CHARACTERIZATION STUDY OF NITROGEN-ION-IMPLANTED AMORPHOUS BRIGHT CHROMIUM DEPOSITED FILMS

Amorphous, bright, chromium deposited (ABCD) films have been developed in order to utilize chromium in high-temperature wear applications. The hardness of these films is increased at elevated temperatures (200-600-degrees-C) whereas conventional chromium films become softer at elevated temperatures. Furthermore, the hardness of ABCD films can be increased by nitrogen-ion implantation and various types of annealing pretreatments. In this study a non-annealed film and a 600-degrees-C annealed film were implanted with nitrogen ions and characterized using Auger electron spectroscopy (AES), electron spectroscopy for chemical analysis (ESCA or XPS) and X-ray diffraction (XRD). The resulting data yield information which relates the hardness of the films to their chemical and structural properties. Specifically, the annealed film is more highly crystalline than the non-annealed film. Diffraction lines due to Cr7C3 and Cr2N are readily apparent. AES and ESCA show that the film compositions are similar but that the chemical states of the surface species differ in that most of the organic carbon contained in the film is converted to carbide during annealing. These differences are responsible for the increase in Knoop hardness (1660 to 2980) derived from annealing the sample prior to implantation.