Application Research Of High-throughput Experiments In Cu-Ti/Ni-x Elastic Copper Alloy

As the representative of the environmentally friendly flexible copper alloys,Cu-Ni-X,Cu-Ti-X alloys are potential alternatives to beryllium bronze.Due to the low efficiency of traditional methods of researching materials,which hinders the developmence of Cu-Ni/Ti-X,A high-throughput experimental method(diffusion multiples)was used to acquire the relationship of compositions and properties efficiently,and the microstructures and properties were studied.The diffusion multiples samples of Cu-Ni-Ti-Al-Sn alloy were prepared successfully by vacuum electron beam welder,hot isostatic pressing,and heat treatment.Interfacial reactions and relationship of compositions and properties of Cu-Ni-Ti-Al-Sn alloys were studied by optical microscope,scanning electron microscope,electronic probe and nano-indentor.Several important conclutions can be summarized as follows:(1)In order to solve the problems of the low success rate of sample preparation in the research work and low diversified diffusion in the past,the structure and transformation of the multi-diffusion envelope shape,the internal component and the alloy interface are studied.After many improvements,The Cu-Ni-Ti-Cu25Al-Cu35Sn multivariate diffusion couple with complex interfacial structure was successfully prepared.The Cu-Ni-Al,Cu-Ni-Ti,Cu-Ti-Al and Cu-Ti-Sn alloys were studied on a single sample for the purpose of high efficiency.(2)Cu,Ni,Ti,Cu25Al and Cu35Sn were interfaced in the interface after heattreat at 600℃,650℃ and 700℃ for 100h,200h and 400h respectively,and formed a distinct diffusion layers at the interface.The thickness of the diffusion layer is determined by the diffusion coefficient and the reaction rate.As the temperature and time change,the relative thickness of each sublayer also changes.Each metal interface shows it’s own characters.Due to the different diffusion rates of different metal elements,Kokendar holes are observed at the edge of the diffusion layer of some metal interfaces.(3)The Cu-Ti interface solid phase sequence was fcc_Al phase→Cu4Ti→Cu4Ti3→Cu-Ti.It is indicated that the fcc Al phase transition layer existed in the Cu-Ni binary interface at 600℃,650℃ and 700℃.The solid phase transition layer sequence of Cu-Ti interface from the Cu-rich side was Cu4Ti→Cu4Ti3→CuTi→CuTi2.The solid phase transition layer sequence of Cu-Cu35Sn interface from the Cu-rich side was FCC_A1→D03_Cu3Sn/Cu3Sn.(4)The relationship of compositions and properties can be acquired efficiently with diffusion multiples and high solution test method.The results of the binary system show that the heat treatment temperature has little effect on the elastic modulus of the system,which mainly related to the phase composition and composition.The change of hardness and elastic modulus of Cu-Ni alloy system is consistent with the change trend of Ni content.In the fee(Cu)region of Cu-Al system,the elastic modulus and hardness increased gradually increased with the Al content,and the elastic modulus of Cu3Al compound is low.The elastic modulus and hardness of Cu-Ti alloy system increases with the increase of Ti content in the fee(Cu)region,and the elastic modulus decreases with the increase of Ti content in hcp(Ti).Cu-Sn system,the change of elastic modulus value is close to the change of Cu composition.(5)The results of Cu-Ni/Ti-X ternary system show that,the interface diffusion layer of Cu-Ni-Cu25Al at 650℃ and 700℃ can be divided into three sub-layers:In the fee(Cu)solid solution layer,the elastic modulus and hardness gradually increased with the Cu content decreased and Ni,Al content increased.In the ternary phase region with more complex structure,the composition and elastic modulus,hardness occurs in varying degrees of fluctuations with the change of the location of the test point.In the fcc(Ni)diffusion layer,the elastic modulus increases slightly with the increase of Ni content.The diffusion layer at the interface of Cu-Ti-Cu25Al system after heat treatment at 700℃ can be divided into four regions:AlCu2Ti layer,CuTi region,Cu4Ti3 region and hcp(Ti)layer.Among them AlCu2Ti ternary compounds have the highest hardness and elastic modulus values of 190 GPa and 6 GPa.The elastic modulus of Cu-Ni-Ti system is consistent with the change trend of hardness,and the elastic modulus of compound and pure substance is slightly higher than that of solid solution.The diffusion layer of Cu-Ti-Sn system can be divided into five sub-regions after heat treatment at 700℃.The change of elastic modulus and hardness value of the system in the two-phase region is greatly affected by the content of Sn.