基于热、动力学计算模拟研发梯度硬质合金

Integrated Computational Materials Engineering(ICME) for developing the graded cemented carbides

摘要:

对于材料研发和过程参数优化来说,包括CALPHAD(相图计算)方法在内的集成计算材料工程(ICME)是强有力的工具。CALPHAD计算结果的准确性在很大程度上取决于热力学和动力学数据库的质量。基于前期建立的热力学数据库(CSUTDCC1)和动力学数据库(CSUDDCC1),本文对硬质合金研发过程中所关心的烧结“碳窗口”、立方相组分等信息进行了计算模拟。本文研究了几种在真空和N₂不同分压下烧结的梯度硬质合金,采用SEM和EPMA研究了梯度层的微观结构和元素浓度分布,并通过热、动力学数据库进行了计算模拟,计算模拟结果与实验数据吻合。本工作探讨了ICME在硬质合金的设计和研发中的应用示范,说明ICME可为新型高性能硬质合金的开发提供理论支撑。

Abstract:

Abstract: It is a powerful and efficient method for materials development and process optimization by gasping the thermodynamic and kinetic information of studied materials and further performing simulations. The quality of CALPHAD-type calculations is strongly dependent on the quality of the thermodynamic and diffusivity databases. Based on previously developed thermodynamic database (CSUTDCC1) and diffusivity database (CSUDDCC1), some simulations concerned during the research and development of cemented carbides, like sintering “carbon window” and cubic phase composition, were performed. Several gradient cemented carbides sintered under vacuum and various partial pressures of N2 have been studied. The microstructure and element concentration in the gradient layer were investigated via SEM and EPMA. Thermodynamic and kinetic simulations were performed and agreed well with experimental data. Examples of thermodynamic and kinetic simulation applications in design and manufacture for gradient cemented carbides were shown, which provides theoretical basis for the development of novel and high-performance gradient cemented carbides.