【摘要】 研究了分级时效工艺参数对Ａｌ－１．９Ｌｉ－２．３３Ｃｕ－０．０９Ｚｒ－０．１１Ｃｅ合金拉伸性能及强化相分布的影响。结果表明，预时效温度对性能影响不显著；随终时效温度升高，强度先升高而后下降，塑性则一直下降；强度随终时效时间延长而上升。预时效及终时效温度偏低或终时效时间偏短均不利于δ＇相的析出，但易使Ｔ_１相直接由α基体上沉淀，并呈细小、弥散分布；预时效或终时效温度偏高时，易使δ＇相粗化并向Ｔ_１相转变，而且会造成Ｔ_１相的粗化及沿晶析出；长时间终时效仅使δ＇相粗化但不会使Ｔ_１相粗化。合适的分级时效可促成强化相的合理分布，从而产生比较明显的沉淀强化。更多还原

【Abstract】 The tests are carried out to investigate the effect of the double-stage ageing treatment on the tensile properties at room temperature and the distribution of precipitated particles for an Al-1. 9 Li-2. 33 Cu-0. 09 Zr-0. 11Ce alloy. The first-stage ageing temperature has an insignificant effect on the strength and ductility. With a rise in the second-stage ageing temperature, the strength increases and then decreases promptly after over the peak point at 185℃ while the ductility always decreases. With a delay in the second-stage ageing time,the yield strength increases and ultimate tensile strength could almost remain constant after it increases to a certain degree while the elongation has an insignificant variation. Under the conditions of lower first and second-stage ageing temperatures or shorter second-stagen ageing time,δ’ particles have an insufficient precipitation and growth but finer T1 particles conld he promoted to precipitate directly from alpha matrix. The elevated first and secondstage ageing temperature could induce δ’ particles to coarsen or to change into T1 phase.Moreover, the elevated first and second-stage temperatures could also induce T1 particles to coarsen or precipitate along the grain boundaries. The longer second-stage ageing time only causes δ’ particles,except T1 particles, to coarsen. A suitable processing of double-stage age ing treatment for the alloy could make the microstructures contain more and larger δ’ particles with finer T1 particles to result in a more significant effect on precipitation hardening.更多还原