ISSN:
1662-9752
Source:
Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Industrial available FeSi, FeCo and FeNi alloys with an initial grain size of 20-50 [removed info]m weresubjected to Severe Plastic Deformation (SPD) up to strain levels where a saturation of themicrostructural refinement is observed. For both SPD conditions, ambient temperature (293 K) andliquid nitrogen temperature (77 K), the microstructure of the severely deformed state is analysed byBack Scattered Electrons (BSE) micrographs captured in a SEM. Additionally, samples that weredeformed at 77 K are examined in a Transmission Electron Microscope (TEM). The magneticproperties were characterised by means of SQUID-magnetography providing information about themagnetization behaviour of the material in the as-processed state. Depending on the SPD conditionsthe mean microstructural sizes in the steady state are about 100-150 nm and 30-80 nm at 293 K and77 K, respectively. The small microstructural sizes influence significantly the magnetic propertiesof these ferritic alloys. The initial soft-magnetic behaviour of the coarse grained state shifts towardsa hard-magnetic with decreasing crystallite size. For crystallite sizes smaller than ~80 nm themagnetic properties become again more soft-magnetic. The experiments show that very lowcoercitivity can be obtained by SPD if the grain size is smaller than ~50 nm
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/02/19/transtech_doi~10.4028%252Fwww.scientific.net%252FMSF.584-586.923.pdf
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