电解液体系对ZrH_(1.8)表面微弧氧化陶瓷层的影响

Characteristics of Coating on Surface of ZrH_(1. 8) Prepared by MAO in Different Electrolyte Systems

采用恒压模式分别在Na2SiO3,Na5P3O10和Na5P3O10＋H2O2电解液体系下对ZrH1.8表面进行微弧氧化（MAO）,利用扫描电子显微镜（SEM）、X射线衍射仪（XRD）、膜层测厚仪测试了陶瓷层的表面形貌、截面形貌、相结构及陶瓷层厚度,通过真空脱氢实验评估了陶瓷层的阻氢性能。研究结果表明：采用微弧氧化技术在氢化锆表面可以制得厚度范围在35～60μm的微弧氧化陶瓷层。不同的电解液体系下在氢化锆表面得到的微弧氧化陶瓷层的厚度不同,Na2SiO3电解液体系下得到的陶瓷层最厚,Na5P3O10＋H2O2电解液体系次之,Na5P3O10电解液体系最薄。氢化锆表面微弧氧化陶瓷层由致密层和疏松层构成,靠近基体一侧为致密层,陶瓷层外层为疏松层。微弧氧化陶瓷层主要由单斜相氧化锆（M-ZrO2）和少量的四方相氧化锆（T-ZrO2）构成;综合比较,在Na5P3O10＋H2O2电解液体系下可以获得厚度适中,表面平整,致密性较好,阻氢性能优异的陶瓷层,陶瓷层的PRF值达到最大值12.1。

Microarc oxidation （MAO） process was conducted on zirconium hydride in Na2SiO3, Na5P3O10 and Na5P3O10＋ H2O2 electrolytes under the constant voltage mode, respectively. Surface and cross-sectional morphologies, phase structures and thicknesses of the oxide layers were characterized by scanning election microscopy（SEM） , X-ray diffraction（XRD） and film thickness gauges, respectively. The hydrogen resistance performance of the oxide layers was evaluated by vacuum dehydrogenation. The results indicated that the thicknesses of the oxide layers on the surface of zirconium hydride changed from 35 to 60 μm in different electrolyte systems. The thickness of the oxide layer in the three electrolyte systems was in the following order： Na2SiO3 , Na5P3O10＋ H2O2 and Na5P3O10. The oxide layer was composed of outer loose layer and inner compact layer. The electrolyte had no obvious influence on the phase structures of the oxide layers, which were mainly composed of M-ZrO2 and T-ZrO2. The oxide layer in Na5P3O10＋ H202 electrolyte system was compact, uniform, and the thickness was moderate, which performed an excellent hydrogen permeation resistance. The PRF value of the oxide layer reached up to the maximum value of 12.1 when zirconium hydride was oxidized in Na5P3O10＋ H2O2 electrolyte system.