电磁搅拌法合成(Al_2O_3+Al_3Zr)p/A356复合材料的凝固组织  

Solidification Microstructure of (Al_2O_3+Al_3Zr)p/A356 Composites Synthesized by Electromagnetic Stirring

作　　者：李桂荣[1] 戴起勋[1] 赵玉涛[1] 王宏明[1] 

机构地区：[1]江苏大学

出　　处：《特种铸造及有色合金》2005年第8期502-504,共3页Special Casting & Nonferrous Alloys

基　　金：国家自然科学基金资助项目(50471050);江苏省高校自然科学基金资助项目(04BJK430022)

摘　　要：在电磁搅拌作用下用A356-Zr(CO3)2组元通过熔体反应法原位合成了Al2O3、Al3Zr颗粒增强铝基复合材料,扫描电镜观察试样凝固组织发现:复合材料中内生增强颗粒粒度为1～3μm,并随着搅拌强度的增加,增强颗粒在基体中的体积分数和弥散度显著提高,原因是电磁搅拌促进了传热和传质扩散,改善了原位合成动力学条件;同时Si相形貌由片状初晶硅向针状、细棒状共晶Si转变,随搅拌强度的增加硅相变质,这是电磁搅拌和内生颗粒共同作用的结果.(Al_2O_3+Al_3Zr)p/A356 composites were synthesized by melt-reaction in A356-Zr(CO_3) system with electromagnetic stirring.Observation of solidified microstructure by SEM show that the volume fraction and dispersity of reinforced particulate with the size of 1～3 μm in matrix can be improved with the stirring intensity increasing due to the electromagnetic stirring promoting heat transfer and solute diffusion to improve in-situ synthesized kinetics.Meanwhile,co-action of electromagnetic stirring and in-situ particulate results in the transformation of Si phase from sheet primary Si to needle-like or fine-rod eutectic Si.

关 键 词：颗粒增强铝基复合材料 电磁搅拌法 原位合成 凝固组织 扫描电镜观察 搅拌强度 内生颗粒 Al2O3 熔体反应法 

分 类 号：TB331[一般工业技术—材料科学与工程]