Optimization of mechanical alloying parameters in 12YWT ferritic steel nanocomposite

• Published in: Materials science & engineering. A, Structural materials : properties, microstructure and processing Vol. 527; no. 26; pp. 6853 - 6857
• Main Authors: Rahmanifard, R., Farhangi, H., Novinrooz, A.J.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier B.V 15-10-2010; Elsevier
• Subjects: Applied sciences; Crystallites; Diffraction; Dispersion hardening metals; Exact sciences and technology; Mathematical models; Mechanical alloying; Metals. Metallurgy; Microstructural properties; Microstructure; Nanocomposite; Nanomaterials; Nanostructure; ODS steel; Powder metallurgy. Composite materials; Production techniques; Structural steels; X-rays; ODS steel; Nanocomposite; Microstructural properties; Mechanical alloying; Particle size; Metal matrix composite; Lattice parameters; X ray diffraction; Dispersion strengthened metal; Dislocation density; Attrition mill; Ferritic steel; Yttrium oxide; Microstructure
• ISSN: 0921-5093; 1873-4936
• DOI: 10.1016/j.msea.2010.07.048

▶ Detailed studies of microstructural properties of ODS steels. ▶ Investigation of effects of different mechanical alloying parameters such as milling time; milling speed; ball-to-powder weight ratio and ball diameter on the microstructural characteristics. ▶ Interpretation of the experimental data using theoretical model by X-ray diffraction line profile analysis.
The effects of different mechanical alloying parameters on the microstructural characteristics and morphology of ODS-ferritic steel nanocomposite powders were investigated. The steady state between the welding and fracturing of the particles was obtained within about 30
h using 8
mm ball diameter and 420
rpm milling speed with the ball-to-powder weight ratio of 10:1. However, for perfect dissolution of the used alloying elements, the mechanical alloying process must be continued up to 80
h of milling. Evaluation of the microstructural characteristics calculated by X-ray diffraction profile analysis revealed that although the average crystallite size reduced more sharply at the initial milling stages under the above conditions, with further milling, it eventually reached nearly the same value in all specimens. The distribution changes of crystallite size also showed a similar behavior of crystallite size. Among the investigated mechanical alloying parameters, milling speed had a considerable effect on the dislocation density so that it was reduced by about one order of magnitude when the milling speed decreased from 420 to 300
rpm.