Experimental Study on the Effect of Cutting Tool Geometry in Micro-Milling of Inconel 718

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RESEARCH ARTICLE–MECHANICAL ENGINEERING

Experimental Study on the Effect of Cutting Tool Geometry in Micro-Milling of Inconel 718 K. Aslantas1

· L. K. H. Alatrushi2

Received: 21 September 2019 / Accepted: 21 July 2020 © King Fahd University of Petroleum & Minerals 2020

Abstract In this study, the effect of tool geometry on the cutting forces, surface roughness, and burr formation in the micro-milling process is investigated. Three different geometric parameters (helix angle, number of cutting edges, and axial rake angle) that may affect the machining performance are taken into account. Inconel 718 superalloy was used as workpiece material, and the tests were performed under dry cutting conditions. According to the results obtained, the minimum cutting forces were obtained at a helix angle of 45°. The increase in the helix angle causes the forces in the F z direction to increase. For the new cutting tool, increasing number of cutting edges and axial rake angle has little effect on cutting forces. For the worn tool, the cutting forces are lower in the four-edges cutting tool, and the cutting forces obtained in the negative axial rake angle are also higher. The dominant damage types in the cutting tool are abrasive wear and chipping. Increased cutting distance causes the edge and corner radii of the tool to increase. As a result, cutting forces, surface roughness, and burr formation also increase. Generally, the maximum top-burr width is obtained on the up-milling side for the new cutting tool. Maximum top-burr width occurs on the down-milling side in the worn tools. Increasing helix angle causes burr width to increase. It has been determined that low number of cutting edge and negative rake angle cause smaller burr width. Keywords Micro-milling · Tool geometry · Tool wear · Burr formation · Surface roughness

1 Introduction Micro-machining is a method of manufacturing cutting tools in the range of 1–1000 µm in general [1–3]. Today, many methods are used in the production of equipment in this range. The main difference between these methods is the mechanism they use to remove material from the part. It describes the working principles of chemical, electrical, and mechanical manufacturing processes [4]. In the manufacture of a product at microscale, it is important to realize a precise production in a considerable shorter time. Commercialization of the developed micro-products depends on their ability to be manufactured in series [5]. Micro-mechanical machining has emerged as a manufacturing method in accor-

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K. Aslantas [email protected]

1

Department of Mechanical Engineering, Faculty of Technology, Afyon Kocatepe University, 03200 Afyonkarahisar, Turkey

2

Department of Mechanic, Mosul Technical Institute, Northern Technical University, Mosul, Iraq

dance with this requirement. Micro-mechanical machining, which is now widely preferred in the production of microequipment, is a machining process that basically allows the traditional turning, milling, and drilling operations to be done at microscale. However