مقایسه خواص مکانیکی و متالورژیکی کامپوزیت میکروساختار و نانوساختار WC-9Co-0.7VC

نوع مقاله : مقاله پژوهشی

نویسندگان

دانشکده مهندسی مواد و متالورژی، تهران، دانشگاه علم و صنعت ایران

چکیده

کامپوزیت‌های WC-Co که به هاردمتال‌ها موسوم اند، استفاده گسترده ای در بخش صنعت حفاری نفت و گاز دارند. چند سالی است که استفاده از این کامپوزیت ها با ساختار نانو، مورد توجه قرار گرفته است. در این تحقیق، کامپوزیت  WC-9Co-0.7VC در دو حالت میکروساختار و نانوساختار  با استفاده از فرآیند پرس داغ سریع ساخته شده و سپس ریزساختار و خواص مکانیکی آن‌ها با یکدیگر مقایسه شده است. خواص مکانیکی کامپوزیتِ هاردمتالِ میکروساختار و نانوساختار از قبیل چگالی، سختی، چقرمگیِ شکست و استحکامِ شکستِ برشی اندازه‌گیری شد. تقریبا در تمام خواص و ویژگی‌های اندازه‌گیری شده، نمونه نانوساختار، نتایج بهتری را در مقایسه با نمونه میکروساختار از خود نشان داد. بررسی ساختار نمونه‌ها به‌کمک میکروسکوپ الکترونی روبشی، نشان داد که کوچک شدن اندازه ذرات کاربید تنگستن به کمتر از nm 100 در نمونه نانوساختار، باعث ارتقا خواص شده است. مقدار سختی و استحکام شکست برشی متوسط در نمونه میکروساختار به‌ترتیب برابر با HV30 1310 و MPa 2604 است که این مقادیر در کامپوزیت نانوساختار به‌ترتیب برابر با HV30 1743 و MPa 3138 است.
 

کلیدواژه‌ها


عنوان مقاله [English]

Comparison of Mechanical and Metallurgical Properties of Microstructure’s with nano-structure’s WC-9Co-0.7VC Composite for Cutting Tools Production

نویسندگان [English]

  • Hossein Sedaghati
  • Morteza Tamizifar
School of Metallurgy and Materials Engineering, Tehran, Iran University of Science and Technology
چکیده [English]

WC-Co composite which is named hardmetal and has widespread application in excavation industry, usage of these composites with nano-structure, is concerned recent years. In this research, WC-9Co-0.7VC composite in two cases, microstructure and nanostructure, was made by rapid hot pressing process, and then their metallographic inspection and mechanical properties were compared with each other. Mechanical properties in micro-hardmetal and nano-hardmetal; such as, density, hardness, fracture toughness and transverse rupture strength were measured. Approximately, in all properties, nano-hardmetal had better results than micro-hardmetal.The microstructure of samples was checked out by using of scanning electron microscope. It seems that nanometer WC grains leads to this upgrade. In measurements, it turned out that, hardness and transverse rupture strength increased %33 and %21, respectively. Due to the application of this composite in oil and gas well drilling, nano-structures can improve function and working life of these tools.
 

کلیدواژه‌ها [English]

