(1. 中南大學(xué) 材料科學(xué)與工程學(xué)院，長沙 410083；
2. 中南大學(xué) 有色金屬材料科學(xué)與工程湖南省重點(diǎn)實(shí)驗(yàn)室，長沙 410083；
3. 中南大學(xué) 粉末冶金國家重點(diǎn)實(shí)驗(yàn)室，長沙 410083)
摘 要: 設(shè)計(jì)并制備一種超高強(qiáng)導(dǎo)電Cu-6.0Ni-1.0Si-0.5Al-0.15Mg-0.1Cr(質(zhì)量分?jǐn)?shù)，%)合金。通過測量合金的硬度，分析經(jīng)固溶處理并分別經(jīng)600~850 ℃等溫處理后再在450 ℃時(shí)效處理1 h的合金力學(xué)性能的變化規(guī)律，建立合金的時(shí)間-溫度-性能(TTP)曲線。通過透射電鏡觀察，研究合金在等溫處理過程中的第二相的析出規(guī)律。結(jié)果表明:合金的鼻尖溫度約為725 ℃，淬火敏感區(qū)域?yàn)?75~775 ℃。合金在淬火敏感區(qū)進(jìn)行等溫處理時(shí)，晶內(nèi)析出的δ-Ni2Si和Ni3Al迅速形核和長大；延長等溫時(shí)間，析出相粗化，合金的硬度隨之降低。合金在鼻尖溫度附近表現(xiàn)出高的淬火敏感性。
關(guān)鍵字: CuNiSiAl合金；等溫處理；淬火敏感性；力學(xué)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
