TC18合金表面防腐耐磨涂层制备与性能研究
发布时间：2019-02-21 18:46
【摘要】：TC18合金具有密度低、比强度高等优点,已经用于飞机起落架制造,但是面临腐蚀和磨损问题。本文设计两种防腐耐磨涂层,包括Al2O3涂层和WC-Co涂层,提高TC18合金的防腐耐磨性能。首先需要对基体进行合适的表面预处理,然后通过正交试验法优化涂层成分,同时采用DSC、IR优化涂层固化工艺,制备防腐耐磨性能兼备的涂层。表征涂层一些物理机械性能,包括硬度、附着力、耐冲击、剪切应力等,涂层的耐磨性能及其耐腐蚀性能。研究结果表明:经过除油、酸洗及化学氧化预处理,涂层金属体系的附着力得到提升,且表面氧化薄膜提高基体的耐蚀性能。正交试验法优化Al2O3涂层的成分(质量百分比)是:800目Al2O3粉:1500目Al2O3粉:偶联剂=24%:22%:2%,余下为环氧树脂和固化剂(比例为1:1.05);WC-Co涂层的各成分(质量百分比)是:WC-Co粉:800目Al2O3粉:偶联剂=29%:6%:2%,余下为环氧树脂和固化剂(比例为1:1.05)。在固化工艺参数为100℃下保温2h条件下,得到涂层颜色均匀、表面完整,硬度、附着力、耐冲击韧性满足使用要求。对TC18合金基体和涂层的耐蚀性能进行研究,电化学测试结果表明,涂层的自腐蚀电位高于基体,自腐蚀电流小于基体,Al2O3涂层对基体的保护效率达到98.8%,高于WC-Co涂层的98.3%,涂层可以起到很好的保护效果。随着浸泡时间延长,涂层的容抗弧幅值不断减小,在25天之后,减小幅度开始降低。对涂层分别进行750h中性盐雾试验和耐湿热试验,结束后涂层表面仍然保持完整,没有起皮、剥离等现象,而基体盐雾试验后表面出现腐蚀坑,涂层湿热试验出现局部缺胶现象。在室温干摩擦磨损条件下,与基体相比,涂层的摩擦系数都比较平稳,磨损量和磨损率小于基体,磨痕的宽度和深度也小于基体,表明涂层可以提供很好的耐磨防护。对于Al2O3涂层和WC-Co涂层的摩擦性能进行比较,Al2O3涂层优于WC-Co涂层。综合耐腐蚀和耐磨损性能,Al2O3涂层的防护效果优于WC-Co涂层。
[Abstract]:TC18 alloy has been used in aircraft landing gear manufacturing because of its low density and high specific strength, but it is faced with corrosion and wear problems. In this paper, two kinds of anticorrosive and wear resistant coatings, including Al2O3 coating and WC-Co coating, are designed to improve the anticorrosion and wear resistance of TC18 alloy. At first, it is necessary to pretreat the substrate properly, then optimize the coating composition by orthogonal test method, and adopt DSC,IR to optimize the coating curing process to prepare the coating with both anticorrosive and wear-resistant properties. Some physical and mechanical properties, including hardness, adhesion, impact resistance, shear stress, wear resistance and corrosion resistance of the coating were characterized. The results showed that the adhesion of the coated metal system was improved after deoiling, acid cleaning and chemical oxidation pretreatment, and the corrosion resistance of the substrate was improved by the surface oxidation film. The composition (mass percentage) of Al2O3 coating was optimized by orthogonal test as follows: 800-mesh Al2O3 powder: 1500 mesh Al2O3 powder: coupling agent = 24: 22: 2, the rest was epoxy resin and curing agent (1: 1.05); The composition (mass percentage) of WC-Co coating is as follows: WC-Co powder: 800 mesh Al2O3 powder: coupling agent = 29. 6: 2. The rest is epoxy resin and curing agent (1: 1.05). When the curing process parameters are 100 鈩，
本文编号：2427790
[Abstract]:TC18 alloy has been used in aircraft landing gear manufacturing because of its low density and high specific strength, but it is faced with corrosion and wear problems. In this paper, two kinds of anticorrosive and wear resistant coatings, including Al2O3 coating and WC-Co coating, are designed to improve the anticorrosion and wear resistance of TC18 alloy. At first, it is necessary to pretreat the substrate properly, then optimize the coating composition by orthogonal test method, and adopt DSC,IR to optimize the coating curing process to prepare the coating with both anticorrosive and wear-resistant properties. Some physical and mechanical properties, including hardness, adhesion, impact resistance, shear stress, wear resistance and corrosion resistance of the coating were characterized. The results showed that the adhesion of the coated metal system was improved after deoiling, acid cleaning and chemical oxidation pretreatment, and the corrosion resistance of the substrate was improved by the surface oxidation film. The composition (mass percentage) of Al2O3 coating was optimized by orthogonal test as follows: 800-mesh Al2O3 powder: 1500 mesh Al2O3 powder: coupling agent = 24: 22: 2, the rest was epoxy resin and curing agent (1: 1.05); The composition (mass percentage) of WC-Co coating is as follows: WC-Co powder: 800 mesh Al2O3 powder: coupling agent = 29. 6: 2. The rest is epoxy resin and curing agent (1: 1.05). When the curing process parameters are 100 鈩，
本文编号：2427790
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