【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(850~1 100℃)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-αAl2O3颗粒,其尺寸为0.1~1μm,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。更多还原

【Abstract】 Novel in-situ（Al₃Zr+Al₂O₃）_p/Al composites was developed by direct melt reaction in the system Al-（Zr（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 8501100℃.X-ray diffraction（XRD） and scanning electron microscope（SEM） analyses indicate that the in-situ formed reinforcements are Al₃Zr and α-Al₂O₃ particles.The size of these particles is in the range of 0.11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min）.The mechanism of key reaction between ZrO₂ and Al in the system AlZr（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.更多还原