Increased performance in high speed turning of Inconel 718 by laser structuring of PcBN tools

In order to improve the cutting performance of PcBN tools, the cutting edge is prepared e.g. by grinding or brushing. Since PcBN is the second hardest material besides diamond, mechanical preparation of PcBN tools is associated with high wear and low productivity, which leads to high process costs. The laser preparation provides a high potential in preparing PcBN tools because of its wear free technology and its short process times. Additionally, several authors have shown that laser preparation can also lead to beneficial effects such as hardness increase or increased compressive residual stresses. Although these effects are known, they have not been linked to cutting performance of PcBN tools. This paper investigates the influence of nanosecond pulsed laser preparation of the cutting edge and the resulting surface topography on the cutting performance. Therefore, PcBN cutting tools were prepared with different laser velocities at the cutting edge and applied in high speed turning of Inconel 718. Surface integrity of the prepared tools was investigated regarding hardness, surface roughness and edge quality. Afterwards the prepared tools are used in turning experiments, showing a decreasing flank wear of 40 % compared to reference tools. Tool life increase is linked to beneficial frictional behavior and less adhesive wear of the laser machined specimens compared to conventional tools.