Physical Nanoindentation: From Penetration Resistance to Phase-Transition Energies - Advances in Materials Physics and Chemistry

AMPC > Vol.9 No.6, June 2019

Physical Nanoindentation: From Penetration Resistance to Phase-Transition Energies ()

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DOI: 10.4236/ampc.2019.96009 589 Downloads 1,241 Views

Author(s)

Gerd Kaupp

Affiliation(s)

University of Oldenburg, Oldenburg, Germany.

ABSTRACT

-The ISO standard 14577 is challenged for its violation of the energy law, its wrong relation of normal force F_N with impression depth h, and for its iterative treatments. The solution of this dilemma is the use of sacrosanct simplest calculation rules for the loading parabola (now F_N = kh^3/2) giving straight lines for cones, pyramids and wedges. They provide the physical penetration resistance hardness k with dimension [Nm^-3/2] and allow for non-iterative calculations with closed formulas, using simple undeniable calculation rules. The physically correct F_N versus h^3/2 plot is universally valid. It separates out the most common surface effects and reveals gradients. It provides unmatched precision, including reliability checks of experimental data. Regression analysis of F_N versus h^3/2 plots reveals eventual unsteadiness kink phase-transition onset with the transition-energy. This is shown for all kinds of solid materials, including salts, silicon, organics, polymers, composites, and superalloys. Exothermic and endothermic single and consecutive multiple phase-transitions with their surface dependence are distinguished and the results compared in 5 Tables. The sharp phase-transition onsets and the transition energies provide unprecedented most important materials’ characteristics that are indispensable for safety reasons. ISO ASTM is thus urged to thoroughly revise ISO 14577 and to work out new standards for the mechanically (also thermally) stressed materials. For example, the constancy of the first phase-transition parameters must be controlled, and materials must only be admitted for maximal forces well below the first phase-transition onset. Such onset loads can now be easily calculated. The nevertheless repeated oppositions against the physical analysis of indentations rest on incredibly poor knowledge of basic mathematics, errors that are uncovered. The safety aspects caused by the present unphysical materials’ parameters are discussed.

KEYWORDS

Energy Law Violation, ISO-14577 Challenge, Calculation Rules for Indentations, Phase-Transition Onset and Energy, Multiple Transitions, Safety Problems

Share and Cite:

Kaupp, G. (2019) Physical Nanoindentation: From Penetration Resistance to Phase-Transition Energies. Advances in Materials Physics and Chemistry, 9, 103-122. doi: 10.4236/ampc.2019.96009.

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