| 摘要: |
| 针对金属陶瓷MoZrO2抗液态铁腐蚀问题，采用CO2激光器对金属陶瓷MoZrO2进行表面重熔。采用X射线衍射仪和扫描电子显微镜分析重熔后金属陶瓷表面的相组成和形貌，用光学显微镜和SEM分析测试了重熔层厚度和孔隙率。结果表明：在激光快速加热和冷却作用下，MoZrO2表面大部分金属钼以MoO3的形式挥发，氧化锆经熔化、凝固，在表面形成以柱状晶为主的氧化锆重熔层；重熔层的厚度随着激光能量密度增大而增大，最大可达430.2 μm；随着激光能量密度增加，重熔层孔隙率出现先增加后降低的变化，最低达到4.29%；重熔层与基体的结合强度，随着激光能量密度的增加而递减；当激光能量密度为4 J/mm2，最大结合强度为17.33 MPa。在1 650 ℃高温条件下，进行6 h熔融金属腐蚀试验，激光重熔使金属陶瓷降低了Mo和Zr元素向熔池扩散速率，显著提高金属陶瓷MoZrO2抗液态铁腐蚀性能。 |
| 关键词: 金属陶瓷 激光重熔 结合强度 柱状晶 |
| DOI：10.11933/j.issn.1007-9289.2015.05.014 |
| 分类号: |
| 基金项目: |
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| Effects of Laser Remelting on Microstructure and Properties of Mo-ZrO2 Cermet |
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LIU Huan, LUO Liping, WANG Dingding, ZHANG Yanjun, XIA Qing
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Institute of Laser Technology, Research Institute of Physical and Chemical Engineering of Nuclear Industry
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| Abstract: |
| To solve the corrosion problem between MoZrO2 cermet and molten Fe, the surface of cermet MoZrO2 was remelted by CO2 laser. The microstructure and composition of the remelted layer were studied by Xray diffraction(XRD) and scanning electron microscope (SEM). The thickness, porosity of the remelted layer were studied by optical microscope (OM) and SEM. Result show that the surface of MoZrO2 cermet is heated and cooled rapidly, and the mental Mo is almost translated into MoO3 and gasified rapidly. The cermet ZrO2 is melted and frozen again. The ZrO2 melted layer consisiting of columnar grain is formed on the surface of cermet MoZrO2. As the laser power density increases, the thickness of the remelted layer also increases, the bonding strength of remelted layer decreases however the porosity of remelted layer first increased and than decreases. The largest thickness of the remelted layer was 430.2 μm, and the least porosity of remelted layer is 4.29%. When the laser power density is 4 J/mm2, the largest bonding strength is 17.33 MPa. The cermet MoZrO2 and remelted MoZrO2 are corrupted by molten metal at 1650 ℃ for 6 h. The speed of metal Mo and ZrO2 power diffusing from cermet to molten metal is depressed significantly using CO2 laser remelting, Which effectively improve the property of corrosion of MoZrO2 cermet. |
| Key words: cermet laser remelting bonding strength columnar grain |
