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A Study on the Creep Deformation Characteristic of AZ31 Mg Alloy at High Temperature  

An Jungo (Graduate School, Pukyong National University)
Kang Daemi (Department of Mechanical Engineering, Pukyong National University)
Koo Yang (Department of Mechanical Engineering, Pukyong National University)
Sim Sungbo (Department of Mechanical Engineering, Pukyong National University)
Publication Information
Transactions of the Korean Society of Automotive Engineers / v.13, no.3, 2005 , pp. 186-192 More about this Journal
Abstract
The apparent activation energy Qc, the applied stress exponent n, and rupture life have been determined from creep test results of AZ31 Mg alloy over the temperature range of 200$^{\circ}C$ to 300$^{\circ}C$ and the stress range of 23.42 MPa to 93.59 MPa, respectively, in order to investigate the creep behavior. Constant load creep tests were carried out in the equipment including automatic temperature controller with data acquisition computer. At the temperature of $200^{\circ}C{\sim}220^{\circ}C$ and under the stress level of 62.43~93.59 MPa, and at around the temperature of $280^{\circ}C{\sim}300^{\circ}C$ and under the stress level of 23.42~39.00 MPa, the creep behavior obeyed a simple power-law relating steady state creep rate to applied stress and the activation energy fur the creep deformation was nearly equal to that of the self diffusion of Mg alloy including aluminum From the above results, at the temperature of $200^{\circ}C{\sim}220^{\circ}C$ the creep deformation for AZ31 Mg alloy seemed to be controlled by dislocation climb but controlled by dislocation glide at $280^{\circ}C{\sim}300^{\circ}C$ .And relationship beween rupture time and stress at around the temperature of $200^{\circ}C{\sim}220^{\circ}C$ and under the stress level of 62.43~93.59 MPa, and again at around the temperature of $280^{\circ}C{\sim}300^{\circ}C$ and under the stress level of 23.42~39.00 MPa, respectively, appeard as fullow; log$\sigma$=-0.18(T+460)(logtr+21)+5.92, log$\sigma$ = -0.25(T+460)(logtr+21)+8.02 Also relationship beween rupture time and steady state creep rate appears as follow; ln$\dot$ =-0.881ntr-2.45
Keywords
크리이프 속도;변형기구;응력지수;활성화 에너지;크리이프 파단수명;
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  • Reference
1 R. Lagneborg, J. of Met. Sci., p.127, 1969
2 W. F. Sheerly and R. R. Nash, Trans Metall. Soc. AIME Vol.218, p.416, 1960
3 O. D. Sherby and P. M. Burke, 'Mechanical Behavior of Elevated Temperature,' Progress in Materials Science, Vol.13, pp.325-390, 1968
4 A. Seeger, 'The Temperature Dependence of the Critical Shear Stress and of Work Hardening of Metal Crystals,' Phil. Mag., Vol.45, pp.771- 773, 1954   DOI
5 K. Linga Murty, M. Gold and Arthur L. Ruoff, 'High- Temperature Creep Mechanisms in a Iron and Other Metals,' J. of App. Phy., Vol.41, pp.4917-4927, 1962
6 C. Sheldon Roberts, Magnesium and Its Alloys, John Wiley & Sons, pp.158-159, 1958
7 D. W. Kim, H. S. Kim and S. I. Park, 'Magnesium for Automotive Applications,' Journal of KSAE, Vol.18, No.5, pp.53-67, 1996
8 N. F. Mott, Phil. Mag., p.742, 1953
9 C. V Vladimiloba and V. A. Likhachov, 'Activation Energy of Creep process of Metals,' Fiz Metal Metalloved, Vol.28, No.4, pp.165-169, 1969
10 J. Breen and J. Weertman, 'Creep of polycrystalline Tin,' Trans. AIME, Vol.203, pp.1230-1234, 1955
11 S. S. Valgarali and T. G. Langdon, J. of Acta Metal., Vol.30, p.1157, 1982   DOI   ScienceOn
12 I. J. Polmear, Proceedings of International Conference on Recent Advances in Science and Engineering of Light Metal, p.201, Japan Inst. Light Metals, 1991