【摘要】 研究了铸造Cu-15Ni-8Sn合金时效过程中组织和力学性能的变化规律。固溶处理获得的单相α固溶体经适当的时效热处理会产生Spinodal调幅结构,亚稳态γ′相,以及不连续沉淀γ相。伴随着组织的变化合金的力学性能也相应发生变化,时效初期合金的强度和硬度随时效时间的延长或温度的升高而升高,而经过最大值后,则随时间的延长或温度的升高而下降;时效过程中合金塑性变化规律与强度和硬度规律相反。更多还原

【Abstract】 Effects of ageing treatment on microstructure and mechanical properties of cast Cu-15Ni-8Sn alloy were investigated. It is found that with ageing at 400 癈 , the supersaturated solid solution a is firstly decomposed spinodally, then the metastable ?’ precipitated phase appears after spi-nodal decomposition, and thereafter discontinuous precipitation ? phase occurs in grain boundary. The microstructure transformation process affects the mechanical properties of the alloy with ageing treatment. Tensile strength, yield strength and hardness of the alloy are gradually increased to a peak value (formation of meatstable ?’precipitated phase ) earlier, then is decreased with increasing the ageing time or temperature. Fracture toughness of the alloy is severely impaired due to the grain boundary precipitates.更多还原