无压自渗制备金属基复合材料的工艺研究

TECHNOLOGY STUDY OF PREPARING METAL MATRIX COMPOSITES BY SELF-INFILTRATING

被密封在陶瓷集合体内部间隙的气体与含镁铝合金反应产生负压 ,合金液在负压的抽吸作用下自发渗入陶瓷集合体内部制得金属基复合材料 (MMC)。增加合金液中镁的浓度可以提高渗入速度。刚玉坩埚气密性好 ,空隙度低 ,能够有效隔绝陶瓷集合体间隙气体与外界大气的联系 ,可用作制备自渗入MMC的容器 ;石墨坩埚多孔透气 ,不适合用作制备自渗入MMC的容器。利用无压自渗制备工艺可制得强度、刚度等性能优于基体合金的MMC。

The fundamental principle of making metal matrix composite(MMC) by self-infiltrating is that the negative pressure is formed by the reaction between the liquid aluminium alloy and the gas sealed in the inside gap of ceramic gathering body,the negative pressure draws liquid metal into the ceramic gathering body to form metal matrix composites.The self-infiltrating rate can be risen by increasing the Mg content in aluminium alloy.The corundum crucible can be used as the container for preparing the self-infiltrating metal matrix composites because of its good air-sealing property and low porosity for isolating the gas that exists in the gap of the ceramic gathering body from the air,while the graphite crucible isn't suiteble for using as the container for preparing the self-infiltrating metal matrix composites because of its porosity.The strength and stiffness and so on of the metal matrix composites prepared by the negative pressure self-infiltrating technology is superior to those of the matrix alloy.