选区激光熔化B4C/Al复合材料的组织与性能

Microstructure and properties investigation of B4C/Al composite materialsfabricated by selective laser melting

  • 摘要: 为了解决B4C/Al复合材料制备过程中B4C颗粒分布不均、团聚及易与Al基体发生剧烈反应的问题。本文采用选区激光熔化法制备了B4C/Al复合材料,研究了激光功率和Ti元素对B4C/Al复合材料微观组织和力学性能的影响。结果表明:B4C/Al复合材料的致密度随激光功率的增大先增大后减少,激光功率240 W时致密度达到最大,为94.1%;制备过程中B4C颗粒易与Al基体发生界面反应并且随激光功率增大而增大,形成界面产物Al3BC和Al3B48C2脆性相和微裂纹,导致界面结合性能降低;加Ti的B4C/Al复合材料的致密度提高到95.2%,形成的界面产物TiC和TiB2能有效抑制界面反应,界面清晰完整,结合性能高,复合材料抗拉强度和伸长率分别提高41%、49.3%,拉伸断裂方式由脆性断裂转变为韧性断裂。

     

    Abstract: In order to solve the problems of uneven distribution of B4C particles, agglomeration and violent reaction with Al matrix during the preparation of B4C/Al composites. In this paper, B4C/Al composites were prepared by selective laser melting method. The effects of laser power and Ti elements on microstructure and mechanical properties of B4C/Al composites were studied. The results show that the density of B4C/Al composites increases first and then decreases with the increase of laser power, and reaches the maximum density of 94.1% at 240 W. During the preparation process, B4C particles are prone to interfacial reaction with Al matrix and increase with the increase of laser power, resulting in brittle phases and micro-cracks of Al3BC and Al3B48C2, resulting in decreased interfacial bonding properties. The density of B4C/Al composite with Ti increases to 95.2%, the resulting interface products TiC and TiB2 can effectively inhibit the interface reaction, and the interface is clear and complete with high bonding properties. The tensile strength and elongation of the composite are increased by 41% and 49.3%, respectively, and the tensile fracture mode changes from brittle fracture to ductile fracture.

     

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