Cu-Cr-Zr-Sn合金的时效析出行为与性能

Aging Precipitation Behavior and Properties of Cu-Cr-Zr-Sn Alloy

摘要:

采用TEM对Cu-0.22Cr-0.05Zr-0.05Sn合金不同形变热处理状态微观组织的演变以及时效过程中析出相的状态进行研究，并以此解释形变热处理过程中合金力学性能和导电性能的变化。结果表明，合金中存在2种析出相，分别是Cr相和Cu4Zr相。其中Cr相在时效过程中分别经历了固溶体、GP区、脱溶并与基体共格以及长大；而Cu4Zr相则以早期Cr析出相为核伴随析出，与基体半共格。由于析出相尺寸很小，且分布较为均匀，使合金具有很强的时效强化效果，经940 ℃固溶1 h后冷加工至变形率为96%并在400 ℃时效4 h，合金的抗拉强度和电导率可分别达到400 MPa和84%IACS。对于该合金，时效温度是决定合金综合性能的关键，而时效时间对综合性能的影响并不显著。

Abstract:

The microstructure evolution and precipitates of Cu-0.22Cr-0.05Zr-0.05Sn alloy under different thermomechanical treatments were studied by TEM and the changes of mechanical property and electrical conductivity of the alloy were explained. Results show that two kinds of precipitates of Cr and Cu4Zr consist in the matrix. Cr precipitates undergo a course of solid solution, GP zone, precipitation, coherence with the matrix and coarsening. Cu4Zr precipitates are nucleated preferentially at the pre-nucleated Cr particles, and semi-coherent with the matrix. The alloy has a better aging strengthening effect duo to that the fine precipitates are well dispersed. The alloy has an excellent combination of tensile strength and electrical conductivity reaching 400 MPa and 84%IACS respectively when subjected to the optimum thermomechanical treatment, i.e., solution-treating at 940 oC for 1 h and cold drawing to 96% strain followed by aging at 400 oC for 4 h. To this alloy, aging temperature is a key factor to determine the combination properties while the effect of aging time is unnoticeable.