Effect of Cooling Rate and Copper Content on the Non-Equilibrium Eutectic Formation in Binary Al-Cu Alloys by Computer- Aided Cooling Curve Method

Subject Areas :

Mehdi Dehnavi ¹ , Mohsen Haddad Sabzevar ²

1 - کارشناسی ارشد، گروه مهندسی متالورژی و مواد، دانشگاه فردوسی مشهد
2 - استاد، گروه مهندسی متالورژی و مواد، دانشگاه فردوسی مشهد، مشهد

Received: 2016-09-13 Accepted : 2016-09-13 Published : 2016-08-22

Keywords: Cooling curve, Latent heat, First Derivative Curve, Non- Equilibrium Eutectic,

Abstract :

In this study, the effect of cooling rate and copper addition was taken into consideration in non- equilibrium eutectic transformation of binary Al-Cu melt via cooling curve analysis.  For this purpose, melts with different copper weight percent of 2.2, 3.7 and 4.8 were prepared and cooled in controlled rates of 0.04 and 0.42 °C/sec. Results show that, latent heat of alloy highly depends upon the post- solidification cooling rate and composition. As copper content of alloy and cooling rate increase, achieved non- equilibrium eutectic phase increases that leads to release of much latent heat and appearing of second deviation in cooling curve. This deviation can be seen in first time derivative curve in the form of a definite peak.

References:

[1]     M. C. Flemings, “Solidification Processing”, Mc Grow-Hill, New York, 1974.

 

[2]     R. N. Grugel, “Meterials Characterization 28”, pp. 213-219, 1992.

 

[3]     L. Backuerud, G. Chai & J. Tamminen “Solidification Characteristics of Aluminum Alloys”, Foundry Alloys, AFS/Skanaluminium, Stockholm, Sweden, Vol. 2, 1990.

 

[4]     D. Eskin, Q. Du, D. Ruvalcaba & L. Katgerman, “Experimental study of structure formation in binary Al–Cu alloys at different cooling rates”, Mater. Sci. Eng, Vol. A 405, pp 1-10, 2005.

 

[5]     O. Fornaro & H. A. Palacio, “Study of dilute Al–Cu solidification by cooling curve analysis”, J. Mater. Sci, Vol. 44, pp. 4342- 4347, 2009.

 

[6]     Y. W. Riddle & M. M. Makhlouf, “Characterizing Solidification by Non-Equilibrium Thermal Analysis”, Magnesium Technology, pp 101- 106, 2003.

 

[7]     L. Bäckerud & B. Chalmers, “Some Aspects of Dendritic Growth in Binary Alloys: Study of the Aluminum-Copper System”, Transactions of the Metallurgical Society of AIME, Vol. 245, pp. 309- 318, 1969.

 

[8]     J. Tamminen, “Thermal Analysis for Investigation of Solidification Mechanisms in Metals and Alloys”, Ph.D. Thesis, U. of Stockholm, Sweden, 1988.

 

[9]     D. Emadi, “Applications of thermal analysis in quality control of solidification processes”, Journal of Themal Analysis and Calorimetry, Vol. 81, pp. 235- 242, 2005.

 

[10] J. O. Barlow & D. M. Stefanescu, “Computer-aided cooling curve analysis revisited”, AFS Trans. 105, pp. 348- 354, 1997.

 

[11] W. T. Kierkus & J. H. Sokolowski, “Recent Advances in CCA: A New Method of Determining Baseline Equation”, AFS Trans, Vol.66, pp. 161- 167, 1999.

 

[12] K. G. Upadhya, D. M. Stefanescu, K. Lieu & D. P. Yeager, “Computer- Aided Cooling Curve Analysis: Principles and Applications in Metal Casting”, AFS Transactions, Vol. 97, pp. 61-66, 1989.

 

[13] S. L. Backerud & G. K. Sigworth, “Recent Developments in Thermal Analysis of Aluminum Casting Alloys”, AFS Transactions. Vol. 97, pp. 459- 464, 1989.

 

[14] Haq, J. S. Shin & Z. H. Lee, “Computer-aided cooling curve analysis of A356 aluminum alloy”, Metals and Materials International, Vol 10, No. 1, pp. 89-96, 2004.

 

[15] M. Dehnavi, H. Vafaeenezhad & M. Haddad- Sabzevar, “Investigation solidification of Al-4.8 wt.%Cu alloy at different cooling rates by computer aided cooling curve analysis”. Metall. Mater. Eng, Vol. 20, No. 2, pp. 107-117, 2014.

 

[16] ASM Hnadbook, Formerly Ninth Edition, Metals Hnadbook, Volume 9, Metallography and microstructures.

 

[17]    م. دهنوی و م. حداد سبزوار، "اثر اندازه دانه بر جدایش میکروسکوپی آلیاژهای آلومینیم – مس"، پایان نامه کارشناسی ارشد، دانشگاه فردوسی مشهد، زمستان 1392.