|About this Abstract
||2017 TMS Annual Meeting & Exhibition
||Fracture Properties and Residual Stresses in Small Dimensions
||Indentation Fracture Experiments on Single Crystal Olivine from 300K to 1100K
||David E.J. Armstrong, Katie Kumamoto, David Wallis, Steve Roberts, Angus Wilkinson, Jessica Warren, Lars Hansen
|On-Site Speaker (Planned)
||David E.J. Armstrong
Olivine is the major constituent mineral of the lithospheric mantle and as such its mechanical behavior has significant influence over processes such as the formation of new tectonic plate boundaries. However, basic deformation mechanisms of olivine at relevant temperature ranges for plates (~300-1500K) are poorly characterized. In this study nano and micro-indentation experiments have been performed on single crystal olivine from room temperature to 1100K in vacuum. At room temperature cracks are seen around indentations after testing. Up to 800K little change in hardness is observed, above this temperature the hardness gradually decreases. Post indentation analysis shows that the degree of fracture seen around indents decreases above 800K. To understand fracture events FIB-SEM sectioning of indents was performed. This showed the cracks emanating from the indentations were shallow and can only be formed during the unloading process, with dislocation motion dominating the deformation during the sample loading at all temperatures.