Biography
Biography: Gerd Kaupp
Abstract
Since 2000, it is experimentally found and since 2015, physically deduced that pyramidal/conical nanoindentations follow the law of normal force FN = k∙h3/2 but not constant h2 (h=indentation depth). However, the unsupported exponent 2 is still used by the ISO-14577 standard, that industry and government must obey, while it does not concur with physics. Also NIST (2009) continued using h2 for defi ning erroneous mechanical parameters in a tutorial, despite their curves supporting h3/2. Only the precisely validated k and h3/2 allow for a wealth of otherwise unachievable characterizations, such as initial surface eff ects, gradients, phase transitions, transformation energy and activation energy. Arithmetically, h3/2 reveals the 80/20 ratio of indentation- and long-range works, independent of material or method. Unfortunately, also ISO hardness and elastic modulus depend on false h2, and the diff erences between h2 and h3/2 are very large. Th us, present mechanical data from indentations create dilemma between ISO standards and physics. It is however possible to obtain the "physical hardness" solely from the penetration resistance k of the loading curve. All deduced mechanical parameters from indentations are in error when depending on h2 instead of h3/2. Miscalculated materials and composites against physics might be the reason for medical or technical failures even growing to disasters. How shall liabilities in these cases be judged and compensated? 50 years published data require the original data or at least loading curves to be corrected for the sake of daily safety.