| 引用本文: | 郝晨帆,孟君晟,李钦东,李成硕,李思捷.La2O3对氩弧熔覆制备Ti-BN-G复合涂层组织及性能的影响[J].中国表面工程,2024,37(5):314~324 |
| HAO Chenfan,MENG Junsheng,LI Qindong,LI Chengshuo,LI Sijie.Effect of La2O3 on Microstructure and Properties of Ti-BN-G Composite Coatings Prepared by Argon Arc Cladding[J].China Surface Engineering,2024,37(5):314~324 |
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| 摘要: |
| 在表面工程领域中，适量添加稀土 La2O3 可以使涂层组织细化硬度耐磨性提升，添加少量或过量的稀土 La2O3 均不能使复合涂层的性能达到最佳。为探究不同质量分数稀土 La2O3对复合涂层组织及性能的影响，利用氩弧熔覆技术在 TC4 表面制备 La2O3 / Ti-BN-G 复合涂层。以 Ti 粉、BN 粉、石墨烯粉和稀土 La2O3 为原料，将配比好的粉末置于玛瑙研体中充分研磨使其混合均匀，预涂敷在 TC4 合金表面，利用氩弧熔覆技术制备出不同 La2O3含量的 Ti-BN-G 涂层。采用 X 射线衍射仪、 扫描电子显微镜及能谱分析仪分析涂层的物相及显微组织，利用显微维氏硬度仪测试涂层的显微硬度；采用摩擦磨损试验机测试涂层的磨损率和摩擦因数分析涂层的耐磨性能。结果表明：涂层物相由颗粒状、枝晶状 Ti(C, N)、针棒状 TiB 和 α-Ti 相构成。随着 La2O3含量的增多，组织发生不同的变化。当 La2O3 质量分数为 4 wt.%时，复合涂层中组织细化效果最佳且分布均匀，通过面扫描分析可知，稀土 La 元素均匀分布在复合涂层中，抑制了组织的生长，从而使性能得到进一步优化，与基体相比复合涂层的显微硬度提高了 3.7 倍，耐磨性提高了 9.6 倍，磨损机制为磨粒磨损；当 La2O3质量分数为 5 wt.%时，复合涂层组织粗大、分布不均匀，硬度与耐磨性均降低。最后得出结论，当稀土 La2O3 质量分数为 4 wt.%时，复合涂层组织致密、细化效果最为显著，表现出较高的硬度和优异的耐磨性，进一步提高了 TC4 合金的力学性能。通过优化复合涂层中稀土 La2O3质量分数得到高性能涂层，研究成果可为解决零部件表面磨损失效问题提供试验依据和理论基础。 |
| 关键词: TC4 合金 La2O3 氩弧熔覆 显微硬度 耐磨性 |
| DOI：10.11933/j.issn.1007-9289.20231023001 |
| 分类号:TG174 |
| 基金项目:山东省自然科学基金（ZR2020KF024）；山东省大学生创新创业训练计划（S202311510154）；山东省大学生创新创业训练计划（S202311510210）；山东省大学生创新创业训练计划项目（S202311510274）；山东交通学院研究生科技创新项目（2023YK109）；浙江省水利水包装备表面工程技术研究重点实验室开放课题（20240302） |
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| Effect of La2O3 on Microstructure and Properties of Ti-BN-G Composite Coatings Prepared by Argon Arc Cladding |
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HAO Chenfan，MENG Junsheng，LI Qindong，LI Chengshuo，LI Sijie
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College of Naval Architecture and Port Engineering, Shandong Jiaotong University, Weihai 264200 , China
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| Abstract: |
| TC4 alloy (Ti-6Al-4V) is the titanium alloy with the most industrial applications. It is widely used in the biomedical, petrochemical, aerospace, and military industries because of its advantages, which include a low density, high specific strength (strength / density), good corrosion resistance, and good low-temperature performance. It is especially prominent in the field of offshore equipment. TC4 alloy is in great demand for ship structures, where it is mainly used for engine parts, pressure-resistant shells, propellers, seawater pipelines, and other key components. However, TC4 alloy is susceptible to oxidation and has poor wear resistance, low hardness, and other defects, which limit its further development in these application areas. With the continuous development of China's science and technology, the wear-and-tear failure of part surfaces is becoming increasingly prominent. Therefore, it is urgent to use surface engineering technology to repair failed parts or strengthen the surfaces of critical parts used under harsh service conditions. In the field of surface engineering, the moderate addition of the rare earth La2O3 can increase the hardness and wear resistance of a coating. The addition of too small or an excessive amount of the rare earth La2O3 can prevent the composite coating performance from reaching the optimal level. In order to investigate the effects of different mass percent contents of this rare earth (La2O3) on the compositions and performances of composite coatings, La2O3 / Ti-BN-G composite coatings were prepared on the surface of TC4 specimens using argon arc cladding technology. Ti powder, BN powder, graphene powder, and La2O3 were used as the raw materials. Measured quantities of these powders were placed in an onyx research body and fully milled to obtain a homogeneous mixture. It was then pre-coated on the surface of the TC4 alloy, and Ti-BN-G coatings with different La2O3 contents were prepared using argon arc melting and cladding technology. An X-ray diffractometer, scanning electron microscope, and energy spectrum analyzer were used to analyze the physical phases and microstructures of the coatings, and the microhardness of each coating was tested using a micro-Vickers hardness tester. A friction wear tester was used to test the wear rate and friction factor of each coating to analyze its wear resistance. The results showed that the coating phase consisted of granular and dendritic Ti(C, N), needle and rod TiB, and α-Ti phases. The organization changed with an increase in the La2O3 content. When the mass percentage content of La2O3 was 4 wt%, the composite coating had the best tissue refinement effect and most uniform distribution. A surface scan analysis showed that the rare earth La elements were uniformly distributed in the composite coating, which inhibited the growth of the tissues. Thus, the properties were further optimized, and the microhardness of the composite coating was increased by 3.7 times compared with that of the substrate, and the wear resistance was improved by 9.6 times. The wear mechanism was abrasive grain wear. When the mass percentage of La2O3 was 5 wt%, the composite coating was coarse and unevenly distributed, and the hardness and wear resistance were reduced. Finally, it was concluded that the most significant organizational densification and refinement effect was obtained for the composite coating when the mass percentage content of La2O3 was 4 wt%. This coating exhibited high hardness and excellent wear resistance, with further improvements in the mechanical properties of the TC4 alloy. By optimizing the mass percentage of this rare earth (La2O3) to obtain a high-performance coating, the research results provided an experimental basis and theoretical foundation for solving the problem of wear loss on the surfaces of parts. |
| Key words: TC4 alloy La2O3 argon arc cladding microhardness wear resistance |
