Structures and superparamagnetic properties of overaged Fe-Al-Mn-C alloys

Journal Article · Fri Dec 10 04:00:00 EST 1999 · Acta Materialia

DOI:https://doi.org/10.1016/S1359-6454(99)00341-9· OSTI ID:20005416

Lin, Y C

Microstructures and superparamagnetic properties in aged-hardened Fe-9%Al-30%Mn-(x)C,Si alloys, resulting from overaging at a temperature of 823 K for 48 h to 313 days, have been investigated by transmission electron microscopy (TEM), X-ray diffraction patterns, and vibrating sample magnetometry (VSM). The results reveal that the precipitate {kappa}-phase [(Fe,Mn){sub 3}AlC] decomposition in this alloy, overaged at 823 K for one week, resulted from two separate mechanisms: (1) wetting of the 1/2 a{prime}{sub 0}{l{underscore}angle}100{r{underscore}angle} antiphase boundary segment (APBs) of D0{sub 3} [(Fe/Mn){sub 3}Al] domains by the B2 [(Fe/Mn)Al] phase; and (2) precipitation of the B2 [(Fe/Mn)Al] phase within the domain. A superparamagnetic behavior was discovered when the alloy was overaged at 823 K for {approx}120--313 days. The super-soft magnetic property was mainly attributable to the ferromagnetic spinel-ordered (B2 [(Fe/Mn)Al] + D0{sub 3} [(Fe/Mn){sub 3}Al]) phases and ordered B2 with monoclinic {alpha}{prime}Mn structures.

• Research Organization: National Kaohsiung Inst. of Science and Technology (TW)
• OSTI ID: 20005416
• Journal Information: Acta Materialia, Journal Name: Acta Materialia Journal Issue: 18 Vol. 47; ISSN 1359-6454; ISSN ACMAFD
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM ALLOYS
ANNEALING
CARBON ADDITIONS
IRON BASE ALLOYS
MAGNETIC PROPERTIES
MANGANESE ALLOYS
MICROSCOPY
MICROSTRUCTURE
PRECIPITATION
X-RAY DIFFRACTION