Effect of Modulation Period and N + Beam Bombarding Energy on the growth of Nanoscale ZrB2/AlN Multilayered Coatings Prepared by IBAD

Monolithic ZrB2, AlN, and ZrB2/AlN multilayered coatings have been synthesized by ion beam assisted deposition at room temperature. Scanning electron microscopy, X-ray diffraction, XP-2 profiler and nano indenter were employed to investigate the influences of modulation period and N + bombarding energy on microstructure and mechanical properties of the coatings. Most of multilayered coatings revealed higher hardness and elastic modulus than the rule-of-mixtures value of monolithic ZrB2 and AlN coatings. N + bombardment at 300 eV resulted in ZrB2/AlN multilayered coating the highest hardness (31.2 GPa) and elastic modulus (372.2 GPa). This hardest multilayer also showed the improved residual stress and fracture resistance. These improved performances are likely a result of more efficient momentum transfer to the deposition particles due to the proper N + bombarding energy.