Hybrid deposition of AlTiN/WN multilayer films with low compressive stress at low temperature

Abstract

AlTiN/WN multilayer films with low compressive stress were deposited by arc evaporation and DC magnetron sputtering at a low temperature. The phase structure, morphologies, mechanical properties, wear behavior, and cutting performance of the AlTiN/WN multilayer films were evaluated. The results show that all the as-prepared AlTiN/WN multilayer films have fcc structure and exhibit (111) preferred orientation. The lowest value of −1.7 ± 0.3 GPa for compressive stress was obtained under low-temperature deposition. The film hardness increases as the temperature increases. High-temperature deposition provides higher energy to grow a dense film, which improves the film hardness. Increasing the WN layer thickness reduces the adhesion strength of the film. Compared with room temperature, the friction coefficients of the films against stainless steel reduce at high temperatures. This was attributed to lubricative oxides WOx formed on the wear surface at high temperatures. Dry cutting experiments were conducted and the longest service life of the coated tool reaches ∼3730 m. The worn flank surface shows that both adhesion and abrasive wear dominate the failure of the coated tools.