Abstract
Chromium nitride (CrN) and tungsten nitride (WN) multilayer coating were fabricated by radiofrequency (rf) magnetron reactive sputtering technique. These two nitride coatings were deposited sequentially with a dual-gun system, and an alternating nanolayered CrN/WN coating was derived. The bilayer period, one CrN and one WN layer, of the multilayer was controlled at 10 nm and 24 nm, respectively. The microstructure of the CrN/WN nanolayered coatings was inspected by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Elemental distribution and periodic feature of the nanolayered coatings were revealed by the Auger electron depth profiling analysis. Nanoindentation technique was employed to evaluate the mechanical properties, including hardness and Young's modulus. The nanolayered CrN/WN coatings exhibited a high hardness around 30 GPa, which was superior to that of the CrN single-layer coating. The nanolayered structure with confined grains of the nitrides in the nano range was beneficial to the enhancement of the mechanical performance for the multilayer coating.