Modeling and analysis of metal cutting process using self-propelled rotary tools

Abstract

Machining difficult-to-cut materials is still one of the challenges facing different industries such as aerospace, nuclear and automotive sectors. That’s mainly because of the excessive heat generated, which affects the tool wear behavior and machinability performance. Rotary tools can be employed to solve these issues as they offer an acceptable tool life compared to traditional tools, especially under dry-environment conditions. Despite the attempts offered in the area of machining with rotary tools, there is a noticeable lack in understanding the physical aspects and mechanics of this process. Thus, the current work focuses on three main pillars to fully address this research gap. The first pillar of this study presents a novel analytical model to predict the cutting forces and tool rotational speeds during the machining process using self-propelled rotary tools with considering the tool bearing friction. The prediction capabilities of this analytical model are higher than all existing models in the open literature. The objective of the second pillar is to propose a hybrid finite element model which is able to predict the temperature distribution during cutting with self-propelled rotary tools. The proposed model addresses the limitation of other previous models as it is purely focused on significant aspects such as; heat partition factor and the contact area between the tool and the chip. The simulation results in terms of cutting forces, temperature, heat flux, and the contact area between the chip and the tool are obtained, and good agreement is observed between the numerical and experimental results. In terms of the third pillar, deep-understanding of the process mechanisms is fully discussed through conducting experimental tests on AISI 4140 hardened-steel, followed by analysis of variance, empirical modeling of the process, and process optimization. Besides, a detailed mechanism for the machining process with self-propelled rotary tools is concluded. It should be stated that this work offers a valuable comprehensive analysis for the metal cutting industry in terms of modeling, optimization, and assessment of the machining process with rotary tools.