Abstract
To investigate the strain-rate sensitivity in nanocrystalline (NC) materials using a single experimental technique over a wide range of strain rate, the micro-scratch testing technique was selected to obtain consistent and systematic data of the strain-rate sensitivity in a fully dense, high purity, and well-characterized electrodeposited NC Ni sample. The scratch characterizations and mechanical properties of the sample under the different scratch velocities were discussed in details. First, some critical parameters under the micro-scratch testing, such as strain rates, scratch ditch widths, were confirmed. Then, the scratch hardness under the different scratch velocity was investigated. From the results, the sample exhibits strain-rate sensitive mechanical properties. Further, the average values of strain-rate sensitivity of the sample were calculated. The values increase with increasing scratch velocity, and exhibit higher values that are of the order of 0.03–0.1. The greater strain-rate sensitivity exponents indicate that the NC Ni samples have different fundamental physical deformation mechanisms. Finally, the fundamental physical deformation mechanism under scratch testing was inspected using SEM and TEM technique. From the SEM and TEM morphologies, the grain boundary dislocation pile-ups should be a carrier of plastic flow under scratch testing in the NC Ni sample.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.