(1. 中南大學(xué) 材料科學(xué)與工程學(xué)院， 長沙 410083；
2. 悉尼大學(xué)澳大利亞微觀分析國家重點實驗室， NSW 2006)
摘 要: 通過時效硬化曲線的測量及時效組織的透射電鏡分析， 研究了微量鈧對Al-Ag合金時效析出行為的影響。 研究結(jié)果表明： 在Al-Ag合金中添加0.2%Sc(質(zhì)量分?jǐn)?shù))， 可增強合金350℃的時效硬化效果， 延長達(dá)到峰時效的時間。微觀組織分析發(fā)現(xiàn)， 微量鈧的添加促使合金中γ′相彌散細(xì)小地析出， 同時鈧的存在減少了γ′相寬面上的位錯臺階數(shù)。 含鈧Al-15Ag合金中γ′相長大過程比較緩慢的微觀機理是微量鈧的添加影響了合金中γ′相寬面上的臺階分布。
關(guān)鍵字: 鋁合金; 時效; 微觀組織; 鈧
（1. School of Materials Science and Engineering, Central South University, Changsha 410083, China;
2. Australian Key Centre for Microscopy and Microanalysis, The University of Sydney, NSW 2006, Australia）
Abstract:The age hardening behaviour and microstructure of Al-Ag-(0.2Sc) alloys were investigated. The results indicate that small addition of Sc can enhance the age hardening response of the Al-Ag alloy and prolong the time taken to the ageing peak. TEM observations show that the small addition of Sc results in a refinement of the distribution of γ′ precipitates. The mechanism by which trace Sc affect the microstructure is to reduce the ledge density of γ′ precipitates.
Key words: aluminium alloys; ageing; precipitation; scandium
