(北京有色金屬研究總院 有色金屬材料制備加工國家重點(diǎn)實(shí)驗(yàn)室，
北京 100088)
摘 要: 研究了7B04合金單級(jí)時(shí)效處理過程中時(shí)效溫度和時(shí)效時(shí)間對(duì)合金力學(xué)性能和電導(dǎo)率的影響， 觀察和對(duì)比了幾種不同時(shí)效處理制度下合金的顯微組織。 結(jié)果表明： 單級(jí)時(shí)效處理的溫度越高， 合金達(dá)到峰時(shí)效所需的時(shí)間越短， 材料的峰時(shí)效強(qiáng)度和延伸率越低。 電導(dǎo)率隨時(shí)效時(shí)間的延長而不斷上升； 時(shí)效溫度越高， 電導(dǎo)率的增長速率越快。 峰時(shí)效合金基體內(nèi)有大量細(xì)小的彌散相析出， 晶界析出相呈連續(xù)分布。 當(dāng)時(shí)效溫度較低時(shí)， 過時(shí)效合金的顯微組織與峰時(shí)效沒有明顯差別； 當(dāng)時(shí)效溫度較高時(shí)， 過時(shí)效合金內(nèi)粗大析出相的數(shù)量明顯增加， 晶界析出相呈不連續(xù)分布。 不同時(shí)效溫度下的峰時(shí)效和過時(shí)效合金中均不存在明顯的晶間無析出帶。
關(guān)鍵字: 7B04合金； 預(yù)拉伸厚板； 單級(jí)時(shí)效； 微觀組織； 力學(xué)性能
LIU Hong-wei, WANG Feng
（ State Key Laboratory for Fabrication and Processing of Nonferrous Metals, General Research Institute for Nonferrous Metals, Beijing 100088, China）
Abstract: The effect of one-step ageing temperature and time upon mechanical properties and electrical conductivity of 7B04 pre-stretched thick plate was studied， and the microstructures of the alloy aged at different temperatures were compared. The results show that the higher the ageing temperature is, the shorter the peak ageing time is. The strength and elongation of the peak-aged alloy will be lowered when the ageing temperature is higher. With increasing the ageing time, the electrical conductivity becomes large. The higher the ageing temperature is, the faster the speed rate of electrical conductivity grows. The microstructure of matrix in peak-aged alloy consists of fine dispersed precipitates and precipitates from grain are continuous. When the ageing temperature is lower than 120 ℃, there are no obvious microstructure difference between peak-aged and over-aged alloys; When the ageing temperature is higher than 125 ℃, there are many coarse precipitates in over-aged alloys and the precipitates from grain are discontinuous. There are no obvious precipitate free zones along the grain boundary in both peak-aged and over-aged alloys under different ageing temperatures.
Key words: 7B04 alloy; pre-stretched thick plate; one-step ageing; microstructure; mechanical property
