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The effect of Zr addition on the melting temperature of the CoCrFeMnNi High Entropy Alloy (HEA), known as the “Cantor’s Alloy”, is investigated, together with its micro-structure, mechanical properties and thermomechanical recrystallization process. The base and Zr-modified alloys are obtained by vacuum induction melting of mechanically pre-alloyed powders. Raw materials are then cold rolled and annealed. recrystallization occurred during the heat treatment of the cold-rolled HEA. The alloys are characterized by X-ray diffraction, electron microscopy, thermal analyses, mechanical spectroscopy and indentation measures. The main advantages of Zr addition are: (1) a fast vacuum induction melting process, (2) the lower melting temperature, due to Zr eutectics formation with all the Cantor’s alloy elements, (3) the good chemical alloy homogeneity, and (4) the mechanical properties improvement of re-crystallized grains with a coherent structure. The crystallographic lattice of both alloys results in FCC. The Zr-modified HEA presents a higher recrystallization temperature and smaller grain size after recrystallization with respect to the Cantor’s alloy, with precipitation of a coherent second phase, which enhances the alloy hardness and strength.

New composite ZrO2/SiO2 coatings on grade 4 titanium have been produced by the sol-gel synthesis and dip coating, in order to improve durability of the substrate. Mechanical testing by scratch test and nanoindentation allowed to identify the coatings with better adhesion, lower tendency to crack, stiffer, harder and with lower friction against diamond in dry sliding. Potentiodynamic polarization tests in Dulbecco’s phosphate-buffered saline solution were used to evaluate a possible extra corrosion protection imparted by the coatings to the already excellent corrosion resistance of the passivated grade 4 titanium substrate. The silica-containing coatings appeared to be the best tradeoff between the improvement of mechanical and corrosion resistance properties.New composite ZrO2/SiO2 coatings on grade 4 titanium have been produced by the sol-gel synthesis and dip coating, in order to improve durability of the substrate. Mechanical testing by scratch test and nanoindentation allowed to identify the coatings with better adhesion, lower tendency to crack, stiffer, harder and with lower friction against diamond in dry sliding. Potentiodynamic polarization tests in Dulbecco’s phosphate-buffered saline solution were used to evaluate a possible extra corrosion protection imparted by the coatings to the already excellent corrosion resistance of the passivated grade 4 titanium substrate. The silica-containing coatings appeared to be the best tradeoff between the improvement of mechanical and corrosion resistance properties.