SrAl2O4基应力发光监测预警涂层的研究进展

采用应力发光材料在目标结构表面构筑功能涂层可对结构损伤进行实时监测预警,不仅提高了设施的安全性,还为检修工作和损伤机理的研究提供了帮助,应用潜力巨大。为促进这类涂层的研发与应用,首先介绍了弹性应力发光材料的发展历程及基本特征,通过对比突出了SrAl₂O₄基材料的综合优势。然后详细分析了SrAl₂O₄基质的晶体结构、缺陷类型对能级分布、电子运动状态以及光的吸收与发射性能的影响,并论述了元素掺杂对发光强度、波段和灵敏度等发光性能的影响。接着介绍了应力发光常用的检测表征方法和基于现象分析形成的应力发光机理。在此基础上,进一步总结归纳了制备应力发光粉末的主要方法以及影响其物相结构、晶体尺寸和发光性能的核心因素,分析了各自的优缺点。详细介绍了制备监测预警涂层的表面技术和工程应用案例,发现该类涂层仍存在敏感度不高、后处理工艺苛刻和界面结合差等问题。最后,从探究应力发光本质、制备实用性更强的预警涂层和制定生产测试标准3个角度提出了一些建议。     

Effect of phenoxy-based coating resin for reinforcing pitch carbon fibers on the interlaminar shear strength of PA6 composites

Carbon fiber-reinforced thermoplastic composites have not been considered as constituent materials for structural parts due to the poor interfacial adhesion between the fiber and the thermoplastic matrix. In this work, polyamide 6 (PA6) composites with pitch carbon fibers (pCF) were fabricated by alternatively stacking PA6 films and pCF fabrics followed by being pressed. In order to improve the interfacial adhesion, phenoxy resin-based materials were coated on the surface of the fiber. The surface analyses of the fiber were carried out by XPS, TGA and dynamic contact angle method. Interlaminar shear strength (ILSS) of the composites was measured to evaluate the effect of the coating materials. The results showed that the composites with the coated pCF had higher ILSS than that with neat pCF by more than 20%. This indicated that a proper coating material can improve mechanical properties of the PA6 composites, which can be applied to the structural parts.     

抗气蚀聚氨酯涂层的研究进展

随着水轮机和螺旋桨等过流件的尺寸和转速不断提高,气蚀损坏问题更加突出,因此易施工涂覆且便于设计调控的聚氨酯涂层始终是耐气蚀领域的研究热点。系统回顾了聚氨酯材料在气蚀防护领域的研究发展历程,深刻指出了这类材料作为耐气蚀涂层使用时存在的突出问题,例如耐水性、附着力、机械性能、耐磨性能和防污能力等较差,系统分析了这些因素导致涂层损坏失效的机理。针对上述问题,重点根据聚氨酯独特的分子结构,分别从表面能、电负性、化学键合、接枝改性、添加功能填料等方面,提出了改善聚氨酯涂层在复杂工况下应用性的解决办法。最后,鉴于我国对能够在海洋等苛刻环境中长期稳定服役的高性能气蚀防护涂层的急迫需求,对发展以自愈合聚氨酯为代表的集防污抗气蚀耐磨损自修复等功能于一体的新型聚氨酯材料进行了展望。