微觀組織的影響
(中國科學(xué)院 金屬研究所, 沈陽 110016)
摘 要: 利用原位反應(yīng)自發(fā)滲透技術(shù)制備了組織均勻且致密度高的TiCp/Mg復(fù)合材料，研究了原位反應(yīng)溫度以及碳顆粒尺寸對(duì)制備的TiCp/Mg復(fù)合材料微觀組織的影響。結(jié)果表明： 當(dāng)使用大尺寸碳粒子(≤100μm)時(shí)，隨著反應(yīng)溫度的提高， 原位生成物TiCp的含量增加，但有殘留反應(yīng)物Ti和C的存在； 碳粒子尺寸減小(≤30μm)時(shí)，原位反應(yīng)較完全， 不再有殘留物存在； 原位反應(yīng)產(chǎn)物組織中， 增強(qiáng)相TiCp主要呈互穿網(wǎng)絡(luò)狀、顆粒狀以及片狀等形態(tài)； 增強(qiáng)相的尺寸隨碳粒子尺寸的減小而減小， 在碳顆粒尺寸為1.5μm時(shí)TiC更易呈現(xiàn)等軸顆粒狀， 尺寸約為0.5～2.0μm。
關(guān)鍵字: 原位反應(yīng)自發(fā)浸滲； 鎂基復(fù)合材料； 碳化鈦； 碳顆粒尺寸； 顯微組織
TiCp reinforced magnesium matrix composites by in situ reactive infiltration process
（Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China）
Abstract: The highly dense TiCp/Mg composites were fabricated by in situ reaction of (Tip+Cp) preform and spontaneous infiltration of molten Mg into TiCp (in situ reactive infiltration process). The effects of processing temperature and carbon particle size on the microstructures of as-fabricated magnesium matrix composites were investigated. The results show that the amount of product TiCp phase increases with increasing processing temperature by using carbon particle with size of less than 100μm. However, there are un-reacted Ti and C phases existing within microstructures in this case. When carbon particle size is reduced to some critical size of about 30μm, the reaction between Ti and C almost completes and no retained Ti and C present. For the microstructures of TiCp/Mg composites, the reinforcement TiC phase has several morphologies, ie interpenetrating network, spheroid-shape and flake-shape, etc. The particle size of the reinforcement TiC decreases with reducing carbon particle size, and there are more 0.5~2.0μm TiCp with spheroid-like morphology formed when carbon particle size is reduced to 1.5μm.
Key words: in situ reactive infiltration； magnesium matrix composites； TiC； carbon particle size； microstructure
