含微纳B_4C/Ti颗粒铜基复合材料的微观组织与力学性能（英文）

Microstructure Characteristics and Mechanical Properties of Cu Matrix Composites Containing Micro-B_4C/Nano-Ti Particulates

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B_4C/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,并测定了烧结态试样的致密度和力学性能。结果表明,(B_4C+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。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。

Micro-B4C/nano-Ti hybrid particulates reinforced copper matrix composites(CTBCs) were 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 relative density and mechanical properties of the as-SPSed samples were also tested. The results demonstrate that there are uniformly distributed(B4C+Ti) particles in the Cu matrix and a good interfacial bond between reinforcement and the Cu matrix. Besides, the interface bonding mechanism is metallurgical bonding and mechanical bonding. Mechanical properties(microhardness, tensile yield strength, ultimate tensile strength and elongation to fracture) of CTBCs are significantly improved in comparison to the pure copper, which is mainly due to the load transfer, grain refinement and thermal mismatch. Finally, the fracture surface of the tensile sample presents ductile fractures.