(1. 中南大學(xué) 材料科學(xué)與工程學(xué)院，長(zhǎng)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(zhǎng)沙 410083；
3. 中南大學(xué) 粉末冶金國(guó)家重點(diǎn)實(shí)驗(yàn)室，長(zhǎng)沙 410083)
摘 要: 通過(guò)等溫淬火方法獲得Cu-6.5Ni-1Al-1Si-0.15Mg-0.15Ce合金的TTP曲線。采用硬度、電導(dǎo)率測(cè)試和透射電鏡(TEM)觀察等方法研究了等溫溫度和等溫時(shí)間對(duì)合金性能和顯微組織的影響。結(jié)果表明：合金TTP曲線的鼻尖溫度約為675 ℃，淬火敏感區(qū)域?yàn)?25~725 ℃；合金在650 ℃附近進(jìn)行等溫處理，δ-Ni2Si和共格的Ni3Al析出相的形核率和長(zhǎng)大速率均很高；隨著等溫時(shí)間的延長(zhǎng)，晶內(nèi)析出的δ-Ni2Si和Ni3Al急劇粗化，同時(shí)，晶界處發(fā)生δ-Ni2Si的不連續(xù)析出，并形成無(wú)襯度析出帶，導(dǎo)致合金經(jīng)等溫時(shí)效處理后硬度急劇下降，并且在鼻尖區(qū)具有很高的淬火敏感性。
關(guān)鍵字: CuNiAlSi合金；等溫處理；淬火敏感性；顯微組織
（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
