超声化学原位合成ZrB2 /A356复合材料的微观组织和力学性能
Microstructure and Mechanical Properties of ZrB2 /A356 Composite Synthesized by Ultrasonic Chemistry In-situ Reaction
刘 磊, 赵玉涛, 贾志宏, 陈 刚
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作者单位：(江苏大学 材料科学与工程学院, 江苏 镇江 212013)
中文关键字：超声化学； 原位反应； 铝基复合材料； 力学性能
英文关键字：ultrasonic chemical; in-situ reaction; aluminum matrix composite; mechanical properties
中文摘要：采用熔体反应法, 以A356-K2ZrF6-KBF4为反应体系，超声化学原位合成了ZrB2 /A356复合材料。利用X射线衍射与扫描电镜对该复合材料的微观组织和力学性能进行了研究。结果表明，生成的颗粒为ZrB2，颗粒细小，平均粒径尺寸小于1 μm，部分颗粒尺寸小于0.1 μm，且形状一致，并弥散分布于A356基体中。复合材料的抗拉强度和伸长率较未施加高能超声的复合材料分别提高了18.16%和12%。室温拉伸断口形貌呈现明显的韧窝断裂特征，为韧性断裂。高能超声能显著地促进A356-K2ZrF6 -KBF4体系的原位化学反应的进程，增加了内生颗粒的形核率，提高了颗粒体积分数，细化了晶粒，且反应过程平稳，内生颗粒弥散分布在基体中。
英文摘要：In-situ ZrB2 /A356 composite was synthesized by direct melt reaction method under high intensity ultrasonic field in A356-K2ZrF6-KBF4 system. The microstructure and properties of the composite were investigated by SEM and XRD. It is found that ZrB2 particulate phases with the same shape are produced, and these particles are in the size of 0.1～1 μm and well-distributed in A356 matrix. The tensile strength and the elongation rate increase by 18.16% and 12% than those without ultrasonic assistance, respectively. The morphology of the composite is dimple-crack characters, and the fracture mechanism is ductile fracture. The high-energy ultrasonic field can speed up in-situ chemical reactions in A356-K2ZrF6 -KBF4 systems, improve volume fraction, optimize the microstructure and refine the grains.