【作者】 王宏明； 李桂荣； 赵玉涛； 程晓农； 陈刚；

【Author】 WANG Hong-ming, LI Gui-rong,ZHAO Yu-tao, CHENG Xiao-nong, CHEN gang (School of Materials Science and Engineering,Jiangsu University,Zhenjiang 212013,China )

【机构】 江苏大学材料科学与工程学院；

【摘要】 以Al-Ce2(CO3)3作为反应组元,采用熔体直接反应法原位合成了亚微米Al2O3颗粒增强铝基复合材料,着重研究了复合材料的微结构和功能特征。通过扫描电镜(SEM)、能谱仪(EDS)和透射电镜(TEM)对合成的复合材料进行了组织表征。在800～900℃范围内组元间的反应可自发进行,与熔体初始温度关系不大,铸态组织中Al2O3颗粒尺寸在200～300nm,属于亚微米级,颗粒在基体中弥散均匀分布。且能够作为凝固时基体的异质形核核心,起到细化基体晶粒作用。无颗粒的7055合金的晶粒尺寸60μm,Al2O3/7055复合材料的晶粒尺寸35μm,尺寸下降了42%。透射电镜观察显示颗粒/基体近界面清洁,无界面反应产物,颗粒周围存在高密度位错。用Turner模型预测复合材料的线膨胀系数,质量分数3%、5%的复合材料较纯铝膨胀系数分别下降6.25%、10%。分析结果表明,亚微米Al2O3颗粒铝基复合材料在具备良好结构性能的基础上,具有低膨胀、高耐热的功能性。更多还原

【Abstract】 Al-Ce2（CO3）3 component was selected to in situ synthesize Al₂O₃ particle reinforced aluminum matrix composites. The microstructure were studied using SEM, EDS and TEM.Furthermore the functional properties of composites were discussed. The reaction between molten aluminum and cerium carbonate can proceed spontaneously in the temperature range of 800-900℃.The size of Al₂O₃ phase is 200-300nm,which is a submicron particle. The particles are well distributed in the matrix. They tend to be the foreign nucleation cores and fine the grain size of matrix during solidification. TEM observation shows that the particle/matrix interface is clean.There are high density dislocation around the particles. Liner expansion coefficients are calculated with Turner model, which are decrease by 6.25% and 10% compared to aluminum matrix when the weight fractions of particles in matrix are 3% and 5%. As a result submicron Al₂O₃ particles reinforced aluminum matrix exhibits not only excellent structural property but also well functional character of low expansion.更多还原