Investigation of Optimum Grinding Condition Using cBN Electroplated End-Mill for CFRP Machining
Shinnosuke Yamashita*, Tatsuya Furuki*,, Hiroyuki Kousaka*, Toshiki Hirogaki**, Eiichi Aoyama**, Kiyofumi Inaba***, and Kazuna Fujiwara***
1-1 Yanagido, Gifu, Gifu 501-1193, Japan
**Doshisha University, Kyotanabe, Japan
***Kamogawa Co., Ltd., Ritto, Japan
Recently, carbon fiber reinforced plastics (CFRP) have been used in various applications such as airplanes and automobiles. In CFRP molding, there are unnecessary portions on the outer area. Therefore, a machining process is required to remove them. Cutting and grinding are conventionally used in the finish machining of CFRPs. End-milling allows the removal of most of these portions. However, uncut fibers easily occur during end-milling. In contrast, a precise machined surface and edge are easily obtained using a grinding tool. Therefore, this research has developed a novel cubic boron nitride (cBN) electroplated end-mill that combines an end-mill and a grinding tool. This is a versatile tool that can cut and grind CFRPs by changing the direction of rotation of the tool. In this study, the effectiveness of the developed tool is investigated. First, the developed tool machined the CFRP by side milling. Consequently, cBN abrasives that were fixed on the outer surface of the developed tool did not detach in certain cutting conditions. Next, in order to generate a sharp edge on the CFRP and restrict the increase in the CFRP temperature with the cBN electroplated end-mill, the optimum abrasive size and grinding condition were investigated through the design of experiments. Moreover, the effectiveness of the developed tool was verified by comparing it with a conventional tool. As a result, smaller burrs and uncut fibers were observed after final machining with the developed tool under the derived optimum condition than those with conventional tools. However, the desired surface roughness could not be achieved as required by the airline industry. Therefore, oscillating grinding was applied. In addition, the formula of the theoretical surface roughness while using the developed tool was derived using the theory of slant grinding. As a result, the oscillating condition that led to the required surface roughness was obtained by theoretical analysis. In addition, the required value for the airline industry was achieved by oscillating grinding.
-  H. Hocheng, H. Y. Tsai, J. J. Shiue, and B. Wang, “Feasibility study of abrasive-waterjet milling of fiber-reinforced plastics,” J. of Manufacturing Science and Engineering, Vol.119, No.2, pp. 133-142, 1997.
-  J. Wang, “Machinability study of polymer matrix composites using abrasive waterjet cutting technology,” J. of Materials Processing Technology, Vol.94, No.1, pp. 30-35, 1999.
-  H. Hocheng, H. Y. Puw, and Y. Huang, “Preliminary study on milling of unidirectional carbon fibre-reinforced plastics,” Composites Manufacturing, Vol.4, No.2, pp. 103-108, 1993.
-  H. Arisawa and S. Akama, “High-Performance Cutting and Grinding Technology for CFRP (Carbon Fiber Reinforced Plastic),” Mitsubishi Heavy Industries Technical Review, Vol.49, No.3, pp. 3-9, 2012.
-  T. Furuki, T. Hirogaki, E. Aoyama, and K. Ogawa et al., “Investigation of cBN electroplated end-mill shape for CFRP machining,” Materials Science Forum, Vol.874, pp. 463-468, 2016.
-  M. Senthilkumar, A. Prabukarthi, and V. Krishnaraj, “Study on Tool Wear and Chip Formation during Drilling Carbon Fiber Reinforced Polymer (CFRP) / Titanium Alloy (Ti6Al4V) Stacks,” Procedia Engineering, Vol.64, pp. 582-592, 2013.
-  T. Furuki, Y. Kabaya, T. Hirogaki, E. Aoyama et al., “Development of cBN electroplated end-mill combined cutting and grinding for precision machining of CFRP,” Int. J. of Abrasive Technology, Vol.8, No.3, pp. 188-202, 2018.
