Effects of modulation period on microstructure, mechanical properties of TiBN/TiN nanomultilayered films deposited by multi arc ion plating

• We synthesized TiBN/TiN multilayers with different modulation periods.
• The TiBN/TiN films contain TiN (111) (200), (220) structures and preferred (111) orientation.
• An decreasing Λ will increase the B contents of the coating.
• The highest hardness reached 31.6 GPa at Λ = 1.9 nm.

TiBN/TiN multilayered coating with different modulation periods (bilayer thickness) have been synthesized using typical cathodic arc plasma deposition equipment. The objective of this work is to study the influence of modulation period on the microstructure, mechanical and tribological properties. TiBN/TiN multilayer coatings exhibited a TiN (111), (200), (220) and TiB2 (220) crystallographic orientations and preferred TiN (111) orientation. With the decrease of modulation period from 12 nm to 1.9 nm, the mole ratio of B increased from 0.079 to 0.162 in addition to the average mole ratio of N was about 0.39 steadily, while the mole ratio of Ti decreased from 0.506 to 0.407. The microstructure of TiBN/TiN multilayered coating evolves form nanocrystalline TiN/a-BN to nanocomposite Ti(B,N) with an dense amorphous BN phase, The maximum values of hardness and elastic modulus reached 31.6 GPa and 336 GPa with a bilayer period of 1.9 nm and B:Ti ratio of 2:5.