Thesis
Yielding and fracture in nanolayered metallic composites
Washington State University
Master of Science (MS), Washington State University
2009
Handle:
https://hdl.handle.net/2376/101324
Abstract
Thin films are currently being used in virtually all forms of electronic devices, as protective coatings, MEMS and even some drug delivery systems. In many cases the strength of films becomes a critical factor in their reliability. For this reason, a better understanding of their mechanical properties is needed. Multilayer metallic films in particular exhibit higher strengths than the constituents alone. This work utilized bulge testing in conjunction with nanoindentation to study the elastic properties, the onset of yielding, and eventual failure of several multilayered film systems and geometries. CuNb, CuNi and CuNbNi multilayers with individual layer thicknesses of 20nm were studied. Though the CuNi films had extremely poor adhesion strength, these films had the highest pressures needed to cause fracture , reaching values approximately 1/3 higher than the CuNb and CuNbNi films. However, the CuNb films were shown to exhibit higher hardnesses than the CuNi and CuNbNi films. These differences were attributed to a difference in the strain hardening abilities of these films. The information found from this work will serve to be the base line for fatigue testing of these films in the future.
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Details
- Title
- Yielding and fracture in nanolayered metallic composites
- Creators
- Nicole Rebecca Overman
- Contributors
- David F. Bahr (Degree Supervisor)
- Awarding Institution
- Washington State University
- Academic Unit
- Mechanical and Materials Engineering, School of
- Theses and Dissertations
- Master of Science (MS), Washington State University
- Publisher
- Washington State University; Pullman, Wash. :
- Identifiers
- 99900525398101842
- Language
- English
- Resource Type
- Thesis