Hardness and yield strength of micro-nano TaC-Fe composite layer characterized through nano-indentation, finite element simulation and dimensional analysis

In this study, yield strength of TaC-Fe composite on steel-based surface micro-nanostructure was studied by nano-indentation, finite element simulation, and dimensional analysis. Finite element analysis was utilized to simulate nano-indentation of TaC-Fe composite layer under different yield strengths, and equivalent stress cloud, equivalent strain cloud, and load-displacement curves with yield strengths of 6, 6.5, 7, and 7.5 GPa were obtained. Nano-indentation experimental result was analyzed with the Pi theorem in dimensional analysis, and the relationship between load-displacement curve function and mechanical parameters, such as yield strength and Poisson's ratio of micro-nano-structured TaC-Fe composite layer, was obtained. The correctness of the dimensional analysis model and the reliability of finite element simulation nano-indentation were validated using the combination of dimension-function relationship, simulation calculations, and load-displacement curve obtained through nano-indentation experimentation. Yield strength of micro-nanostructured TaC-Fe composite layer was determined as 7.05 GPa.