SBIR-STTR Award

Currently, there exists a broad range of applications for which the ability to produce an adherent, tribological (hard, wear-resistant), thin coating plays a critical role. These include, but are not limited to, protective overcoats on magnetic hard disks and other magnetic recording media, protective coatings on orthopedic implants, scratch-resistant coatings for optical fibers and lenses, and coatings for both automotive engine and fascia applications. These hardened surfaces can mitigate the effects of corrosion, a major source of energy losses for the economy. The capacity to mechanically characterize these coatings is often paramount in evaluating their potential performance. Quasi-static tests, such as nanoindentation, are widely used to assess the quality of these hard coatings. However, as the thickness of the coatings decreases to less than 20 nanometers, the ability to characterize their properties using even the most advanced indentation techniques becomes increasingly difficult due to physical limitations of the indenter geometry; in addition, normal indentation tests do not always correlate well with wear properties. Dynamic tribological properties at the nanometer scale are therefore of interest. While no true nanometer-scale tribological systems exist, the ability to perform dynamic, nanometer-scale scratch-test experiments of a limited nature has been successfully demonstrated. The goal of this Phase I project is to address the issues and design criteria necessary to enable dynamic tribological testing to be performed at the nanometer scale. Commercial Applications and Other Commercial Benefits as described by the awardee: The commercial benefit is the development of an instrumented, depth-sensing, dynamic tribological system capable of investigating the wear behavior of materials on the sub-micrometer-to-nanometer scale. Given the large amounts of energy lost every year to the economy by friction and wear, development of such testing systems would have a significant economic impact.

There currently exists a broad range of applications for which the ability to produce an adherent, tribological (hard, wear-resistant) thin coating plays a critical role. These hardened surfaces can mitigate the effects of corrosion, a major source of energy losses in general. The capacity to mechanically characterize the dynamic tribological properties of these coatings at the nanometer level is often paramount in evaluating their potential performance. This project will design and develop a dynamic tribological system capable of performing instrumented wear tests on the sub-micrometer to nanometer scale. Both co-planar and perpendicular systems (both with one-dimensional, simple harmonic load-controlled features) will precisely control both normal and lateral forces on the surface of a sample in a dynamic fashion. Phase I examined the feasibility of performing dynamic tribological experiments on the nanometer scale with existing nano-indenter lateral-force measurement technology. It also laid the groundwork for performing true dynamic nanometer scale tribological experiments by focusing on a technique capable of continuously monitoring the stiffness of a contact during a scratch experiment. Phase II will carry out the final design and construction of a dynamic, two-dimensional tribological testing system.

Commercial Applications and Other Benefits as described by the awardee:
The instrument and techniques should be applicable to microelectronics, magnetic storage media, optical materials, biomedical materials, automotive materials, and any other industry which relies upon protective coatings. Product life increases should result from reductions in friction, wear, and corrosion.