features induced by spray processing and hot extrusion of an Al–18% Si–5% Fe–1.5% Cu alloy.pdf

Acta Materialia 54 (2006) 1741–1748 Microstructural features induced by spray processing and hot extrusion of an Al–18% Si–5% Fe–1.5% Cu alloy A.K. Srivastava a,*, V.C. Srivastava b, A. Gloter c, S.N. Ojha d a Electron Microscope Section, Division of Materials Characterization, National Physical Laboratory, Dr. K.S. Krishnan Road, New Delhi 110012, India b Metal Extraction and Forming Division, National Metallurgical Laboratory, Jamshedpur 831007, India c ˆ ´ Laboratoire de Physique des Solides, Batiment 510, Universite Paris-Sud, 91405 Orsay, France d Department of Metallurgical Engineering, Banaras Hindu University, Varanasi 221005, India Received 15 September 2005; received in revised form 17 November 2005; accepted 21 November 2005 Available online 9 February 2006 Abstract An inert gas atomization technique was employed to produce spray deposits of an Al–18Si–5Fe–1.5Cu (wt.%) alloy. The spray-depos- ited alloy was subsequently hot extruded with a reduction ratio of 6:1 and extrusion temperature of 480 C. The microstructural features of the as-spray-deposited and extruded alloys were examined using optical, scanning electron and transmission electron microscopy tech- niques, and chemical analyses of phases were carried out using energy dispersive X-ray analysis and spectroscopic methods. The micro- structure of the spray-deposited alloy revealed the presence of a cellular and plate-like morphology of b-Al5SiFe phase coexisting with d- Al Si Fe phas