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通过外加颗粒SiO2 采用粉末冶金法成功制备了原位生成陶瓷相增强Al基复合材料 ,定量研究了复合材料的物相组成和反应机制。主要反应方程式为颗粒内Al + 1/ 2Mg +SiO2 =1/ 2MgAl2 O4 +Si和颗粒外 2Mg +Si=Mg2 Si。最终物相由约为 16.5 %～ 18.4%MgAl2 O4 ,3 %～ 5 %Si,11.7%Mg2 Si,及大于 0 .5 2 %MgO ,其余为Al组成 ,约 7%Al参加了反应 ,Mg和SiO2 基本消耗尽。反应是以SiO2 颗粒为核心进行的。这种反应及元素的扩散可以用“逐层反应机制”和“元素微观通道扩散机制”来描述。
In situ preparation of ceramic matrix reinforced Al matrix composites was successfully prepared by powder metallurgy with addition of SiO2 particles. The phase composition and reaction mechanism of the composites were quantitatively studied. The main reaction equation is intragranular Al + 1 / 2Mg + SiO2 = 1 / 2MgAl2 O4 + Si and extragranular 2Mg + Si = Mg2Si. The final phase consisted of approximately 16.5% to 18.4% MgAl 2 O 4, 3% -5% Si, 11.7% Mg 2 Si, and more than 0.52% MgO with the balance consisting of Al and about 7% Al participating in the reaction with Mg and SiO2 basically exhausted. The reaction is based on SiO2 particles as the core. This reaction and elemental diffusion can be described by “layer-by-layer reaction mechanisms” and “elemental microchannel diffusion mechanisms.”