ζ相碳化物多型体行为及其对Ta4C3-x-Cu/Ag复合材料微结构调控和力/热/电综合性能的影响

ζ-Ta4C3-x具有极高熔点（接近4000°C）、很好的抗弯强度、断裂韧性、电导率、热导率和抗烧蚀能力，可作为功能第二相与Ag、Cu等金属复合，制备接触电阻低而稳定、抗熔焊、抗烧蚀、抗磨损和耐疲劳等综合性能优良的电触点材料。本项目拟采用粉末冶金法制备Ag/ζ-Ta4C3-x和Cu/ζ-Ta4C3-x两类复合材料，深入研究ζ-Ta4C3-x反应规律和ζ相晶体结构多型体转变问题，揭示ζ-Ta4C3-x晶粒形貌演变对复合材料组织结构调控的影响规律，揭示材料成分、制备工艺及电弧损伤对复合材料力/热/电学性能的影响规律，拓展Ta-C陶瓷材料应用领域，为新型电触点材料研发提供理论及试验依据。

This project is based on excellent high-temperature ablation resistance (hence good arc erosion resistance) and non-formation of oxide scale (hence low and stable contact resistance) of TaC ceramics, which indicates an interesting potential for Ag/ζ-Ta4C3-x and Cu/ζ-Ta4C3-x composites as electrical contact materials. Therefore, two types of Ag/ζ-Ta4C3-x and Cu/ζ-Ta4C3-x composites will be prepared by powder metallurgy. Systematic researches will be carried out on issues that are involved in electrical applications of the composites and stability of the ζ-Ta4C3-x phase. Possible polytypes of ζ-Ta4C3-x will be searched by altering stacking of the Ta atom layers and positioning of the C atoms in the octahedral interstice. Reaction processes ofζ-Ta4C3-x from TaC+Ta powder mixture and its effect on microstructural evolution due to ζ-Ta4C3-x laminate growth will be clarified. Mechanical, thermal, and electrical properties of the Ag/ζ-Ta4C3-x and Cu/ζ-Ta4C3-x composites will be investigated to comprehensively illustrate influences of composition, processing and arc erosion. Completion of the project will provide insight into a new electrical contact material system of Ag/ζ-Ta4C3-x and Cu/ζ-Ta4C3-x, and thus open a new feasible field for TaC applications.