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:
Microstructural evolution in pure copper during multi-directional forging (MDF) attemperature of 77 K was studied. Flow stress during MDF at 77 K showed a monotonical increaseat all strain. Ultra fine (sub)grains of 0.15μm in diameter were evolved, which was accompaniedby deformation twinning, at strain of Σε = 2.4. In higher strain region, Σε = 6.0, lamellar-lookstructure of twins extensively appeared. The lamellar spacing was 10-100nm. For comparison,samples were also MDFed at 300 K. The flow stress curves showed an apparent steady state flow atabove strain of Σε =2.0, which implies occurrence of dynamic recovery. The evolved (sub)grainsize was 0.3 μm at high strain of Σε = 6.0. Therefore, grain refinement seems to take place moreeasily by MDF at 77 K compared with that at 300 K due to effect of deformation twin.Microstructures evolved under MDF at 77 K and 300 K showed different annealing behavior. Staticrecrystallization started earlier and faster in the samples MDFed at 77K than those MDFed at 300K
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/01/39/transtech_doi~10.4028%252Fwww.scientific.net%252FAMR.15-17.649.pdf
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