EFFECT OF CARBON ON THE DIMENSIONAL CHANGES OF IRON-BASED POWDER METALLURGY COMPACTS

References: 17th International Multidisciplinary Scientific GeoConference SGEM 2017, www.sgem.org, SGEM2017 Conference Proceedings, ISBN 978-619-7408-12-6 / ISSN 1314-2704, 29 June - 5 July, 2017, Vol. 17, Issue 61, 119-124 pp, DOI: 10.5593/sgem2017/61/S24.016

ABSTRACT

The purpose of this paper was to study the effect of carbon content on the dimensional characteristics of some powder metallurgy (PM) materials. The powders used in this study are atomized pure iron and prealloyed iron-based powders with Cu, Ni and Mo. Some elements as copper, nickel, molybdenum, manganese and phosphorus are the most common alloying element added in powders form because of its low cost, availability and capability to improve the properties of alloys. The particle size of the analyzed powders is ranging from 45 to 150 μm. The powders were mixed for 30 minutes to obtain a homogenous mass. The powders were single pressed resulting green compacts. The applied pressure was 600 MPa and the disc specimens have the dimensions of  8  6 mm. The green compacts were sintering in a laboratory furnace at 1150º C for 90 minutes. After sintering, the compacts were subjected to a thermochemical treatment, carburization in fluidized bed. The fluidized bed carburizing conditions were heating at 930° C during 60 minutes. Specimens were then air-cooled to room temperature. The density of green, sintered and carburized in fludized bed specimens, the mechanical properties and dimensional changes were evaluated.

Keywords: powder metallurgy, carbon, dimensional characteristics