The effect of wear-resistant coatings composition based on niobium nitride on the structural parameters, mechanical properties and efficiency of the cutting tool

Single-layer wear-resistant coatings based on niobium nitride deposited on a carbide cutting tool are considered in this article. The influence of one and two alloying elements on the change of the coating structure, mechanical properties and efficiency of the cutting tool was studied. It was revealed that in all cases, alloying with titanium, zirconium, aluminum and chromium leads to a change in the microstructure and an increase in the mechanical properties of the coatings and the inclusion of two elements into the composition of coatings increases mechanical properties to a greater extent. Research has shown that cutting tools with coatings based on niobium nitride are characterized by a decrease in the stress state of the tool base and an increase in the total compressive stresses in the coating. Compared to titanium nitride, the niobium nitride coating reduces the temperature on the front surface of the cutting tool, but for complex-alloy coatings, there is a slight increase in contact temperatures. Changing the heat-stressed state and increasing the mechanical properties leads to an increase in the crack resistance of such coatings. It is shown that the use of developed compositions of multi-element coatings can improve the efficiency of the cutting tool.