磁控溅射过饱和固溶CuCr合金薄膜微观结构及其力学性能研究

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

CuCr合金被广泛应用于电接触材料,过饱和固溶的CuCr合金薄膜,其微观结构及力学性能与Cu和Cr两相组成的假合金不同。本文利用磁控溅射方法制备了非平衡态过饱和固溶的CuCr合金薄膜,利用X射线、透射电镜,扫描电镜,纳米压入仪,研究了在整个Cu和Cr成份比例范围内薄膜的微观结构、表面形貌和力学性能的变化规律,发现过饱和固溶CuCr合金薄膜的硬度随着Cr含量的变化,呈现双峰形,强化机制主要是固溶强化和细晶强化。在Cu和Cr原子比大于61∶39时,薄膜的结构从面心立方结构(FCC)转变为体心立方结构(BCC),当Cr原子含量为39%时,表面呈现较粗大的三棱锥形貌,此时硬度和弹性模量在整个成份比例范围内最低。

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.