Al-Zr(CO_3)_2体系反应合成复合材料的反应机制及动力学模型  

Reaction mechanism and kinetic model of in-situ synthesized composites in system Al-Zr(CO_3)_2

作　　者：赵玉涛[1] 孙建祥[1] 戴起勋[1] 程晓农[1] 林东洋 

机构地区：[1]江苏大学材料科学与工程学院,镇江212013

出　　处：《中国有色金属学报》2005年第9期1343-1349,共7页The Chinese Journal of Nonferrous Metals

基　　金：国家自然科学基金资助项目(50471050);教育部科学技术重点基金资助项目(00170);江苏省科技攻关资助项目(BE2002039);江苏高校高新技术产业化发展资助项目(JH-039);江苏省铝基复合材料工程技术研究中心研发资助项目(BM2003014)

摘　　要：开发了Al-Zr(CO3)2体系熔体反应法合成新型(Al3Zr+Al2O3)p/Al复合材料,研究了Al-Zr(CO3)2体系的反应热力学、反应动力学及反应机制.结果表明:Al-Zr(CO3)2体系起始反应温度为850℃,且在铝熔体(850～1100℃)温度范围内反应能自发进行.X射线衍射(XRD)及扫描电镜(SEM)分析表明:反应合成的强化相为Al3Zr和α-Al2O3颗粒,其尺寸为0.1～1 μm,且在基体中弥散分布.反应过程中复合熔体水淬实验分析表明:反应析出的Zr量随反应时间延长而增大,当反应进行10 min就达到了总增量的90%,整个合成反应时间为15 min,且合成过程前期(反应3 min前)主要受化学反应控制,合成过程后期(反应10 min后)主要受扩散控制.Al-Zr(CO3)2体系中关键反应ZrO2与Al按反应-扩散-破裂机制进行,并建立了反应原理图、反应动力学模型和反应时间的动力学方程.Novel in-situ （Al3Zr＋ Al2O3 ）p/Al composites was developed by direct melt reaction in the system AlZr（CO3）2. The reactive thermodynamics, kinetics, and mechanism of in-situ Al-Zr（CO3 ）2 system were investigated. The results indicate that the initial reactive temperature of Al-Zr（CO3 ）2 system is 850 ℃. The reaction between Zr（CO3）2 powder and aluminum melt can proceed spontaneously at the range of 850 - 1 100 ℃. X-ray diffraction （XRD） and scanning electron microscope （SEM） analyses indicate that the in-situ formed reinforcements are Al3 Zr and α-Al2O3 particles. The size of these particles is in the range of 0. 1 - 1 μm. These particles are well distributed in the matrix. Analysis of water-quenched samples during reactive process shows that zirconium content in aluminum melt increases rapidly with the increasing reactive time and increases by 90% for 10 min. The whole time of in-situ synthesis is 15 min. In-situ synthesis process in Al-Zr（CO3 ）2 system is controlled mainly by chemical reaction at earlier stage （before 3 min）, whereas it is controlled mainly by the particulate diffusion at later stage （after 10 rain）. The mechanism of key reaction between ZrO2 and Al in the system Al-Zr（CO3 ）2 is the reaction-diffusion-crack. Furthermore, the reactive kinetic model, the reactive principle sketch and, the reactive time formula in the system Al-Zr-O were established.

关 键 词：Al-Zr(CO3)2体系 反应机制 动力学模型 熔体反应法 原位复合材料 

分 类 号：TB331[一般工业技术—材料科学与工程]