Paper:
Effect of Vibration Direction of Ultrasonic Vibrating Cutting Edge on Internal Stress Fluctuation of Workpiece
Hiromi Isobe*,, Masatoshi Okuda*, Keisuke Hara**, and Jun Ishimatsu***
*Nagaoka University of Technology
1603-1 Kamitomioka, Nagaoka, Niigata 940-2188, Japan
Corresponding author
**National Institute of Technology, Ichinoseki College, Ichinoseki, Japan
***Universiti Teknologi Malaysia, Kuala Lumpur, Malaysia
The aim of this study is to investigate the dynamic phenomenon of ultrasonic vibration-assisted cutting by utilizing a stress distribution visualization system. The vibrating cutting-edge is considered to be a cause of dynamic changes in the cutting force at ultrasonic frequencies. However, many researchers have explained the effect of ultrasonic vibration-assisted cutting by evaluating the time-averaged cutting force, because existing dynamometers are unable to measure the dynamically changing cutting force at ultrasonic frequencies. There are some reports that the vibration direction of cutting edge strongly affects tool wear. However, in practical ultrasonic cutting, the vibration of the cutting edge has yet to be measured in a production environment. In this study, the instantaneous stress distribution on the workpiece was visualized by a photoelastic method that combines a pulsed laser emission synchronized with tool vibration. The developed photographic system can capture 360 frames in one ultrasonic vibration period. The dynamic cutting force was calculated by Flamant’s stress distribution theory. It was experimentally confirmed that the stress distribution under vibration-assisted conditions showed periodical changes synchronized with vibration. Because these results are compatible with well-known vibration-cutting theories, the imaging system was able to show the periodic changes in stress distribution in the ultrasonic frequency band. This indicates that the dynamic change in cutting force during the ultrasonic vibration period affects intermittent cutting conditions. In this report, the vibration direction was adjusted from −9.5° to +9.5° along the cutting direction. When the tool moved in upwards for the cutting phase and downwards for withdrawal phase, the stress distribution was continuously observed over one tool vibration period; no intermittent cutting was observed. The locus of the cutting force vector was affected by the ultrasonic vibration direction and rake angle of the cutting tool. A negative rake angle showed that the direction of the cutting force vector shifted toward the workpiece side near the most advanced position of the cutting edge.
- [1] F. Gao, B. Zhao, F. Jiao, and C. Liu, “Research on the Characteristics of the Cutting Force in the Vibration Cutting of a Particle-reinforced Metal Matrix Composites SiCp/Al,” J. Materials Processing Technology, Vol.129, No.1-3, pp. 196-199, 2002.
- [2] R. Mumhammad, A. Maurotto, A. Roy, and V. Silberschmidt, “Ultrasonically Assisted Turning of β-Ti Alloy,” Procedia CIRP 2012, Vol.1, pp. 336-341, 2012.
- [3] K. Hara and H. Isobe, “Effect of cutting speed on ultrasonically added turning in soft magnetic stainless steel,” Advanced Materials Research, Vol.806, pp. 390-393, 2015.
- [4] T. Yamazaki, K. Tsuchiya, and U. Sato, “Ultrasonic vibration cutting of Ti-6mass%Ai-4mass%V alloy,” J. of Japan Institute of Light Metals, Vol.57, No.4, pp. 152-156, 2007 (in Japanese).
- [5] H. Isobe, Y. Uehara, K. Hara, and T. Onuma, “Experimental Verification of Machining Process of Ultrasonic Drilling,” Key Engineering Materials, Vol.516, pp. 275-280, 2012.
- [6] H. Isobe, K. Kazuya, and K. Hara, “Improvement of cutting performance by ultrasonic vibration drilling,” J. of Japanese Society for Abrasive Technology, Vol.59, No.6, pp. 328-333, 2015 (in Japanese).
- [7] J. Wang, H. Zha, P. Feng, and J. Zhang, “On the mechanism of edge chipping reduction in rotary ultrasonic drilling A novel experimental method,” Precision Engineering, Vol.44, pp. 231-235, 2016.
- [8] K. Egashira, R. Kumagai, R. Okina, K. Yamaguchi, and M. Ota, “Drilling of microholes down to 10 um in diameter using ultrasonic grinding,” Precision Engineering, Vol.38, No.3, pp. 605-610, 2014.
- [9] D. Lv, H. Wang, Y. Tang, Y. Huang, and Z. Li, “Influences of vibration on surface formation in rotary ultrasonic machining of glass BK7,” Precision Engineering, Vol.37, pp. 839-848, 2013.
- [10] Y. Wang, N. Suzuki, E. Shamoto, and Q. Zhao, “Investigation of tool wear suppression in ultraprecision diamond machining of die steel,” Precision Engineering, Vol.35, pp. 677-685, 2011.
- [11] H. Saito, H. Jung, and E. Shamoto, “Elliptical vibration cutting of hardened die steel with coated carbide tools,” Precision Engineering, Vol.45, pp. 44-54, 2016.
- [12] H. Isobe and C. Yamaguchi, “High-speed Capturing of Stress Distribution of Workpiece Under Ultrasonically Assisted Cutting Condition,” J. of Japanese Society for Precision Engineering, Vol.81, No.5, pp. 441-445, 2015 (in Japanese).
- [13] T. Onuma and Y. Otani, “A Dynamic Measurement System for Two-dimensional Birefringence Distribution with Sub-millisecond Time Resolution,” J. of Japanese Society for Precision Engineering, Vol.78, No.12, pp. 1082-1086, 2012 (in Japanese).
- [14] E. Umezawa, “Stress Distribution Measurement Techniques Using Photoelasticity – Current Status and Future Prospects –,” J. of Japanese Society for Precision Engineering, Vol.79, No.7, pp. 607-610, 2013 (in Japanese).
- [15] A. Kumabe and K. Yamamoto, “Study on Behavior of Cutting Strain in Ductile Material by Photoelastic Coating Method,” J. of Japanese Society for Precision Engineering, Vol.54, No.11, pp. 2144-2148, 1988 (in Japanese).
- [16] K. Iwata, K. Osakada, and Y. Terasaka, “Process Modeling of Orthogonal Cutting by the Rigid-Plastic Finite Element Method,” J. Eng. Mater. Technol., Vol.106, No.2, pp. 132-138, 1984.
- [17] H. Isobe and K. Hara, “Visualization of Fluctuations in Internal Stress Distribution of Workpiece During Ultrasonic Vibration-assisted Cutting,” Precision Engineering, Vol.48, pp. 331-337, 2017.
- [18] N. Takahashi and J. Shinozuka, “Contributions of High-Speed Cutting and High Rake Angle to the Cutting Performance of Natural Rubber,” Int. J. Automation Technol., Vol.8, No.4, pp. 550-560, 2014.
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