Machining

Abstract

Nickel-based alloys are frequently applied in the aerospace and power generation industries due to their excellent material properties, such as high temperature strength and high corrosion resistance. These advantageous material properties, however, result in challenges for cutting operations. Contrary to turning, where good results for the machining of nickel-based alloys have been obtained, drilling processes are less investigated until now. In general, coated cemented carbide drills have been proven to show good performances in drilling operations based on their higher strength compared to high speed steel (HSS) tools. Hence, they can be utilized with more efficient process parameters, whereby tool life will likely be reduced as a consequence of the higher loads. In order to find reasonable trade-offs between efficiency and tool life, a multi-objective optimization based on both criteria is presented in this article. The optimization of the cutting parameters is performed for drilling the popular nickel-based alloy Inconel 718. It is assisted by empirical models based on statistical experimental design techniques. By these means, the trade-off surface between process efficiency and tool wear can be approximated within a small experimental effort. In addition, the dominant mechanisms behind the tool wear for different process parameters are discussed.