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

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