2090铝锂合金中δ′相和T_1相的复合强化作用

Co-strengthening contribution of δ′ and T_1 phases of Al-Li alloy 2090

采用TEM观察2090和2090+Ce两种铝锂合金中δ′相和T1相与位错的交互作用行为,利用图形定量分析结果和微观变形理论分别计算两个相的强化贡献,进而分析两相复合强化作用形式。分析结果表明:在近峰值时效区域,δ′和T1相强化作用的叠加关系与q=1.4的关系符合较好;欠时效时,δ′、T1相强化贡献的叠加关系接近线性关系(q=1);过时效时,却与抛物线型关系(q=2)符合较好。δ′和T1相强化作用的叠加关系对时效时间表现出较强的依赖性。

The microstructures of dislocation in two kinds of aluminum-lithium alloy 2090 and 2090＋ Ce were observed by TEM. The contribution of precipitates of δ′ and T1 phases were separately calculated by the results of quantitative metallography and micro-deformation theory. Furthermore, the co-strengthening effects of δ′ and T1 phases were studied. The results show that the adding relationship of co-strengthening of δ′ and T1 phases accords with that of q= 1.4 at near peak-aged condition. But the adding relationship is approximately linear relation （q= 1） at under-aged condition, and become parabola form at over-aged （q= 2）. The adding relation of co-strengthening contribution of δ′ and T1 phases is obviously dependent on aging time.