Influence of the application of wear-resistant coatings on force parameters of the cutting process and the tool life during end milling of titanium alloys

Abstract

The studies were focused on the process of end milling of VT20 titanium alloy with uncoated end milling cutters and cutters with the Ti-TiN-(Ti,Cr,Al)N and Zr-ZrN-(Zr,Cr,Al)N coatings. The investigation of the coating microstructures has revealed that the coatings have nanolayer structures, with the thicknesses of nanolayers within a range of 2–20 nm and the period λ = 75–92 nm. Curves of instantaneous cutting force components (Fp,Fx,Fy) were built. According to the results of the cutting tests, tools with the coatings under study demonstrate the tool life of 2.5–3 times higher compared to the tool life of an uncoated tool. The studies were conducted to investigate the wear and fracture patterns on the coatings during the end milling, and the differences in the processes of coating wear and fracture were revealed.