(中南工業(yè)大學(xué)材料科學(xué)與工程系，長(zhǎng)沙 410083)
摘 要: 制備了Al-5Mg、Al-5Mg-0.2Sc、Al-5Mg-0.1Zr和Al-5Mg-0.2Sc-0.1Zr四種鑄態(tài)合金，采用金相顯微鏡和掃描電鏡觀察分析了微量Sc和Zr對(duì)Al-Mg合金鑄態(tài)組織的晶粒細(xì)化作用及其機(jī)理。結(jié)果發(fā)現(xiàn)，0.2%的Sc并未使Al-Mg合金產(chǎn)生晶粒細(xì)化作用，而 0.2%的Sc與0.1%的Zr復(fù)合添加則使Al-Mg合金產(chǎn)生了極其強(qiáng)烈的晶粒細(xì)化作用。這一作用的產(chǎn)生，是由于Sc、Zr與Al在合金熔體中生成了A l-3Sc和Al-3Zr復(fù)合粒子，這種粒子在合金凝固過(guò)程中，起到了非均質(zhì)晶核細(xì)化晶粒的作用。
關(guān)鍵字: 鈧 Al-Mg合金 非均質(zhì)晶核 細(xì)化作用
（Central South University of Technology, Changsha 410083）
Abstract:Al-5Mg, Al-5Mg-0.2Sc, Al-5Mg-0.1Zr and Al-5M g-0.2Sc-0.1Zr cast alloys have been prepared. The effect of trace Sc and Zr on grain refinement of Al-5Mg cast alloy was studied using optical microscopy and scanning electron microscopy with EDS. The results showed that adding 0.2%Sc and 0 .1%Zr to Al-5Mg alloy leads to strong grain refinement but adding only 0.2%Sc to Al-5Mg alloy has no grain refinement phenomenon. This is because, during solidification, Al-3Sc/Al-3Zr composite particles were formed in the melt playing a role of the nuclei of imhomogenized crystallization.
Key words: scandium aluminium alloy grain refinement
