多场耦合侵蚀下环保Ag/Ti_(2)SnC复合电接触材料的微/纳米力学行为及微结构演变  

Micro/Nano-Mechanical Behavior and Microstructure Evolution of Eco-Friendly Ag/Ti_(2)SnC Composite Electrical Contacts Under Multi-Field Coupled Erosion

作　　者：丁宽宽 丁健翔 张凯歌 白忠臣[3] 张培根[2] 孙正明 DING Kuankuan;DING Jianxiang;ZHANG Kaige;BAI Zhongchen;ZHANG Peigen;SUN Zhengming(School of Materials Science and Engineering,Anhui University of Technology,Maanshan 243002,China;Jiangsu Key Laboratory of Advanced Metallic Materials,School of Materials Science and Engineering,Southeast University,Nanjing 211189,China;Guizhou Province Key Laboratory for Photoelectronic Technology and Application,Guizhou University,Guiyang 550025,China)

机构地区：[1]安徽工业大学材料科学与工程学院,马鞍山243002 [2]东南大学材料科学与工程学院、江苏省先进金属材料重点实验室,南京211189 [3]贵州大学贵州省光电子技术与应用重点实验室,贵阳550025

出　　处：《金属学报》2024年第12期1731-1745,共15页Acta Metallurgica Sinica

基　　金：国家自然科学基金项目Nos.52101064和52171033;江苏省博士后科研基金项目No.2020Z158;先进金属材料绿色加工与表面技术重点实验室开放项目No.GFST2020KF04。

摘　　要：实际服役过程中低压开关的过早失效主要归因于电弧侵蚀,因此阐明材料微观结构、力学性能退化及电弧侵蚀机理对进一步开发环保MAX相增强银基复合电接触材料进而推动低压开关材料更新换代具有重要意义。本工作沿Ag/Ti_(2)SnC电触头横截面从电弧侵蚀层到近电弧侵蚀层再到基体内部依次进行了微/纳米压痕实验,分析对比了不同区域显微硬度、纳米硬度、弹性模量、蠕变以及塑性/弹性性能沿电弧侵蚀方向的梯度变化行为。在综合分析不同区域微观形貌和元素组成的基础上,揭示了增强相Ti_(2)SnC和Ag基体的结构和成分演变,解析了Ag/Ti_(2)SnC复合材料微观结构梯度变化与微/纳米力学性能之间的内在关系。使用COMSOL模拟进一步验证了多场耦合侵蚀下Ag/Ti_(2)SnC复合材料的物理特征,进而提出电弧侵蚀机理。Silver(Ag)-matrix-composite electrical contact materials(ECMs)are widely used in railway,manufacturing,electric power distribution,and aerospace systems,owing to their excellent electrical and thermal conductivities and good mechanical and anti-erosion properties.In particular,they play a key role in low-voltage switches,which are vital in the global electrical economy.To date,substituting the toxic Ag/CdO ECMs has become a bottleneck in the development of low-voltage switches.Over the past decades,Ag/SnO2,Ag/ZnO,Ag/Ni,and Ag/C have been exploited as substitutes for Ag/CdO ECMs,but their intrinsic defects make them unsuitable;therefore,there is still an urgent need to develop eco-friendly substitutes for CdO.Recently,MAX-phase materials,which combine attractively dual metal and ceramic properties,have shown potential in replacing CdO as a reinforcement for Ag-matrix composites.Moreover,arc erosion is a common cause of the premature failure of low-voltage switches in applications.To aid the further development of MAX-reinforced Ag-matrix-composite contacts,there is a need to understand the mechanism of arc erosion and degradation of the microstructural and mechanical properties of the composites.Nano-indentation is the most common and stable method of evaluating the micromechanical properties of materials.In this study,micro-/nano-indentation tests were performed along the crosssection of Ag/Ti_(2)SnC contacts(from the arc erosion layer to the near arc erosion layer and then to the matrix interior).The gradient variation of the microhardness,nanohardness,modulus,creep behavior,and plastic/elastic depth in different areas was analyzed and contrasted in the direction of the electrical arc erosion.The micromorphology and elemental composition were comprehensively analyzed,and the structural and compositional evolution of the Ti_(2)SnC reinforcement phase and Ag matrix were investigated.The relationship between the gradient structural change and micro-/nano-mechanical properties of the Ag/Ti_(2)SnC composites was anal

关 键 词：Ag/Ti_(2)SnC复合材料 微/纳米力学行为 微结构演变 COMSOL模拟 多场耦合侵蚀 

分 类 号：TM2[一般工业技术—材料科学与工程]