Machining Parameters Mapping S Of Inconel 718 And Aluminum A Lloy

Key Engineering Materials ISSN: 1662-9795, Vol. 846, pp 99-104 doi:10.4028/www.scientific.net/KEM.846.99 2020 Trans Tech Publications Ltd, Switzerland Submitted: 2019-10-03 Accepted: 2019-10-04 Online: 2020-06-03 Machining Parameters Mapping’s of Inconel 718 and Aluminum Alloy 1100 in Micro-Milling Process Gandjar Kiswanto1,a, Maulana Azmi1,b, Adrian Mandala1,c, Dede Lia Zariatin2,d and Tae Jo Ko3,e Departement of Mechanical Engineering, Universitas Indonesia, Indonesia 1 Mechanical Engineering, Universitas Pancasila, Indonesia 2 School of Mechanical Engineering, Yeungnam University, Republic of Korea 3 gandjar kiswanto@eng.ui.ac.id, bmaulanaazmi@gmail.com, cmandalaadrian@gmail.com, d dedeliazariatin@univpancasila.ac.id, etjko@yu.ac.kr a Keywords: Micro-milling, Machinability, Machining Parameters, Inconel 718, Aluminum Alloy 1100 Abstract. The development of micro-products in industry, like aviation, medical equipment, electronics, etc, has been increasing lately. The need for scaling down of product has been increasing to make the product simpler and complex. Micro-milling has capabilities in producing complex parts. In this study, mapping and comparing the result of the machining process of Inconel 718 and Aluminum Alloy 1100 was employed. In this experiment, Inconel 718 was used as workpiece material and the result of Aluminum Alloy taken from recent studies. Then, A cutting tool with a diameter 1 mm carbide coating TiAlN was used in this experiment. The machining process was performed with three varieties of spindle speed and feed rate with a constant depth of cut. After the machining is done, the mapping of the result surface roughness of Inconel 718 and AA1100 performed. It was found that Inconel 718 has poor machinability compared with AA 1100. Inconel 718 also has a high manufacturing cost compared to AA 1100 because the cutting tool was easy to wear. Introduction The development of micro-products in industry, like aviation, medical equipment, electronics, etc, has been increasing lately. The need for scaling down of product has been increasing to make the product simpler and complex. The aviation industry, like aircraft’s engine, use hard material like Inconel 718 because it offers high strength, corrosion resistance, and can work in high temperature. Unfortunately, Inconel 718 is categorized in hard-to-cut material which means it has poor machinability. Unlike Inconel 718, Aluminum Alloy 1100 has excellent machinability but it is not a high-strength material like Inconel 718. It can be shaped into many different products, for the example fin stock, cooking utensils, chemical equipment, etc. Because the product has a more complex form, a flexible machining process is needed. Therefore, there is a need a manufacturing process that can produce a good product quality, like good surface quality and tight geometry accuracy for a complexity form products. There is a micromanufacturing process for micro-channels, like micro-EDM, etching, electroplating, bio machining, micro-milling, etc. These processes with their advantages used to manufacture a product but these processes also have fewer material restrictions [1]. The processes of machining that using cutting tool dimension from 1 to 1000 µm is defined as micromachining processes [2]. Micro-milling is one of the micro-manufacturing processes that have the capability of machining in micro-scale. Micro-milling also called as a flexible machining process, since it can produce 3D complex parts. It offers good surface quality and tight accuracy geometry. But it all depends on the combination of machining parameters. Micro-milling is one of the technologies used for production of microstructures and tooling inserts for micro-injection moulding and hot embossing[3]. Ardila et. al. [4] manufactured a microfluidic mould by using micro-milling process. Good quality products can be achieved by selecting a good machining parameter. Machining All rights reserved. No part of contents of this paper may be reproduced or transmitted in any form or by any means without the written permission of Trans Tech Publications Ltd, www.scientific.net. (#540475089, Hong Kong University of Science & Technology, Kowloon, Hong Kong-23/06/20,17:28:25)

