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:
Nanocrystalline metals demonstrate a broad range of fascinating mechanical properties atthe nanoscale, namely a significant increase in hardness and superior yield stress. In this regard,understanding grain growth in nanocrystalline metals is crucial, particularly because nano sizegrains are characterized by a high curvature, which results in a high driving force for grain growth.In this work, the effect of annealing conditions on grain size of copper nanocrystalline thin filmswas investigated. The nanocrystalline copper thin films were first deposited by d.c. magnetronsputtering on a copper substrate. The specimens were then annealed in vacuum at 100, 300 and500ºC from 10 minutes to 5 hours. Transmission electron microscopy observations revealed that theas-deposited thin films have a bimodal grain size distribution; an average grain size of 43±2nm andthe presence of nanotwins. Abnormal grain growth was observed for some samples annealed.Increasing the annealing time induced significant grain growth and promoted twin formation in thelarger grains. Finally, the hardness of these nanocrystalline Cu thin films was determined usingatomic force microscope. The relation between mechanical properties, annealing conditions andgrain size was analyzed
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/02/19/transtech_doi~10.4028%252Fwww.scientific.net%252FMSF.587-588.483.pdf
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