Interface design to tune stress distribution for high performance diamond/silicon carbide coated cemented carbide tools

Abstract

The stress distribution of the interface plays a key role in adhesion and performances of diamond coated tools. Herein, we report a combined simulation and experimental strategy to significantly minimize the thermal stress by interface design in the diamond/SiC architectures. Different diamond/SiC films, including pure diamond, composite, single SiC interlayer, gradient interlayer and multilayer, were simulated by finite element analysis and synthesized on cemented carbide tools by hot filament chemical vapor deposition (HFCVD). The stress distribution was tailored over the diamond/SiC architecture, and the maximum stress value at the cutting edge was best suppressed for the composite (58% reduction) and the gradient film (49% reduction), which resulted in the best film adhesion and were sufficient for cutting performances. The pure diamond surface ending on the gradient coated tool allowed for non-sticking machining Al-13 wt% Si alloy, resulting in enhanced workpiece quality and extended tool lifetime. Its tool lifetime was at least 7 times longer than that of the pure diamond film, and at least 4 times longer than a commercial diamond coated end mill. The diamond/SiC architectures represent a potent solution for adherent diamond coated tools with excellent machining performances.