(1. 中南大學(xué) 材料科學(xué)與工程學(xué)院，長沙 410083；
2. 哈爾濱工業(yè)大學(xué) 材料科學(xué)與工程學(xué)院，哈爾濱 150001)
摘 要: 采用金相顯微鏡、透射電子顯微鏡和高分辨電鏡等手段，研究不同高溫真空熱處理工藝條件下，高體積分?jǐn)?shù)Sip/Al復(fù)合材料(φ(Si)=65%)中硅鋁界面特征與硅相形貌的演變過程。結(jié)果表明：熱處理過程中硅相形貌演變?yōu)榧饨氢g化的顆粒狀、球化的孤島顆粒狀和三維網(wǎng)絡(luò)結(jié)構(gòu)狀。基于擴(kuò)散理論將硅相形貌的演變分為3個階段：不規(guī)則形狀硅顆粒的尖角逐漸溶解到鋁合金中，發(fā)生顆粒的鈍化現(xiàn)象；較小硅顆粒周圍逐漸溶解在鋁合金中的硅在濃度梯度的作用下，通過擴(kuò)散逐漸在較大硅顆粒周圍析出并長大；長大的硅顆粒互相接觸聯(lián)結(jié)，形成網(wǎng)狀結(jié)構(gòu)。鑄態(tài)Sip/Al復(fù)合材料中Si-Al界面平直，干凈，無析出物，同時存在大量位錯；高溫?zé)崽幚砗蟮腟i-Al界面變得圓滑，界面附近有細(xì)小的硅相析出物存在，幾乎不存在位錯。
關(guān)鍵字: Sip/Al復(fù)合材料；硅相；形貌演變；界面；析出相
Si-Al interface of Sip/Al composites
（1. School of Materials Science and Engineering, Central South University, Changsha 410083, China;
2. School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001, China）
Abstract: The evolution of silicon phase configuration and Si-Al interface in Sip/Al composites (φ(Si)=65%) fabricated by squeeze casting technology during high temperature heat-treatment were investigated. The microstructure was observed by optical microscopy, transmission electron microscopy and high resolution electron microscopy. The results show that the silicon phase configuration becomes round, annular and reticular. The configuration evolution is based on the diffusion of silicon atoms, and the process is comprised of three parts as follows: the irregular corners and edges of silicon particles are dissolved, the silicon atoms dissolved from smaller particles diffuse to larger particles, because of the concentration gradient exists between them, and the larger particles grow up, then the grown particles connect with each other, and form network configuration silicon. The Si-Al interface of composites is straight and free from interfacial reaction products, lots of dislocations are found. But after the heat treatment, the interface becomes smooth and dislocations disappear. Around the interfaces, fine silicon phases precipitate.
Key words: Sip/Al composites; silicon phase; configuration evolution; interface; precipitated phase
