Synthesis by a PECVD technique and mechanical properties of nc-Ti(B,N)/a-BN coatings

Synthesis by a PECVD technique and mechanical properties of nc-Ti(B,N)/a-BN coatings

Ternary Ti-B-N coatings with different B contents were deposited on AISI 304 stainless steel substrates and Si wafers using a plasma enhanced chemical vapor deposition (PECVD) technique in a gaseous mixture of TiCl4, BCl3, H2, N2 and Ar. The chemical composition, microstructure and mechanical properties of the Ti-B-N coatings were systematically investigated. The results indicated that the B contents significantly affected the microstructure and mechanical properties of Ti-B-N coatings. An increase of the B content in the coatings resulted in a decreased grain size and a finer microstructure. At a B content of 11.41 at.%, the coating exhibited a nanocomposite microstructure consisting of Ti(B,N) nanocrystals and a surrounding amorphous BN tissue phase. At this B content, the highest microhardness of ~38 GPa was reached. With a further increase in the B content, the microhardness of the coatings decreased. Lower friction-coefficients were also observed due to B additions in the coatings.

Ternary Ti-B-N coatings with different B contents were deposited on AISI 304 stainless steel substrates and Si wafers using a plasma enhanced chemical vapor deposition (PECVD) technique in a gaseous mixture of TiCl4, BCl3, H2, N2 and Ar. The chemical composition, microstructure and mechanical properties of the Ti-B-N coatings were systematically investigated. The results indicated that the B contents significantly affected the microstructure and mechanical properties of Ti-B-N coatings. An increase of the B content in the coatings resulted in a decreased grain size and a finer microstructure. At a B content of 11.41 at.%, the coating exhibited a nanocomposite microstructure consisting of Ti(B,N) nanocrystals and a surrounding amorphous BN tissue phase. At this B content, the highest microhardness of ~38 GPa was reached. With a further increase in the B content, the microhardness of the coatings decreased. Lower friction-coefficients were also observed due to B additions in the coatings.