ISSN:
1662-9752
Quelle:
Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
Thema:
Maschinenbau
Notizen:
A novel canning technology to forge gamma-TiAl alloys was developed at the BTUCottbus. A TiAl specimen was encapsulated with multilayer stainless steel foil and glass. The steelfoil layers prevented the heat loss through radiation and the glass layer reduced the temperaturedecrease through conduction. First, the effect of steel foil on the cooling rate was investigated.Cooling curves were recorded for TiAl specimens without steel foil layer, with 1, 2, 3 and 4 layers ofsteel foil, as well as with 3 coated steel foil layers, respectively. While the unprotected specimencooled from 1200 °C to 1100 °C within 12 s, the specimen with 3 coated steel foil layers needed 52 sfor the same temperature decrease. The efficiency of the glass layer was examined with forging ofsteel specimens. The cooling rate during forging of the specimen with a glass layer was only half ofthat without a glass layer. Based on the results, Ti-45Al-0.5Mo-0.5Cu-0.2Si specimens, canned withsteel foil and glass, were successfully forged at strain rates of 0.1 s-1 and 0.04 s-1 with warm dies whichwere heated to 500 °C. Visual and metallographic examinations revealed no cracks, pores ormicropores. The microstructures are fine-equiaxed grains
Materialart:
Digitale Medien
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/02/16/transtech_doi~10.4028%252Fwww.scientific.net%252FMSF.546-549.1421.pdf
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