(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) 教育部有色金屬材料科學(xué)與工程實(shí)驗(yàn)室，長(zhǎng)沙 410083)
摘 要: 采用透射電子顯微鏡(TEM)、選區(qū)電子衍射(SADP)和硬度測(cè)試等手段研究1973高強(qiáng)高韌鋁合金在不同溫度下的單級(jí)時(shí)效析出及硬化行為。結(jié)果表明：1973鋁合金在120和140 ℃有很強(qiáng)的抗過時(shí)效能力，峰時(shí)效過后，硬度在長(zhǎng)時(shí)間內(nèi)基本保持在195 HV附近。1973鋁合金的析出序列為：α過飽和固溶體(SSS)→GPⅠ區(qū)/GPⅡ區(qū)→η'亞穩(wěn)相→η平衡相→T相。在140 ℃單級(jí)時(shí)效過程中，GPⅡ區(qū)和η'相一直都存在于時(shí)效合金中，對(duì)合金起著最大的強(qiáng)化作用。
關(guān)鍵字: 1973合金；時(shí)效硬化；析出相；析出序列
（1. School of Materials Science and Engineering, Central South University, Changsha 410083, China；
2. Key laboratory of Nonferrous Metal Materials Science and Engineering, Ministry of Education, Changsha 410083）
Abstract:The ageing precipitation and hardening behavior of 1973 high strength and high toughness aluminum alloy were studied by means of transmission electron microscopy (TEM), select area electron diffraction (SAED) and hardness measurements at different ageing temperatures. The results show that this alloy has obvious anti-over-aging capability at 120 and 140 ℃. And this alloy can keep the hardness of 195 HV in a long time after peak-ageing. Furthermore, the precipitation sequence of 1973 aluminum alloy can be described as follows: supersaturated solid solution(α)→ GPⅠ/GPⅡ zone→ metastable η'→ stable η→T phase. There are GPⅡ zone and η' phase with the greatest strengthening effect on the 1973 aluminum alloy during the whole ageing process at 140 ℃.
Key words: 1973 aluminum alloy; ageing hardening; precipitation; precipitation sequence
