Microstructure and High Temperature Impression Creep Properties of Mg–3Ca–xZr (x = 0.3, 0.6, 0.9 wt%) Alloys
The current study has investigated the influence of zirconium (Zr) addition to Mg–3Ca–xZr (x = 0.3, 0.6, 0.9 wt%) alloys prepared using argon arc melting on the microstructure and impression properties at 448–498 K under constant stress of 380 MPa. Microstructural analysis of as-cast Mg–3Ca–xZr alloys showed grain refinement with Zr addition. The observed grain refinement was attributed to the growth restriction effect of Zr in hypoperitectic Mg–3Ca–0.3 wt% Zr alloys. Heterogeneous nucleation of α-Mg in properitectic Zr during solidification resulted in grain refinement of hyperperitectic Mg–3Ca–0.6 wt% Zr and Mg–3Ca–0.9 wt% Zr alloys. The hardness of Mg–3Ca–xZr alloys increased as the amount of Zr increased due to grain refinement and solid solution strengthening of α-Mg by Zr. Creep resistance of Mg–3Ca–xZr alloys increased with the addition of Zr due to solid solution strengthening of α-Mg by Zr. The calculated activation energy (Qa) for Mg–3Ca samples (131.49 kJ/mol) was the highest among all alloy compositions. The Qa values for 0.3, 0.6 and 0.9 wt% Zr containing Mg–3Ca alloys were 107.22, 118.18 and 115.24 kJ/mol, respectively.
KeywordsMg–3Ca Zirconium Grain refinement Impression creep
Authors acknowledge the financial support provided by Universiti Teknologi MARA, Malaysia during the implementation of this project.
- 2.Polmear I. and John D S, Light Alloys: From Traditional Alloys to Nanocrystals, (4th ed). Butterwoth-Heinemann, Oxford (2005).Google Scholar
- 4.Yang M, Cheng L, Pan F, Li S S, Tang B, and Zeng D B, Trans Nonferrous Met Soc China 437 5 (2007) 317.Google Scholar
- 5.Lee Y C, Dahle A K, and St John D H, Metall Mater Trans A 31a (2000) 2895.Google Scholar
- 7.Friedrich H E and Mordike B L, Magnesium Technology: Metallurgy, Design Data, Applications, Springer, Berlin (2006).Google Scholar
- 12.Nayeb-Hashemi A A and Clark J B, Bull Alloy Phase Diagr 8 (1987) 29.Google Scholar
- 13.Nayeb-Hashemi A A and Clark J B, Phase Diagram of Binary Magnesium Alloys, ASM International, Ohio (1988).Google Scholar
- 15.Roylance D, The Dislocation Basis of Yield and Creep, Modules in Mechanics (2001). Available at http://web.mit.edu/course/3/3.11/www/modules/.
- 16.Dieter G E, Mechanica Metallurgy, McGraw-Hill Book Company, New York (1961).Google Scholar
- 18.Frost H J and Ashby M F, Deformation-Mechanism Map, The plasticity and Creep of Metals and Ceramics. Pergamon Press, Oxford (1982).Google Scholar