|About this Abstract
||2018 TMS Annual Meeting & Exhibition
||Mechanical Behavior at the Nanoscale IV
||Microstructure and Fracture Toughness of Electrodeposited Ni-W Thick Films Using In-situ Microcantilever Bend Tests
||Denise Yin, Christopher Marvel, Richard Vinci, Martin Harmer
|On-Site Speaker (Planned)
Nanocrystalline Ni-W has been shown to exhibit properties superior to nanocrystalline Ni and coarse-grained materials, but studies regarding its fracture behavior are limited. This work investigates the fracture behavior of Ni-W and establishes structure-property relationships via correlation to the microstructure. As-deposited and heat-treated Ni-21 at.% W was evaluated by aberration-corrected microscopy and in-situ microcantilever bend testing. Due to non-negligible plasticity, linear elastic fracture mechanics was insufficient, and elastic-plastic fracture mechanics had to be used and tailored for small-scale testing. Periodic partial unloading was implemented along with J-integral interpretation. Samples displayed a range of microstructures, including two length scales of mesoscale grain colonies that had a significant impact on the fracture process. The associated deformation mechanisms are discussed. Overall, toughness measurements varied between 5.1 and 8.9 MPa√m depending on the heat treatment. Annealing significantly increased the microhardness but deteriorated the toughness, thus implying a trade-off between the two.
||Planned: Supplemental Proceedings volume