外加20%SiO2原位生成陶瓷相增强铝基复合材料显微组织及相组成的研究

外加质量分数为20%的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,研究了复合材料烧结后的油磨性能、物相组成和组织形貌.油磨条件下,在98～1764N载荷内,复合材料的体积磨损量始终小于基体合金196N时的体积磨损量1.67mm3,在1764N时的最大磨损量小于0.8mm3.复合材料的最终物相为MgAl2O4、MgO、Mg2Si、Si和Al.在颗粒SiO2与Al-Mg反应过程中,约有复合材料中质量分数为2.8%Mg和7.0%Al及0.26%Cu扩散入颗粒内,颗粒内约有质量分数为9.74%Si, 0.23%O被置换到颗粒外,颗粒主要由MgAl2O4组成.

Study on microscopic structures and phase compositions of Al matrix composites reinforced by in situ formed ceramics phases formed by adding 20% SiO2

Al matrix composites reinforced by in situ ceramics phases formed by adding SiO 2 particles have been fabricated by powder metallurgy process. The wear resistant, microscopic structures and phase compositions of the composites were studied, it was shown that under lubricated wear condition, the wear resistant of the composites always behaves very well in larger range of load (98～1764N) than that of the matrix alloy under 196N. The largest volume loss of the composites is not more than 0.8mm 3. The phase compositions of the composites are composed of MgAl 2O 4, MgO, Mg 2Si, Si and Al. During the reaction between SiO 2 particles and Al-Mg, about 7.0wt%Al, 2.8wt%Mg and 0.26wt%Cu diffuse from the outside to the inside of particles, about 9.74wt%Si and 0.23wt%O do on the contrary. The final particles mainly consist of MgAl 2O 4.mpositesarecomposedofM