Date of Award

Fall 2010

Project Type


Program or Major

Mechanical Engineering

Degree Name

Master of Science

First Advisor

Brad Kinsey


Sheet metal forming of parts with microscale dimensions is gaining importance due to the current trend towards miniaturization, especially in the electronics industry. In microforming although the process dimensions are scaled down, the polycrystalline material stays the same (e.g., the grain size remains constant). When the specimen feature size approaches the grain size, the properties of individual grains begin to affect the overall deformation behavior. This results in inhomogeneous deformation and increased data scatter of the process parameters. In this research, the influence of the specimen size and the grain size on the distribution of plastic deformation through the thickness during 3-point microbending operations is investigated via digital image correlation. Results showed that with miniaturization, a decrease in the strain gradient existed In addition, an analytical model to predict the dislocation density increases, and thus strain gradient hardening, during microbending is presented. The results from this analytical model matched the experimental results and previous research in terms of the feature size where modest and significant strain gradient hardening was observed.