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Coated polycrystalline cubic boron nitride (PcBN) tools are increasingly used for industrial applications with stringent requirements. However, information on the mechanical integrity of these systems is quite limited. Within this context, the adhesion strength of two TiN/TiAlN-coated and microstructurally different PcBN substrates – high- and low-cBN content grades with metallic and ceramic binders, respectively – is investigated by means of Rockwell C indentation testing. In doing so, special attention is paid to substrate microstructure effects on emergence and evolution of damage as applied load is increased. For both coated systems, it is found that damage scenario evolves from early adhesive delamination within the contact area towards radial cracking and spalling outside the residual imprint. However, critical loads for transition between damage stages are discerned to depend on microstructural assemblage of the substrate. Higher resistance to radial cracking and delamination is exhibited by the high cBN-content grade, in agreement with its higher hardness and toughness. Failure micromechanisms associated with cracking and spalling are similar for both coated-PcBN systems. Very interesting, delamination outside the residual imprint is determined to be of cohesive nature within the substrate, an experimental fact resulting from interaction among indentation-induced radial, cone-like and lateral fissures in PcBN.

Yttria-doped zirconia ceramics have many applications in a wide range of industries mainly due to their excellent mechanical properties, corrosion resistance and biocompatibility. In this study, micromechanical properties of yttria-doped zirconia produced by Direct-Ink Writing (DIW) were investigated and compared to the ones produced by Cold Isostatic Pressing (CIP). In doing so, mechanical response was assessed at different length scales, from macro- up to submicrometric-, by means of Vickers hardness, nanoindentation, and nanoscratch tests. Microstructure was also characterized by determining grain size, crystal structure and phase tetragonal to monoclinic phase transformation. Results revealed that printed samples displayed 20–25% lower hardness values compared to those exhibited by the respective CIP pairs. Differences in hardness between 3 and 8 mol% yttria content evaluated for CIP samples were slight for printed samples, due to the effect of microstructural defects like porosity, resulting from the processing parameters used. At the local level, such an effect was found to be lower. In this sense, hardness and elastic modulus achieved by nanoindentation were closer, when comparing printed and CIP samples. Scratch tests carried out from 0 to 250 mN revealed that 3 mol% Y2O3 samples developed micro-fracture events in the track length, being the printed samples the ones heavily deformed.

Cycling contact fatigue indentation tests in dry and wet conditions were conducted in cemented carbides CVD-coated with Ti(C,N)/a-Al2O3 and Zr(C,N)/a-Al2O3 systems. In dry contact experiments, all imprints presented a deformed area where the coating was still present after the test. Formation of cracks was visible at the edge of the contact point of the imprint. On the other hand, under wet conditions, almost all imprints presented a ring where the a-Al2O3 had been removed, driven by a corrosion-fatigue process. Exceptionally, for Cr-containing cemented carbides combined with Zr(C,N)/a-Al2O3 coating, no delamination of a-Al2O3 was observed after the test under wet conditions. This result suggests that the combination of fine-grained cemented carbides and coating systems with low coefficient of thermal expansion may be of advantage to resist degradation by cyclic contact fatigue. Furthermore, the response to fatigue by contact loads can be enhanced by tailoring/combining cemented carbides and CVD coating systems which present higher chemical stability, and both higher intrinsic plasticity and resistance to plastic deformation.

Since the discovery of the second generation High Superconductor Materials (2G-HTSC) in 1986, their magnetic properties have been widely studied by different research groups around the world. During the last years, the mechanical properties at micro-/ and nanometric scale are starting to be studied in order to know and improve the durability of conventional devices. In this book chapter, we would like to focus our attention on the magnetical response and also the mechanical properties of 2G-HTSC. In relation to the magnetic response, the Meissner effect is one important signature of the superconductivity. In this case, a diamagnetic response is observed due to exclusion of the magnetic flux of the interior of the superconducting material when the temperature is below the critical temperature. This important property allows to distinguish a superconducting material from a conducting one. But in several cases the superconducting materials exhibit a paramagnetic response instead of the conventional diamagnetism. This effect is frequently called paramagnetic Meissner effect (PME). In this case, the magnetic flux is not expelled, and a paramagnetic state can be originated. This effect is observed in several magnetic field regimes, and in some cases the paramagnetic response increases with the applied magnetic field, but in others the paramagnetic response decreases when the magnetic field increases...