(1. 中南大學(xué) 材料科學(xué)與工程學(xué)院，長沙410083；
2. 中南大學(xué) 有色金屬材料科學(xué)與工程教育部重點(diǎn)實(shí)驗(yàn)室，長沙410083；
3. 湖南省有色稀有金屬材料科學(xué)與工程重點(diǎn)實(shí)驗(yàn)室，長沙 410083；
4. 國網(wǎng)遼寧省電力有限公司，沈陽 110042)
摘 要: 采用金相顯微鏡(OM)、掃描電鏡(SEM)、電子探針(EPMA)、透射電鏡(TEM)和掃透電鏡(STEM)以及硬度、電導(dǎo)率和拉伸性能測試等方法研究微量Si元素對(duì)Al-Zr-Sc-Er合金組織和性能的影響。結(jié)果表明：添加Si元素能夠促進(jìn)富Er初生相的形成，增加鑄態(tài)合金硬度，但會(huì)顯著降低電導(dǎo)率；在Al-Zr-Sc-Er合金中，經(jīng)適當(dāng)熱處理可形成核-雙殼結(jié)構(gòu)的Al3(Er,Sc,Zr)復(fù)合相，添加Si能夠增大合金時(shí)效響應(yīng)速度，促進(jìn)Zr、Sc、Er析出，并參與第二相形核，形成(Al,Si)3(Er,Sc,Zr)相。相較于未添加Si的合金，添加0.05% Si的合金經(jīng)(300 ℃, 24 h)+(400 ℃, 48 h)雙級(jí)時(shí)效后硬度和電導(dǎo)率均提高，但Si的添加會(huì)導(dǎo)致析出相粗化，從而降低合金的再結(jié)晶溫度。
關(guān)鍵字: Al-Zr-Sc-Er合金；Si元素；顯微組織；電導(dǎo)率；硬度
（1. School of Materials Science and Engineering, Central South University, Changsha 410083, China;
2. Key Laboratory of Nonferrous Metal Materials Science and Engineering, Ministry of Education, Central South University, Changsha 410083, China;
3. Key Laboratory of Nonferrous and Rare Metal Materials Science and Engineering, Changsha 410083, China;
4. State Grid Liaoning Electric Power Supply Co., Ltd., Shenyang 110042, China）
Abstract:The effects of trace Si on microstructure and properties of dilute Al-Zr-Sc-Er alloys were investigated by OM, SEM, EPMA, TEM, STEM, hardness tests, electrical conductivity tests and tensile tests systematically. The results show that the addition of Si promotes to form more Er-rich primary phases in as-cast alloys, which enhances hardness but obviously decreases electrical conductivity of as-cast alloys. Core-double shell structureAl3(Er,Sc,Zr) precipitated with proper heat treatment in Al-Zr-Sc-Er alloys. Si increases the ageing response speed of the alloy, promotes the precipitation of Zr, Sc, Er elements. Si can participate in the nucleation of the (Al,Si)3(Er,Sc,Er) phase. After a two-stage aging treatment (300 ℃, 24 h+400 ℃, 48 h), the hardness and electrical conductivity of alloys with 0.05% Si addition is higher than with no Si addition alloys. However, the addition of Si causes coarsening of the precipitated phase, thereby reducing the recrystallization temperature of the alloy.
Key words: Al-Zr-Sc-Er alloys; Si element; microstructure; electrical conductivity; hardness
