多相复合陶瓷刀具材料残余热应力的有限元模拟

以SiC和(W,Ti)C颗粒增强Al₂O₃多相复合陶瓷刀具材料为基础,运用有限元方法详细研究了材料内部残余热应力的大小与分布形态。计算结果发现,单元模型取法、弥散相颗粒大小、分布及其含量均对多相复合陶瓷刀具材料中的残余热应力有较大影响。基体内不仅存在拉应力区,而且存在不同程度和范围的压应力区,拉、压应力区的结构形式与弥散相颗粒的分布方式密切相关。研究表明,残余热应力的存在与材料的力学性能和微观结构有着密切的关系。 

FINITE ELEMENT MODELING OF THE RESIDUAL THERMAL STRESSES IN MULTIPHASE COMPOSITE CERAMIC TOOL MATERIAL

Based on the multiphase composite ceramic tool material Al 2O 3 reinforced by SiC and (W,Ti)C particles, the magnitude and the distribution of the residual thermal stress are analyzed in detail with the finite element modeling method. The results show that the residual thermal stress in the multiphase composite ceramic tool material is affected noticeably by the distribution unit models, size and distribution forms of the dispersed phases and their volume fractions. Tensile stress fields are found to exist in the matrix together with the compressive stress fields to different extents and in different ranges. The structure of both tensile and compressive stress fields has close relations with the distribution forms of the dispersed SiC and (W,Ti)C particles. The research here denotes that close relations exist between the residual thermal stress and the microstructure and the mechanical property of the composite ceramic tool material.