نوع مقاله : مقاله پژوهشی

نویسندگان

1 دانشگاه صنعتی خواج ه نصیرالدین طوسی ، تهرا ن.

2 دانشجوی کارشناسی ارشد ، مهندسی مکانیک ، دانشگاه صنعتی خواج ه نصیرالدین طوسی ، تهرا ن.

3 - دانشیار ، مهندسی مواد ، دانشگاه صنعتی خواجه نصیرالدین طوسی ، تهرا ن.

10.22068/jstc.2018.60199.1289

چکیده

مواد هدفمند، نوع جدیدی از کامپوزیت‌ها با ریزساختار ناهمگن هستند که خواص فیزیکی و مکانیکی آنها در راستای ضخامت ماده به صورت پیوسته تغییر می‌کند. تحقیقات زیادی در زمینه ساخت و تخمین خواص و همچنین تحلیل های سازه‌ای و حرارتی مواد هدفمند صورت گرفته است. با تغییر درصد حجمی مواد تشکیل دهنده می‌توان خواص مکانیکی، فیزیکی و ترمودینامیکی مختلف را از آنها انتظار داشت. در این پژوهش، کامپوزیت هدفمند پنج لایه مس- آهن با تغییر ترکیب لایه‌ها به صورت پله ای بین مس خالص و آهن خالص به کمک روش متالورژی پودر ساخته شد. ابتدا پودر فلزات به وسیله پرس در فشار بالا فشرده شد و پس از آن، قطعات خام اولیه برای اتصال بهتر لایه‌ها و افزایش استحکام در کوره مناسب، تفجوشی شدند. برای مقایسه نتایج از دو نوع پرس مختلف شامل پرس تک محوره و پرس ایزواستاتیک سرد برای ساخت قطعات استفاده شد. جهت مشاهده ریزساختار و چگونگی تغییر ترکیب لایه‌های ماده هدفمند، میکروسکوپ نوری بکار رفت. نتایج مطالعات میکروسکوپی، اتصال خوب لایه‌ها و ذرات فلز و میزان نسبتاً کم حفره‌ها در هر لایه را نشان دادند. برای تعیین خواص مکانیکی کامپوزیت نیز، نمونه های مس- آهن هدفمند ساخته شده مورد آزمایش‌های خمش و کشش قرار گرفتند. نمودارهای تنش- کرنش به دست آمده از آزمایش، افزایش استحکام خمشی و کششی ماده هدفمند مس- آهن را در مقایسه با مس و آهن خالص ساخته شده به روش متالورژی پودر نشان دادند. همچنین پرس ایزواستاتیک سرد در افزایش استحکام قطعات نسبت به پرس تک محوره بسیار موثرتر واقع گردید.

کلیدواژه‌ها

عنوان مقاله [English]

Fabrication and mechanical characterization of Cu-Fe FGM produced by powder metallurgy method

نویسندگان [English]

  • Seyed Mohammad Reza Khalili 1
  • Maryam Torabian 2
  • Reza Eslami-Farsani 3

1 Faculty of Mechanical Engineering, K. N. Toosi University of Technology, Tehran, Iran.

2 Faculty of Materials Science and Engineering, K. N. Toosi University of Technology, Tehran, Iran.

3 Faculty of Materials Science and Engineering, K. N. Toosi University of Technology, Tehran, Iran.

چکیده [English]

Functionally graded materials (FGM) are a new type of composites with non-homogenous microstructure, which their physical and mechanical properties vary in the thickness direction continuously. Many researches in the field of property estimation, structural and thermal analysis of materials have been targeted. Different mechanical, physical and thermo-dynamical properties can be expected from these materials by changing the containing materials volume fraction. In this research, five layered Cu-Fe FGM specimens were fabricated with changing stepwise in the layers composition between pure copper and pure iron by powder metallurgy method. First the metal powders were compressed by press in high pressures and then the green specimens were sintered in a proper furnace was used to improve the layers connection and to increase the strength of the specimens. Two press systems containing uniaxial press and cold iso-static press were used in the fabrication of specimens to compare the results. Optical microscope was used to observe the microstructure and the combination of FGM layers. The results of microscopic investigations showed fine connectivity of the layers and powders and low density of pores in each layer. The produced Cu-Fe FGM specimens were tested in bending and tension to achieve their mechanical properties. The obtained stress-strain curves of these specimens showed enhancement in flexural and tensile strength of Cu-Fe FGM compared with the existing curves for pure copper and iron made by powder metallurgy method. Also cold iso-static press was highly more effective than uniaxial press in increasing the strength of specimens.

