W-Mo-Cu复合材料优化设计及其电场快速烧结的基础研究

Since the properties of W-Mo-Cu composite can be controlled uninterruptedly and filled a gap between W-Cu and Mo-Cu composites, the development potential of W-Mo-Cu composite as a high-temperature functional material is immense. However, there is few study on this material at home and abroad up till now. Therefore, W-Mo-Cu system is the subject investigated in this project, and W-Mo-Cu composite will be prepared by a rapid sintering under an electric field, which is more potent than that of SPS. In this method, the sintering temperature can be lowed and the sintering time can be shorted greatly due to the promoter action of electric field, as a result the good property materials can be obtained. Based on the combination of theory and experiment in this project, the thermodynamic properties of W-Mo-Cu ternary system will be studied firstly, and then the optimal design will be done by establishing the physical property modeling of W-Mo-Cu composite. Due to rapid sintering under an electric field by using the thermal simulation instrument, the dynamic process and the analysis of composite microstructure can be combined very well. According to the investigation on the mechanism of electric field how to play roles in solid-solution alloying and diffusion of the system, as well as the kinetics process and the microstructure evolution of W-Mo-Cu composite in rapid sintering, the sintering mechanism of W-Mo-Cu composite under an electric field will be revealed. This research production not only can enrich the thermodynamic theory of W-Mo-Cu ternary system, but also can offer a new way for the high added-value utilization of tungsten and molybdenum resource in China.

W-Mo-Cu复合材料可实现性能在W-Cu和Mo-Cu材料之间的连续可调，并能填补二者之间的空白，在高温应用上具有很大发展潜力，但当前国内外研究甚少。项目以W-Mo-Cu体系为研究对象，采用一种电场作用比SPS更强的快速烧结方法制备W-Mo-Cu材料，利用电场的促进作用大幅降低烧结温度和缩短烧结时间，获得性能优异的材料。采用理论和实验相结合的方法，在对W-Mo-Cu三元系热力学性质的研究基础上，建立物理性能模型对W-Mo-Cu材料进行优化设计。利用热模拟机进行电场烧结实验，可实现材料烧结动态过程与显微组织结构分析的有机结合。通过研究电场对体系固溶合金化和原子间扩散的影响作用机制，以及W-Mo-Cu材料电场快速烧结的动力学过程和微观组织结构演变规律，揭示W-Mo-Cu复合材料电场快速烧结的机理。该成果即可丰富W-Mo-Cu体系热力学，也可为我国钨钼资源高附加值的利用提供一条新途径。

本项目以综合W-Cu、Mo-Cu二元材料性能优势的W-Mo-Cu三元新体系为研究对象，采用理论计算对W-Mo-Cu三元系热物理性质和热力学性质进行了研究，并建立模型对W-Mo-Cu复合材料的物理性能进行计算和评价。借助热模拟机进行大电流电场烧结实验，在大电流电场的促进作用下实现了快速烧结制备W-Mo-Cu三元复合材料。通过研究电流、烧结温度、烧结时间和压力等因素对W-Mo-Cu体系烧结致密化的影响，电场对体系固溶合金化和原子间扩散的影响，以及W-Mo-Cu复合材料电场快速烧结的致密化过程和微观组织结构演变规律，揭示了W-Mo-Cu复合材料电场快速烧结的机理。研究结果表明：W-Mo-Cu三元系符合具有正偏差的正规溶液特性，性能在W-Cu、Mo-Cu之间连续可调；电场作用可大幅降低W-Mo-Cu体系的烧结温度和缩短烧结时间，符合“绿色合成”的发展要求；烧结温度、烧结时间、压力和电流等因素对W-Mo-Cu复合材料的微观结构和性能具有显著影响；电场可有效促进Mo、W、Cu原子间的扩散和固溶，通过电场烧结制备的W-Mo-Cu复合材料由W相、Mo相、Cu相、新生成的W-Mo有序相及伴有纳米晶的非晶相、Cu0.4W0.6金属间化合物以及Mo-Cu固溶体组成，且新生成相均为体心立方结构。取得的研究结果既丰富了W-Mo-Cu体系热力学，又为电场烧结制备W-Mo-Cu复合材料奠定了基础，可为我国钨钼资源高附加值的利用提供一条新途径，具有重要的工程应用价值。本项目研究成果在国内外重要刊物发表SCI、EI论文6 篇，申请国家发明专利5项（已授权2项），培养3名博士研究生和1名硕士研究生，研究工作实现了预期目标。