Investigation of depth-area relationships associated with nanoindentations
Determination of hardness from indentation testing requires the measurement of the contact area. For indents generated at very low loads (<20 mN) or shallow depths (<250 nm), optical methods do not have sufficient resolution. One approach utilized in current state-of-the-art mechanical properties microprobes (MPM) involves the measurement of indenter depth. Calculation of the plastic area then requires a relation between depth and contact area. This relation is generally derived either by assuming the indenter is perfectly sharp (``Ideal Indenter`` assumption) or by calibrating the shape using materials having known hardness and elastic modulus values. The validity of both approaches was examined by using a Scanning Force Microprobe (SFM) to measure the actual dimensions of the residual impressions made by the MPM. The SFM data revealed that the ``Ideal Indenter`` assumption underestimates the actual plastic area. This result accounts for the fact that hardness values measured with the MPM are typically higher than those obtained with conventional hardness testers.
- Research Organization:
- Oak Ridge National Lab., TN (United States)
- Sponsoring Organization:
- USDOE, Washington, DC (United States)
- DOE Contract Number:
- AC05-84OR21400
- OSTI ID:
- 10189127
- Report Number(s):
- CONF-940865-3; ON: DE95001353
- Resource Relation:
- Conference: Conference on plastic deformation of ceramics,Snowbird, UT (United States),7-12 Aug 1994; Other Information: PBD: [1994]
- Country of Publication:
- United States
- Language:
- English
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