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:
Severe plastic straining is an established method for producing submicron grain (SMG)structures in alloys. However, the development of such a fine grained structure in single-phase alloysis usually futile if they are to be exposed or processed at elevated temperatures. This is a directconsequence of the natural tendency for rapid and substantial grain coarsening which completelyremoves the benefits obtained by grain refinement. This problem may be avoided by the introductionof nanosized, highly stable particles in the metal matrix. In this work, a SMG structure was generatedin an Al-0.3 wt.% Sc alloy by Equal Channel Angular Pressing (ECAP). The alloy was preparedinitially to produce a fine grained microstructure exhibiting a large fraction of high angle grainboundaries and a dispersion of nanosized Al3Sc particles. The evolution of microstructure duringannealing at temperatures up to 550 °C was examined in detail and grain size distributions generatedfrom the data. It was shown that grain coarsening is rapid at temperatures above 450 °C and theinitial log-normal grain size distribution exhibiting low variance and skewness was alteredconsiderably. The statistical information generated from the grain size distributions confirms thatdiscontinuous grain coarsening occurs in this alloy only at temperatures greater than 500 °C
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/02/13/transtech_doi~10.4028%252Fwww.scientific.net%252FMSF.519-521.1617.pdf
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