Effect of milling on morphological and microstructural properties of powder particles for High-Cr Oxide dispersion strengthened ferritic steels

The morphological and microstructural properties of powder particles were examined systematically to optimize the milling time for producing high-chromium oxide dispersion strengthened (ODS) ferritic steels. The XRD and SEM results showed that peak broadening in the XRD patterns occurred due to a decrease in the grain size and the particle diameter of the powder during mechanical milling. The particle size distribution range decreased first with increasing the milling time up to 12 h and then clearly increased thereafter. After 12 h milling, the particles were nearly spherical with nearly uniform mean size of 5.9 mu m. SEM-EDS analysis of the particle surface showed all distributed homogeneously. (c) 2007 Elsevier B.V. All rights reserved.