Forming of AlSi8Cu3Fe alloy in the semi-solid state

AlSi8Cu3Fe alloy is a general purpose die casting alloy widely used to manufacture automotive parts. Forming of this alloy in the semi-solid state could largely eliminate problems inherent in die casting process and thus offers a number of advantages. Low superheat casting was employed in the present work to produce non-dendritic AlSi8Cu3Fe alloy feedstock. The ingots thus obtained were thixoformed in a laboratory press after they were held at 570 degrees C for 5 min, yielding a microstructure with predominantly alpha-Al globules and interglobular Si particles. The thixoformed parts attain hardness values as high as 125 HB after T6 heat treatment, implying a considerable age hardening potential. However, with a reheating temperature range of 568-572 degrees C, thixoforming of AlSi8Cu3Fe alloy components under industrial conditions may be challenging. (C) 2008 Elsevier B.V. All rights reserved.