ISSN:
1662-9779
Source:
Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
Topics:
Physics
Notes:
An ultra-fine grained microstructure was obtained in high purity nickel by a combinationof (a) equal-channel angular pressing (ECAP) and (b) hydrostatic extrusion (HE) with a cumulativetrue strain of ~11.2. The resulting microstructure was examined by light and TEM microscopy.Mechanical properties have been measured by tensile and hardness tests. It was found that HE ofECAP-ed samples leads to a significant grain size refinement (from 330 to 160nm) and to anincrease in microstructural homogeneity. SPD nickel, made by a combination of the ECAP andhydrostatic extrusion methods, has high strength and ductility (i.e.: YS=1120MPa and εf = 11%).The microstructure transformation was accompanied by a strength increase of 78% compared toECAP alone. The results obtained fit well with the Hall-Petch relationship. A combination ofECAP and HE has achieved much better properties than either single process and show it to be apromising procedure for manufacturing bulk UFG nickel
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/02/22/transtech_doi~10.4028%252Fwww.scientific.net%252FSSP.114.51.pdf
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