WEIBULL DISTRIBUTION OF ELECTRICAL CONDUCTIVITY OF A356 ALUMINIUM ALLOYS VIA VIBRATIONAL CASTING

Year 2020, Volume: 11 Issue: 1, 13 - 22, 01.03.2020

Çağlar Yüksel , Abdulhadi Koşatepe

Abstract

Mechanical vibration is the easiest and cheapest way to enhance properties of the castings, such as mechanical, electrical, chemical. Also, chemical agents such as grain refiners could assist to improve the casting properties. In this study, coupled actions of mechanical vibration and grain refiners were applied to the castings to investigate the electrical conductivity of Al7Si0,3Mg (A356) aluminium alloy. Grain refiner, Al5Ti1B, was added to Al7Si0.3Mg alloy in the form of three different addition of 0.1, 0.2, and 0.3 wt.%. The castings were carried out with and without grain refiner on vibrational casting technique. Another investigation of this study is to demonstrate the effect of excess grain refiners on the microstructure having solidified under vibrational forces. The results were evaluated by means of electrical conductivity with Weibull Distribution, and SEM micrographs. Reliable and reproducible results were found in the middle section of 0.1 wt.% Ti grain refined samples which had a Weibull Modulus of 512 and 33.73 IACS%. It is demonstrated that vibrational casting has no effect on the distribution of grain refiners in the microstructure.

Keywords

Weibull distribution, electrical conductivity, vibrational casting, aluminium alloys, grain refining

