【摘 要】
：
研究以LM13铝硅合金为基体、陶瓷颗粒为增强相,采用搅拌铸造法制备的复合材料(AMCs)的干滑动磨损行为.分别采用两种不同的陶瓷颗粒增强相:合成的B4C和天然的钛铁矿陶瓷颗粒.光学显微镜结果显示,增强颗粒均匀分散在基体材料中,增强颗粒使共晶硅的晶粒尺寸细化,形貌变为球形.B4C增强复合材料(BRCs)的硬度提高最大,而钛铁矿增强复合材料(IRCs)由于界面化合物的形成导致基体?增强相界面结合较强,摩擦因数降低最大.与基体合金相比,复合材料的干滑动磨损性能显著提高.B4C颗粒的低密度和高硬度导致BRCs中颗
【机 构】
：
Mechanical Engineering Department, Thapar Institute of Engineering and Technology, Patiala 147004, P
论文部分内容阅读
研究以LM13铝硅合金为基体、陶瓷颗粒为增强相,采用搅拌铸造法制备的复合材料(AMCs)的干滑动磨损行为.分别采用两种不同的陶瓷颗粒增强相:合成的B4C和天然的钛铁矿陶瓷颗粒.光学显微镜结果显示,增强颗粒均匀分散在基体材料中,增强颗粒使共晶硅的晶粒尺寸细化,形貌变为球形.B4C增强复合材料(BRCs)的硬度提高最大,而钛铁矿增强复合材料(IRCs)由于界面化合物的形成导致基体?增强相界面结合较强,摩擦因数降低最大.与基体合金相比,复合材料的干滑动磨损性能显著提高.B4C颗粒的低密度和高硬度导致BRCs中颗粒周围高的位错密度.另一方面,钛铁矿颗粒的低热导率导致IRCs表面发生早期氧化并形成摩擦层.可见,尽管两种类型的增强相的作用机制存在很大不同,他们都能改善AMCs的耐磨性能.因此,低成本钛铁矿颗粒可替代高成本B4C颗粒,制备耐磨复合材料.“,”Dry sliding wear behaviour of stir-cast aluminium matrix composites (AMCs) containing LM13 alloy as matrix and ceramic particles as reinforcement was investigated. Two different ceramic particle reinforcements were used separately: synthetic ceramic particles (B4C), and natural ceramic particles (ilmenite). Optical micrographs showed uniform dispersion of reinforced particles in the matrix material. Reinforced particles refined the grain size of eutectic silicon and changed its morphology to globular type. B4C reinforced composites (BRCs) showed maximum improvement in hardness of AMCs. Ilmenite reinforced composites (IRCs) showed maximum reduction in coefficient of friction values due to strong matrix?reinforcement interfacial bonding caused by the formation of interfacial compounds. Dry sliding wear behaviour of composites was significantly improved as compared to base alloy. The low density and high hardness of B4C particles resulted in high dislocation density around filler particles in BRCs. On the other hand, the low thermal conductivity of ilmenite particles resulted in early oxidation and formation of a tribo-layer on surface of IRCs. So, both types of reinforcements led to the improvement in wear properties of AMCs, though the mechanisms involved were very different. Thus, the low-cost ilmenite particles can be used as alternative fillers to the high-cost B4C particles for processing of wear resistant composites.
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