摘要:
选取TC4合金进行热浸镀铝及高温退火处理, 采用SEM、XRD、EDS等微观分析手段表征了镀层形貌、物相和成分, 采用销-盘式高速磨损机研究了TC4合金镀层和基体在不同速度和载荷下的干滑动磨损行为, 并探讨其磨损机制。结果表明:扩散层以TiAl3为主相, 与基体结合良好, 表面平整均匀。在同一载荷下, 速度0.54 m/s时, TC4合金镀层的磨损率都要低于基体, 耐磨性好。镀层和基体的磨损率均呈现出较为相似的变化趋势。0.50.75m/s时, 磨损率先降低, 之后磨损率迅速上升, 2.68 m/s时达到顶值, 2.684 m/s时磨损率再次降低。0.75 m/s时主要为粘着磨损、磨粒磨损;2.68 m/s时为剥层磨损;4 m/s时以氧化轻微磨损为主。
Abstract:
The aluminized TC4 alloy was prepared by hot-dip aluminizing and subsequently high-temperature annealing treatment. The morphology,phase and compositions of aluminized coating were characterized with SEM,XRD and EDS.Dry sliding wear behaviors at different velocities and loadings were conducted for the aluminized and uncoated TC4 alloy on a pin-on-disc wear tester,and the wear mechanism was also explored.The results show that the coating is mainly composed of TiAl3 combined well to the substrate with a smooth surface. Compared with uncoated TC4 alloy,the aluminized coating has a more excellent wear resistance at sliding velocities of 0.5 ~4 m/s under the same loads.The aluminized and uncoated TC4 alloy present a similar variation of wear rate as a function of velocity.At 0.5 ~0.75 m/s,the wear rate first decrease and then increase rapidly,reaching the top value at 2.68 m/s.Furthermore,the wear rate decreases again from 2.68 to 4 m/s.The main wear mechanism at 0.75 m/s is adhesive wear and abrasive wear,while it is delamination wear at 2.68 m/s and slightly oxidative wear at 4 m/s.
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