热锻模具激光再制造熔覆层材料-组织-性能调控机理

模具是工业生产的基础工艺装备，热锻模具长期在高温高压和交变载荷下工作，极易造成磨损、塑性变形及热疲劳等损伤和失效。由于具有功率密度高、界面结合强度好、热影响区小、柔性高等特点，激光熔覆技术在热锻模具再制造领域应用前景广阔。针对该领域存在的关键科学问题，本项目拟开展热锻模具再制造熔覆层材料-组织-性能调控机理研究，阐明熔覆层异质/梯度材料成分匹配设计原理和方法；研究热影响区、基体特性及热处理制度等对再制造零件组织性能的影响；揭示材料界面组织演化行为和机理。通过热力耦合数值模拟、成形过程重要参量检测与控制及综合性能评价与表征，探索熔覆层特定部位材料-组织-性能最佳裁剪和定制方法，提升热锻模具再制造质量和服役性能，为热锻模具激光熔覆再制造技术的推广应用奠定理论基础，也可为压铸模和热挤压模等其他热作模具成形和再制造提供参考，丰富和发展再制造理论与内涵，具有重要的科学价值和社会经济效益。

Dies and molds are fundamental process equipments in industrial production. Hot forging dies are always working in conditions of long-term high temperature, high pressure and alternating loads, and are liable to damage and failure in forms of abrasion, plastic deformation, thermal fatigue and so on. Because of the characteristics of higher power density, better bonding strength of the interface, smaller heat affected zone and better flexibility, laser cladding technology will have a wide application prospect in the field of hot forging die remanufacturing. According to the key scientific problems exist in this field, adjustment and control mechanics between materials, microstructure and properties of remanufactured hot forging die remanufacturing cladding layers will be studied. Matching design principles and methods of heterostructure/gradient materials of the cladding layers will be illustrated. Influences of characteristics of the heat affected zone and the substrate and the heat treatment regime on the microstructure and properties of the remanufactured components will be studied. And the evolution behavior and mechanism of the microstructure in the material interface will be revealed. Through the coupled numerical simulation of the temperature and force fields, measurement and control of the key parameters in the forming process and evaluation and characterization of the comprehensive properties, optimal tailored and customized methods among materials, microstructure and properties at certain locations of the cladding layers will be explored to enhance the remanufacturing quality and service performance of the hot forging dies, which will provide a theoretical basis for the propagation and application of the laser cladding remanufacture technology of hot forging dies. The research results will also provide references for the forming and remanufacturing of other hot working dies such as pressure-casting dies, hot extrusion dies and so on. The theory and connotation of remanufacture can be enriched and developed, and it will have important scientific values and better social and economic benefits.