郭昱,张英乔,张涛,刘盛耀.AZ91D镁合金表面激光熔覆Al/Zr+B4C/Y2O3复合涂层组织与性能研究[J].表面技术,2018,47(1):176-180.
GUO Yu,ZHANG Ying-qiao,ZHANG Tao,LIU Sheng-yao.Microstructures and Properties of Laser Cladding Al/Zr+B4C/Y2O3 Composite Coatings on AZ91D Magnesium Alloys[J].Surface Technology,2018,47(1):176-180 |
| AZ91D镁合金表面激光熔覆Al/Zr+B4C/Y2O3复合涂层组织与性能研究 |
| Microstructures and Properties of Laser Cladding Al/Zr+B4C/Y2O3 Composite Coatings on AZ91D Magnesium Alloys |
| 投稿时间：2017-07-19 修订日期：2018-01-20 |
| DOI：10.16490/j.cnki.issn.1001-3660.2018.01.027 |
| 中文关键词: 激光熔覆 镁合金 ZrC Y2O3 显微硬度 耐腐蚀性 |
| 英文关键词:laser cladding magnesium alloy ZrC Y2O3 microhardness corrosion resistance |
| 基金项目:山西省重点研发计划（201603D121002-1） |
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| Author | Institution |
| GUO Yu | School of Materials Science and Engineering, North University of China, Taiyuan 030051, China |
| ZHANG Ying-qiao | School of Materials Science and Engineering, North University of China, Taiyuan 030051, China |
| ZHANG Tao | School of Materials Science and Engineering, North University of China, Taiyuan 030051, China |
| LIU Sheng-yao | School of Materials Science and Engineering, North University of China, Taiyuan 030051, China |
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| 中文摘要: |
| 目的 提高AZ91D镁合金表面硬度，改善其耐腐蚀性。方法 在AZ91D镁合金上涂覆Zr/B4C/Y2O3混合粉末，之后使用Nd: YAG固体激光器进行激光熔覆。采用光学显微镜（OM）、扫描电镜（SEM）、X射线衍射仪（XRD）对涂层的形貌和物相组成进行分析。利用显微硬度计以及电化学工作站对涂层的硬度和耐腐蚀性进行测定。结果 涂层主要包含ZrC、Al3Zr和Al12Mg17等金属间化合物以及Al3Y等稀土化合物。添加0.8%Y2O3的涂层中有部分微小气孔，而添加1.6%Y2O3的涂层中气孔消失。析出相主要以颗粒状和棒状的形式存在，并且为了减小表面积，使得表面能降低，部分析出相聚集在一起长大。涂层硬度整体呈梯度分布，涂层外层的硬度最高（添加0.8%Y2O3的涂层为306.10HV，添加1.6%Y2O3的涂层为310.15HV）。添加0.8%Y2O3和1.6%Y2O3的涂层的平均硬度分别为291.613HV和294.495HV，相较于基体提高了4倍。添加0.8%Y2O3和1.6%Y2O3的涂层的自腐蚀电位分别为−1.269 V和−1.215 V，自腐蚀电流密度分别为7.655×10−5 A/cm2和 2.048×10−6 A/cm2，相对于基体耐腐蚀性有了显著的提高。结论 涂层中各种陶瓷相、金属间化合物和稀土化合物的存在使复合涂层的硬度、耐腐蚀性能均有了明显的提高。 |
| 英文摘要: |
| The work aims to improve hardness and corrosion resistance of the surface of magnesium alloys. AZ91D magnesium alloy was coated with Zr/B4C/Y2O3 mixed powder, and then laser cladding was applied to substrate surface with Nd:YAG solid laser. Morphology and phase composition of the coatings were analyzed with optical microscope (OM), scanning electron microscope (SEM) and X-ray diffractometer (XRD). Hardness and corrosion resistance of the coatings were measured with microhardness tester and electrochemical workstation. The coatings mainly contained ZrC, intermetallic compounds such as Al3Zr and Al12Mg17, and rare earth compounds including Al3Y. Though there were some tiny pores in the coating with 0.8%Y2O3, pores disappeared in the coating with 1.6%Y2O3. Precipitates were mainly in the form of particles and bars. For the purpose of reducing surface area and surface energy, some precipitates gathered together for development. Overall hardness distribution curve of the coatings was graded, the hardness of the top of coatings was the highest (coating with 0.8%Y2O3 is 306.10HV, coating with 1.6%Y2O3 is 310.15HV). Average hardness of the coatings with 0.8%Y2O3 and with 1.6%Y2O3 was 291.613HV and 294.495HV, respectively, which was 4 times higher than that of the substrate. Self-corrosion potential of the coatings with 0.8%Y2O3 and with 1.6%Y2O3 was −1.269 V and −1.215 V, respectively, and self-corrosion current density was 7.655×10−5 A/cm2 and 2.048×10−6 A/cm2, respectively. Corrosion resistance of the coatings was obviously improved compared with the substrate. The presence of various ceramic phases, intermetallic compounds and rare earth compounds in the coatings remarkably improves the hardness and corrosion resistance of the composite coatings. |
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