  • Hard-Metal
  • Nano-Composite
  • Drill Bit
  • Mechanical Properties
[1]. Li W., “Nanostructured tungsten carbide cobalt alloys processing and properties,” Ph.D. Thesis, The State University of New Jersey, United States, 1993.##
[2]. Upadhyaya G. S., “Cemented tubgsten carbide : production, properties, and testing,” Noyes Publications, pp. 9-11, 1998.##
[3]. Upadhyaya G. S., “Sintering of submicron WC-10wt.%Co hard metals containing Nickel and Iron,” Materials Science and Engineering, Vol. A105/106, pp. 249-256, 1987.##
[4]. Wang X., “Grain growth densification and mechanical properties of Nanocrystalline WC-Co, in department of metallurgical engineering,” Ph.D. Thesis, The University of Utah, United States, 2008.##
[5]. Wang X., Fang Z. and Sohn H., “Grain growth during the early stage of sintering of Nanosized WC–Co Powder,” Int. J. of Refractory Metals & Hard Materials, Vol. 26, pp. 232-241, 2008.##
[6]. Sun J., Fang, Z., and Shen J., “Characterizations of ball-milled Nanocrystalline WC–Co Composite powders and subsequently rapid hot pressing sintered cermets,” Materials Letters, Vol. 57, pp. 3140-3148, 2003.##
[7]. Akbarpour M. R. and Salahi E., “Effect of Nanoparticle content on the microstructural and mechanical properties of Nano-SiC dispersed bulk ultrafine-grained Cu matrix composites,” Materials and Design, Vol. 52, pp. 881–887, 2013.##
[8]. Chandrasekhar S. B. and Sudhakara Sarma S., “Microstructure and properties of hot extruded Cu–1 wt% Al2O3 Nano-composites synthesized by various techniques,” Materials Science & Engineering A, Vol. 591, pp. 46–53, 2014.##
[9]. Mohan K., “Microstructure of consolidated nanocomposite tungsten carbid-Cobalt,” Ph.D. Thesis, University of Connecticut, United States, 1996.##
[10]. Chengchang J. and Lan S., “Hot pressing of Nanometer WC–Co powder,” Int. J. of Refractory Metals & Hard Materials, Vol. 25, pp. 53-56, 2005.##
[11]. Tamara Aleksandrov F. and Željko A., “Influence of consolidation process and sintering temperature on microstructure and mechanical properties of near nano and nano-structured WC-Co cemented carbides,” Int. Journal of Refractory Metals and Hard Materials, Vol. 54, pp. 82–89, 2015.##
[12]. Chang S. and Chang P., “Study on the mechanical properties, microstructure and corrosion behaviors of nano-WC–Co–Ni–Fe hard materials through HIP and hot-press sintering processes,” Materials Science & Engineering A, Vol. 618, pp. 56–62, 2014.##
[13]. Enayati M. H. and Aryanpour G. R., “Production of nanostructured WC–Co powder by ball milling,” Int. J. of Refractory Metals & Hard Materials, Vol. 27, pp. 159-163, 2009.##
[14]. Hewitt S. and Kibble K. A., “Effects of ball milling Time on the synthesis and consolidation of nanostructured WC–Co composites,” Int. J. of Refractory Metals & Hard Materials,Vol. 21, pp. 205-213, 2009.##
[15]. Mahmoodan M., Aliakbarzadeh H. and Gholamipour R., “Microstructural and mechanical characterization of high energy ball milled and sintered WC–10 wt%Co–xTaC nano powders,” Int. J. of Refractory Metals & Hard Materials, Vol. 27, pp. 801-805, 2009.##
[16]. Mahmoodan M., Aliakbarzadeh H. and Gholamipour R., “Sintering of WC-10%Co Nano powders containing TaC and VC grain growth inhibitors,” Transactions of Nonferrous Metals Society of China, Vol. 21, pp. 1080-1084, 2010.##
[17]. Sedaghati H. and Tamizifar M., “Wear behavior in micro and Nano-structured WC-9Co-0.7VC cemented carbide produced by rapid hot press sintering,” Advanced Ceramics Progress, Vol. 2, pp. 34-39, 2015.##
[18]. Cha S.I. and Hong S. H., “Hardness and fracture toughness of ultra-fine WC-10Co-X cemented carbides prepared from Nanocrystalline powders,” International Journal of Materials Research, Vol. 2, pp. 172-176, 2005.##
[19]. Jianfei S. and Faming Z., “Characterizations of ball-milled Nanocrystalline WC–Co composite powders and subsequently rapid hot pressing sintered cermets,” Materials Letters, Vol. 57, pp. 3140–3148, 2003.##