Nanostructured PVD Smart Wear Resistant Coatings for In-Situ Health Prognostics

This project is a collaboration between Tribologix, Inc. with core expertise in the deposition and testing of hard wear resistant coatings, and Mound Laser & Photonics Center, Inc., for development of a low cost smart coating wear sensor, and General Electric Aviation, a manufacturer of Gas Turbine Engines for military and commercial applications. Our approach uses the spectral response of layers found in our nanostuctured graded hard coatings combined with a low cost reflectance sensor capable of accurately detecting a change in color as the material is worn away. The focus in Phase I will be to optimize a new class of advanced hard wear resistant coatings which are based on nano composite structures as well as in situ health prognostics. Under this effort we shall grow gradient coatings that vary in color or reflectivity as a function of composition. For example, Titanium Nitride (TiN) is a gold coating, Titanium Carbo Nitride (TiCN) is a pink or blue coating and Titanium Aluminum Nitride (TiAlN) is a dark grey or black coating. These colors vary with the degree of C, N and Al in the coating structure. Each coating type has a unique spectral response. We will use appropriate lighting sources and a spectrometer to quantify and detect the color change as a function of composition. After we have calibrated these measurements, we will then make a gradient coating and measure the color change as the coating is worn away. We will be able to create the wear with a pin-on-disk arrangement initially, allowing us to directly correlate the optical signal with the wear and friction history. We will effectively create a situation in which the optical signal indicates the remaining thickness of the coating, and thus the remaining wear life with out interrupting the rotation of the sample.