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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1μm,部分颗粒尺寸小于0.1μm,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。
A356-K2ZrF6-KBF4 was used as the reaction system to synthesize ZrB2 / A356 composites in situ by means of melt reaction. The microstructure and mechanical properties of the composites were studied by X-ray diffraction and scanning electron microscopy. The results show that the particles are ZrB2, the particles are small, the average particle size is less than 1μm, the particle size is less than 0.1μm, and the shape is consistent and dispersed in the A356 matrix. The tensile strength and elongation of the composites were increased by 18.16% and 12% respectively compared with that of the composites without high energy ultrasound. Tensile fracture morphology at room temperature showed obvious dimple fracture characteristics, ductile fracture. High-energy ultrasound can significantly promote the in-situ chemical reaction process of A356-K2ZrF6-KBF4 system, increase the nucleation rate of endogenous particles, increase the volume fraction of particles, refine the grains, and the reaction process is stable. Endogenous particles Dispersed in the matrix.