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通过组织观察、性能检测和差热分析(DSC)试验,研究了不同Er元素含量下Al-Mg-Si-Zr-XEr合金时效硬化曲线、TEM组织、β″相的析出激活能和TTT曲线,并得到对应的β″相析出动力学方程和TTT表达式。结果表明:Er元素的添加促进了β″相的析出,在540℃固溶1 h+180℃时效5 h时,Al-Mg-Si-Zr-0.3Er合金中的β“相细小均匀的弥散析出;随Er元素含量增加,合金硬化速率明显加快,软化速率降低,合金β″相析出激活能降低,分别为96.3、93.6和84.9 k J/mol;析出动力学方程分别为:Y?(Er0.1)=1–exp[–1.534×10~(13)t~(1.5)exp(–17382.7/T)]、Y_(Er0.2)=1–exp[–5.865×10~(12)t_(1.5)exp(–16895.3/T)]、Y_(Er0.3)=1–exp[–2.965×10~(11)t~(1.5)exp(–15324.9/T)];TTT曲线方程分别为:T_(Er0.1)=17382.7/[30.4+1.5lnt–lnln(1-Y)~(-1)]、T_(Er0.2)=16895.3/[29.4+1.5lnt-lnln(1–Y)~(-1)]、T_(Er0.3)=15324.9/[26.4+1.5lnt–lnln(1–Y)~(-1)]。
The activation energy and TTT curve of the aging hardening curve, the TEM structure and the β ”phase of Al-Mg-Si-Zr-XEr alloy under different Er contents were investigated by microstructure observation, performance measurement and differential thermal analysis (DSC) The corresponding β “phase precipitation kinetic equation and TTT expression are obtained. The results show that the addition of Er element promotes the precipitation of β ”phase. The microstructure of β“ phase in Al-Mg-Si-Zr-0.3Er alloy after solution treatment at 540 ℃ for 1 h and aging at 180 ℃ for 5 h With the increase of Er content, the hardening rate of alloy increases obviously and the softening rate decreases. The activation energy of β ”phase precipitation decreases to 96.3,93.6 and 84.9 kJ / mol, respectively. The kinetic equations of precipitation are Y ¼ Er0.1 = 1-exp [-1.534 × 10 ~ (13) t ~ (1.5) exp (-17382.7 / T)] and Y_ (Er0.2) = 1-exp [-5.865 × 10 ~ (12) t_ (1.5) exp (-16895.3 / T)], Y_ (Er0.3) = 1-exp [-2.965 × 10-11 t -1.55 exp (-15324.9 / T)]; Is: T_ (Er0.1) = 17382.7 / [30.4 + 1.5lnt-lnln (1-Y) -1], T_ (Er0.2) = 16895.3 / [29.4 + 1.5lnt-lnln ) -1 -1], T Er0.3 = 15324.9 / [26.4 + 1.5lnt-lnln (1-Y) -1].