| The Cu10Ni15MnTiAl alloy was made by using the suspending melt-water cooling Cu-crucible equipment.Using the hardness measurement,the tensile test and electrical resistance test at room temperature,optical microscopy,XRD and SEM,the mechanical and electric properties and the microstructure of the alloy after different heat treatment were studied,and were also analyzed and explained in theory.The results show that:The first,the Cu-Ni-Mn alloy casting structure became very uniform by using the suspending melt-water cooling Cu-crucible equipment.It was confirmed that the cupronickel alloy was made by vacuum suction casting method had compact and regular fir-tree crystal structure and particular superiority compared with the common cast.The second,the best solution treatment was confirmed after the experimental results were analyzed.The best solution treatment was 650℃,60min.The properties of the alloy were HV=115.2,σb=540MPa,σ0.2=283MPa,δ=35%,σ=46.1%IACS.The third,the Cu10Ni15MnTiAl was the aging strengthing alloy,the aging treatment can further improve the all(?)y's properties.Through the long time ordering of the solution atom,the phase MnNi was separated,the properties of alloy can be promoted.(The alloy had the long time incubation period,the solution atoms mostly went along with ordering at the incubation period,during the late stages of development,the phase MnNi separated in transgranular which was the mainly cause of the aging strengthing.)The fourth,the best aging treatment was 450℃,72h after the integrated consideration in the experiments.The properties of the alloy were HV=398.4,σb=1288MPa,σ0.2=1185MPa,δ=12.9%,E=138.5GPa,σ=52.3%IACS.The fifth,the fractures were treated by the solution treatment compared with thoses by the aging treatment,the fracture mechanism changing with the temperature and aging time increasing was discovered.It was transformated from the toughness fracture to the complex fracture mechanism,which was the intergranular-toughness fracture mechanism.Due to alloy atoms strongly nailed at the grain boundary so that the combining power was boost up greatly between intercrystalline.The alloy had higher tensile strength,yield strength and tiny elongation percentage.The sixth,the thermo-mechanical treatment(solution-cold-drawing-aging)can increase alloy's strength greatly and hardly decrease the conductibility of the alloy. The alloy in aging after cold-drawing was influenced by the interaction of precipitation and recrystallization.The precipitates not only can strengthen the matrix,but also can restrain recrystallization.The strengthening mechanisms of the alloy mainly include solution strengthening,strain strengthening and aging strengthening.The seventh,The solid solution alloy in aging treatment 450℃,72h after 40% cold drawing was used aging treatment.The properties of the alloy were:HV=461,σb =1385MPa,σ0.2=1264MPa,δ=4.2%,E=141.9GPa,σ=52.4%IACS.
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