ISSN:
1662-8985
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:
In this paper, a rapid solidification (RS) method was employed to produceyttrium-containing TiAl based alloy ribbons. The microstructure evolution was investigated in termsof yttrium addition and RS parameters. For comparison, the conventionally cast counterpart alloyswere studied as well. It was found that the microstructure of as cast alloys is sensitive to the Ycontent. The alloys with addition of 0 to 1.0at.% Y were of lamellar microstructures, but the alloysamples with 1.5 and 2.0at.% Y additioin were of strip-like microstructure. The yttrium-free alloyexhibited full γ phase, while the Y-bearing alloys contain γ phase, a small amount of α2, and yttriumcontaining phases. With increasing Y content, the secondary dendritic arm spacing (SDAS)gradually reduced. In the case of the rapidly solidified alloys, the microstructure was refinedevidently when compared with the as cast counterparts. The fine Y-rich precipitates werehomogeneously distributed in the matrix with a particle size of several tens of nanometers. A bccphase (a=0.314 nm) was found in the alloys containing more than 1.5at.% Y, which was attributedto the extension of the solubility of Y in the matrix by rapid solidification
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/01/40/transtech_doi~10.4028%252Fwww.scientific.net%252FAMR.29-30.103.pdf
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