Bio-inspired fabrication, mechanical characterization and cutting performance evaluation of Al2O3/TiC micro-nano-composite ceramic with varying microscopic surfaces

摘要

Bio-inspired fabrication, mechanical characterization and intermittent cutting performance evaluation were conducted for Al2O3/TiC micro-nano-composite ceramic with varying microscopic surfaces. Functions and geometry features of the epidermis were analyzed for two biological species, namely, catharsius molossus and bullhead shark. The biomimetic microscopic texture on ceramic tool surface was designed and fabricated considering tool-chip contact area and chip flow direction. Varying combinations of laser beam angle and spacing were utilized in the fabrication of biomimetic microscopic texture. Microscopic hardness, fracture toughness and fractal dimension of the indentation-induced crack were analyzed and compared for the textured ceramics. A tool performance indicator CP was proposed. Ceramic tool stress in cutting process, mechanical features of the intrinsic microcrack and fractal dimension of the indentation-induced crack were reflected in the indicator. The indicator CP was employed to evaluate the intermittent cutting performance of ceramic tools with different biomimetic microscopic textures. The optimum combination of laser beam angle psi and spacing L-d was found to be 60 degrees and 105 mu m. The lowest CP and the lowest experimental tool wear VB appeared at this optimum combination. A proper balance between external loads, micromechanical properties and fracture resistance can be achieved for the textured ceramic tool by using the optimum combination of psi and L-d.