钛合金超硬超厚微弧氧化膜层的制备技术毕业论文
2022-03-22 20:38:28
论文总字数:18982字
摘 要
本论文主要采用电源模式为双极脉冲电源的微弧氧化设备对TC4(Ti-6Al-4V)进行微弧氧化(MAO)研究,通过控制不同微弧氧化时间来制备微弧氧化膜层。采用漆膜磁性测厚仪研究微弧氧化时间与膜层厚度的关系;通过金相显微镜分析氧化膜的表面形貌;采用端面摩擦磨损试验机测试氧化膜的摩擦磨损性能;采用电化学工作站来研究膜层的耐蚀性能。研究表明:
1)膜层厚度和微弧氧化时间关系表明:微弧氧化时间增加的过程中,膜层逐渐增厚,前期膜层厚度的增长速率较快,后期增长趋于平缓;
2)氧化膜表面形貌分析表明:微弧氧化时间较短可以得到一层较为致密的氧化膜;随着时间的延长,氧化膜开始呈现疏松的形态结构;
3)摩擦磨损试验表明:微弧氧化处理后氧化膜的摩擦系数高于原始样的摩擦系数。氧化后的摩擦系数不断降低波动的幅度较大,而氧化前的摩擦波动幅度较小;通过计算后的磨损率可以看出,对TC4钛合金进行微弧氧化处理15min可以获得磨损率最低的表面氧化膜层;
4)电化学实验结果表明,经过微弧氧化处理后试样的耐蚀性能提高。由电流密度以及极化曲线分析可以看出TC4钛合金进行微弧氧化20分钟后的腐蚀电流密度最小,能获得耐蚀性能最佳的氧化膜。
关键词:TC4-0.55Fe 微弧氧化 微观结构 磨损性能 耐蚀性能。
Research on Surface Morphology and Properties of TC4 after MAO
Abstract
In this paper, the experiment used the bipolar pulse power to study the micro arc oxidation, and the experiments of TC4 were carried out by controlling the different oxidation time. The film magnetic measuring thickness gauge was used to study the relationship between the micro arc oxidation time and film thickness; oxide film surface morphology was analyzed by optical microscopy; the friction and wear properties of oxide film were tested by a friction and wear testing machine; the study also used the electrochemical workstation to test the corrosion resistance of the oxide film. Experimental investigation showed that:
1)The relationship between the thickness of the coating and the oxidation time showed that the film thickness increased with the increase of the oxidation time, the growth rate at the early stage was relatively fast, and the later growth was slower;
2)The surface morphology analysis showed that the relatively dense oxide film can be obtained at the short oxidation time. And the oxide film had a loose structure with the increase of time;
3)The friction coefficient of the oxide film was higher than that of the original sample. After oxidation, the friction coefficient continuously reduced with a big fluctuation, while the friction curve, before oxidation, behaved more stable. Wear rate data showed that, compared with the original sample, micro arc oxidation treatment can obtain equivalent wear-resisting performance of the TC4 oxide film;
4)Polarization curves and AC (alternating current) impedance tests showed that the corrosion resistance of the samples increased after the micro arc oxidation treatment. Current density showed that the best corrosion resistance of the oxide film was obtained in 20 minutes.
Key Words: TC4; MAO; oxidation time; wear property; corrosion resistance
目 录
摘 要 I
Abstract II
第一章 绪论 1
1.1 研究背景 1
1.2 微弧氧化技术(MAO)的产生与发展 2
1.3 微弧氧化技术(MAO)的影响因素 2
1.3.1 基体材料 2
1.3.2 电解液成分与浓度 3
1.3.3 温度 3
1.3.4 电源模式 3
1.3.5 电源电学参数 4
1.4 微弧氧化技术(MAO)的应用 5
1.5 研究本课题的目的和意义 6
第二章 实验部分 7
2.1 实验原料与试剂 7
2.1.1 实验原料 7
2.1.2 实验中使用的化学试剂 7
2.2 实验仪器设备及原理 7
2.3 实验步骤 9
2.4 实验流程图 10
2.5 微弧氧化膜层的检测 10
2.5.1 膜厚 10
2.5.2 耐磨性 10
2.5.3 显微分析 11
2.5.4 电化学实验 11
第三章 实验结果与讨论 13
3.1 微弧氧化TC4表面形貌与断面形貌分析 13
3.2 TC4微弧氧化膜层厚度与氧化时间的关系 15
3.3 TC4微弧氧化耐磨性与氧化时间的关系 15
3.4 TC4微弧氧化后的极化曲线分析 18
第四章 结论与展望 19
4.1 实验结论 19
4.2 展望 19
参考文献 21
致谢 23
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