Strengthening contribution of precipitates and anisotropy of yield strength in Al-Li alloys 2090 and 2090+Ce
来源期刊：中国有色金属学报2000年第z1期
论文作者：赵志龙 刘林 陈铮
文章页码：42 - 45
Key words：precipitates； heat treatments； aluminum-lithium alloy； anisotropy
Abstract: The yield strength or critical resolved stress （CRSS） of alloys 2090 and 2090+Ce were examined as a function of sheet orientation, with specific emphasis on the role of precipitation in the variation of anisotropy. The three heat treatments （solution, peak aging and reversion after peak aging） were used in order to identify the contribution of precipitates T1, δ′and θ′ to CRSS. The results show that the strengthening contribution of T1 phase is greatly different at various orientations with respect to rolling direction, by comparing with the co-strengthening effect of δ′and θ′ phases. The precipitation of T1 phase can weaken the anisotropy of mechanical properties. The peak aged and reverted specimens have a stronger tendency of delaminating along grain boundary, which may be a direct reason for the decrease of anisotropic yield strength. This is correlated with the precipitation of T1 phase at subgain boundaries.