کلیدواژه‌ها [English]

  • Functionally graded material
  • Powder metallurgy
  • Microstructure
  • Bending strength
  • Tensile strength
[1]   Kieback, B. Neubrand, A. and Riedel, H., "Processing Techniques For Functionally Graded Materials" Materials Science and Engineering, Vol. 362, No. 1, pp. 81-106,  2003.     
[2]   Sobczak, J. and Ludmil, D., "Metallic Functionally Graded Materials: A Specific Class of Advanced Composites" Journal of Materials Science & Technology, Vol. 29, No. 4, pp. 297-316, 2013.
[3]   Di Maggio, R. et al., "The Microstructure and Mechanical Properties of Fe–Cu Materials Fabricated by Pressure-Less-Shaping of Nanocrystalline Powders" Journal of Materials Science, Vol. 42, No. 22, pp. 9284-9292, 2007.
[4]   Watanabe, Y. et al., "Fabrication of Fiber-Reinforced Functionally Graded Materials by a Centrifugal in Situ Method from Al–Cu–Fe Ternary Alloy" Composites Part A: Applied Science and Manufacturing, Vol 37, No .12, pp. 2186-2193, 2006.
[5]   Yadroitsev, I. et al., "Application of Laser Assisted Technologies for Fabrication of Functionally Graded Coatings and Objects for the International Thermonuclear Experimental Reactor components" Journal of Nuclear Materials, Vol. 362, No. 2, pp. 189-196, 2007.
[6]   Kawasaki, A. and Ryuzo, W., "Concept and P/M Fabrication of Functionally Gradient Materials", Ceramics International Journal, Vol. 23, No. 1, pp. 73-83, 1997.
[7]   Ogel, B. and R. Gurbuz., "Microstructural Characterization and Tensile properties of Hot Pressed Al–SiC Composites Prepared from Pure Al and Cu Powders" Materials Science and Engineering,  Vol. 301, No. 2, pp. 213-220, 2001.
[8]   Zhu, J. et al., "Fabrication of ZrO 2–NiCr Functionally Graded Material by Powder Metallurgy" Materials Chemistry and Physics, Vol. 68, No. 1, pp. 130-135, 2001.
[9]   Jin, G. et al., "Properties of Multilayered Mullite/Mo Functionally Graded Materials Fabricated by Powder Metallurgy Processing" Materials Chemistry and Physics, Vol. 89, No. 2, pp. 238-243, 2005.
[10] Syed, W. et al., "Single-step Laser Deposition of Functionally Graded Coating by Dual ‘wire–powder’or ‘powder–powder’feeding—A Comparative Study", Applied Surface Science Vol. 253, No. 19, pp. 7926-7931, 2007.
[11] Gelbstein, Y. Dashevsky, Z. and Dariel, M. P., "Powder Metallurgical Processing of Functionally Graded p-Pb 1− xSnxTe Materials for Thermoelectric Applications" Physica B: Condensed Matter, Vol. 391, No. 2, pp. 256-265, 2007.
[12]   Nemat-Alla, M. M. et al., "Powder Metallurgical Fabrication and Microstructural Investigations of Aluminum/Steel Functionally Graded Material" Materials Sciences and Applications, Vol. 2, No. 12, pp. 1708, 2011.
[13] Cavdar, U. et al., "Effect of the Copper Amount in Iron-based Powder-metal Compacts." Materiali in tehnologije, Vol. 48, No. 6, pp. 977-982, 2014.
[14]   Jeong, J. S. and Ki-Hoon, Sh., "Property Estimation of Functionally Graded Materials Between M2 Tool Steel and Cu Fabricated by Powder Metallurgy" Transactions of the Korean Society of Mechanical Engineers, Vol. 38, No. 9, pp. 953-958,  2014.
[15] Dandan, Q. et al., "Characterization of W/Fe Functionally Graded Materials Manufactured by Resistance Sintering Under Ultra-High Pressure" Fusion Engineering and Design, Vol. 91, pp. 21-24, 2015.
[16] Erdemir, F. A. Canakci, and T. Varol., "Microstructural Characterization and Mechanical Properties of Functionally Graded Al2024/SiC Composites Prepared by Powder Metallurgy Techniques" Transactions of Nonferrous Metals Society of China, Vol 25, No. 11, pp. 3569-3577, 2015.
 [17] Eisen, W. B. et al., "ASM Handbook Volume 07: Powder Metal    Technologies and Applications" ASM International, USA, Vol. 82, pp. 111-122, 1998.
[18] ASTM Standard B925- 03, “Standard Practices for Production and Preparation of Powder Metallurgy (PM) Test   Specimens ", ASTM International, West Conshohocken, PA, DOI: 10.1520/B0925-15, 2015.
[19] Zhao, P. et al., "Fabrication of W–Cu Functionally Graded   Material with Improved Mechanical Strength" Journal of Alloys and Compounds. Vol. 601, pp. 289-292, 2014.
 [20] Delfosse, D. Cherradi, N. and Ilschner, B., "Influence of Residual Stresses on the Tensile Behavior of a Cu-Ni FGM" International Symposium of Structure Functinally Graded Materaterials, Vol. 3, 1995.