(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: 设计并制备一种超高强导电Cu-6.0Ni-1.0Si-0.5Al-0.15Mg-0.1Cr(质量分数，%)合金。通过测量合金的硬度，分析经固溶处理并分别经600~850 ℃等温处理后再在450 ℃时效处理1 h的合金力学性能的变化规律，建立合金的时间-温度-性能(TTP)曲线。通过透射电镜观察，研究合金在等温处理过程中的第二相的析出规律。结果表明:合金的鼻尖温度约为725 ℃，淬火敏感区域为675~775 ℃。合金在淬火敏感区进行等温处理时，晶内析出的δ-Ni2Si和Ni3Al迅速形核和长大；延长等温时间，析出相粗化，合金的硬度随之降低。合金在鼻尖温度附近表现出高的淬火敏感性。
关键字: CuNiSiAl合金；等温处理；淬火敏感性；力学性能
（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:A novel Cu-6.0Ni-1.0Si-0.5Al-0.15Mg-0.1Cr (mass fraction, %) alloy was designed and prepared. The changes of mechanical properties of the alloy under different isothermal conditions(600-850 ℃) after solution treated with 980 ℃ were studied, and on the basis of micro-hardness measurement, time-temperature-property (TTP) curves of the alloy were established. The transformation behavior during isothermal heat treatment was studied by transmission electron microscopy. The results show that the nose-temperatures of the curve is about 725 ℃, and quenching sensitivity region ranges from 675 ℃ to 775 ℃. As the alloy is isothermally treated in the quenching sensitivity region, the nucleation rate and growth rate of δ-Ni2Si and Ni3Al particles are high. With the isothermal holding time, the precipitated phases are coarsened rapidly, and the micro-hardness decreases. The alloy shows high quench sensitivity as it is treated around the nose-temperature.
Key words: CuNiAlSi alloy; isothermal treatment; quenching sensitivity
