Spatial correlation between local misorientations and nanoindentation hardness in nickel-base alloy 690
2016 (English)In: Journal of Materials Science and Engineering: A, ISSN 2161-6213, Vol. 674, 171-177 p.Article in journal (Refereed) Published
Misorientation increases with plastic strain in metals, and this observation has been used as an empirical assessment of plastic strain in recent years. The method has been validated for a sample area corresponding to a 100 µm×100 µm square, but on the micrometer scale misorientations no longer seem to correlate with plastic strain. Misorientations are however not dependent on plastic strain but rather on dislocation density, which means it should also be related to hardness. Therefore, we have in this work compared maps of predicted hardness calculated from misorientation determination with maps of actual hardness measured by nanoindentation. It was shown that the predicted and measured hardness maps do indeed correlate spatially in nickel-base Alloy 690, although the measured values have a significantly smaller hardness variation. This is explained by a presumably high and uniform density of statistically stored dislocations, which contribute to hardness but do not affect the misorientation determination from electron backscatter diffraction. Thus local misorientation can be used to qualitatively map the local effective plastic strain distribution, for example to identify regions of increased hardness.
Place, publisher, year, edition, pages
Elsevier, 2016. Vol. 674, 171-177 p.
EBSD, Nanoindentation, Local Misorientation, Hardening, Plasticity, Nickel Based Superalloys
Applied Mechanics Metallurgy and Metallic Materials
IdentifiersURN: urn:nbn:se:kth:diva-193478DOI: 10.1016/j.msea.2016.07.123ScopusID: 2-s2.0-84982839184OAI: oai:DiVA.org:kth-193478DiVA: diva2:1014967
QC 201610042016-10-032016-10-032016-10-04Bibliographically approved