Reactive co-sputter deposition and properties of CrAlSiN hard films for enhancement of cutting tools

• Cr, W and Si targets are used to form a reactive co-sputter CrAlSiN hard film.
• The CrAlSiN hard film was deposited on tungsten carbide tool for milling of MAR-M247 super alloy and results are good.
• The orthogonal array offers an efficient way to increase experimental efficiency.
• The optimal CrAlSiN hard film's hardness, Young's modulus and friction coefficient were 31.26 GPa, 258 GPa and 0.5, respectively.

This paper evaluates chromium aluminum silicon nitride (CrAlSiN) hard films fabricated using reactive magnetron co-sputter with adjusted deposition parameters. The hard films were prepared on glass and tungsten carbide tools at a substrate temperature of 350 °C. The targets were Cr, W and Si, with 40 sccm Ar as the plasma gas and 40 sccm N2 as the reactive gas. An orthogonal array, the signal-to-noise ratio and analysis of variance are used to analyze the effect of the deposition parameters. Using the Taguchi method for design of a robust experiment, the interactions between factors are also investigated. The main deposition parameters, such as Cr direct current (DC) power (reverse time 5 μs), Al DC power (reverse time 5 μs), Si radio frequency (RF) power, and bias the substrates with RF power, were optimized, with regard to the microstructure, morphology, mechanical and tribological properties of CrAlSiN films. The results of this study show that the substrate bias has the most significant effect on hardness. The experimental results also show that the Taguchi method allows a suitable solution to the problem, with the minimum number of trials compared to a full factorial design. With the optimized CrAlSiN hard films deposition conditions, the hardness, Young's modulus and friction coefficient were 31.26 Gpa, 258.58 Gpa and 0.50, respectively. Further, this study also investigates the properties of machining MAR-M247 nickel-based superalloy, testing differently coated tools in dry conditions.