References

• [1] W. Weibull, "A statistical distribution function of wide applicability", Journal of applied mechanics, vol.18(3), pp. 293-297, 1951.
• [2] J. Campbell, Complete Casting Handbook: Metal Casting Processes, Metallurgy, Techniques and Design. Butterworth-Heinemann, 2015.
• [3] D. Dispinar, S. Akhtar, A. Nordmark, M. Di Sabatino, and L. Arnberg, "Degassing, hydrogen and porosity phenomena in A356" Materials Science and Engineering: A, vol. 527(16-17), pp. 3719-3725, 2010.
• [4] D. Dispinar, and J. Campbell. "Use of bifilm index as an assessment of liquid metal quality." International Journal of Cast Metals Research, vol. 19(1), pp. 5-17, 2006.
• [5] M. Uludağ, R. Çetin, L. Gemi, and D. Dispinar, "Change in porosity of A356 by holding time and its effect on mechanical properties", Journal of Materials Engineering and Performance, vol. 27(10), pp. 5141-5151, 2018.
• [6] T. Tunçay, and S. Bayoğlu. "The effect of iron content on microstructure and mechanical properties of A356 cast alloy", Metallurgical and Materials Transactions B, vol. 48(2), pp. 794-804, 2017.
• [7] H. Zahedi, M. Emamy, A. Razaghian, M. Mahta, J. Campbell, and M. Tiryakioğlu, "The effect of Fe-rich intermetallics on the Weibull distribution of tensile properties in a cast Al-5 pct Si-3 pct Cu-1 pct Fe-0.3 pct Mg alloy", Metallurgical and Materials Transactions A, vol. 38(3), pp. 659-670, 2007.
• [8] E. Tan, A. R. Tarakcilar, and D. Dispinar, "The effect of melt quality and quenching temperature on the Weibull distribution of tensile properties in aluminium alloys: Die Wirkung der Schmelzequalität und der Abschrecktemperatur auf die Weibull‐Verteilungen der Zugeigenschaften in Aluminiumlegierungen", Materialwissenschaft und Werkstofftechnik, vol .46(10), pp. 1005-1013, 2015.
• [9] Ç. Yüksel, "Weibull analysis of fluidity and hardness of ultrasonically degassed secondary Al7Si0,3Mg aluminum alloy", China Foundry, vol. 16, pp. 352-257, 2019.
• [10] G. Timelli, A. De Mori, and R. Haghayeghi, "Reliability of a high-pressure die cast Al alloy radiator", Engineering Failure Analysis, vol. 105, pp. 87-97, 2019.
• [11] M. H. Ku, F. Y. Hung, and T. S. Lui, "The effect of hyper-rotation on the Weibull distribution of tensile properties in a friction stirred AA7075 aluminum alloy", Materials Chemistry and Physics, vol. 226, pp. 290-295, 2019.
• [12] Q. Chen, and W. D. Griffiths, "The investigation of the floatation of double oxide film defect in liquid aluminium alloys by a four-point bend test", International Journal of Cast Metals Research, pp. 1-8, 2019.
• [13] S. Kirtay, and D. Dispinar, "Effect of ranking selection on the Weibull modulus estimation", Gazi University Journal of Science, vol. 25(1), pp. 175-187, 2012.
• [14] A. Hazen, "Water supply", American civil engineers handbook, 1930.
• [15] J. J. Filliben, "The probability plot correlation coefficient test for normality", Technometrics, vol. 17(1), pp. 111-117, 1975.
• [16] W. M. Balaba, L. T. Stevenson, K. Wefers, and M. N. Tackie, "Probability estimators for Weibull statistics of the failure strengths of brittle powder compacts", Journal of materials science letters, vol. 9(6), pp. 648-649, 1990.
• [17] M. H. Mulazimoglu, R. A. L. Drew, and J. E. Gruzleski, "The electrical conductivity of cast Al− Si alloys in the range 2 to 12.6 wt pct silicon" Metallurgical Transactions A, vol. 20(3), pp. 383-389, 1989.
• [18] D. Argo, R. A. L. Drew, and J. E. Gruzleski. "A Simple Electrical Conductivity Technique for Measurement of Modification and Dendrite Arm Spacing in Al-Si Alloys", AFS Transactions, vol. 95, pp. 455-64, 1987.
• [19] D. Argo, R. A. L. Drew, and J. E. Gruzleski, "Electrical Conductivity as a Process Control Method for Aluminum-Silicon Castings". In Proceedings of the International Symposium on Quality and Process Control in the Reduction and Casting of Aluminum and Other Light Metals, Canada, 1987, pp. 133-154.
• [20] J. E. Gruzleski, and M. Bernard, "The treatment of liquid aluminum-silicon alloys", American Foundrymens Society, 1990.
• [21] N. R. Green, and J. Campbell, "Statistical distributions of fracture strengths of cast Al-7Si-Mg alloy", Materials Science and Engineering: A, vol. 173(1-2), pp. 261-266, 1993.
• [22] C. Nyahumwa, "Multiple defect distributions on Weibull statistical analysis of fatigue life of cast aluminium alloys", African Journal of Science and Technology, vol. 6(2), pp. 43-54, 2005.
• [23] Z. Nashwan, and W.D. Griffiths, "Entrainment Defects in Cast Iron". In Shape Casting, pp. 17-29. Springer, 2019.
• [24] G. B. Eisaabadi, P. Davami, S. K. Kim, and M. Tiryakioğlu, "The effect of melt quality and filtering on the Weibull distributions of tensile properties in Al–7% Si–Mg alloy castings", Materials Science and Engineering: A, vol. 579, pp. 64-70, 2013.
• [25] G. K. Sigworth, and T. A. Kuhn, "Grain refinement of aluminum casting alloys", International Journal of Metalcasting, vol. 1(1), pp. 31-40, 2007.
• [26] Ö. Çelikaslan, A. Kabil, Ç. Yüksel, and D. Dışpınar, "Effect of different amplitude of vibration during solidification of Al7Si0,3Mg on electrical conductivity", In International Eurasian Conference on Science, Engineering and Technology (EurasianSciEnTech 2018), Türkiye, 2018, pp. 163.
• [27] A Koşatepe, "Effect of Grain Refinement Additives on Vibrated Casting Al7Si0,3Mg Alloy", Atatürk University, Digital Repository, Erzurum, 2019.