Effect of Tool Coating and Cutting Parameters on Surface Roughness and Burr Formation during Micromilling of Inconel 718

Atif Muhammad,Danil Yurievich Pimenov,Tadeusz Mikołajczyk,Munish Kumar Gupta,Khaled Giasin

doi:10.3390/met11010167

Abstract

Surface roughness and burr formation are among the most important surface quality metrics which determine the quality of the fabricated parts. High precision machined microparts with complex features require micromachining process to achieve the desired yet stringent surface finish and dimensional accuracy. In this research, the effect of cutting speed (m/min), feed rate (µm/tooth), depth of cut (µm) and three types of tool coating (AlTiN, nACo and TiSiN) were analyzed to study their effect on surface roughness and burr formation during the micromachining of Inconel 718. The analysis was carried out using an optical profilometer, scanning electron microscope and statistical technique. Machining tests were performed at low speed with a feed rate (µm/tooth) below the cutting-edge radius for 10 mm cutting length using a carbide tool of 0.5 mm diameter on a CNC milling machine. From this research, it was determined that the depth of cut was the main factor affecting burr formation, while cutting velocity was the main factor affecting the surface roughness. In addition, cutting tool coating did not significantly affect either surface roughness or burr formation due to the difference in coefficient of friction. The types of burr formed during micromilling of Inconel 718 were mainly influenced by the depth of cut and feed rate (µm/tooth) and were not affected by the cutting velocity. It was also concluded that the results for the surface finish at low-speed machining are comparable to that of transition and high-speed machining, while the burr width found during confirmation experiments at low-speed machining was also within an acceptable range.

Highlights

There is an increased demand for the miniaturization of components in industrial products, which has many functions and requires acceptable dimensional accuracy [1].Micromachining is a process of producing miniature parts and components in mass production [2]
Several definitions exist on what is meant by micromachining. It can be defined based on size metrics as a process which can produce small and intricate three-dimensional features ranging from 1 to 999 μm according to size aspects as a material removal process in which material is being removed in microlevels [3,4]
The current study aims to determine the effect of different tool coatings and cutting The current study aims to determine the effect of different tool coatings and cutting parameters on burr formation and surface roughness during the micromachining of Inparameters on burr formation and surface roughness during the micromachining of Inconel conel 718 using an end mill tool with a diameter of 0.5 mm

Summary

Introduction

There is an increased demand for the miniaturization of components in industrial products, which has many functions and requires acceptable dimensional accuracy [1].Micromachining is a process of producing miniature parts and components in mass production [2]. Demand for microparts and components has increased in different industrial sectors Examples of such parts include, but are not limited to, the following: connectors, diagnostic devices, microreactors, medical implants, microengines, switches, micropumps drug delivery systems, and printing heads [5,6,7,8,9]. Micromilling of Inconel alloys is among the most investigated materials in the open literature due to its large base of applications in many industries. This is thanks to the ability of micromilling to produce a required design on nickel-based microcomponents [19,20,21,22]

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