Digital Image Correlation Of Heterogeneous Deformations In Polycrystalline Material With Electron Backscatter Diffraction

Author

Javier Esquivel, Purdue University

Date of Award

Fall 2014

Degree Type

Thesis

Degree Name

Master of Science (MS)

Department

Aeronautics and Astronautics

First Advisor

Michael D. Sangid

Committee Member 1

Alten F. Grandt

Committee Member 2

James F. Doyle

Abstract

This work establishes the ability to conduct digital image correlation (DIC) investigations at varying length scales. DIC allows for a computational method of strain field measurements using multiple images to track random speckle patterns on material surfaces. The use of a powder silicon oxide speckle allows for high optical magnification correlation using conventional load frames. Self-assembling gold nanoparticles provide sub-micron resolution speckle patterns to study microstructure influences on deformation using scanning electron microscopy. The complex microstructure in aerospace grade aluminum and nickel-based superalloys, give rise to varied deformation fields, which can be studied using electron backscatter diffraction. Specimen preparation techniques, speckle patterns, and image correlation analysis are discussed. Experimental identification of strains at grain level can help validate computational crystal plasticity finite element models, which in turn provide better predictive computational models.

Recommended Citation

Esquivel, Javier, "Digital Image Correlation Of Heterogeneous Deformations In Polycrystalline Material With Electron Backscatter Diffraction" (2014). Open Access Theses. 321.
https://docs.lib.purdue.edu/open_access_theses/321