Optimal Design of Steppers in Single Step High Pressure Torsion (SIHPT) Process as a Novel SPD Method

Subject Areas : metal forming

Mehdi Eskandarzadeh ¹ , Ghader Faraji ² , A. Masoumi ³ , Ali Kalaki ⁴

1 - 1School of Mechanical Engineering, College of Engineering, University of Tehran, Tehran, Iran.
2 - Department of Mechanical Engineering, University of Tehran, Iran
3 - 1School of Mechanical Engineering, College of Engineering, University of Tehran, Tehran, Iran.
4 - Department of Technical and Corrosion Protection, Iranian Central Oil Fields Company, Iran

Received: 2018-01-29 Accepted : 2018-08-10 Published : 2019-03-01

Keywords: Slippage, Friction, Single Step Incremental High Pressure Torsion (SIHPT),

Abstract :

Single Step High Pressure Torsion (SIHPT) is a newly developed HPT based method for processing of materials which is capable of producing nanostructured long samples with characteristics comparable to conventional HPT process. While, conventional HPT can be applied only on thin samples; it is possible to produce nanostructured parts with about 10 cm long using SIHPT method. However, SIHPT needs some technical improvements in order to be used for production in industrial scale. One of key component of SIHPT is the steppers which help different sections of the sample to be twisted. This study investigates main parameters of Steppers including the corner radius, thickness and rotation speed. The experimental results revealed that for the lowest length of sample’s contact inside the Steppers (lower contact length) of 5mm; there is considerable slippage in pressures below 1GP. However, the amount of slippage decreases gradually by increasing the magnitude of the applied pressure and the amount of the lower contact length. Moreover, it found that the rotational speed influences the amount of slippage in low pressures (lower than 1 GPa) but not in high pressures. In addition, according to Finite Element (FE) analysis it was found that 1 mm corner radius of steppers is the optimal value for the SIHPT process.

References:

[1]     Valiev, R., Kuznetsov, O., Musalimov, R. S., and Tsenev, N., Low-Temperature Superplasticity of Metallic Materials, Soviet Physics Doklady, 1988, pp. 626.

[2]     Zhilyaev, A. P., Langdon, T. G., Using High-Pressure Torsion for Metal Processing: Fundamentals and Applications. Progress in Materials Science, Vol. 53, 2008, pp. 893-979.

[3]     Polakowski, N. H., Ripling, E. J., Strength and Structure of Engineering Materials.  1rd ed, Prentice Hall, 1966, pp. 346-348, 978-0138517908.

[4]     Levitas, V. I., Zarechnyy, O. M., Numerical Study of Stress and plastic Strain Evolution Under Compression and Shear of a Sample in a Rotational Anvil Cell, High Pressure Research, Vol. 30, 2010, pp. 653-691.

[5]     Kim, H. S., Finite Element Analysis of High Pressure Torsion Processing, Journal of Materials Processing Technology Vol. 113, No. 21, 2001, pp. 617-618.

[6]     Lee, D. J., Yoon, E. Y., Lee, S. H., Kang, S. Y., and Kim, H. S., Finite Element Analysis for Compression Behavior of High Pressure Torsion Processing, Rev Adv Mater Sci, Vol. 31, No. 30, 2012, pp. 25-30.

[7]     Wang, W., Song, Y., Gao, D., Yoon, E. Y., Lee, D. J., and Lee, C. S., et al, Analysis of Stress States in Compression Stage of High Pressure Torsion Using Slab Analysis Method and Finite Element Method, Metals and Materials International, Vol. 19, No. 7, 2013, pp. 1021-1022.

[8]     Zhilyaev, A, Oh-Ishi, K., Langdon, T., and McNelley, T., Microstructural Evolution in Commercial Purity Aluminum During High-Pressure Torsion, Materials Science and Engineering: A, Vol. 410, No. 80, 2005, pp. 277-278.

[9]     Draï, A., Aour, B., Analysis of Plastic Deformation Behavior of HDPE During High Pressure Torsion Process, Engineering Structures, Vol. 46, No. 93, 2013, pp. 87-93.

[10]  Verleysen, P., Van den Abeele, F., and Degrieck, J., Numerical Simulation of HPT Processing, IOP Conference Series: Materials Science and Engineering: IOP Publishing, 2014, pp. 012043.

[11]  Figueiredo, R. B., Cetlin, P. R., and Langdon, T. G., Using Finite Element Modeling to Examine the Flow Processes in Quasi-Constrained High-Pressure Torsion, Materials Science and Engineering: A, Vol. 528, No. 204, 2011, pp. 8198-8198.

[12]  Song, Y., Wang, W., Gao, D., Yoon, E., Lee, D., and Kim, H., Finite Element Analysis of the Effect of Friction in High Pressure Torsion, Metals and Materials International, Vol. 20, No. 50, 2014, pp. 445-446.

[13]  Figueiredo, R. B., Pereira, P. H. R., Aguilar, M. T. P., Cetlin, P. R., and Langdon, T. G., Using Finite Element Modeling to Examine the Temperature Distribution in Quasi-Constrained High-Pressure Torsion, Acta Materialia, Vol. 60, No. 8, 2012, pp. 3190-3191.

[14]  Jahedi, M., Knezevic, M., and Paydar, M. H., High-Pressure Double Torsion as a Severe Plastic Deformation Process: Experimental Procedure and Finite Element Modelling, Journal of Materials Engineering and Performance, Vol. 24, No. 82, 2015, pp. 1471-1472.

[15]  Yoon, S. C., Horita, Z., and Kim, H. S., Finite Element Analysis of Plastic Deformation Behavior During High Pressure Torsion Processing, Journal of Materials Processing Technology, Vol. 201, No. 6, 2008, pp. 32-33.

[16]  Halloumi, A., Busquet, M., and Descartes, S., Parametric Study of Unconstrained High-Pressure Torsion-Finite Element Analysis, IOP Conference Series: Materials Science and Engineering: IOP Publishing, 2014, pp. 012036.

[17]  Hohenwarter, A., Incremental High Pressure Torsion as a Novel Severe Plastic Deformation Process: Processing Features and Application to Copper, Materials Science and Engineering: A, Vol. 626, No. 5, 2015, pp. 80-81.

[18]  Eskandarzade, M., Masoumi, A., Faraji, G., Mohammadpour, M., and Yan, X. S., A New Designed Incremental High Pressure Torsion Process for Producing Long Nanostructured Rod Samples, Journal of Alloys and Compounds, Vol. 695, No. 46, 2017, pp. 1539-1540.

[19]  Sharifi Miavaghi, A., Kangarlou, H., and Eskandarzade, M., Comparison Between Frictional Behavior of the Soft and Brittle Materials at Different Contact Pressures, Lebanese Science Journal, Vol. 18, No. 1, 2017, pp. 98. 

[20]  Gurău, G., Gurău, C., Potecaşu, O., Alexandru, P., and Bujoreanu, L. G., Novel High-Speed High Pressure Torsion Technology for Obtaining Fe-Mn-Si-Cr Shape Memory Alloy Active Elements, Journal of Materials Engineering and Performance, Vol. 23, No. 402, 2014, pp. 2396-2397.

[21]  Chung, S. W., Kim, W. J., Kohzu, M., and Higashi, K., The Effect of Ram Speed on Mechanical and Thermal Properties in ECAE Process Simulation, Materials Transactions, Vol. 44, No. 80, 2003, pp. 973.