Properties of nanostructured TiN-Ni ceramic-metal coatings obtained by ion-plasma vacuum-arc method

Abstract

Physicomechanical and tribological properties of TiN-Ni ceramic-metal coatings prepared by ion plasma vacuum arc deposition are investigated. It is established that the hardness (H) increases from 23 to 54 GPa with the Ni content from 0 to 12 at %, which is determined by the influence of the nanostruc tured nitride component of coatings. Coefficients HE -1 and H 3 E -2 , which characterize the material resis tance against the elastic and plastic failure deformation, reach 0.104 and 0.567 GPa, respectively. The further increase in the nickel concentration in coatings to 26 at % leads to a decrease in H to 23-25 GPa, which is associated with the influence of the increasing amount of soft plastic metal and the formation of noticeable porosity in the bulk of coatings. The friction coefficient of studied coatings is 0.45, against 0.58 (for the TiN coating) and 0.72 (for the hard alloy base). The cohesion failure mechanism of TiN-Ni nanostructured coat ings (C Ni = 2.8-12 at %) is established, and critical loads which characterize the appearance of the first crack (13.5-14.2 N) and the local coating attrition up to the substrate (61.9-64.4 N) are determined. The complete attrition of coatings does not occur up to a load of 90 N, which points to their high adhesion strength. The developed nanostructured ceramic-metal coatings are characterized by high heat resistance up to 800°C.

Thermal stability and chemical resistance of (Ti,Al)N-Cu and (Ti,Al)N-Ni metal-ceramic nanostructured coatings

“…As these metals do not dissolve in titanium nitride, they are located on the boundaries of the nitride phase nuclei under formation, thereby blocking its growth and forming metal-ceramic nanostructured coatings [8]. The results of our researches [9,10] confirmed these conclusions. Thus, the grain structure of the coating ceramic phase is reduced from 120 to 100 to 20-15 nm (Fig.…”

“…However, their plasticity does not change, which was determined by the value of the relative work of plastic deformation that reached 65-70%. At the same time, the values of tensile stress that can adversely affect the adhesion strength in the coating-substrate system are reduced [9,10].…”

Structural and Phase Changes in Tin Coatings Subjected to Thermal Treatment

“…After annealing of 800 °С there is occurs an increase in TiN intensity with the formation of Ti2N and TiNi, diffraction reflection of γ-Co (111) is absent. In work [15] it was found that the content of less than 12 at.% Nickel in the coating is in the x-ray amorphous state, and when it increases in the composition of the coatings is formed intermetallic TiNi. In work [16] is reported that Ti2N was always present in such coatings (figure 3, b).…”