Ultrasonic-Assisted Innovative Polyurethane Tool to Polish Mold Steel
Ming-Yi Tsai, Yue-Feng Lin, Jihng-Kuo Ho, and Jing-Guang Yang
Department of Mechanical Engineering, National Chin-Yi University of Technology
No.57, Section 2, Zhongshan Road, Taiping District, Taichung 41170, Taiwan
High-quality die and mold production is becoming increasingly important in modern mass production. Surface quality is one of the most frequent and stringent customer specifications for machined parts, of which the major consideration and indication of quality is their surface roughness. In this study, a novel ball-ended polishing tool made of polyurethane impregnated with micro cubic boron nitride (CBN) was developed. The polishing tool was mounted on a three-axis machining center; the rotary polishing action was achieved via ultrasonics. Polishing experiments were conducted on specimens of hardened Stavax stainless mold steel. Four types of polishing tools – containing 10 wt% of pure CBN particles and Al2O3 coated CBN with two different degrees of hardness (Shore 25 and 45) – were fabricated; the results of the experiments were compared with those obtained using a traditional elastic-ball polishing tool. It was found that the surface quality achieved using the Al2O3 coated CBN tool was superior to that with pure CBN particles because the hardness of the polishing tool increased with the increase in the surface roughness of the workpiece. In addition, ultrasonic-assisted polishing yielded a better surface finish.
-  J. H. Ahn, Y. F. Shen, H. Y. Kim, H. D. Jeong, and K. K. Cho, “Development of a sensor information integrated expert system for optimizing die polishing,” Robotics and Computer Integrated Manufacturing, Vol.17, pp. 269-276, 2001.
-  J. H. Ahn, M. C. Lee, H. D. Jeong, S. R. Kim, and K. K. Cho, “Intelligently automated polishing for high quality surface formation of sculptured die,” J. of Materials Processing Technology, Vols.130-131, pp. 339-344, 2002.
-  B. S. Ryuh, S. M. Park, and G. R. Pennock, “An automatic tool changer and integrated software for a robotic die polishing station,” Mechanism and Machine Theory, Vol.41, pp. 415-432, 2006.
-  X. Wu, Y. Kita, and K. Ikoku, “New polishing technology of free form surface by GC,” J. of Materials Processing Technology, Vols.187-188, pp. 81-84, 2007.
-  M. Joshi, S. More, R. K. Singh, S. S. Joshi, R. Balasubramaniam, and V. K. Suri, “Experimental characterization of hydrodynamic nano polishing of flat steel plate,” Precision Engineering, Vol.36, pp. 424-434, 2012.
-  F. J. Shiou and C. H. Chuang, “Precision surface finish of the mold steel PDS5 using an innovative ball burnishing tool embedded with a load cell,” Precision Engineering, Vol.34, pp. 76-84, 2010.
-  P. Balland, L. Tabourota, F. Degre, and V. Moreau, “Mechanics of the burnishing process,” Precision Engineering, Vol.37, pp. 129-134, 2013.
-  J. Guo, H. Suzuki, and T. Higuchi, “Development of micro polishing system using a magnetostrictive vibrating polisher,” Precision Engineering, Vol.37, pp. 81-87, 2013.
-  J. Y. Choi and H. Jeong, “A study on polishing of molds using hydrophilic fixed abrasive pad,” Int. J. of Machine Tools and Manufacture, Vol.44, pp. 1163-1169, 2004.
-  F. Nagata, T. Hase, Z. Haga, M. Omoto, and K. Watanabe, “CAD/CAM-based position/force controller for a mold polishing robot,” Mechatronics, Vol.17, pp. 207-216, 2007.
-  H. Hocheng and K. L. Kuo, “Fundamental study of ultrasonic polishing of mold steel,” Int. J. of Machine Tools and Manufacture, Vol.42, pp. 7-13, 2002.
-  F. J. Shiou and H. S. Ciou, “Ultra-precision surface finish of the hardened stainless mold steel using vibration-assisted ball polishing process,” Int. J. of Machine Tools and Manufacture, Vol.48, pp. 721-732, 2008.
-  Y. T. Su, S. H. Liu, and Y. W. Chen, “A preliminary study on smoothing efficiency of surface irregularities by hydrodynamic polishing process,” Wear, Vol.249, pp. 808-820, 2001.
-  H. Suzuki, S. Hamada, T. Oondo, Y. Yamagata, and T. Higuchi, “Ultra precision finishing of micro-aspheric surface by ultrasonic two-axis vibration assisted polishing,” CIRP Annals – Manufacturing Technology, Vol.59, pp. 347-350, 2010.
-  H. Suzuki, T. Moriwaki, T. Okino, and Y. Ando, “Development of ultrasonic vibration assisted polishing machine for micro aspheric die and mold,” CIRP Annals – Manufacturing Technology, Vol.55, pp. 385-388, 2006.
-  Z. Ke, H. Qing, L. Liang, and R. Yi, “Study on chemical mechanical polishing of silicon wafer with megasonic vibration assisted,” Ultrasonics, Vol.80, pp. 9-14, 2017.
-  F. Lakhdari, D. Bouzid, N. Belkhir, and V. Herold, “Surface and subsurface damage in Zerodur® glass ceramic during ultrasonic assisted grinding,” The Int. J. of Advanced Manufacturing Technology, Vol.90, pp. 1993-2000, 2017.
-  R. Azlan, R. Izamshah, M. Hadzley, M. S. Kasim, M. Arfauz, and M. Akmal, “Experimental investigation of surface roughness using ultrasonic assisted machining of hardened steel,” Proc. of Mechanical Engineering Research Day, pp. 212-213, 2016.
-  M. Y. Tsai, C. T. Chang, and J. K. Ho, “The Machining of Hard Mold Steel by Ultrasonic Assisted End Milling,” Applied Sciences, Vol.6, pp. 1-12, 2016.
-  S. Amini, A. Bagheri, and R. Teimouri, “Ultrasonic-assisted ball burnishing of aluminum 6061 and AISI 1045 steel,” Materials and Manufacturing Processes, pp. 1-10, 2017.
-  D. Liu, R. Yan, and T. Chen, “Material removal model of ultrasonic elliptical vibration-assisted chemical mechanical polishing for hard and brittle materials,” The Int. J. of Advanced Manufacturing Technology, Vol.92, pp. 82-99, 2017.