Application Research Of The Diffusion Multiples Technology In Cu-Ni-Sn Elastic Copper Alloy

Cu-Ni-Sn alloy is one of the most important copper matrix elastic alloys. As for its high strength and hardness, excellent elasticity and good anti-stress relaxation properties, it has been widely used in electronics, information, aerospace, and other industries. However, the Cu-Ni-Sn alloys system is very complex, the components have significant influence on the performance, and the efficiency of traditional methods of researching materials is very low, which hinders the development of Cu-Ni-Sn alloy.The high-throughout experiment was carry out to research the Cu-Ni-Sn alloy. The interface characteristics of Cu-Ni-Cu35Sn diffusion multiples were studied by optical microscope, scanning electron microscope, electronic probe and nano-indentor, and the relationship of compositions and properties efficiently of part of Cu-Ni-Sn alloy was acquired efficiently. Several important conclutions can be summarized as follows:(1) there were different diffusion layer between different metals after the Cu-Ni-Cu35Sn diffusion multiples were heated at the temperature of 650℃ for different time between 100-400h, and some cracks were linear distributing in the diffusion layer, which were considered to be original layer. The microstructure characteristics of the Cu-Ni, Cu-Cu35Sn, and Ni-Cu35Sn interface is different, because of the mutual interference between Cu, Ni, and Sn atoms, the closer to the ternary junction, the less obvious of the binary interface microstructure characteristics.(2) The solid phase transition layer sequences Cu-Ni-Cu35Sn diffusion multiples were observed and analyzed by means of CALPHAD and the results of diffusion multiple experiment. The solid phase transition layer sequences of Cu-Ni, Cu-Cu35Sn, Ni-Cu35Sn interfaces in the Cu-Ni-Sn diffusion couple were optimized theoretically based on the range of element activity, respectively. The results showed that the unique fcc_A1 phase transition layer existed in the Cu-Ni binary interface at 650℃. The solid phase transition layer sequence of Cu-Cu35Sn interface from the Cu-rich side was fcc_Alâ†'D03_Cu3Sn/Cu3Sn. And the solid phase transition layer sequence of Ni-Cu35Sn interface was fcc Al+Ni3Sn LTâ†'fcc Al+Ni3Sn2â†'Ni3Sn2+D03 Cu3Sn/Cu3Sn.(3) By mean of electron probe X-ray microanalysis and nano-indentation, the relationships of composition and hardness/elastic modulus were researched. It is indicated that:after the diffusion treatment at the temperature of 650℃ for 400h, the hardness of Cu-Ni alloy reached its maximum value then the Cu content is about 50at.%., and its elastic modulus decreased with the increasing of Cu content. The hardness and elastic modulus of Cu-Sn alloy had a negative correlation with the Cu content. Meanwhile the quantitative relationship of composition and hardness/elastic modulus were acquired.