100 Engineering and Innovative Materials VIII parameters consist of spindle speed, feed rate, depth of cut, length of the cut, machining time, etc. Each of them will affect the quality of machined products, like surface roughness, burr, and geometry accuracy. Machining parameters also affect the wear of the cutting tool and also the productivity of the industry in producing parts. Inconel 718 is a hard-to-cut material which has poor machinability. Recently, there is a development on the machining parameter for Inconel 718. It was found that the feed rate is the most influential parameters to the surface roughness [5]. The increasing of feed per tooth will lead to an increase in surface roughness. It happened because of the increasing of the chip load that affects the increase of cutting force. It also found that the depth of cut did not significantly affect the surface roughness. [6]. Lu et.al. (2018) investigated and also optimized the machining parameters to achieve machining efficiency. In their research also found the curve of the prediction of cutting tool condition through the machining process of micro-milling process. It found that there are parameters that can achieve machining efficiency but in the safe cutting tool zone [7]. Besides of Inconel 718, there is also a development of machining parameters on aluminum alloy. Machining aluminum is considered relatively easy [8]. Kiswanto et. al. (2015) investigated the effect of machining parameters on the surface roughness on aluminum alloy 1100. It was found that the surface roughness will be increasing along the machining time because of the cutting tool went wear. The increasing feed rate will lead to an increase in surface roughness. In their research also found that machining time and feed rate have a significant impact on the surface roughness [9]. Campos et. al. (2016) studied the cutting forces on micro-milling aluminum alloy. It found that specific cutting force influenced by cutting velocity [10]. Unfortunately, there is no mapping of machining parameters of the material that categorized as hard-to-cut materials that have poor machinability and material that easy-to-cut that has excellent machinability. Therefore, this research will do mapping the cutting parameter of both materials to get the characteristics or different behavior of the machining process on poor machinability materials and excellent machinability materials. This research will map the effect of machining parameters on the surface roughness of Inconel 718 and Aluminum Alloy 1100. The experiments of Aluminum Alloy 1100 already done lately in our lab with referred to Kiswanto et.al. (2015) [9]. Experimental Setup In this research, a miniaturized 5-axis micro-milling machine was used in this experiment for the machining process. The machine tool can be seen in Fig. 1. The machine tool has 5-axis movement which is actuated with a motor stepper that has resolution 1 micron. These motor stepper for each axis controlled with three control units DS102 Suruga Seiki. In this research, the machine tool’s spindle is powered with an electric motor. Nakanishi HES 810 electric motor spindle used in this experiment which can provide spindle speed up to 80.000 RPM. Inconel 718 with dimension 10 mm x 10 mm x 4,8 mm was selected as workpiece material. In these experiments, the workpiece material has hardness with value 66 HRC. The cutting tool was used in this experiments is DIXI 7242 with a diameter of the cutting tool was 1 mm and the number of flutes was 2. The shank diameter was 3 mm. The length of the cutting tool was 38 mm. The material of the cutting tool is carbide. The TiAlN, Titanium Aluminum Nitride, the coating was used on the cutting tool to increase the hardness of the cutting tool. The condition of the cutting tool can be seen in Fig. 1. Before the machining process, cleaning of workpiece material and the cutting tool was done by using an ultrasonic cleaner to remove dust and dirt. Since it's a micro process, dust and dirt must be considered since it could affect the micro-cutting process. Then, before done the machining process, facing process to the workpiece was employed to get a flat surface on the workpiece so there will be less effect of the irregularity of the surface. The overhang length of the cutting tool was 15 mm to prevent chatter vibration and high cutting force.

Key Engineering Materials Vol. 846 (a) 101 (b) Fig. 1. A condition of new cutting tool DIXI 7242. In this research, there are three variations of spindle speed and feed rate. The depth of cut in this research is constant at 10 µm. The machining parameters can be seen in Table 1. Dry cutting in this machining process was employed. This experiments performed slot milling process for each machining parameters. The length of the slot is 4,2 mm. The surface roughness of every machining parameters measured by using SURFCOM 2900 SD3 and the cutting tool condition is captured with Dino-Lite. Table 1. Machining parameters of this experiments. Spindle Speed Feed Rate Depth of cut Machining Time Length of cut No [RPM] [mm/s] [µm] [s] [mm] 1 30000 1,5 2,8 4,2 2 30000 3 1,4 4,2 3 30000 6 0,7 4,2 4 50000 1,5 2,8 4,2 5 50000 3 10 1,4 4,2 6 50000 6 0,7 4,2 7 80000 1,5 2,8 4,2 8 80000 3 1,4 4,2 9 80000 6 0,7 4,2 Results and Discussion After every machining process of machining parameter was done, the surface roughness was measured by using SURFCOM 2900 SD3. The result of machining parameters on aluminum alloy 1100 referred to Kiswanto et. al. (2015) which can be seen in Table 3 [9]. Then, the result of machining parameters on Inconel 718 of these experiments can be seen in Table 2. In this research, mapping is the process of creating the sea of machining parameters of materials wherein this research the materials is Inconel 718 and Aluminum Alloy 1100. The results of the surface roughness of each machining parameters for each material will be mapped into one graph. The graph will show the characteristics of machining parameters of each material. Based on Fig. 2, it can be seen the mapping of cutting parameters from both materials. Based on the graph, Inconel 718 has a higher starting point of surface roughness than Aluminum Alloy 1100 where the Inconel only machined with the length of cut 4.2 mm while the AA 1100 machined with the length of cut 45 mm, nearly 10 times of the length of cut of Inconel 718. Inconel 718 has higher surface roughness than Aluminum Alloy 1100. So that can be said that Inconel 718 is a poor machinability material than Aluminum Alloy 1100.