Similarities and differences in the microstructure of attritor-milled Fe-Al-N compositions
- Old Dominion U., Norfolk, VA
Although numerous studies of high-energy, ball-milled metal powders have been conducted, to date few studies have characterized the mechanical processing of identical elemental compositions of prealloyed powders and of powder blends. This study reports on the mechanical processing (attritor ball milling) in argon and nitrogen gas environments of (a) iron powder and prealloyed iron–2 wt.% aluminum powder, and (b) iron-aluminum, iron-aluminum nitride, and iron-iron nitride powder blends. When nitrogen was milled into iron particles either from nitride powder or by gas infusion, the nitrogen dissolved interstitially in bcc-Fe (principally at the grain boundaries) or was present as bct-Fe nanoparticles at the bcc-Fe nanograin boundaries. The resulting nitrogen distribution was independent of how the nitrogen was added. Milled blends of iron and aluminum powder and prealloyed iron-aluminum powder resulted in similar microstructures: micrometer size particles with similar nanograin size. The aluminum in the blended powder mixture developed an ultrafine distribution on the grain boundaries, but it did not become uniformly distributed within the bcc-Fe grains. In contrast, the aluminum in prealloyed Fe–Al powder remained in solid solution during the mechanical milling.
- Research Organization:
- Albany Research Center (ARC), Albany, OR (United States)
- Sponsoring Organization:
- USDOE - Office of Fossil Energy (FE)
- DOE Contract Number:
- None cited
- OSTI ID:
- 923220
- Report Number(s):
- DOE/ARC-1997-018; CODEN JMREEE; TRN: US200804%%970
- Journal Information:
- Journal of Materials Research, Vol. 12, Issue 4; ISSN 0884-2914
- Publisher:
- Materials Research Society, Warrendale, PA
- Country of Publication:
- United States
- Language:
- English
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