Microstructural evolution during sintering of the blended elemental Ti-5Al-2.5Fe alloy

The Ti-5Al-2.5Fe (in wt.%) alpha-beta alloy was processed by powder metallurgy using the blended elemental (BE) technique. Samples of this alloy were prepared by cold pressing followed by vacuum sintering between 973 and 1673 K. The holding time at each temperature was 2 h. The sintering behavior of both elemental (Ti + Al + Fe) and intermetallic (Ti + Fe2Al5 + TiAl3) powder mixtures and their corresponding microstructural evolution were investigated. Scanning electron microscopy (SEM) in the backscattered mode was used to image the samples. The chemical composition of the individual phases was determined by standardless energy-dispersive spectrometry (EDS) in SEM. Sintered densities were determined by conventional gravimetric method. The aim of the present work is to compare the sintering behavior and the nature of the evolving phases during sintering of BE-Ti-5Al-2.5Fe alloy using both elemental and intermetallic powders. (C) 2008 Elsevier B.V. All rights reserved.