Investigation of tribological and mechanical properties of Nb-Al-N coatings before and after annealing
Coatings Nb-Al-N were deposited on a silicon substrate under argon and nitrogen by magnetron sputtering at a substrate temperature of 350 °C and a constant current of 250 mA at the aluminum cathode. The analysis of the dependence chemical composition, morphology, structure and mechanical properties of the annealing temperature were performed for different series of coatings. Coatings demonstrated high thermal stability after annealing to 1000 °C.
Effects of Heat-treatment on Mechanical Properties and Corrosion Resistance of NbN Films☆
Abstract The NbN and Nb films are prepared by the technique of radio frequency (RF) magnetron sputtering and heat-treated at 300 °C and 400 °C respectively in the present work. The influences of heat-treatment on the morphology, chemical composition, structure, nanomechanical properties and corrosion resistance of the films are studied. Results show that the particles in the films prepared by the above method are all in nano-size. The polygon shaped particles in the Nb films are very thin and small, while the particles in the NbN films prepared under the same condition are pebble-like, larger, and more compact. The nanomechanical properties and corrosion resistance of both the films are improved apparently after the heat-treatment. The corrosion resistance and mechanical properties of NbN film are always better than those of Nb film. The mechanism about the heat-treatment on the property considering the structural evolution is also discussed in this paper.
High current density, broad beam ion implantation
Abstract A simple, broad beam, high current density, gaseous ion implanter that has been built and shown to operate reliably over an extended period of time is described. Wear tests of nitrogen-implanted iron conducted on an oscillating pin-on-rotating-disc wear tester are used to demonstrate substantial improvements in wear resistance induced by implantation. The data indicate that significant nitrogen diffusion does not occur during the wear process and it is pointed out that results obtained using a fixed pin-on-rotating-disc wear tester could be interpreted erroneously to suggest it does. Numerical analysis is used to suggest that inadequately heat-sink-treated thin targets of low carbon martensitic steel can suffer substantial subsurface hardness losses due ot tempering when they are implanted at high current densities. Experimental results are cited that indicate such hardness losses are not as likely as expected and it is suggested that the length of time that samples are at high temperature may be too short for equilibrium tempering to develop.