-  S. Kondo, C. Ohkawa, T. Hanawa, T. Sugawara et al., “Differences in Surface Roughness between Up and Down Cutting and Grinding on Composite Resins,” Dental Materials J., Vol.4, No.2, pp. 223-230, 1985.
-  Y. Kabaya, T. Furuki, T. Hirogaki, E. Aoyama et al., “Influence of grit size in high speed milling of CFRP with cBN electroplated end-mill,” J. of the Japan Society for Precision Engineering, pp. 405-406, 2015 (in Japanese).
-  T. Chen, J. Xiang, F. Gao, and X. Liu et al., “Study on cutting performance of diamond-coated rhombic milling cutter in machining carbon fiber composites,” Int. J. of Advanced Manufacturing Technology, Vol.103, No.9, pp. 4731-4737, 2019.
-  P. M. George, B. K. Raghunath, L. M. Manocha, and A. M. Warrier, “EDM machining of carbon-carbon composite – A Taguchi approach,” J. of Materials Processing Technology, Vol.145, No.1, pp. 66-71, 2004.
-  Y. H. Ren, B. Zhang, and Z. X. Zhou, “Specific energy in grinding of tungsten carbides of various grain sizes,” CIRP Annals, Vol.58, No.1, pp. 299-302, 2009.
-  R. L. Hecker and S. Y. Liang, “Predictive modeling of surface roughness in grinding,” Int. J. of Machine Tools and Manufacture, Vol.43, No.8, pp. 755-761, 2003.
-  T. Tashiro, J. Fujiwara, S. Hanasaki, and S. Fujiwara, “Formation mechanism of ground surface of CFRP,” J. of the Japan Society for Abrasive Technology, Vol.49, No.2, pp. 99-104, 2005 (in Japanese).
-  T. Kaneeda and M. Takahashi, “CFRP Cutting Mechanism (2nd Report),” J. of the Japan Society for Precision Engineering, Vol.56, No.6, pp. 1058-1063, 1990 (in Japanese).
-  H. Wang, J. Sun, J. Li, L. Lu et al., “Evaluation of cutting force and cutting temperature in milling carbon fiber-reinforced polymer composites,” Int. J. of Advanced Manufacturing Technology, Vol.82, No.9, pp. 1517-1525, 2016.
-  H. Fukagawa, “Processing of the Hard to Cut Materials and Heat-resistant Alloys for Aircrafts,” J. of the Society of Mechanical Engineers, Vol.115, No.1128, pp. 762-766, 2012 (in Japanese).
-  K. Kanda, S. Takehana, S. Yoshida, R. Watanabe et al., “Application of diamond-coated cutting tools,” Surface and Coatings Technology, Vol.73, Nos.1-2, pp. 115-120, 1995.
-  T. Nakajima, S. Tsukamoto, T. Teraoka, and Y. Ono, “Determination of Oscillation Conditions for Optimizing Surface Roughness in Internal Grinding,” J. of the Japan Society for Precision Engineering, Vol.65, No.4, pp. 604-609, 1999 (in Japanese).
-  K. Shimada, P. J. Liew, T. Zhou, J. Yan et al., “Statistical Approach Optimizing Slant Feed Grinding,” J. of Advanced Mechanical Design, Systems, and Manufacturing, Vol.6, No.6, pp. 898-907, 2012.
-  N. Yoshihara and T. Kuriyagawa, “Statistical Approach to Ground Surface Roughness Formation Mechanism,” Proc. of JSPE Semestrial Meeting, Vol.2005S, pp. 863-864, 2005 (in Japanese).
-  K. Ono, “Influences of Grit Profile and Grit Distribution on Ground Surface Roughness,” Japan Society of Mechanical Engineers, Vol.30, No.211, pp. 361-368, 1964 (in Japanese).
-  T. Mori, K. Tasaka, M. Ichimiya, and T. Ogasawara, “Surface Roughness Parameter and Slip Coefficient of Friction Type of High Strength Bolted Connections,” J. of Japan Society of Civil Engineers, Ser. A1 (Structural Engineering & Earthquake Engineering (SE/EE)), Vol.67, No.2, pp. 446-453, 2011 (in Japanese).