电磁搅拌条件下合成净化铝基复合材料的机制  

Mechanism of (Al_2O_3+Al_3Zr+ZrB_2)_P/Al composites preparation and clean up under electromagnetic stirring

作　　者：戴起勋[1] 李桂荣[1] 赵玉涛[1] 王宏明[1] 朱延山[1] 

机构地区：[1]江苏大学材料科学与工程学院,江苏镇江212013

出　　处：《江苏大学学报（自然科学版）》2005年第5期425-428,共4页Journal of Jiangsu University：Natural Science Edition

基　　金：国家自然科学基金资助项目(50471050);江苏省"十五"科技攻关项目(BE2002040);江苏省高等学校高新技术产业化发展项目(JH02-039)

摘　　要：在电磁搅拌条件下,研究Al-Zr(CO3)2-KBF4组元通过熔体反应法原位合成的Al2O3、Al3Zr、ZrB2颗粒增强铝基复合材料,用扫描电镜观察增强相的形貌、大小和分布.原位合成反应热力学和动力学分析表明:在试验温度条件下原位反应可以自发进行,主要是固液相间的反应,颗粒在形核生长阶段,交变电磁场产生的洛仑兹力使得熔体处于强烈的混合对流运动状态,传热和传质速度增加,增加了铝液和固态ZrO2颗粒的接触机会,增强颗粒 Al2O3、Al3Zr生成量增加,最后阶段电磁力促进颗粒在基体中弥散分布.凝固组织显示复合材料中增强相颗粒的体积分数和弥散度增加,颗粒粒度2～3μm,同时缩孔类缺陷明显减少,铝基体得到了净化.With electromagnetic stirring method, the composites of in-situ Al2O3, Al3Zr and ZrB2 particles reinforced aluminum matrix were synthesized by Al-Zr（ CO3 ）2-KBF4 components through the direct melt reaction method. Scanning electronic microscope（SEM） was used to observe the shape,size and distribution. Thermodynamics and kinetics conditions were analyzed. The in-situ reaction could proceeded spontaneously between solid and liquid phases. The melt were convecting intensely during nucleation and the mass transfer was accelerated because of the Lorenz force induced by imposing alternating electromagnetic field. The amount of reinforced particles Al2O3 and Al3Zr were increased because of the more contact between aluminum and ZrO2. In the last Lorenz force led to the uniform distribution of particles in the matrix. SEM analysis indicated that the fraction volume of particles in the aluminum matrix was enhanced and the particles were well distributed in the matrix. The granularity of particles was about 2 -3μm. Deformations as shrinkage hole were dramatically decreased, which led to a high cleanness of aluminum matrix.

关 键 词：铝基复合材料 电磁搅拌 原位合成 净化 

分 类 号：TB331[一般工业技术—材料科学与工程] TG146.21[金属学及工艺—金属材料]