نوع مقاله : مقاله پژوهشی

نویسندگان

1 دانشجوی کارشناسی ارشد، دانشکده مهندسی مواد، دانشگاه علم وصنعت ایران، تهران، ایران

2 دانشیار، دانشکده مهندسی مواد، دانشگاه علم و صنعت ایران ،تهران، ایران

3 دانشیار، دانشکده مهندسی مواد. دانشگاه علم و صنعت ایران، تهران، ایران

چکیده

چکیده
ریخته‌گری گریز از مرکز یکی از روش‌هایی است که برای تولید کامپوزیت‌های دوفلزی و به دو روش، افقی و عمودی، به‌کار گرفته می‌شود. حالت عمودی این روش، که در این تحقیق به‌کار گرفته شد، برای تولید قطعاتی متداول است که نسبت ارتفاع به قطرشان کم‌تر از واحد باشد. در این تحقیق، مذاب آلومینیم با نسبت‌های مذاب به جامد 5/1 و 5/2 درون بوش برنجی پیش‌گرم شده تا دمای 100 درجه‌ی سلسیوس و در حال چرخش با سرعت‌های دوران 800، 1600 و 2000 دور بر دقیقه ریخته‌گری شد. از میکروسکوپ نوری (OM) و میکروسکوپ الکترنی روبشی (SEM) برای مشاهدات میکروسکوپی و نیز از طیف‌سنج پراش پرتو ایکس (EDS) برای شناسایی فازهای تشکیل شده، استفاده شد. به نظر می‌رسد که جریان یافتن مذاب در حوزه‌ی گریز از مرکز با گسیختن فیلم اکسیدی سطحی مذاب آلومینیم همراه است به‌گونه‌ای که شرایط برای تشکیل پیوند متالورژیکی مساعد می‌شود. از طرف دیگر، پاره شدن این فیلم اکسیدی سطحی به‌همراه تلاطم ذاتی فرآیند ممکن است موجب بروز عیوبی در قطعه ‌شود. نتایج این تحقیق نشان داد کامپوزیت‌های تولید شده به ازای دور 2000 بیش‌تر از سایر قطعات در معرض عیوب هستند. این مقاله عیوب مختلف مشاهده شده را دسته‌بندی کرده و اثر متغیرهای مختلف موثر را بررسی می‌کند.

کلیدواژه‌ها

عنوان مقاله [English]

Defects characterization of Al-brass composite produced via centrifugal process

نویسندگان [English]

  • Morteza Gholami 1
  • Mehdi Divandari 2
  • Mohammad Taghi Salehi 3

1 Department of Material Engineering, Iran University of Science and Technology, Tehran, Iran

2 Department of Material Engineering, Iran University of Science and Technology, Tehran, Iran

3 Department of Material Engineering, Iran University of Science and Technology, Tehran, Iran

چکیده [English]

Centrifugal casting is one of the methods which is used for producing bimetallic composite parts. This method runs both horizontal and vertical mode. Vertical mode, used in this work, is currently taken to produce casting parts with height to diameter ratio less than unity. In this study, aluminum melt with 1.5 and 2.5 melt-to-solid volume ratio was cast into 100°C preheated  brass bush rotating at 800, 1600, and 2000 (rpm), respectively. In order to characterize the cast samples, possible phases and casting defects various equipment such as optical microscope (OM), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) have been used. Flowing of Al melt, at centrifugal field, is possibly associated with surface oxide film rupture so that metallurgical bonding is attained. On the other hand, these oxide films flowing at the melt surface and inherent turbulence of this process may cause defects in the casting. It was noted that bimetal composites produced at 2000 rpm are subjected to more defects than the other. This article categorizes various defects seen and analyzes different effective parameters.

کلیدواژه‌ها [English]

