E. Godlewska

FeAl materials from intermetallic powders

FeAl materials with the aluminium concentration of 40 at.% were prepared from intermetallic powders, obtained by milling and screening of the products of self-propagating high-temperature synthesis (SHS), carried out in a loosely packed mixture of elemental powders. Pressureless sintering of the compacted intermetallic powders yielded porous materials that were densified by hot forming. The properties of dense bodies were strongly related to the grain size of the starting intermetallic powders. Two fractions with grain sizes of less than 25 mm and in the range from 25 to 40 mm were investigated. The amount of an oxide phase distributed along the grain boundaries of the intermetallic matrix was remarkably higher in the former case. The oxide dispersions adversely affected the room temperature strength and ductility of the material. # 2003 Elsevier Science Ltd. All rights reserved.

Comparing Doping Methodologies in Mg 2 Si/AgMg System

Morphological and optical characterizations for the Mg2Si samples doped with Ag are presented. Two different doping methodologies with silver, namely in situ and ex situ doping, were studied for the case of Mg2Si of self-propagating high-temperature synthesis. Electron microscopy measurements in both scanning and transmission configurations verified the presence of AgMg precipitates embedded in the Mg2Si matrix and similar results were also yielded by FTIR spectroscopy. Finally, the dependence of silver content in both forms of dopant and inter-metallic constituent is studied upon doping technology.