Auto-detection of Intermetallic and Eutectic Phases in Microstructure of the AZ91 Mg-alloys by Image Processing Techniques

Yıl 2022, Cilt: 4 Sayı: 2, 247 - 258, 26.10.2022

Abdullah Elen Levent Elen

https://doi.org/10.46387/bjesr.1163661

Öz

AZ91, which is used in the production of parts in the aerospace, defense and automotive industries, can be enhanced by the addition of an alloying element or the cooling rate, due to the weak strength and formability properties of advanced technology Mg-alloys. The microstructure change in Mg alloys significantly affects the mechanical properties. By analyzing the microstructure of these alloys, a close estimate of the mechanical properties can be made. In this study, an image processing-based model is proposed that automatically recognizes the intermetallic and eutectic phases required for the analysis of microstructural properties in AZ91 Mg-alloys. The proposed method consists of two stages; In the first step, the eutectic phase template is obtained as a binary image. In the second step, the binary image containing the intermetallic and eutectic phases is obtained and the result image with only the intermetallic phases is obtained by taking the difference of these two patterns. Experimental studies have shown that the proposed method gives a result close to the real value in the detection of eutectic phases.

Anahtar Kelimeler

AZ91 Mg-alloys, Image Processing, Microstructure, Intermetallic Phase, Eutectic Phase

AZ91 Mg Alaşımlarının Mikroyapısındaki İntermetalik ve Ötektik Fazların Görüntü İşleme Teknikleriyle Otomatik Tespiti

Öz

Havacılık, savunma ve otomotiv endüstrilerinde parça üretiminde kullanılan AZ91, ileri teknoloji Mg alaşımlarının zayıf mukavemet ve şekillendirilebilirlik özelliklerinden dolayı bir alaşım elementi ilavesi veya soğutma hızı ile geliştirilebilir. Mg alaşımlarındaki mikroyapı değişimi, mekanik özellikleri önemli ölçüde etkiler. Bu alaşımların mikroyapısı incelenerek, mekanik özellikler hakkında yakın bir tahminde bulunulabilir. Bu çalışmada, AZ91 Mg alaşımlarında mikroyapı özelliklerinin analizi için gerekli olan intermetalik ve ötektik fazları otomatik olarak tanımayı sağlayan görüntü işleme tabanlı bir model önerilmiştir. Önerilen yöntem iki aşamadan meydana gelmektedir; ilk aşamada ikili görüntü olarak ötektik faz şablonu elde edilir. İkinci aşamada ise intermetalik ve ötektik fazları içeren ikili görüntü elde edilir ve bu iki şablonun farkı alınarak yalnızca intermetalik fazların olduğu sonuç görüntüsüne ulaşılır. Yapılan deneysel çalışmalarda, önerilen yöntemin ötektik fazların tespitinde gerçek değere yakın bir sonuç verdiğini göstermiştir.

Anahtar Kelimeler

AZ91 Mg Alaşımları, Görüntü İşleme, Mikroyapı, İntermetalik Faz, Ötektik Faz

Kaynakça

• L. Gaines, R. Cuenca, S. Wu, and F. Stodolsky, “Potential automotive uses of wrought magnesium alloys,” Argonne National Lab., IL (United States), ANL/ES/CP-89958; CONF-9604136-21, 1996.
• Blawert, C., Hort, N. and Kainer, K. U., “Automotive Applications of Magnesium and Its Alloys,” Trans. Indian Inst. Met., vol. 57, no. 4, 12, 2004.
• L. Elen, “Effects of Bi and Sb Additions with Solidification Rate on The Microstructure and Mechanical Properties of The AZ91 Alloys”, M.Sc. Thesis, Karabük University, Graduate School of Natural and Applied Sciences Department of Metal Education, 2012.
• S. Candan, M. Ünal, E. Koç, Y. Türen, and E. Candan, “Effects of Titanium Addition on Mechanical and Corrosion Behaviours of AZ91 Magnesium Alloy”, Journal of Alloys and Compounds, vol. 509, no. 5, pp. 1958-1963, 2011.
• Y. Türen, “Effect of Sn Addition on Microstructure, Mechanical and Casting Properties of AZ91 Alloy”, Materials & Design, vol. 49, pp. 1009-1015, 2013.
• L. Elen, Y. Türen, and E. Koç, “Effects of Solidification Rate on Microstructure and Mechanical Properties with Sb at Different Ratio of AZ91 Quality Mg Alloy”, International Journal of Engineering Research and Development, vol. 11, no. 2, pp. 451-463, 2019.
• L. Elen, B. Çiçek, E. Koç, Y. Türen, Y. Sun, and H. Ahlatcı, “Effects of Alloying Element and Cooling Rate on Properties of AM60 Mg Alloy”, Mater. Res. Express, vol. 6, no. 9, pp. 096511, 2019.
• M. Ünal, “Effects of Solidification Rate and Sb Additions on Microstructure and Mechanical Properties of As Cast AM60 Magnesium Alloys”, International Journal of Cast Metals Research, vol. 27, no. 2, pp. 80–86, 2014.
• A. Campbell, P. Murray, E. Yakushina, S. Marshall, and W. Ion, “New Methods for Automatic Quantification of Microstructural Features Using Digital Image Processing,” Materials & Design, vol. 141, pp. 395-406, 2018.
• ASTM E112, “Test Methods for Determining Average Grain Size,” ASTM International.
• ASTM E562, “ASTM E562: Standard Test Method for Determining Volume Fraction by Systematic Manual Point Count.”
• A. Elen, and M. K. Turan, “A new approach for fully automated segmentation of peripheral blood smears”, International Journal of Advanced and Applied Sciences, vol. 5, no. 1, pp. 81-93, 2018.
• L. Rauch, and L. Madej, “Application of the Automatic Image Processing in Modeling of the Deformation Mechanisms Based on the Digital Representation of Microstructure”. International Journal for Multiscale Computational Engineering, vol. 8, no. 3, pp. 343–356, 2010.
• R. Bourne, “Fundamentals of digital imaging in medicine”, Springer Science & Business Media, pp. 20-21, 2010.
• R. Kirsch, “Computer determination of the constituent structure of biological images”, Computers and Biomedical Research, vol. 4, no. 3, pp. 315-328, 1971.
• L.-K. Huang, and M.-J. J. Wang, “Image thresholding by minimizing the measures of fuzziness”, Pattern Recognition, vol. 28, no. 1, pp. 41–51, 1995.