  • Aluminum-brass composite
  • centrifuge casting
  • defects
  • surface oxide film
[1]  Xu, G. Luo, A. A. Chen, Y. and Sachdev, A. K., "Interfacial Phenomena in Magnesium/Aluminum Bi-metallic Castings" Materials Science&Engineering A, Vol. 595, pp. 154-158, 2014.
[2]  Campbell, J. "Complete Casting Handbook" University of Birmingham, UK, pp. 979-985, 2011.
[3]  Diouf, P. and Jones, A. "Investigation of Bond Strength in Centrifugal Lining of Babbitt on Cast Iron" Metallurgical and Materials Transactions A, Vol. 41, pp. 603-609 2010.
[4]  Sarvari, M. and Divandari, M. "Melt Behavior and Shrinkage Force Effect of Al Melt in Al/Mg Bimetal Casted via Centrifugal Casting" In Persian, Modares Mechanical Engineering, Vol. 15, No. 7, pp. 131-138, 2015.
[5]  Papis, K. J. M. Loeffler, J. F. and Uggowitzer, P. J. "Light Metal Compound Casting" Science in China Series E: Technological Sciences, Vol. 52, pp. 46-51, 2009.
[6]  Pola, A. "Advanced Casting Methodologies" Comprehensive Materials Processing, Vol. 5, pp. 47-51, 2014.
[7]  Watanbe, Y. Watanbe, S. and Matsuura, K. "Nickel-Aluminides/Steel Clad Pipe Fabricated by Reactive Centrifugal Casting Method from Liquid Aluminum and Solid Nickel" Metallurgical and Materials Transactions A, Vol. 35, pp. 1517-1524, 2003.
[8]  Shailesh, R. A. Tattimani, M. S. and Rao, S. S. "Understanding Melt Flow Behavior for Al-Si Alloys Processed Through Vertical Centrifugal Casting" Materials and Manufacturing Processes, Vol. 30, pp. 1305-1311, 2015.
[9]  Changyun, L. Haiyan, W. Shiping, W. Lei, X. Kuangfei, W. and Hengzhi, F. "Research on Mould Filling and Solidification of Titanium Alloy in Vertical Centrifugal Casting" Rare Metal Materials and Engineering, Vol. 39, No. 3, pp. 388-392, 2010.
[10]   Divandari, M. and Campbell, J. "Oxide Film Characteristics of Al–7Si–Mg Alloy in Dynamic Conditions in Casting" International Journal of Cast Metals Research, Vol. 17, No. 3, pp. 182-187, 2004.
[11]   Reilly, C. Green, N. R. and Jolly, M. R. "Surface Oxide Film Entrainment Mechanisms in Shape Casting Running Systems" Metallurgical and Materials Transactions B, Vol. 40, pp. 850-858, 2009.
[12]   Zhou, J. X. Shen, X. Yin, Y. J. Guo, Z. and Wang, H. "Gas-liquid Two Phase Flow Modelling of Incompressible Fluid and Experimental Validation Studies in Vertical Centrifugal Casting" Materials Science and Engineering, Vol. 84, 2015.
[13]   Trejo, E. "Centrifugal Casting of an Aluminium Alloy" Doctor of Philosophy Thesis, University of Birmingham, 2011.
[14]   ImageJ. www.ImageJ.com, Accessed.
[15]   Xiong, B. Cai, C. and Lu, B. "Effect of Volume Ratio of Liquid to Solid on the Interfacial Microstructure and Mechanical Properties of High Chromium Cast Iron and Medium Carbon Steel Bimetal" Journal of Alloys and Compounds, Vol. 509, pp. 6700–6704, 2011.
[16]   Biswas, A. Siegel, D. J. Wolverton, C. and Seidman, D. N. "Precipitates in Al–Cu Alloys Revisited: Atom-probe Tomographic Experiments and First-principles Calculations of Compositional Evolution and Interfacial Segregation" Acta Materialia, Vol. 59, pp. 6187–6204, 2011.
[17]   Shoilock, B. A. M. Grovenor, C. R. and Knowlcs, K. M. "Compositional Studies of Ω and Ө’ Precipitates in an Al-Cu-Mg-Ag Alloy" Scripta Metallurgica, Vol. 24, pp. 1239-1244, 1990.
[18]   Wei, B. and Herlach, D. M. "Rapid Solidification of Undercooled Eutectic and Monotectic Alloys" Materials Science and Engineering A, Vol. 173, pp. 357 -361, 1993.
[19]   Liu, X. R. Cao, C. D. and Weisheng, B. "Microstructure Evolution and Solidification Kinetics of Undercooled Co–Ge Eutectic Alloys" Scripta Materialia, Vol. 46, pp. 13–18, 2002.
[20]   Limin, J. Daming, X. Min, L. and Fu, H. "Casting Defects of Ti-6Al-4V Alloy in Vertical Centrifugal Casting Processes with Graphite Molds"Met. Mater. Int, Vol. 18, No. 1, pp. 55-61, 2012.
[21]   Suzuki, K. and Yao, M. "Simulation of Mold Filling and Solidification during Centrifugal Precision Casting of Ti-6Al-4V Alloy" Metals and materials international, Vol. 10, No. 1, pp. 33-38, 2004.
[22]   Adelakin, T. K. and Suárez, O. M. "Study of Boride-Reinforced Aluminum Matrix Composites Produced via Centrifugal Casting" Materials and Manufacturing Processes, Vol. 26, pp. 338-345, 2011.
[23]   Shiping, W. Jingjie, G. Yanqing, S. Chengzhi, Z. and Jun, J. "Numerical Simulation of Off-centred Porosity Formation of TiAl-based Alloy Exhaust Valve during Vertical Centrifugal Casting" Modelling and Simulation in Materials Science and Engineering, Vol. 11, pp. 599–608, 2003.
[24]   Hajjari, E. Divandari, M. Razavi, S. H. Homma, T. and Kamado, S. "Microstructure Characteristics and Mechanical Properties of Al 413/Mg Joint in Compound Casting Process" Metallurgical and Materials Transactions A, Vol. 43, pp. 4667-4677, 2012.
[25]   Divandari, M. and Campbell, J. "Morphology of Oxide Films of Al–5Mg Alloy in Dynamic Conditions in Casting" International Journal of CastMetals Research, Vol. 18, pp. 187-192, 2005.
[26]   Pan, J. Yoshida, M. Sasaki, G. and Fukunaga, H. "Metal Pipe Joining with Aluminum Alloy by Ultrasonic Insert Casting" Materials and ManufacturingProcesses, Vol. 15 , pp. 867-881, 2000.
[27]   Dai, X. Jolly, M. R. Yang, X. and Campbell, J. "Modelling of Liquid Metal Flow and Oxide Film Defects in Filling of Aluminium Alloy Castings" Materials Science and Engineering, Vol. 33, 2012.