低压触头材料电弧侵蚀与微结构相关性研究

The interaction between arc discharge and erosion has been one of the important research fields in the electrical contact materials. Due to lack of deep understanding of the interaction between arc motion behavior and microstructure and their physical essence, the arc motion behavior of low voltage contact materials with different microstructures has not been clarified so far. In this research program, the arc emotion behaviors of the conductive TiB2 ceramic reinforced Ag matrix contact material and the non-conductive SnO2 ceramic reinforced Ag matrix contact material with different sizes, amount and distribution of second reinforced phase are explored, and the factors that affect arc erosion are determined. Based on the research, the evolutions of microstructural morphology and constituents are systematically researched, and the correlation among microstructure, arc motion and arc erosion is established so as to disclose the physical essence of arc erosion for the low voltage contact materials. From the investigation, more deep insights can be got on the arc motion behavior, the relevance between microstructure, arc motion characteristic and arc erosion, and the slection and regulation of strengthening phase as well. Thus, it can provide the theory basis for the design and fabrication of novel low voltage contact material.

电弧放电和触头材料烧蚀之间的交互作用一直是电工材料领域研究的重要课题，目前对低压触头材料电弧运动行为与微结构之间的交互关系和物理本质缺乏深入的理解，尚不能明确解释具有不同微结构特征的低压触头材料的电弧运动行为和电弧侵蚀机理。本项目通过研究具有不同微结构特征的导电陶瓷TiB2增强的的AgTiB2和非导电陶瓷SnO2增强的AgSnO2两种触头材料的第二相粒子的尺寸、数量和分布对电弧运动行为的影响规律，确定影响电弧侵蚀的因素。在此基础上系统研究两种触头材料在电弧作用下组织形貌和成分的演变，构建材料微结构与电弧运动和电弧侵蚀之间的关联，揭示低压电触头材料电弧侵蚀的物理本质。研究结果一方面能使人们从更深的层次认识和理解电弧运动行为，获得触头材料的微结构与电弧运动特性及其电弧侵蚀之间的关联，另一方面能使人们对低压触头材料的强化相选择和控制有深入的理解，为新一代新型银基触头材料的设计和制备提供理论依据。

为了阐明低压触头材料电弧行为与微结构之间的交互关系和物理本质，揭示具有不同微结构特征的低压触头材料的电弧侵蚀行为,本项目通过研究导电陶瓷TiB2增强的AgTiB2和非导电陶瓷SnO2增强的AgSnO2两种触头材料的粒度大小、含量和空间分布对电弧运动行为的影响规律，构建了材料微结构与电弧运动和电弧侵蚀之间的关联。研究发现，Ag基触头材料的性能与制备技术和工艺密切相关。复压复烧、添加剂和等离子电火花烧结技术均有助于提高Ag基触头材料致密度、硬度和导电导热性能。随着TiB2、SnO2和Ag颗粒的减小以及增强相在Ag基体中空间分布的改善，集中烧蚀减小，蚀坑变浅，燃弧时间缩短，质量损失减少，说明细小的颗粒和良好的空间分布有助于提高Ag基触头材料的耐电弧侵蚀性能。随着SnO2含量的增加，燃弧时间增加，侵蚀面积减小，侵蚀坑变深，金属喷溅增强。在相同侵蚀条件下，Ag-TiB2触头材料燃弧时间短，侵蚀区域面积明显增大，蚀坑小且浅，质量损失小，而Ag-SnO2触头材料燃弧时间长，表面电弧烧蚀严重，烧蚀坑大且深，质量损失大。对Ag-8wt.%TiB2触头材料和Ag-8wt.%SnO2触头材料熔池温度场模拟结果表明Ag-8wt.%TiB2触头材料表面熔池体积较小，材料喷溅量少。说明导电导热良好的TiB2增强的AgTiB2触头材料具有比非导电、导热差的SnO2增强的Ag基触头材料具有更好的耐电弧烧蚀性能。研究结果可加深人们从材料的角度理解触头材料的微结构与电弧运动特性及其电弧侵蚀之间的关系，为新一代新型银基触头材料的强化相选择、组织调控和制备提供理论依据。