Journal of the Korean Society for Heat Treatment (열처리공학회지)

The Korean Society for Heat Treatment (한국열처리공학회)
권호 표지
DOI QR코드

DOI QR Code

Effect of CaO Addition on Age Hardening Behavior of AZ91 Alloy

AZ91 합금의 시효경화 거동에 미치는 CaO 첨가의 영향

  • Jun, Joong-Hwan (Advanced Fusion Process R&D Group, Korea Institute of Industrial Technology)
  • 전중환 (한국생산기술연구원 융합신공정연구그룹)
  • Received : 2011.06.07
  • Accepted : 2011.06.24
  • Published : 2011.07.30
Download PDF
⟨ Previous Next ⟩

Abstract

Effect of CaO addition on age hardening response has been studied by using optical microscopy, scanning electron microscopy and differential thermal analysis in AZ91 and CaO-containing ECO-AZ91 alloys. After solution treatment, the ${\beta}$($Mg_{17}Al_{12}$) phase formed during solidification mostly disappeared in the microstructure in the AZ91 alloy, whereas numerous ${\beta}$ precipitates containing Ca were still observed in the ECO-AZ91 alloy due to its enhanced thermal stability. The ECO-AZ91 alloy showed the delayed peak aging time and higher peak hardness compared with those of the AZ91 alloy. The activation energies for ${\beta}$ precipitation calculated by means of Kissinger method increased from 71.4 to 85.6 kJ/mole by the addition of CaO, which implies that CaO plays a role in reducing ${\beta}$ precipitation rate in the AZ91 alloy.

Keywords

References

  1. S. H. Ha, J. K. Lee and S. K. Kim : Mater. Trans., 49 (2008) 1081. https://doi.org/10.2320/matertrans.MC200786
  2. J. K. Lee and S. K. Kim : Mater. Trans., 52 (2011) 1483. https://doi.org/10.2320/matertrans.M2010397
  3. D. I. Jang, J. K. Lee, D. U. Kim and S. K. Kim : Trans. Nonferrous Met. Soc. China, 19 (2009) s76. https://doi.org/10.1016/S1003-6326(10)60248-8
  4. J. H. Seo and S. K. Kim : Kor. J. Kor. Found. Soc., 31 (2011) 11. https://doi.org/10.7777/jkfs.2011.31.1.011
  5. B. L. Mordike and T. Ebert : Mater. Sci. Eng. A, 302 (2001) 37. https://doi.org/10.1016/S0921-5093(00)01351-4
  6. K. N. Braszczynska-Malik : J. Alloy Comp., 477 (2009) 870. https://doi.org/10.1016/j.jallcom.2008.11.008
  7. S. Celotto : Acta Mater., 48 (2000) 1775. https://doi.org/10.1016/S1359-6454(00)00004-5
  8. J. F. Huang, H. Y. Yu, Y. B. Li, H. Cui, J. P. He and J. S. Zhang : Mater. Des., 30 (2009) 440. https://doi.org/10.1016/j.matdes.2008.06.001
  9. A. Luo and M. O. Pekguleryuz : J. Mater. Sci., 29 (1994) 5259. https://doi.org/10.1007/BF01171534
  10. P. Humble : Mater. Forum, 21 (1997) 45.
  11. S. M. Zhu, M. A. Gibson, J. F. Nie, M. A. Easton and T. B. Abbott : Scripta Mater., 58 (2008) 477. https://doi.org/10.1016/j.scriptamat.2007.10.041
  12. B. A. Esgandari, H. Mehrjoo, B. Nami and S. M. Miresmaeili : Mater. Sci. Eng. A, 528 (2011) 5018. https://doi.org/10.1016/j.msea.2011.03.022
  13. L. Han, H. Hu and D. O. Northwood : Mater. Lett., 62 (2008) 381. https://doi.org/10.1016/j.matlet.2007.05.047
  14. A. Srinivasan, U. T. S. Pillai and B. C. Pai : Mater. Sci. Eng. A, 452-453 (2007) 87. https://doi.org/10.1016/j.msea.2006.10.119
  15. N. Balasubramani, A. Srinivasan, U. T. S. Pillai and B. C. Pai : Mater. Sci. Eng. A, 457 (2007) 275. https://doi.org/10.1016/j.msea.2006.12.132
  16. Y. X. Tong and Y. Liu : J. Allos Comp., 449 (2008) 152. https://doi.org/10.1016/j.jallcom.2006.01.146
  17. Q. M. Amir and S. P. Gupta : Can. Metall. Quart., 34 (1995) 43.
  18. B. Nami, S. G. Shabestari, H. Razavi, S.H. Mirdamadi and S. M. Miresmaeili : Mater. Sci. Eng. A, 528 (2011) 1261. https://doi.org/10.1016/j.msea.2010.10.004
  19. D. A. Porter and K. E. Easterling : Phase Transformations in Metas and Alloys, Chapman & Hill, (1981).