时效时间对Cu-3.5Ag合金性能及其纳米析出相特征的影响

Effect of aging time on properties and nano precipitates characteristics of Cu-3.5Ag alloy

通过热型水平连铸工艺制备了Cu-3.5Ag合金,经950℃×1 h固溶,以及450℃下分别保温2、4、6和8 h的时效热处理,研究了时效时间对合金性能和析出相特征的影响。结果表明:随着时效时间的增加,合金的硬度呈先急剧升高后缓慢下降趋于平缓的趋势,合金的导电率基本保持不变;随着时效时间增加,析出相形貌、大小和数量均发生显著改变,富Ag相和铜基体始终保持半共格关系且两者具有完全一致的取向,半共格界面有效阻碍了位错运动从而使基体得到强化,相同的取向关系降低了析出相对电子的散射,进而对合金硬度和导电率具有改善效果。试验范围内,Cu-3.5Ag合金经450℃×4 h时效热处理后,硬度和导电率分别为122.62 HV0.1和86.20%IACS,综合性能较好。

Cu-3.5 Ag alloy was prepared by horizontal Ohno continuous casting process,and then the alloy was treated by solid solution treatment at 950℃ for 1 h and aging at 450℃ for 2 h,4 h,6 h and 8 h.The effect of aging time on properties and nano precipitates characteristics of the alloy was studied.The results show that with the increase of the aging time,the hardness of the alloy increases rapidly and then decreases slowly,the conductivity of the alloy remains basically the same.As the aging time increases,the morphology,size and quantity of the precipitates change significantly,and the Ag-rich phase and copper matrix have a consistent semi-coherent relationship,and they have the same orientation.The semi-coherent interface effectively hinders the dislocation movement and strengthens the matrix,and the same orientation relationship reduces the scattering of the precipitates-related electrons,and then improves the hardness and electrical conductivity of the alloy.In the test range,the hardness and electrical conductivity of the Cu-3.5 Ag alloy are 122.62 HV0.1 and 86.20%IACS,respectively after aging at 450℃ for 4 h,and its comprehensive properties are good.