Change in the Oxide Structure of Al-12Si Melts in the Presence of Sr

Yıl 2023, Cilt: 26 Sayı: 4, 1299 - 1305, 01.12.2023

Cem Kahruman , Uğur Alev , Derya Dıspınar

https://doi.org/10.2339/politeknik.872350

Öz

Bifilm defects are the surface entrained double oxide films that are introduced into melts during turbulence and disturbance to the surface of the melt. These defects lead to porosity formation if they are not cleaned from the melt. Thus, the characterisation of the dross that is formed on the surface of the melt becomes a key parameter. In this work, Sr containing Al12Si alloy was used. For the modification process, 100, 200 and 300 ppm Sr was added to the alloy. The oxidation tests were carried out in liquid state at 700, 750 and 800 °C for holding durations of 12, 24, 36 and 48 hours. The structure was characterised by optical microscopy, Scanning Electron Microscopy, X-Ray Diffraction and X-ray photoelectron spectroscopy techniques. It was found that after 12 hours of holding, spinel oxides were formed on the surface mainly SrO.Al2O3 and MgO.Al2O3.

Anahtar Kelimeler

Strontium modification, Al-12Si, oxide films, XPS

Al-12Si Alaşımlarında Yüzey Oksit Uapısının Sr Varlığında Değişimi

Öz

Alüminyum alaşımlarının döküm proseslerinde yüzeyden sıvı metale karışan bifilm hataları en önemli hatalardan biri olarak değerlendirilirler. Bu yüzden, ergitme prosesleri sırasında yüzeyde oluşan oksit yapılarının karakterizasyonu çok önemlidir. Bu çalışmanın amacı Sr içeren Al12Si alaşımlarında farklı sıcaklık ve bekleme sürelerinde yüzeyde oluşan oksit yapısının karakterize edilmesidir. 100, 200 ve 300 ppm seviyelerinde Sr ilave edilen Al12Si alaşıma 700, 750 ve 800 oC’lerde 12, 24, 36 ve 48 saat boyunca bekleme sürelerinde oksit yapısındaki değişim incelenmiştir. Optik mikroskop, taramalı elektron mikroskobu, XRD ve XPS analizleri ile yüzeyde oluşan oksitler karakterize edilmiştir. 12 saat bekleme süreleri sonrasında yüzey oksit yapısının SrO.Al2O3 ve MgO.Al2O3 yapılarından oluşmaya başladığı tespit edilmiştir.

