ALBUQUERQUE, A. C.; http://lattes.cnpq.br/1934705500562212; ALBUQUERQUE, Albéria Cavalcanti de.
Abstract:
The austempered ductile cast iron (ADI) is a material that offers
improved product performance while reducing costs and, in many applications,
surpasses steel forgings, weldments, carburized steel, malleable, gray iron and
aluminium components. Besides, the ADI displays remarkable mechanical
properties as high tensile strength and wear resistance, beyond of excellent
fracture toughness and fatigue strength. In the present work the mechanical
properties and fracture toughness were investigated on unalloyed and alloyed with
copper and molibdenium ADI. The unnalloyed and alloyed with 0,2% molibdenium
ADI was inoculated with 0.5, 0.7 and 0.9% of FeSi75A, while 0.5% of inoculant
FeSi75B was used to inoculate the alloyed with 0.0, 0.4 e 0.8% copper ADI. The
tests were realized at room temperature in a MTS 810 hidraulic machine. The
mechanical properties and fracture toughness of the unalloyed ADI was
comparable to that of the alloyed ADI, however it was noticed a little difference in
the tolerance to the crack. The alloys inoculated with FeSi75B presented
nodularity bigger than those inoculated with FeSi75A, what was attributed to the
largest inoculant potential of the FeSi75B. The fracture of all samples happened in
a fragile mode, however presenting mixed fracture micromorphology, constituded
of microdimples and cleavage or quasi-cleavage facets.