Investigation of Manufacturing Conditions of Powder Metallurgy Parts with Control of Microstructure and Mechanical Properties
- سال انتشار: 1384
- محل انتشار: اولین کنفرانس بین المللی و هفتمین کنفرانس ملی مهندسی ساخت و تولید
- کد COI اختصاصی: ICME07_112
- زبان مقاله: انگلیسی
- تعداد مشاهده: 1369
نویسندگان
Assistant Professor of Mechanical Engineering, Department Materials Group of Khajenasir Universityof Technology, Materials Research Center of SAPCO, Tehran, Iran
M.Sc. of Department of Materials science and Eng., Shiraz University -TOPCO, Tehran, Iran
Materials Research Center of SAPCO, Tehran, Iran
Mashad Powder Metallurgy Co .
چکیده
In the present work, two kinds of steel powder were (Distaloy HP-1 & Ultrapac-LA) selected and subjected to powder metallurgy processing. For Ultrapac-LA a heterogeneous microstructure consisting of tempered martensite, nickel-rich ferrite, divorced pearlite and nickel-rich regions surrounding pores is observed. For Distaloy HP-1, in slow cooling rates (0.4 °C.s-1) the amounts of martensite and bainite varies between 50-60% and 30-40% , however, for fast cooling rates (1.2 °C.s-1) the variation is between 70-80% and 10-20% . The mechanical properties of the prepared samples were studied with controlled production conditions such as cooling rate and heat treatment. Increasing porosity plays an important role in the tensile stress and fatigue strength. The ultimate tensile strength and fatigue strength were more than 1000 MPa and 400 MPa in this research (for Distaloy HP-1, 7.2 g.cm-3, 0.5% carbon content and fast cooling rates). Macroscopic examination of the fracture surfaces for all specimens revealed that fatigue crack growth and final fracture regions were brittle and without noticeable permanent deformation. The final fracture regions for all tests were very similar, final fracture in these two material conditions revealed brittle macrobehaviour and ductile microbehaviour.کلیدواژه ها
Manufacturing, Powder Metallurgy, Microstructure, Fatigueمقالات مرتبط جدید
اطلاعات بیشتر در مورد COI
COI مخفف عبارت CIVILICA Object Identifier به معنی شناسه سیویلیکا برای اسناد است. COI کدی است که مطابق محل انتشار، به مقالات کنفرانسها و ژورنالهای داخل کشور به هنگام نمایه سازی بر روی پایگاه استنادی سیویلیکا اختصاص می یابد.
کد COI به مفهوم کد ملی اسناد نمایه شده در سیویلیکا است و کدی یکتا و ثابت است و به همین دلیل همواره قابلیت استناد و پیگیری دارد.