Experimental investigation on the performance of novel double cone integrated tool in one-shot drilling of metal stacks

In order to reduce misalignment, enhance tight tolerance, and improve machining efficiency, a novel double cone integrated tool was developed and experimentally investigated during one-shot drilling of aluminum and aluminum alloy stacks in this paper. This special tool geometry can finish drilling, reaming, and countersinking processes at the same time. Its machining properties were comparatively evaluated with a standard twist drill (reference drill) by means of a series of experiments. Experimental results highlighted the influence of tool geometry on cutting force and vibration signals for drilling, reaming, and countersinking processes, respectively. The results indicated that the double cone integrated drill can induce a little larger thrust force than a reference drill due to its longer cutting edge. In addition, the chip morphologies generated by different processes and cutting variations also have been comparatively analyzed. The double cone drill under a larger feed rate was prone to produce smaller chips. Furthermore, the double cone drill can achieve smaller burrs, better surface integrity, and lighter tool wear compared with reference drill. The information obtained from this study can provide a better understanding of the one-shot drilling process and guidance for achieving higher efficiency and better hole quality.