Creep deformation mechanism of magnesium-based alloys
- 238 Downloads
Two heat-resistant magnesium alloys AJC421 and Mg-2Nd were prepared. Both as-cast Mg-2Nd and AJC421 alloys exhibited good creep resistance in comparison with commonly used magnesium alloys. The improvement in creep properties through Nd addition to pure magnesium is attributed to both solid solution and precipitation hardening. The stress exponents of 4.5–5.5 and activation energies of 70.0–96.0 kJ/mol obtained from the as-cast Mg-2Nd alloy at low temperatures and low stresses indicate the five power law can be used for predicting the creep mechanism. The additions of alkaline earth elements Sr and Ca into Mg–Al alloys suppress the discontinuous precipitation of Mg17Al12 and form thermal-stable intermediate phases at grain boundaries, leading to effective restriction to grain boundary sliding and migration. However, the mechanism responsible for creep deformation of Mg–Al based alloys with Ca and Sr additions is not consistent with the results of microstructure observations performed on the alloys before and after creep tests.
KeywordsMagnesium Alloy Apparent Activation Energy Creep Test Stress Exponent Creep Property
This research was supported by the Natural Science Foundation of Jiangsu Province (No. BK2004208) and the Foundation for Excellent Doctoral Dissertation of Southeast University.
- 4.Blawert C, Hort N, Kainer KU (2004) Trans Indian Inst Metab 57:397Google Scholar
- 10.Evans RW, Wilshire B (1985) Creep of metals and alloys. The Institute of Metals, New YorkGoogle Scholar
- 11.Xue S, Sun YS, Zhu TB et al (2005) Trans Nonferr Met Soc 15:863Google Scholar
- 13.Nagasaki S, Hirabayashi M (2002) Binary alloy phase-diagrams. AGNE Gijutsu Center Co Ltd, TokyoGoogle Scholar
- 14.American Society for Metals (1973) Metals handbook. Metals Park, OhioGoogle Scholar
- 15.Nabarro FRN (2007) Encyclopedia of materials: science and technology. Elsevier Science Ltd, Oxford, p 1788Google Scholar
- 16.Dargush MS, Dunlop GL, Pettersen K (1998) In Mordike BL, Kainer KU (eds) Proceedings volume sponsored by Volkswagen AG. Werkstoff-Informationsgesellschaft, Frankfurt, p 277Google Scholar
- 19.Kassner ME, Pérez-Prado M-T (2004) Fundamentals of creep in metals and alloys. Elsevier Science Ltd, OxfordGoogle Scholar
- 21.Jones RB, Harris JE (1963) Joint international conference on Creep, Part 3A. Inst Mech Eng Proc, NewYorkGoogle Scholar
- 27.Mordike BL, Stulikova I (1983) In: Proceedings of the international conference on metallic light alloys. Institution of Metallurgists, London, p 146Google Scholar