Tensile deformation and fracture micromorphology of an Fe-28Al-4Cr-0.1Ce alloy

Fracture and mechanical properties of a vacuum cast and hot extruded Fe-28A l-4Cr-0.1Ce (at.%) alloy were studied as a function of temperature and stra in rate. The tensile deformation tests were carried out at temperatures ran ging from 20 to 700 degrees C, at strain rates of similar to 10(-4) s(-1) a nd similar to 10(-2) s(-1). The effects of strain rate and testing temperat ure are well recognized in the fractographic features. At room temperature the main fracture mechanism is intergranular decohesion with a certain prop ortion of transgranular cleavage. With increasing temperature the proportio n of transgranular cleavage and ductile dimple fracture gradually increase at the expense of intergranular decohesion. The plastic deformation at each testing temperature is more developed at lower strain rate. The changes in the micromorphology of fracture correlate better with reduction of area th an with elongation to fracture. Room temperature ductility of 6.5 and 8.6%, was found for the strain rate of similar to 10(-4) s(-1) and similar to 10 (-2) s(-1), respectively. (C) 2000 Elsevier Science S.A. All rights reserve d.