(西北工業(yè)大學(xué)機(jī)械系，西安 710072)
摘 要: 利用TEM技術(shù)觀察和分析了2090和2090+Ce兩種合金中，位錯(cuò)與T1相之間的交互作用行為，發(fā)現(xiàn)T1相與位錯(cuò)間的交互作用是一種切過和繞過的混合型；并利用脫溶相強(qiáng)化理論建立了相關(guān)的物理模型。實(shí)算結(jié)果表明，在190℃時(shí)效3～48h，T1相的強(qiáng)化作用約占總的臨界剪切應(yīng)力（CRSS）的30%～60%，其強(qiáng)化作用隨時(shí)效時(shí)間的延續(xù)而增強(qiáng)，但過時(shí)效后增強(qiáng)作用平緩。2090和2090+Ce兩種合金對(duì)比結(jié)果表明，在欠時(shí)效時(shí)，兩合金中T1相的強(qiáng)化作用沒有多大差異，而過時(shí)效狀態(tài)下，含Ce合金中T1相的強(qiáng)化作用略大于前者，在僅考慮切過機(jī)制的情況下這種傾向尤為明顯。欠時(shí)效時(shí)兩合金基體強(qiáng)化作用約相差3.2 MPa，而過時(shí)效時(shí)兩合金基體的強(qiáng)化作用約相差8.7 MPa左右。
關(guān)鍵字: 鋁鋰合金； T1(Al2CuLi)相；強(qiáng)化作用
（Department of Mechanics, Northwestern Polytechnic University, Xi'an 710072, P.R.China）
Abstract: The behavior of interaction between dislocation an d T1-phase was observed and analyzed by means of TEM technique. The observing results show that the interaction between dislocation and T1-phase is a mixture-type of cutting and around mechanism, and the physical model are established by theory of precipitates strengthening. The results of calculation illustrate that the contribution of T1-phase is about 30%～60％ to the total critical resolved shear stress (CRSS), and that the strengthening effects of T1-phase in 2090 and 2090+minor Ce alloys are little different at under-aged condition, but the strengthening effect of T1 precipitates in alloy containing cerium is less bigger than that of 2090 not containing cerium under over-aged condition, especially the cutting mechanism is only considered. The difference between strengthening effect of matrix in two alloys is about 3.2 MPa under-aged and 8.7 MPa or so under over-aged condition.
Key words: Al-Li alloy; T1(Al2CuLi)-phase; strengthening effect
