脱溶相的强化贡献与2090板材屈服强度的各向异性

The Strengthening Contribution of Precipitates and Anisotropy of Yielding Strength

对２０９０ 和２０９０ 加微量Ｃｅ 两种铝锂合金板材不同取向（ 与轧向呈０°、４５°和９０°） 以及不同热处理状态（ 固溶处理、峰值时效和峰值时效后回归） 试样的力学性能测试和微观分析结果表明：与δ′和θ′相的复合强化作用相比，Τ１ 相的强化贡献在不同取向上存在较大差异；Τ１ 相的析出对板材力学性能各向异性有削弱作用。峰值时效和回归试样具有较强的沿晶分层倾向，成为其屈服强度各向异性下降的直接原因；该现象与Τ１ 相在亚晶界沉淀有关。

The mechanical properties and characteristics of microstructure of two Al\|Li alloy sheets of 2090 and 2090 added minor cerium with different angle (0°,45° and 90°) to rolling direction and with different processing of heat treatment (solution, peak aging and reversion after peak aging) have been investigated. The experimental results show that the strengthening contribution of Τ\-1 phase has great difference at different orientation comparing with the co\|strengthening effect of δ′ and θ′ phases. The precipitation of Τ\-1 phase can weaken the anisotropy of mechanical properties. The peak aged and reverted samples have a stronger tendency of delaminating along grain boundary, which may be a direct cause for decrease of anisotropy of yielding strength. This phenomenon is correlated with the precipitation of Τ\-1 phase in subgrain boundaries.