Filtered cathodic vacuum Arc deposition of nano-layered composite coatings for machining hard-to-cut materials

Abstract

In coated tools, the grain boundaries and coating layers are areas of intense energy dissipation, which hardens the coating material by increasing its toughness and its resistance to the formation and development of cracks. An increase in the efficiency of the coatings was achieved by applying nano-dispersed multilayer composite structure. This paper proposes using nano-scale multilayer composite coating based on TiN-CrN compound to improve thermal stability, where, barrier layers based on ZrNbN have been introduced. The ZrNbN barrier does not interact with TiN and CrN at temperatures around 1000°C. The influence of process parameters of the filtered cathodic vacuum arc deposition on the composition, structure and properties of the coatings based on variation of TiAlN-ZrNbN-CrN was analyzed. The results presented here show that the hardness of the developed coatings was as high as 38 GPa. Subsequently, the carbide tools used in this study with the new coatings had an increased lifetime of 1.5-2.0 times compared to tools with commercial coatings. The coated tools were tested in turning and milling of steels, nickel and titanium alloys.

Research of mechanical and cutting properties, wear and failure mechanisms of nano-structured multilayered composite coating Ti-TiN-(NbZrAl)N

“…For coating deposition, a vacuum-arc VIT-2 unit was used, which was designed for the synthesis of coatings on substrates of various tool materials [1][2][3]13]. The unit was equipped with an arc evaporator with filtration of vapour-ion flow, which in this study were named as filtered cathodic vacuum arc deposition (FCVAD) [1][2][3][4]13,14], which were used for deposition of coatings on tool of significantly reduces the formation of droplet phase during the formation of coating.…”

“…The unit was equipped with an arc evaporator with filtration of vapour-ion flow, which in this study were named as filtered cathodic vacuum arc deposition (FCVAD) [1][2][3][4]13,14], which were used for deposition of coatings on tool of significantly reduces the formation of droplet phase during the formation of coating.…”

“…Out of various types of wear-resistant coatings, developed and implemented in recent years, multilayered composite coatingswith gradient structure, as well as multi-component coatings should be noted [1][2][3][4][5][6][7][8][9][10][11][12][13][14].…”

“…The coating Ti-TiN-(NbZrAl)N under study has a threelayered architecture [1][2][3][4], including adhesive sublayer Ti, intermediate layer TiN, and wear-resistance layer (NbZrAl)N.…”

“…Nano-structured multilayered composite coating Ti-TiN-(NbZrAl)N was selected as an object of the study due to the following factors [1,3,4]: ■ ■ a good combination of high hardness and resistance to brittle fracture, which was shown by the coatings on the basis of system (NbZrAl)N during earlier studies; ■ ■ a role of coating Ti, confirmed during earlier studies, as an optimal adhesive sublayer that provides good adhesion both between tool substrate and coating and between adhesive and intermediate layers of coating; ■ ■ good results in tool life of metal cutting tool with the above coating shown during tests conducted earlier [1,3,4]. One of the objectives of this research was to study failure mechanism of nano-layered multi-component systems operating under conditions of high thermal and mechanical stresses arising in the cutting zone.…”