Anahtar Kelimeler

Sr modifikasyonu, Al12Si alaşımı, oksit oluşumu, XPS

Kaynakça

• [1] Zamani, M., “Al-Si Cast alloys-microstructure and mechanical properties at ambient and elevated temperatures”, Doctoral dissertation, Jönköping University, School of Engineering, (2017).
• [2] Serratos, M., Poirier, D. R. and Lyman, W. D., "Effect of Stirring on Oxide Skins and Porosity in a 356 Aluminum Alloy", Transactions of the American Foundry Society and the One Hundred Fourth Annual Castings Congress. 719–724, (2000).
• [3] Samuel, A. M., Doty, H. W., Valtierra, S. and Samuel, F. H., "Influence of oxides on porosity formation in Sr-treated alloys", International Journal of Metalcasting, 11(4): 729–742, (2017).
• [4] Miresmaeili, S.M., Shabestari, S.G. and Boutorabi, S.M.A., "Effects of Sr-modification and melt cleanliness on melt hydrogen absorption of 319 aluminium alloy", Journal of materials science, 16(6): 541–548, (2003).
• [5] Iwahori, H., Yonekura, K., Yamamoto, Y. and Nakamura, M., "Occurring behavior of porosity and feeding capabilities of sodium-and strontium-modified al-si alloys", AFS Trans, 98, 167–173, (1990).
• [6] Farhoodi, B., Raiszadeh, R., and Ghanaatian, M.-H., "Role of double oxide film defects in the formation of gas porosity in commercial purity and Sr-containing Al alloys", Journal of Materials Science & Technology, 30 (2): 154–162, (2014).
• [7] Bartar Esfahani, H., Raiszadeh, R., and Doostmohammadi, H., "The effect of strontium on the strength of layers of double oxide film defects", Metallurgical and Materials Transactions A, 47 (3):1331– 1338, (2016).
• [8] Gyarmati, G., Fegyverneki, G., Mende, T., and Tokár, M., "Characterization of the double oxide film content of liquid aluminum alloys by computed tomography", Materials Characterization, 157, p. 109925, (2019).
• [9] Miresmaeili, S. M., "Effect of strontium on the oxidation behavior of liquid Al–7Si alloys", Oxidation of metals, 71(1–2): 107–123, (2009).
• [10] Liu, L., Samuel, A. M., Samuel, F. H., Doty, H. W. and Valtierra, S., "Influence of oxides on porosity formation in Sr-treated Al-Si casting alloys", Journal of materials science, 38(6): 1255–1267, (2003).
• [11] Garat, M., Laslaz, G., Jacob, S., Meyer, P., Guerin, P. H. and Adam, R., "State of the art use of Sb, Na and Sr modified Al-Si casting alloys." AFS Trans, 146, 821–832, (1992).
• [12] Emadi, D., Gruzleski, J. E. and Pekguleryuz, M., "Melt oxidation behavior and inclusion content in unmodified Al-Si and Sr", Transactions of the American Foundrymen's Society, 104, 763–768, (1996).
• [13] Yuen, P., Drew, R., Gruzleski, J.E., and Dennis, K., "Effects of strontium on the oxidation behavior of molten aluminum alloys containing silicon and magnesium", 6th International AFS Conference, Molten Aluminum Processing, (2001).
• [14] Najafzadeh Bakhtiarani, N., and Raiszadeh, R., "The behaviour of double oxide film defects in Al–4.5 wt% Mg melt", Journal of materials science, 46(5): 1305–1315, (2011).
• [15] Bartar Esfahani, H., Doostmohammadi, H., and Raiszadeh, R., "Decrease in the rate of diffusion of hydrogen through layers of bifilm defects in Al melt in the presence of Sr", International Journal of Cast Metals Research, 29(3): 179–185, (2016).
• [16] Nateghian, M., Raiszadeh, R., and Doostmohammadi, H., "Behavior of double-oxide film defects in Al-0.05 wt pct Sr alloy", Metallurgical and Materials Transactions B, 43(6): 1540–1549, (2012).
• [17] Mehrabian, M., Nayebi, B., Bahmani, A., Dietrich, D., Lampke, T., Ahounbar, E., and Shokouhimehr, M., “Deformation, cracking and fracture behavior of dynamically-formed oxide layers on molten metals”, Metals and Materials International, 27(6): 1701-1712, (2019).
• [18] Ozer, G., Yuksel, C., Comert, Z. Y., and Guler, K. A., “The effects of process parameters on the recycling efficiency of used aluminium beverage cans (UBCs)”, Materials Testing, 55(5): 396-400, (2013).
• [19] Bhagyanathan, C., Karuppuswamy, P., Raghu, R., Gowtham, S., and Ravi, M., “Recycling of LM25 aluminum alloy scraps”, Materials Testing, 60(9): 848-854, (2018).
• [20] Mohanty, P. S., Samuel, F. H., and Gruzleski, J. E., Trans. Am. Foundrymen’s Soc., 103, 555–564, (1995).
• [21] Young, V., and T. Otagawa. "XPS studies on strontium compounds", Applications of surface science, 20(3):: 228-248, (1985).
• [22] Kirsch, P. D., and Ekerdt, J. G., “Interfacial chemistry of the Sr/SiO x N y/Si (100) nanostructure”, Journal of Vacuum Science & Technology A: Vacuum, Surfaces, and Films, 19(5): 2222-2231, (2001).
• [23] El Kazzi, M., Delhaye, G., Merckling, C., Bergignat, E., Robach, Y., Grenet, G., and Hollinger, G., “Epitaxial growth of SrO on Si (001): Chemical and thermal stability”, Journal of Vacuum Science & Technology A: Vacuum, Surfaces, and Films, 25(6): 1505-1511, (2007).
• [24] Spreitzer, M., Egoavil, R., Verbeeck, J., Blank, D. H., and Rijnders, G., “Pulsed laser deposition of SrTiO 3 on a H-terminated Si substrate”, Journal of materials chemistry C, 1(34): 5216-5222, (2013).
• [25] Eguskiza, S., Niklas, A., Fernández-Calvo, A. I., Santos, F., and Djurdjevic, M., “Study of strontium fading in Al-Si-Mg and Al-Si-Mg-Cu alloy by thermal analysis”, International Journal of Metalcasting, 9(3): 43-50, (2015).
• [26] Zhang, W., Ma, S., Wei, Z., and Bai, P., “The relationship between residual amount of Sr and morphology of eutectic Si phase in A356 alloy”, Materials, 12(19), 3222, (2019).
• [27] K. Dennis, “Effects of magnesium, silicon, and strontium on the oxidation of molten aluminum”, McGill University Libraries, (1999).
• [28] Logofatu, C., Negrila, C. C., Ghita, R. V., Ungureanu, F., Cotirlan, C., Manea, C. G. A. S., and Lazarescu, M. F., “Study of SiO2/Si interface by surface techniques”, Crystalline Silicon-Properties and Uses, 23-42, (2011).
• [29] Werrett, C. R., Pyke, D. R., and Bhattacharya, A. K., “XPS studies of oxide growth and segregation in aluminium–silicon alloys”, Surface and Interface Analysis: An International Journal devoted to the development and application of techniques for the analysis of surfaces, interfaces and thin films, 25(10): 809-816, (1997).
• [30] Wagner, C. D., “NIST X-ray photoelectron spectroscopy database” NIST Standarad Reference Database 20, (2000).