δ′相的强化贡献及微量稀土Ce的影响

The Strengthening Contribution of δ′Phase and the Influence of Trace Addition of Rare-earth Element Cerium

利用 TEM技术及体视分析原理 ,研究 2 0 90铝锂合金和 2 0 90 +Ce稀土高强铝锂合金 (Ce添加量为 0 .0 5 % )中位错组态、δ′相体积分数随时效条件的变化 ,并利用微观力学原理分析和计算δ′相的强化机制及强化贡献。研究目的在于探讨δ′相的强化作用随时效条件的变化以及微量稀土 Ce的添加对δ′相强化贡献的影响。研究结果表明 :时效初期 ,Ce的添加对δ′相的沉淀有一定的抑制作用 ;理论计算结果表明 ,δ′相的强化贡献约在 30 MPa～ 6 0 MPa,2 0 90 +Ce合金中δ′相的强化贡献略低于同等时效条件的 2 0

In this paper, the dislocation microstructure and volume fraction of δ′ phase in two alloys of 2090 and 2090 with trace addition (2090+Ce) as a function of aging condition have been investigated by means of transmission electron microscopy (TEM) and stereoscopic analysis. Based on the observation of the micro deformation characteristics and the analysis of microcosmic mechanics, the theoretical contribution of δ′ phase to the strengthening has been deduced. The results indicate that the trace addition of cerium had a certain effect to retard the growth of δ′ phase in the initial stages of aging treatment, and the results of theoretical calculation show that the strengthening contribution of δ′ phase is about at the range of 30 MPa to 60 MPa. The strengthening contribution of δ′ phase in alloy 2090+Ce is slightly lower than that in alloy 2090 at the same aging conditions.