Understanding the factors that control friction and wear are of vital industrial and economic importance. The function, reliability, and lifetime of many mechanical, electromechanical and even biological systems are impacted by the complex relationships between materials, surfaces, design, and the environments that they are exposed to. Increasing complexity and performance requirements that are driven by economics, and a heightened awareness of health and safety issues with traditional chemical plating processes offers new opportunities and challenges for novel coatings and advanced surface engineering techniques. This tutorial is intended for engineers, designers, managers and purchasing professionals who have a need to specify, develop and procure coatings for tribological applications (i.e., those applications in which wear must be reduced or prevented and/or friction minimized). These coatings will likely require corrosion-resistant properties to operate in arduous conditions and must also exhibit functional characteristics (color, adhesion scratch resistance, etc.) that span the complete range from industrial to consumer products. The tutorial begins with a description of the mechanics of wear and discusses the criteria for selecting coatings for optimal tribological performance. An overview of the main processes for producing tribological coatings is provided with emphasis on vacuum deposition methods. Tribological test methods also are reviewed, including tests for adhesion and mechanical properties. Finally, coatings developed for enhanced tribological and decorative properties are described and examples of applications are presented.
Allan Matthews - Manchester University