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:
The radiotracer technique was applied for measuring grain boundary diffusion of Ni inultrafine grained (UFG) copper materials with different nominal purities and in a Cu—1wt.%Pballoy. The UFG specimens were prepared by equal channel angular pressing at room temperature.The stability of the microstructure was studied by focused ion beam imaging. Grain boundarydiffusion of the 63Ni radioisotope was investigated in the temperature interval from 293 to 490Kunder the formal Harrison type C kinetic conditions. Two distinct short-circuit diffusion paths wereobserved. The first (relatively slow) path in the UFG materials corresponds unambiguously torelaxed high-angle grain boundaries with diffusivities which are quite similar to those in therespective coarse-grained reference materials. The second path is characterized by significantlyhigher diffusivities. The experimental data are discussed to elucidate the contribution of nonequilibriumgrain boundaries in the deformed materials. Alternative contributions of other shortcircuitdiffusion paths cannot be ruled out, particularly for the Cu-Pd alloy
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/02/19/transtech_doi~10.4028%252Fwww.scientific.net%252FMSF.584-586.380.pdf
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