铝合金表面高耐磨自润滑硬质阳极氧化膜的制备

以硫酸、草酸、氨基磺酸为基础电解液,分别添加0,5,15和25mL/L的PTFE乳液,在2024铝合金表面制备了PTFE复合硬质Al2O3氧化膜.利用扫描电镜、硬度计和摩擦磨损试验机等手段,对制备氧化膜的组织结构与性能及其复合机理进行了研究.结果表明:随着PTFE添加量的增加,氧化膜的厚度由没有添加PTFE样品的42μm增加到了51μm;硬度呈现先增加后降低的趋势,硬度最高为417HV.当PTFE乳液的添加量为25mL/L时,磨损时的失重量为7mg,是没有添加PTFE颗粒样品的三分之一.磨损时复合在氧化膜中的PTFE与对摩擦件接触时可形成润滑膜层,在保持高硬度的同时降低了摩擦系数,提高了膜的耐磨和自润滑性能.

Preparation of High-Wearability and Self-lubricating Anode Oxide Film on Aluminum Alloy Surface

Using H2SO4, H2C2O4 and C7H6O6S · 2H2O as basic electrolyte with 0, 5, 15 and 25 mL/L PTFE emulsion taken as additives separately, the hard Al2O3-PTFE composite films were prepared on the surface of 2024 aluminum alloy. The structure, performance and formation mechanism of the composite films were studied by SEM, hardometer and tribo-wearometer. The result showed that the film sample thickness is 42 μm without PTFE added in, and it increases to 51 μm with PTFE added increasingly. The hardness tends to increase then decrease, and biggest hardness is 417 HV. When the concentration of added PTFE is 25 mL/L, the wear loss is 7 mg, i.e. about one third of that without PTFE added. The PTFE contained in the oxide film will form a lubricating layer when it is in contact with a frictional part, thus decreasing the friction coefficient to improve the wearability and self-lubricating performance of the anodizing film with its hardness kept up.