Realising the potential of duplex surface engineering

We are now close to the new millennium and on the threshold of an era of rapid change. Limitations to the further advance of manufacturing industry in the 21st century are most likely to be surface-related. Many mechanical systems will operate under ever more severe application conditions, such as intensive loads, high speeds and harsh environments, in order to achieve high productivity, high power efficiency and low energy consumption. Consequently, many challenging complex design situations have emerged where the combination of several properties (such as wear resistance, load bearing capacity, and fatigue performance) are required. These new challenges can be met only through realising the potential of duplex surface engineering. Indeed, there are thought to be great technical and economic benefits available through the application of duplex surface engineering technologies in many new market sectors. The present paper is a synthesis of several strands of recent surface engineering research at the University of Birmingham, including the duplex ceramic coating-nitrided steel system and the duplex DLC coating-oxygen diffusion treated titanium system. The prediction of the performance of duplex systems based on advanced contact mechanics modelling is also discussed. (C) 1998 Elsevier Science Ltd. All rights reserved.