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:
Grain boundary engineering through the control of grain boundary character distribution(GBCD) has been extensively employed as a powerful tool for achieving enhanced properties and fordevelopment of high performance both structural and functional polycrystalline materials. Manyefforts were made firstly to increase the frequency of low-energy CSL boundaries of polycrystallinematerials in grain boundary engineering. However, the connectivity of grain boundaries can be animportant microstructural parameter governing bulk properties of polycrystalline materials as well asthe GBCD. In the present work, the connectivity of random grain boundaries was quantitativelyevaluated using both the triple junction distribution and random boundary cluster length on the basisof SEM-EBSD/OIM observations, and then these evaluated parameters were linked to intergranularcorrosion of SUS304 stainless steel. We have found that the length of the maximum randomboundary cluster drastically decrease with increasing CSL boundaries in the fraction ranging 60 –80% CSL boundaries, which leads to percolation threshold occurring at approximately 70±5% CSLboundary fraction (at 30±5% random boundary fraction). The experimentally observed percolationthreshold is much higher than theoretically obtained one based on randomly assembled network (at35% resistant bonds for a 2D hexagonal lattice). In addition, the fraction of resistant triple junctions isfound to increase with increasing the the CSL boundary fraction. An increase in the frequency ofresistant triple junctions can enhance intergranular corrosion resistance of polycrystalline austeniticstainless steel even if the GBCD is the same
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/02/15/transtech_doi~10.4028%252Fwww.scientific.net%252FMSF.539-543.2371.pdf
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