Hao Lu, Jinghong Chen, Yulu Yang, Chen Wang, Xiaoyan Song
Faculty of Materials and Manufacturing, Key Laboratory of Advanced Functional Materials, Ministry
of Education of China, Beijing University of Technology, Beijing 100124, China 

EXTENDED ABSTRACT: Cemented carbides are usually prepared by powder metallurgy methods, inevitably leading to as-prepared stress with large magnitude and complicated distribution. The interactions between the as-prepared stress and the applied load during service would affect the mechanical behavior and performance of the materials. Therefore, quantitative investigations on the as-prepared stress distribution from global to local microstructure of cemented carbides, and the stress-strain response characteristics of the material with the as-prepared stress during the load-bearing process are crucial to comprehensively understand the mechanical behavior, failure mechanism and performance enhancement of cemented carbides. This study developed a method to construct finite element models with real microstructure and phase distribution of materials with multiphases, and a new method for establishing a macro-mesoscopic coupled model was proposed. The effects of grain size, binder phase content, grain morphology and as-prepared stress on the mechanical behavior of cemented carbides were systematically analyzed, and the asymmetric strain response characteristics with different applied loads were investigated. The stress state obtained from the finite element model simulation was transferred to the molecular dynamics simulation model, and the crystal defects and their evolution laws under the interaction of the as-prepared stress and applied load were further analyzed at the atomic scale, revealing the correlation between the as-prepared stress-microstructure­mechanical behaviors of cemented carbides. This study provides a new strategy to improve the mechanical properties of ceramic-metal composites, such as cemented carbides, by optimizing the microstructure to regulate the stress distribution in the preparation state.
Keywords: multiscale modeling; microstructure tailoring; ceramic-metal composites; stress distribution