Effect of Ultrasonic Vibration on Deformation in Micro-blanking Process with Copper Foil

Abstract

Effect of ultrasonic vibration on deformation in micro-blanking was investigated with copper foils of different grain sizes using a developed device. It is found that maximum shearing strength is decreased by ultrasonic vibration, and this effect becomes bigger for coarse grain than that for fine grain, which can be attributed to acoustic softening effect considering the absorbed acoustic energy. Surface roughness R _a of smooth zone decreases for the polishing effect of vibration at the lateral contact surface. When ultrasonic vibration is applied, the sheared deformation area becomes relatively narrow, and it leads to the reduction of radius of rollover. The analysis of cross section in sheared deformation area shows that the crack initiation is inhabited for the existence of acoustic softening, and the proportion of smooth zone is increased. Also, angle of crack propagation becomes smaller because of periodic strain, and the angle of facture surface is decreased. As a result, the quality of micro-sheet parts is improved by applying ultrasonic vibration.

Keywords

micro-blanking / ultrasonic vibration / maximum shearing strength / acoustic softening effect / periodic strain / crack initiation and propagation

References

[1] Vollertsen F, Schulze Niehoff H, Hu Z. State of the Art in Micro Forming[ J]. International Journal of Machine Tools & Manufacture, 2006, 46: 1172-1179.

[2] Wang CJ, Wang CJ, Shan DB, et al. Manufacturing High Aspect Ratio Microtubine by Isothermal Microforging Process[J]. Materials and Manufacturing Processes, 2014, 29: 42-45.

[3] Fu MW, Chan WL. A Review on the State–of–the–art Microforming Technologies[J]. International Journal of Advanced Manufacturing Technology, 2013, 67: 2 411-2 437.

[4] Fu MW, Wang JL, Korsunsky AM. A Review of Geometrical and Microstructural Size Effects in Micro–scale Deformation Processing of Metallic Alloy Component[J]. International Journal of Machine Tools & Manufacture, 2016, 109: 94-125.

[5] Wang CJ, Guo B, Shan DB, et al. Experimental Research on Micro–deep Drawing Processes of Pure Gold Thin Sheet Using DLC–coated Female Die[J]. International Journal of Advanced Manufacturing Technology, 2013, 67: 2 477-2 487.

[6] Wang CJ, Wang CJ, Shan DB, et al. Effects of Tribological Behaviors of DLC Film on Micro–deep Drawing Processes[J]. Transactions of Nonferrous Metals Society of China, 2014, 24(9): 2 877-2 882.

[7] Xu J, Guo B, Wang CJ, et al. Blanking Clearance and Grain Size Effects on Micro Deformation Behavior and Fracture in Micro–blanking of Brass Foil[J]. International Journal of Machine Tools & Manufacture, 2012, 60: 27-34.

[8] Wang CJ, Wang CJ, Xu J, et al. Interactive Effect of Microstructure and Cavity Dimension on Filling Behavior in Micro Coining of Pure Nickel[J]. Scientific Reports, 2016, 6: 23 895-23 904.

[9] Blaha F, Langenecker B. Elongation of Zinc Monocrystals under Ultrasonic Action[J]. Die Naturwissenschaften, 1955, 42(20): 556

[10] Yao ZH, Kim GY, Wang ZH, et al. Acoustic Softening and Residual Hardening in Aluminum: Modeling and Experiments[J]. International Journal of Plasticity, 2012, 39: 75-87.

[11] Wang CJ, Liu Y, Guo B, et al. Acoustic Softening and Stress Superposition in Ultrasonic Vibration Assisted Uniaxial Tension of Copper Foil: Experiments and Modeling[J]. Materials & Design, 2016, 112: 246-253.

[12] Siu KW, Ngan AHW, Jones IP. New Insight on Acoustoplasticity–ultrasonic Irradiation Enhances Subgrain Formation during Deformation[J]. International Journal of Plasticity, 2011, 27: 788-800.

[13] Hayashi M, Jin M, Thipprakmas S, et al. Simulation of Ultrasonic–vibration Drawing using the Finite Method (FEM)[J]. Journal of Materials Processing Technology, 2003, 140: 30-35.

[14] Huang YM, Wu YS, Huang JY. The Influence of Ultrasonic Vibration–assisted Micro–deep Drawing Process[J]. International Journal of Advanced Manufacturing Technology, 2014, 71: 1 455-1 461.

[15] Bunget C, Ngaile G. Influence of Ultrasonic Vibration on Micro–extrusion[ J]. Ultrasonics, 2011, 51: 606-616.

[16] Bai Y, Yang M. Investigation on Mechanism of Metal Foil Surface Finishing with Vibration–assisted Micro–forging[J]. Journal of Materials Processing Technology, 2013, 213: 330-336.

[17] Yeh W, Chu T, Wang S, et al. Finite Element Analysis of Blanking Process by Superimposing Ultrasonic Vibrations[J]. Advanced Materials Research, 2011, 201–203: 126-132.

[18] Kakemasu T, Yamasaki S, Miura H, et al. Development of New Piercing System for Micro–holes by Continuous Striking of a Punch Using Ultrasonic Vibration[C], 2005 In: Proceeding of the 8th ICTP.

[19] Witthauer AT, Kim GY, Faidley LE, et al. Effects of Acoustic Softening and Hardening in High–frequency Vibration–assisted Punching of Aluminium[ J]. Materials and Manufacturing Processes, 2014, 29: 1 184-1 189.