(中南大学 材料科学与工程学院，长沙 410083)
摘 要: 研究一种Al-Zn-Mg-Cu合金在连续冷却过程中的固态相变和连续冷却转变曲线。通过力学性能检测和显微组织观察确定临界固溶温度，采用连续的相对电阻法和X射线衍射法测出了该合金的相变开始点，结合显微组织观察和析出相定量分析测出了相变结束点，分析比较了不同冷却速度对应的微观组织，通过逐步减小实验冷却速度范围逼近临界冷却速度。结果表明：采用连续的相对电阻法能有效地研究铝合金的固态相变，针对不同冷却速度范围采用不同方法的分段综合测试可以获得较为完整的连续冷却转变曲线。
关键字: Al-Zn-Mg-Cu合金；连续电阻法；连续冷却转变曲线
（School of Materials Science and Engineering, Central South University, Changsha 410083, China）
Abstract:The solid phase and continuous cooling transformation(CCT) of Al-Zn-Mg-Cu alloy during continuous cooling were studied. The critical solution temperature was established by mechanical properties test and microstructures observation. The resistance testing and X-ray diffraction were used to establish the activated temperature of phase transformation. The completed temperature of phase transformation was measured by microstructures observation and quantificational analysis. The critical cooling velocity was approached by reducing the experimental cooling velocity step by step. The microstructures of samples cooled at different cooling velocity were analyzed and compared. The results show that continuous resistance testing can be utilized to study phase transformation in aluminum alloy effectively. The relatively complete CCT curves of aluminum alloy can be obtained by different methods at different cooling velocity.
Key words: Al-Zn-Mg-Cu alloy; continual resistance testing method; continuous cooling transformation curve
