(上海大學(xué) 上海市現(xiàn)代冶金及材料制備重點(diǎn)實(shí)驗(yàn)室，上海 200072)
摘 要: 為了建立Ti-Al-Cr-Mn系的熱力學(xué)數(shù)據(jù)庫(kù)，對(duì)該四元系中子三元系A(chǔ)l-Cr-Mn體系的富Al角作了熱力學(xué)評(píng)估。對(duì)于該三元系中的化學(xué)計(jì)量比化合物，如Al6Mn和Al12Mn等采用模型Alm(Cr,Mn)n，θ_Al7Cr、η_Al11Cr2及μ_Al4(Cr,Mn)相選用點(diǎn)陣模型Alm(Al,Cr,Mn)n，T_HTAl11Mn4及γ2_αAl8(Cr,Mn)5相的點(diǎn)陣模型分別處理為(Al,Mn)29(Cr,Mn)10和(Al,Cr)12(Al,Cr,Mn)5(Al,Cr,Mn)9。并對(duì)該系進(jìn)行一系列熱力學(xué)優(yōu)化及相圖計(jì)算并與相應(yīng)的實(shí)驗(yàn)結(jié)果作了比較，發(fā)現(xiàn)計(jì)算結(jié)果與大部分實(shí)驗(yàn)結(jié)果基本吻合，但在1 283 K等溫面中，Al8(Cr,Mn)5化合物只存在一個(gè)γ2_αAl8(Cr,Mn)5結(jié)構(gòu)，而實(shí)驗(yàn)相圖中還存在γ1_βAl8(Cr,Mn)5結(jié)構(gòu)。分析Al-Mn體系認(rèn)為，γ1_βAl8(Cr,Mn)5在1 283 K時(shí)不會(huì)穩(wěn)定存在，且 1 173 K等溫面中出現(xiàn)η_Al11Cr2相，而實(shí)驗(yàn)相圖中不存在該相。通過(guò)對(duì)Al-Cr系調(diào)研可以發(fā)現(xiàn)，η_Al11Cr2相在溫度下降到1 204 K時(shí)通過(guò)L+Al4Cr→Al11Cr2生成，因此，在外推Al-Cr-Mn三元系時(shí)，η_Al11Cr2相在1 173 K時(shí)會(huì)穩(wěn)定存在。
關(guān)鍵字: Al-Cr-Mn；熱力學(xué)優(yōu)化；相圖計(jì)算
（Shanghai Key Laboratory of Modern Metallurgy and Materials Processing,
Shanghai University, Shanghai 200072, China）
Abstract:In order to build up Ti-Al-Cr-Mn thermodynamical database, the Al-rich corner of the Al-Cr-Mn system in Ti-Al-Cr-Mn system was assessed by CALPHAD method. The model of stoichiometric compounds, such as Al6Mn and Al12Mn were considered as Alm(Cr,Mn)n, θ_Al7Cr, η_Al11Cr2 and μ_Al4(Cr,Mn) were modeled as Alm(Al,Cr,Mn)n. The model of T_HTAl11Mn4 and γ2_αAl8(Cr,Mn)5 were taken as (Al,Mn)29(Cr,Mn)10 and (Al,Cr)12(Al,Cr,Mn)5(Al,Cr,Mn)9, respectively. After that, a serious of thermodynamic optimization and phase diagram calculation were carried. By comparing the calculated the experimental ones, it is shown that the present calculated results are in good agreement with most of the experimental ones, however, Al8(Cr,Mn)5 compound only exists as γ2_αAl8(Cr,Mn)5 formal at 1 283 K, the phase diagram of γ1_βAl8(Cr,Mn)5 is also presented. By analyzing Al-Mn system, it is found that γ1_βAl8(Cr,Mn)5 is not stable at 1 283 K, η_Al11Cr2 is presented at 1 173 K where it can not be found in the experimental ones. By investigating the Al-Cr system, it is found that η_Al11Cr2 is formed by liquid+Al4Cr→Al11Cr2 at temperature below 1 204 K, so when extrapolating into Al-Cr-Mn ternary system, η_Al11Cr2 will exist stably.
Key words: Al-Cr-Mn; thermodynamic optimization; calculation of phase diagram
