(中南大學(xué) 材料科學(xué)與工程學(xué)院，長沙 410083)
摘 要: 通過顯微硬度測試、拉伸實驗、掃描電鏡和透射電鏡觀察，研究微量Sn對Al-2.5Cu-1.5Mg(質(zhì)量分?jǐn)?shù)，%)合金的力學(xué)性能及微觀組織演變的影響。結(jié)果表明：在Al-2.5Cu-1.5Mg合金中添加少量Sn能提高合金第二階段的時效硬化和強化效果，微量Sn能夠顯著地提高合金的塑性，含Sn合金的峰時效伸長率能達(dá)到20.5%；經(jīng)150 ℃時效1 000 h后，合金的伸長率仍有10.5%；微量Sn的添加能促進(jìn)Al-2.5Cu-1.5Mg合金中S相析出，并能抑制其粗化。
關(guān)鍵字: Al-2.5Cu-1.5Mg合金；鋁合金；時效特性；顯微組織；Sn
（School of Materials Science and Engineering, Central South University, Changsha 410083, China）
Abstract:The effects of trace Sn additions on the ageing behavior and microstructure evolution of Al-2.5Cu-1.5Mg alloy were investigated by the microhardness test, tensile test, SEM and TEM. The results indicate that the trace Sn addition can increase the hardening and strengthening of the second stage of ageing. Adding trace Sn can significantly improve the ductility of Al-2.5Cu-1.5Mg alloy, the elongation of Sn-containing alloy at peak aged is 20.5%, and the alloy elongation is still 10.5% after aged at 150 ℃ for 1 000 h. The trace Sn addition can promote S phase precipitate and inhibit the S phase coarsen at over-aged.
Key words: Al-2.5Cu-1.5Mg alloy; aluminum alloy; ageing characteristics; microstructure; Sn
