(1. 中南大学 材料科学与工程学院，长沙 410083；
2. 中南大学 有色金属材料科学与工程湖南省重点实验室，长沙 410083；
3. 中南大学 粉末冶金国家重点实验室，长沙 410083)
摘 要: 通过等温淬火方法获得Cu-6.5Ni-1Al-1Si-0.15Mg-0.15Ce合金的TTP曲线。采用硬度、电导率测试和透射电镜(TEM)观察等方法研究了等温温度和等温时间对合金性能和显微组织的影响。结果表明：合金TTP曲线的鼻尖温度约为675 ℃，淬火敏感区域为625~725 ℃；合金在650 ℃附近进行等温处理，δ-Ni2Si和共格的Ni3Al析出相的形核率和长大速率均很高；随着等温时间的延长，晶内析出的δ-Ni2Si和Ni3Al急剧粗化，同时，晶界处发生δ-Ni2Si的不连续析出，并形成无衬度析出带，导致合金经等温时效处理后硬度急剧下降，并且在鼻尖区具有很高的淬火敏感性。
关键字: CuNiAlSi合金；等温处理；淬火敏感性；显微组织
（1. School of Material Science and Engineering, Central South University, Changsha 410083, China;
2. Key Laboratory of Nonferrous Metal Materials Science and Engineering of Hunan Province,
Central South University, Changsha 410083, China;
3. Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, China）
Abstract:The TTP curves of Cu-6.5Ni-1Al-1Si-0.15Mg-0.15Ce alloy were established by isothermal treatment. Micro-hardness test, electrical conductivity test and transmission electron microscope observation were applied to study the influence of isothermal temperature and time on the properties and microstructure of the alloy. The results show that the nose temperature is about 675 ℃, and the quench sensitivity region is from 625 ℃ to 725 ℃. When the alloy is isothermally treated around 650 ℃, the nucleation rate and growth rate of δ-Ni2Si and Ni3Al are high; δ-Ni2Si and Ni3Al particles precipitate in the matrix coarsened rapidly, the discontinuous δ-Ni2Si particles precipitate at the grain boundary and precipitation free zone forms along the grain boundary with prolonging isothermal time. As a result, the micro-hardness decreases rapidly after isothermal treated at 650 ℃, and the alloy shows high quench sensitivity as it is treated at the temperature.
Key words: CuNiAlSi alloy; isothermal treatment; quench sensitivity; microstructure
