About this Abstract |
| Meeting |
MS&T25: Materials Science & Technology
|
| Symposium
|
Engineering Ceramics: Microstructure-Property-Performance Relations and Applications
|
| Presentation Title |
Small Tests that Make a Big Difference: Correction of the Plastic Size Effect During Micromechanical Testing |
| Author(s) |
Alyssa Stubbers, Sajjad Hossain, Christopher Weinberger, Gregory Thompson |
| On-Site Speaker (Planned) |
Alyssa Stubbers |
| Abstract Scope |
Size effects in micromechanically tested materials arise due to convergence of a material’s plastic zone size and tested specimen size. This makes interpretation of micro-specimen testing difficult, where plasticity characteristics artificially inflate reported fracture toughness values. However, we hypothesize that it is possible to deconvolute plasticity effects from toughness values based on theoretical plastic zone size. Here we describe fabrication techniques of single grain cantilevers in W, Ta2C, and HfC. When used with computational techniques we evaluated distortion effects of plasticity on measured fracture toughness values. Results showed as specimen thickness (B) approaches plastic zone size (ry) there is an increase in reported fracture toughness that can be described by the relationship (0.9ry^2/B^2). From this observation, we proposed an adjustment factor that corrected W, Ta2C, and HfC specimens to agree with calculated KI. Our results facilitate use of micromechanical testing as a quantitative method for materials characterization regardless of scale. |