A Study on Very High Cycle Fatigue Properties of Low Flammability Magnesium Alloy in Rotating Bending and Axial Loading

Abstract:

In order to use a low flammability magnesium alloy as structural components, very high cycle fatigue properties of this alloy (AMCa602) were investigated. S-N properties obtained in both rotating bending and axial loading were compared with each other. It was found that S-N curve in the axial loading appeared a little lower than that in the rotating bending due to the differences of stress distributions and critical volumes for both loading types. Moreover, the statistical aspect on the fatigue property was analyzed as P-S-N characteristics in the rotating bending. After fatigue tests, fracture surfaces of failed specimens were observed by means of a scanning electron microscope (SEM) and the microstructures at the crack initiation site and the propagation path were also observed by combining FIB technique and EBSD analysis. Thus, it was found that some specimens failed from surface inclusions and their fatigue lives were lower in comparison to those of the specimens without surface inclusions. In addition, the fracture surfaces of this alloy revealed very rough in the usual life region, whereas a characteristic smooth area was observed on the fracture surfaces of specimens failed in the surface inclusion-initiated fracture and in very high cycle regime. A stress intensity factor range at the front of the smooth area (ΔK_smooth) tended to a definite value so that the fracture mechanism of this alloy was governed by a concept of ΔK.

• Periodical: Applied Mechanics and Materials (Volume 782)
• Pages: 27-41
• DOI: https://doi.org/10.4028/www.scientific.net/AMM.782.27
• Online since: August 2015
• Authors: Tatsuo Sakai, Shoichi Kikuchi, Yuki Nakamura, Noriyuki Ninomiya
• Keywords: Fatigue, Fractography, Magnesium Alloy, S-N Property, Very High Cycle Fatigue

References

[1] Y. Kitahara, K. Ikeda, H. Shimazaki, H. Noguchi, M. Sakamoto and H. Ueno, Fatigue strength characteristics of non-combustible Mg alloy, Transactions of the Japan Society of Mechanical Engineers (series A) 72, 717, (2006), pp.661-668.

DOI: 10.1299/kikaia.72.661

[2] K. Masaki, Y. Ochi, T. Kakiuchi, K. Kurata, T. Hirasawa, T. Matsumura, Y. Takigawa and K. Higashi, High cycle fatigue property of extruded non-combustible Mg Alloy AMCa602, Materials Transactions, 49, 5, (2008), pp.1148-1156.

DOI: 10.2320/matertrans.mc2007108

[3] T. Fujii, K. Morishige, S. Hamada, H. Noguchi, M. Sakamoto and H. Ueno, Fatigue strength characteristics of non-combustible Mg Alloy, Journal of Solid Mechanics and Materials Engineering, 2, 6, (2008), pp.763-770.

DOI: 10.1299/jmmp.2.763

[4] F. Yang, S. M. Yin, S. X. Li and Z. F. Zhang, Crack initiation mechanism of extruded AZ31 magnesium alloy in the very high cycle fatigue regime, Materials Science and Engineering A 491, 1-2, (2008), pp.131-136.

DOI: 10.1016/j.msea.2008.02.003

[5] K. Shiozawa, T. Kashiwagi, T. Murai and T. Takahashi, Fatigue behavior and fractography of extruded AZ80 magnesium alloys in very high cycle regime, Procedia Engineering, 2, (2010), pp.183-191.

DOI: 10.1016/j.proeng.2010.03.020

[6] Y. Ochi, K. Masaki, T. Hirasawa, X. Wu, T. Matsumura, Y. Takigawa and K. Higashi, High cycle fatigue property and micro crack propagation behavior in extruded AZ31 magnesium alloys, Materials Transactions, 47, 4, (2006), pp.989-994.

DOI: 10.2320/matertrans.47.989

[7] K. Tokaji, M. Kamakura, Y. Ishizumi and N. Hasegawa, Fatigue behaviour and fracture mechanism of a rolled AZ31 magnesium alloy, International Journal of Fatigue, 26, 11, (2004), pp.1217-1224.

DOI: 10.1016/j.ijfatigue.2004.03.015

[8] T. Kakiuchi, Y. Ochi, K. Tanaka and T. Matsumura, Effect of surface texture and humidity environment on high cycle fatigue property of wrought magnesium alloys AZ31 and AZ61, Journal of Solid Mechanics and Materials Engineering 4, 11, (2010).

DOI: 10.1299/jmmp.4.1722

[9] T. S. Shih, W. S. Liu and Y. J. Chen, Fatigue of as-extruded AZ61A magnesium alloy, Materials Science and Engineering, A325 (2002), pp.152-162.

DOI: 10.1016/s0921-5093(01)01411-3

[10] D. K. Xu, L. Liu, Y. B. Xu and E. H. Han, The crack initiation mechanism of the forged Mg-Zn-Y-Zr alloy in the super-long fatigue life regime, Scripta Materialia, 56, (2007), pp.1-4.

