【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.更多还原

【Abstract】 With electromagnetic stirring method, the composites of in-situ Al₂O₃, Al₃Zr and ZrB₂ parti-cles reinforced aluminum matrix were synthesized by Al-Zr（CO₃）₂-KBF₄components 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 （2～3） μm. Deformations as shrinkage hole were dramatically decreased, which led to a high cleanness of aluminum （matrix）.更多还原