CaO insulator coatings and self-healing of defects on VCrTi alloys in liquid lithium system
CaO insulator coatings and self-healing of defects on VCrTi alloys in liquid lithium system
复制标题
液态锂体系中VCrTi合金CaO绝缘体涂层及缺陷自修复
DOI：
10.1016/s0022-3115(96)00234-6
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发表时间：
1996
影响因子：
3.1
通讯作者：
T. Kassner
中科院分区：
文献类型：
--
作者：
J. Park;T. Kassner
在熔融第一壁/熔覆层应用中，液态金属/结构界面需要电绝缘和耐腐蚀涂层。在温度为250 ~ 600℃时，测量了在含有0.5 ~ 85 wt%溶解Ca的液态Li中，在V5%Cr5%Ti上生成的CaO涂层的电阻与时间的关系。液态Li中的溶质元素Ca与合金基体在400-420℃下反应生成CaO涂层。在400℃时，原位测得涂层在液态锂中的电阻为≈106Ω。300 ~ 700℃之间的热循环改变了涂层的电阻，这与绝缘体的行为一致。这些结果表明，通过控制曝光时间、温度和液态金属的成分，可以在各种形状的表面上产生薄而均匀的涂层。该技术可以应用于各种形状（例如，管内/管外，复杂的几何形状），因为涂层是通过液相反应形成的。冷却至室温后对试样进行检查，发现没有剥落，但在CaO涂层中存在均匀的裂纹。对裂纹原位自愈行为的进一步研究表明，在≥360°C时，裂纹发生快速自愈。
Electrically insulating and corrosion-resistant coatings are required at the liquid metal/structural interface in fusion first-wall/blanket applications. The electrical resistance of CaO coatings produced on V5%Cr5%Ti by exposure of the alloy to liquid Li that contained 0.5–85 wt% dissolved Ca was measured as a function of time at temperatures between 250 and 600°C. The solute element, Ca in liquid Li, reacted with the alloy substrate at 400–420°C to produce a CaO coating. Resistance of the coating layer measured in-situ in liquid Li was ≈ 106Ω at 400°C. Thermal cycling between 300 and 700°C changed the coating layer resistance, which followed insulator behavior. These results suggest that thin homogeneous coatings can be produced on variously shaped surfaces by controlling the exposure time, temperature, and composition of the liquid metal. The technique can be applied to various shapes (e.g., inside/outside of tubes, complex geometrical shapes) because the coating is formed by liquid-phase reaction. Examination of the specimens after cooling to room temperature revealed no spallation, but homogeneous crazing cracks were present in the CaO coating. Additional tests to investigate the in-situ self-healing behavior of the cracks indicated that rapid healing occurred at ≥ 360°C.