Study on Thixotropic Property of A356 Alloy in Semi-Solid State

Abstract:

In the present work, the thixotropic property of a semisolid aluminium alloy (A356) under deformation is investigated numerically where the Couette flow between two parallel plates is considered. The flow field is represented by momentum conservation equations where the non-Newtonian behavior of the semisolid material is represented by the Herschel-Bulkley model. The agglomeration and the de-agglomeration phenomena of the suspended particles under shear are represented using a time dependent structural parameter influenced by the rate of strain and shear stress. The simulation predicts the flow field, rate of strain and apparent viscosity of the semisolid materials under transient and steady state conditions. It is found that the apparent viscosity shows a transient nature during sudden change in the shear rate, and its value decreases with increasing shear rate and vice-versa. It is also found that the present prediction shows a good agreement with prior work.

• Periodical: Solid State Phenomena (Volumes 192-193)
• Pages: 335-340
• DOI: https://doi.org/10.4028/www.scientific.net/SSP.192-193.335
• Online since: October 2012
• Authors: Sudip Simlandi, Nilkanta Barman, Himadri Chattopadhyay
• Keywords: Apparent Viscosity, Modeling, Thixotropic Behavior

References

[1] G. R. Burgos, N. Andreas, A. N. Alexandrou, V. Entov, Thixotropic rheology of semisolid metal suspensions, Journal of Materials Processing Technology, 110 (2001) 164-176.

DOI: 10.1016/s0924-0136(00)00731-7

[2] J. Koke, M. Modigell, Flow behaviour of semi-solid metal alloys, J. Non-Newtonian Fluid Mech., 112 (2003) 141–160.

DOI: 10.1016/s0377-0257(03)00080-6

[3] B. P. Gautham, P. C. Kapur, Rheological model for short duration response of semi-solid metals, Materials Science and Engineering A, 393 (2005) 223–228.

DOI: 10.1016/j.msea.2004.10.028

[4] K. Dullaert, J. Mewis, A structural kinetics model for thixotropy, J. Non-Newtonian Fluid Mech., 139 (2006) 21–30.

DOI: 10.1016/j.jnnfm.2006.06.002

[5] A. N. Alexandrou, On the Modeling of semisolid suspentions, Solid State Phenomena, 141-143 (2008) 17-23.

DOI: 10.4028/www.scientific.net/ssp.141-143.17

[6] A. N. Alexandrou, G. Georgiou, On the early breakdown of semisolid suspensions, Non-Newtonian Fluid Mech., 142 (2007) 199–206

DOI: 10.1016/j.jnnfm.2006.09.003

[7] H. V. Atkinson, Modelling the semisolid processing of metallic alloys, Progress in Materials Science, 50 (2005) 341–412

DOI: 10.1016/j.pmatsci.2004.04.003

[8] W. C. Keung, Y.F. Lee, W. Shan, S. Luo, Thixotropic Strength and Thixotropic Criteria in Semisolid Processing, Solid State Phenomena, 141-143 (2008)319-323

DOI: 10.4028/www.scientific.net/ssp.141-143.319

[9] P. K. Kundu, I. M. Cohen, Fluid Mechanics, 2nd Edition, Academic Press, New York, (2002)

[10] Y. Zhang, W. Mao, Z.. Zhao, Z. Liu, Rheological Behavior of Semisolid A356 alloy at steady state ,Acta Metallurgica Sinica, 42(2) (2006) 163-166