搅拌摩擦挤压法制备纯镁线的耐磨耐蚀性能评价

摘要

A solid-state process—friction stir extrusion (FSE) was applied to produce wires from Mg chips. The FSE process was performed using tool rotational speed of 150, 250 and 355 r/min at a constant plunge rate of 20 mm/min. The microstructural evolution, tribological behavior and corrosion resistance of the reference specimen and the friction stir extruded specimens were investigated. Microstructural characteristics of the specimens were investigated by optical microscopy (OM) and scanning electron microscopy (SEM). The evaluations of mechanical properties include microhardness and dry sliding wear test. The corrosion resistance of the extruded specimens was characterized by potentiodynamic polarization test. The results show that the extruded specimens possess good surface quality and the process is beneficial for the improvement of hardness and wear resistance of the first machined chips. The produced wires are also found to have adequate corrosion resistance. These results demonstrate that FSE is an effective strategy for converting the machined Mg chips into the usable wires.%采用搅拌摩擦挤压法来将镁屑制成镁线。在搅拌摩擦挤压过程中，探头的旋转速率分别为150、250和355 r/min，切入速率固定为20 mm/min。研究对比试样和搅拌摩擦挤压试样的显微组织演化、摩擦磨损行为和耐腐蚀性能。通过光学显微镜和扫描电镜对样品的显微结构进行表征。力学性能的评价包括显微硬度和干滑动磨损测试。通过动电位极化测试对挤出试样的耐腐蚀性能进行表征。结果表明，挤出试样具有较好的表面质量，搅拌摩擦挤压过程有利于改善机械加工碎屑的硬度和耐磨性，同时，所得到的线条具有足够的耐腐蚀性。这些结果表明搅拌摩擦挤压法是一种将机械加工产生的镁屑转变成有用的镁线的有效方法。