New Characterization of Solid Materials and Anisotropy: An Approach towards Phase-Transition Energies

The detection of phase transitions under load and their transition energy is made possible by non-iterative analysis of the indentation findings. On the basis of the empirically based normal force depth3/2 relation, the closed algebraic equations have been derived. The precise transition onset position is obtained by linear regression of the FN = kh3/2 plot, where k is the penetration resistance, which also provides the axis cuts of both polymorphs of first order phase transitions. The phase changes can be endothermic or exothermic. They are normalized per
N or mN normal load. The validity of the loading curves, including those from calibration standards that display previously undiscovered phase-transitions and are thus unreliable, is checked using analyses of indentation loading curves with self-similar diamond indenters. The loading curves from instrument vendor handbooks are utilized to calculate the phase-transition energy for fused quartz. For the first time, the anisotropic behavior of phase transition energies is examined. A helpful test item is
-quartz. On the basis of the local crystal structure under and surrounding the inserting tip, the causes of the packing-dependent changes are explained.