時(shí)效行為及微觀組織結(jié)構(gòu)演化的影響
(中南大學(xué) 材料科學(xué)與工程學(xué)院，長沙 410083)
摘 要: 采用計(jì)算機(jī)模擬與透射電鏡相結(jié)合研究微量Si和Ag對(duì)低Cu/Mg比Al-Cu-Mg合金時(shí)效行為和微觀組織結(jié)構(gòu)演變的影響。結(jié)果表明：微量Si和Ag的添加改變了該合金的時(shí)效析出過程，顯著增強(qiáng)了合金的時(shí)效硬化效應(yīng)。微量Si的存在導(dǎo)致了合金時(shí)效早期Mg原子團(tuán)簇、Cu-Mg原子團(tuán)簇彌散化，而微量Ag的添加導(dǎo)致形成大量Mg-Ag原子團(tuán)簇。微量Si和Ag極大地改變了合金時(shí)效早期的原子團(tuán)簇化過程從而導(dǎo)致了時(shí)效過程中微觀組織結(jié)構(gòu)的不同演化過程。
關(guān)鍵字: 鋁合金；時(shí)效；微觀結(jié)構(gòu)；Si；Ag
microstructure evolution of Al-Cu-Mg alloy
（School of Materials Science and Engineering, Central South University, Changsha 410083, China）
Abstract:The effects of trace additions of Si and Ag on the ageing behaviour and microstructure evolution of low Cu/Mg ratio Al-Cu-Mg alloy were investigated by using analytical transmission electron microscopy and Monte Carlo simulation. The results indicate that the age hardening response can be enhanced by the trace Si addition as well as Ag. The Monte Carlo simulation results show that the addition of Si results in a refinement of Mg clusters and Cu-Mg clusters, and the addition of Ag promotes the formation of lots of Mg-Ag clusters. Trace Si and Ag additions significantly alter the clustering process during early stages of ageing, resulting in different microstructural evolution processes during subsequent aging process.
Key words: aluminium alloy; ageing; microstructure; Si; Ag
