微观组织的影响
(中国科学院 金属研究所, 沈阳 110016)
摘 要: 利用原位反应自发渗透技术制备了组织均匀且致密度高的TiCp/Mg复合材料，研究了原位反应温度以及碳颗粒尺寸对制备的TiCp/Mg复合材料微观组织的影响。结果表明： 当使用大尺寸碳粒子(≤100μm)时，随着反应温度的提高， 原位生成物TiCp的含量增加，但有残留反应物Ti和C的存在； 碳粒子尺寸减小(≤30μm)时，原位反应较完全， 不再有残留物存在； 原位反应产物组织中， 增强相TiCp主要呈互穿网络状、颗粒状以及片状等形态； 增强相的尺寸随碳粒子尺寸的减小而减小， 在碳颗粒尺寸为1.5μm时TiC更易呈现等轴颗粒状， 尺寸约为0.5～2.0μm。
关键字: 原位反应自发浸渗； 镁基复合材料； 碳化钛； 碳颗粒尺寸； 显微组织
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
