electro-contact materials, and the microstructure and mechanical properties of the supersaturated solid solution CuCr alloy films are different from those of the pseudo-alloys composed of Cu and Cr two phases.In this paper, the non-equilibrium supersaturated CuCr solidified alloy film was prepared by magnetron sputtering deposition, and the microstructure, surface morphology, and mechanical properties of films were studied by X-ray diffraction, transmission electron microscope, scanning electron microscope, and nano-indenter in the complete concentration range.The hardness of supersaturated CuCr solidified alloy film presents the double-peaked shape with the change of Cr content, and the strengthening mechanism is mainly solid solution strengthening and grain boundary strengthening.The phase transition from a face-centered cubic structure(FCC) to a body-centered cubic structure(BCC) in CuCr alloy film occurs when the ratio of Cu atom to Cr atom is greater than 61:39,and the surface morphology of the film is a larger pyramid shape when the content of Cr is 39%; meanwhile, the hardness and elastic modulus are the lowest in the whole composition ratio range.