Adhesion and mechanical properties of layered nano films TiN/ZrN and TiN/Ti/ZrN: pseudopotential simulation

Energetics and mechanical properties of layered TiN/ZrN and TiN/Ti/ZrN structures are explored by means of the density functional theory and pseudopotentials. It has been shown that nitride layers of these compounds have a good adhesion each to other and especially to metallic titanium, and that leads to their stability. Young's modulus of TiN/Ti/ZrN is twice larger than that of TiN/ZrN, while their shear moduli are approximately the same. Modeling of surface expansion for TiN/ZrN and TiN/Ti/ZrN indicates that the TiN/Ti/ZrN surface is much stronger than the TiN/ZrN surface. Its break appears at twice larger deformation and at twice larger applied stress. Therefore, TiN/Ti/ZrN coatings are much steadier against formation of cracks than TiN/ZrN coatings. [GRAPHICS] .