基于激光诱导击穿光谱技术的复合材料定量在线检测方法研究

With rapid development of the materials science and engineering, more and more polymer composites had been used in transmission lines and equipment. With weak ability of weather resistance, the polymer composites would age under multiple aging factors, becoming weaker in their mechanical, electrical and chemical properties and even losing their insulation property. The aging process and mechanism of polymer composites had been studied by many researchers, but by far the available research methods were limited to normal material analysis methods such as hydrophobic angle testing, organic groups change and electrical properties decrease tests. These methods were time-consuming given the efforts to cut down and carry the samples back to lab because of the need for specific laboratory equipment. There was no online quantitative technique for testing the aging performance and characterize components of the materials. In this study, we presented a novel method based on the laser-induced breakdown spectroscopy (LIBS) to study silicone rubber composites, which were primarily used in the outdoor insulation. The theory model of the laser ablation with the silicone rubber materials would be built with the laser chemical ablation and laser thermal ablation models. The LIBS test devices would be improved to detect the samples at a long distance to get the test results of elements composition and surface properties. In the accelerated aging experiments with strong light, high temperature, and UV light etc., the silicone rubber composites would be studied layer-by-layer with LIBS, by which the aging depth and the aging rate would be measured. Accompany with the mechanical and electrical properties decrease, the 3D aging model would be set up and the online quantitative test method of silicone rubber materials would be provide finally. This will be of great help to maintain the security of electrical system.

大量高分子材料应用于电力输变电设备。高分子材料的耐候性较差，在多种老化因素作用下，容易发生老化性能下降，甚至丧失绝缘作用。目前复合材料的老化过程、老化机理、老化特征表征等研究，仅限于采用常见的材料分析方法，现场取样后，在实验室专用仪器测试其憎水性、有机基团变化、力学和电气特性衰减等，尚无有效的技术手段进行在线的、定量的复合材料状态分析和老化表征。为了解决这一问题，本项目提出，基于激光诱导击穿光谱的方法，构建纳秒激光烧蚀硅橡胶复合材料的理论模型，改进现有激光诱导击穿平台，实现远程在线分析硅橡胶材料的元素组成和表面状态；对硅橡胶材料进行多因素加速老化试验，采用“layer-by-layer”的方式检测老化层厚度和老化速度，得到复合材料老化状态表征的特征信息，与复合材料力学和电气性能的变化联系，建立硅橡胶复合材料的三维老化模型，最终提出定量在线老化表征检测的方法，为指导电力安全运行提供理论基础。

硅橡胶材料广泛应用于高压输变电设备外绝缘。高分子材料的耐候性差，在电场与环境因素作用下容易发生老化。利用激光诱导击穿光谱方法开展硅橡胶材料的在线带电检测，对于检测输电线路设备运行状态，维护线路运行安全具有重要意义。本项目基于激光诱导击穿光谱技术，开展了硅橡胶材料的带电在线定量检测方法研究。建立了纳秒脉冲激光烧蚀硅橡胶材料的光热仿真模型，揭示了材料参数、激光参数对烧蚀形貌的影响规律；结合电感耦合等离子体光谱、能谱等方法，建立了硅橡胶材料多种元素的定量关系曲线，得到了Na，Ca，Mg等表面污秽元素的定标曲线，并绘制了绝缘子表面元素的分布图；研究揭示了利用激光诱导击穿光谱特征数据表征硅橡胶表面硬度、粗糙度、耐漏电起痕能力的方法，提出了硅橡胶材料老化状态在线评估的新方法；研究搭建了可在5米范围内进行精确测量的共轴式远程LIBS平台，并获得了优化的系统参数。项目研究成果在深圳供电局、河北电科院等多家电网单位试用，为后期成果实用与转化打下了基础。