DOI: 10.1016/j.scriptamat.2006.09.006

[11] S. A. Khan, Y. Miyashita, Y. Mutoh and Z. B. Sajuri, Influence of Mn content on mechanical properties and fatigue behavior of extruded Mg alloys, Materials Science and Engineering, A 420, (2006), pp.315-321.

DOI: 10.1016/j.msea.2006.01.091

[12] T. Sakai, Y. Ochi and J. W. Jones, Special issue on the international conference on very high cycle fatigue (VHCF-3) held in Kyoto/Kusatsu, Japan, International Journal of Fatigue, 28, 11, (2006), p.1437.

DOI: 10.1016/j.ijfatigue.2006.02.045

[13] K. S. R. Chandran, G. T. Cashman, J. M. Larsen and T. Sakai, Special issue on competing failure modes and variability in fatigue, International Journal of Fatigue, 32, 3, (2010), p.481.

DOI: 10.1016/j.ijfatigue.2009.08.006

[14] JSMS Committees on Fatigue of Materials and Reliability Engineering, Standard Regression Method of S-N Curves, The Society of Materials Science, Japan, (2008).

[15] R. E. Peterson: Stress concentration design factors, John Wiley & Sons, Inc., (1953).

[16] T. Sakai, T. Furusawa, R. Takizawa, N. Oguma, H. Hohjo and H. Ikuno, Development of multi-type high efficiency fatigue testing machines in rotating bending and axial loading, Proceedings of the Hael Mughrabi Honorary Symposium, TMS Annual Meeting, (2008).

[17] T. Yamamoto, A. Kokubu, T. Sakai, Y. Nakamura, Development and Several Additional Performances of Dual-Spindle Rotating Bending Fatigue Testing Machine GIGA QUAD, Proceedings of VHCF-6, (2014), [AAI06].

DOI: 10.1299/jsmekansai.2014.89._11-9_

[18] T. Sakai, Review and prospects for current studies on very high cycle fatigue of metallic materials for machine structural use, Journal of Solid Mechanics and Materials Engineering, 3, 3, (2009), pp.1573-1587.

DOI: 10.1299/jmmp.3.425

[19] M. Nakajima, N. Kamiya, H. Itoga, K. Tokaji and H. N. Ko, Experimental estimation of crack initiation lives and fatigue limit in subsurface of a high carbon chromium steel, International Journal of Fatigue, 28, 11 (2006), pp.1540-1546.

DOI: 10.1016/j.ijfatigue.2005.05.017

[20] K. S. R. Chandran, P. Chang and G. T. Cashman, Competing failure modes and complex S-N curves in fatigue of structural materials, International Journal of Fatigue, 32, 3, (2010), pp.482-491.

DOI: 10.1016/j.ijfatigue.2009.08.004

[21] G. T. Cashman, A review of competing modes fatigue behavior, International Journal of Fatigue, 32, 3, (2010), pp.492-496.

DOI: 10.1016/j.ijfatigue.2009.04.018

[22] W. Li, T. Sakai, M. Wakita and S. Mimura, Effect of surface finishing and loading condition on competing failure mode of clean spring steel in very high cycle fatigue regime", Materials Science and Engineering, A, Vol. 552, (2012), pp.301-309.

DOI: 10.1016/j.msea.2012.05.044

[23] T. Sakai, B. Lian, M. Takeda, K. Shiozawa, N. Oguma, Y. Ochi, M. Nakajima, T. Nakamura, Statistical duplex S-N characteristics of high carbon chromium bearing steel in rotating bending in very high cycle regime, International Journal of Fatigue, Vol. 32, 3, (2010).

DOI: 10.1016/j.ijfatigue.2009.08.001

[24] K. Shiozawa, M. Murai, Y. Shimatani and T. Yoshimoto, Transition of fatigue failure mode of Ni-Cr-Mo low-alloy steel in very high cycle regime, International Journal of Fatigue, 32, 3, (2010), pp.541-550.

DOI: 10.1016/j.ijfatigue.2009.06.011

[25] S. Ando and H. Tonda, Deformation and fatigue behaviors in Mg, Materia Japan, 42, 2, (2003), pp.124-132.

[26] M. Battaini, E. V. Pereloma and C. H. J. Davies, Orientation effect on mechanical properties of commercially pure titanium at room temperature, Metallurgical and Materials Transactions A 38, 2, (2007), pp.276-285.

DOI: 10.1007/s11661-006-9040-2

[27] Y. Murakami and M. Endo, Effects of defects, inclusions and inhomogeneities on fatigue strength, International Journal of Fatigue, 16, 3, (1994), pp.163-182.

DOI: 10.1016/0142-1123(94)90001-9

[28] Z. Nan, S. Ishihara, T. Goshima and R. Nakanishi, Fatigue behavior of AZ31 extruded magnesium alloy in laboratory air, Transactions of the Japan Society of Mechanical Engineers, 70, 696, (2004), pp.1146-1152.

DOI: 10.1299/kikaia.70.1146