An improved instrumented indentation technique for single microfibers

作者：Cole Daniel P; Strawhecker Kenneth E^*

来源：Journal of Materials Research, 2014, 29(9): 1104-1112.

DOI：10.1557/jmr.2014.83

• nanoindentation
• microfiber
• fiber mounting technique
• atomic force microscope
• processing
• structure
• property relationship

We describe an improved experimental approach for characterizing the elastic modulus and hardness of single microfibers through instrumented indentation. A sample mounting technique on a curved surface is presented that ensures contact between an unmodified fiber and substrate. The indentation analysis considers three separate corrections to the well-known Oliver and Pharr method: (i) overestimation of the projected contact area due to sample curvature, (ii) overestimation of projected contact area due to substrate curvature, and (iii) underestimation of fiber stiffness due to the structural compliance of the sample. The method is applied to four types of high performance ballistic fibers: KM2 Plus, Twaron, AuTx, and Dyneema; the results are presented according to both the modified analyses as well as the standard Oliver and Pharr analysis. The modified analyses resulted in an increase in the elastic modulus and hardness of up to 35 and 60%, respectively, compared to the Oliver-Pharr method. The technique has the potential to be applied to single microfilaments under various environmental conditions that may otherwise be compromised by traditional fiber mounting methods.

• 出版日期2014-5-14