|Investigation of mechanical properties before and after sintering of cold isostatically pressed metallic powders|
EKSI, A. K.
vol. 44 (2006), no. 4, pp. 191 - 1981
In this work, Al and Fe powders are pressed and sintered up to 600 MPa with 100 Mpa pressure intervals in a CIP unit made of SAE 1040 steel that can withstand up to 650 Mpa pressure. Packing densities were initially 48 % and 33 % and these values have reached to 98 % and 89.2 % under pressures of 600 MPa for Al and Fe powders, respectively. Pressed specimens were sintered at 600, 620 and 640°C for 20 minutes for aluminium and 1200°C for 30, 60 and 90 minutes durations for iron under argon atmosphere in a tube furnace. In order to observe the effects of pressing pressure and sintering temperature and duration on sintering behaviour of samples after and before sintering densification values of samples have been measured. When these pressed specimens were sintered at 600°C /20 minutes and 1200°C /30 minutes, the increase in amount of densification for Al and Fe powders was to 1.3 % and 2.5 %, respectively. Pressing process resulted with significant increase in microhardness of iron and aluminium powders. All products were examined by Scanning Electron Microscope (SEM) in order to determine the morphological change of powders in block samples. Light and scanning electron microscopy examinations revealed that severe plastic deformations took place in the powders of aluminium and iron.
sintered aluminium and iron, mechanical properties, cold isostatic pressing
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