含微纳B4C/Ti颗粒铜基复合材料的微观组织与力学性能

Microstructure Characteristics and Mechanical Properties of Cu Matrix Composites Containing Micro-B4C/nano-Ti Particulates

摘要:

采用高能球磨(HEBM)和放电等离子烧结(SPS)工艺成功制备出微纳B₄C/Ti颗粒增强铜基复合材料(CTBCs),通过X射线衍射(XRD)、光学显微镜(OM)、扫描电子显微镜(SEM)以及能谱(EDS)等测试手段对其微观组织形貌进行表征。结果表明,(B₄C+Ti)颗粒在基体中均匀分布,增强体与铜基体界面结合良好,且其结合形式为冶金结合和机械结合并存。采用阿基米德排水法测定出烧结态试样的致密度。复合材料的显微硬度、拉伸屈服强度、抗拉强度和延伸率等力学性能相较于纯铜试样得到显著提高,这主要归因于载荷传递、细化晶粒与热错配等强化机制。复合材料的拉伸断口表现出明显的韧性断裂特征。

Abstract:

Micro-B₄C/nano-Ti hybrid particulates reinforced copper matrix composites (CTBCs) were successfully prepared by high energy ball milling (HEBM) and spark plasma sintering (SPS). The microstructures and morphologies were characterized by X-ray diffraction (XRD), optical microscopy (OM), and scanning electron microscopy (SEM) equipped with energy dispersive spectroscopy (EDS). The results demonstrate that presence of uniformly distributed (B₄C+Ti) particles and a good interfacial bond between reinforcement and the Cu matrix. Besides, the interface bondingSmechanism was metallurgical bonding and mechanical bonding. The relative density of the as-SPSed samples was tested by Archimedes drainage method. Mechanical properties (microhardness, tensile yield strength, ultimate tensile strength and elongation to fracture) of CTBCs were significantly improved in comparison to the pure copper, which was mainly due to the load transfer, grain refinement and thermal. Finally, the fracture surface of the tensile sample presented ductile fractures.