Fractographic Analysis of Very Small Theta Specimens

Abstract:

The theta test specimen is a versatile tool for evaluating the strength of extremely small structures. Round and hexagonal rings are compressed vertically on their ends creating a uniform tension stress in the middle gauge section. The simple compression loading scheme eliminates the need for special grips. A conventional nanoindentation hardness machine with a flat indenter applied load, monitored displacement, and recorded fracture loads. Prototype miniature specimens with web sections as thin as 7.5 m were fabricated by deep reactive ion etching (DRIE) of single crystal silicon wafers. The strength limiting flaws were 200 nm to 500 nm deep surface etch pits.

• Periodical: Key Engineering Materials (Volume 409)
• Pages: 201-208
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.409.201
• Online since: March 2009
• Authors: George D. Quinn
• Keywords: Etch Pit, Flaw, Silicon, Strength, Theta Specimen

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