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:
We have developed the new process for refinement of metallic materials duringsolidification without addition of refiners or without rapid cooling. This process useselectromagnetic body force based on the vibrations caused by simultaneous imposition of directmagnetic field and alternative electric current on the alloy melt during solidification. Thevibrations create cavitation in the melt and it breaks out during growth of it. Then explosive forceis released toward the surroundings such as the primary solid particles and they are fractured finely.Finally fractured solid particles solidified as very fine grains.This process was applied to hyper- and hypo-eutectic Al-Si alloys, and AZ91D Mg alloys.Primary silicon crystals in Al-17mass%Si alloy decreased the size remarkably by the optimumelectromagnetic vibration condition. Primary aluminum dendrites particles in Al-7mass%Si andprimary magnesium dendrite particles in AZ91D are also decreased its size markedly.This process has also been applied to create non-equilibrium state metallic materials such asmetallic glasses. We have succeeded to obtain metallic glasses in Mg-Y-Cu alloy system andFe-Co-Si-B-Nb alloy system. These alloys solidified as fully crystals in this cooling rate withoutelectromagnetic vibrations. These glasses are bulky and are used as structural material
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/02/14/transtech_doi~10.4028%252Fwww.scientific.net%252FMSF.539-543.323.pdf
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