Grain Refinement Mechanism in Al–4B Master Alloy Added Pure Mg

Abstract:

Al–4B master alloy has been prepared by the reaction of fluoride salt KBF₄ with molten Al and different amounts of this master alloy (0.5, 1, 1.5 and 2 wt%) has been added to pure Mg to study in detail its effect on the grain refinement of pure Mg. Considerable reduction in grain size from 1300 to 210μm is obtained and maximum reduction is observed with 2 wt% master alloy addition. The grain refinement is caused by both the growth restriction effect of Al and the presence of potent AlB₂ nucleant particles. Improvement in mechanical properties is obtained with Al–4B master alloy and is attributed to increase in grain boundary area due to the grain refinement and the particle strengthening due to AlB₂.

• Periodical: Materials Science Forum (Volume 710)
• Pages: 161-166
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.710.161
• Online since: January 2012
• Authors: Murugavel Suresh, Amirthalingam Srinivasan, Uma Thanu Subramonia Pillai, Bellambettu Chandrasekhara Pai
• Keywords: Grain Refinement, Magnesium, Microstructure

References

[1] J. Du, J. Yang, M. Kuwabara, W. Li, J. Peng, Improvement of grain refining efficiency for Mg– Al alloy modified by the combination of carbon and calcium, J. Alloys. Compd. 470 (2009) 134- 140.

DOI: 10.1016/j.jallcom.2008.02.052

[2] A.A. Luo, Recent magnesium alloy development for elevated temperature applications, Int. Mater. Rev. 49 (2004) 13-30.

[3] L. Lu, A.K. Dahle, D.H. StJohn, Grain refinement efficiency and mechanism of aluminium carbide in Mg–Al alloys, Scr. Mater. 53 (2005) 517–522.

DOI: 10.1016/j.scriptamat.2005.05.008

[4] J. Du, J. Yang, M. Kuwabara,W. Li, J. Peng, Effect of strontium on the grain refining efficiency of Mg–3Al alloy refined by carbon inoculation, J. Alloys. Compd. 470 (2009) 228–232.

DOI: 10.1016/j.jallcom.2008.03.012

[5] D.H. StJohn, M. Qian, M.A. Easton, P. Cao, Z. Hildebrand, Grain refinement of magnesium alloys, Metal. Mater. Trans. A 36A (2005) 1669- 1679.

DOI: 10.1007/s11661-005-0030-6

[6] B.S. Murty, S.A. Kori, M. Chakraborty, Grain refinement of aluminium and its alloys by heterogeneous nucleation and alloying, Inter. Mater. Rev. 47 (2002) 3-28.

DOI: 10.1179/095066001225001049

[7] P.S. Mohanty, J.E. Gruzleski, Grain refinement mechanisms of hypoeutectic Al-Si alloys, Acta. Mater. 44 (1996) 3749-3760.

DOI: 10.1016/1359-6454(96)00021-3

[8] S.A. Kori , B.S. Murty, M. Chakraborty, Development of an efficient grain refiner for Al–7Si alloy, Mater. Sci. Eng. A 280 (2000) 58–61.

DOI: 10.1016/s0921-5093(99)00656-5

[9] A.K. Prasada Rao, K. Das, B.S. Murty, M. Chakraborty, Effect of grain refinement on wear properties of Al and Al–7Si alloy, Wear 257 (2004) 148–153.

DOI: 10.1016/j.wear.2003.10.017

[10] P.S. Mohanty, J.E Gruzleski, Mechanism of grain refinement in aluminium, Acta. Mater. 43 (1995) 2001-2012.

DOI: 10.1016/0956-7151(94)00405-7

[11] L. Lu, A.K. Dahle, D.H. StJohn, Heterogeneous nucleation of Mg–Al alloys, Scr. Mater. 54 (2006) 2197-2201.

DOI: 10.1016/j.scriptamat.2006.02.048

[12] Y.C. Lee, A.K. Dahle, D.H. StJohn, The role of solute in grain refinement of magnesium, Metal. Mater. Trans. A 31A (2000) 2895-2906. 13] N. Nishino, H. Kawahara, Y. Shimizu, H. Iwahori, in: K.U. Kainer (Ed.), Magnesium Alloys and their Applications, Wiley–VCH, Inc., Weinheim, 2000, p.59–64.

DOI: 10.1002/3527607552.ch10

[14] M.A Easton, D.H StJohn, A model of grain refinement incorporating alloy constitution and potency of heterogeneous nucleant particles, Acta. Mater. 49 (2001) 1867-1878.

DOI: 10.1016/s1359-6454(00)00368-2

[15] H. Ding, X. Liu, The grain refinement efficiency of Ni–C on Mg–Al alloys, Mater. Lett. 63 (2009) 635-637.

DOI: 10.1016/j.matlet.2008.12.012