Tribology of Diamond-Like Carbon : a Review
Abstract
During the past decades, diamondlike carbon (DLC) films have attracted an overwhelming interest from both industry and the research community. These films offer a wide range of exceptional physical, mechanical, and tribological properties that make them scientifically fascinating and commercially essential for numerous industrial applications. Mechanically, certain DLC films are extremely hard and resilient, while tribologically, they provide some of the lowest known friction and wear coefficients. Thus DLC can be very useful in meeting the multifunctional application needs of advanced mechanical systems.. Depending on the type of carbon source being used during the film deposition, the type of bonds that hold carbon atoms together in DLC may vary a great deal and can affect their mechanical, electrical, optical, and tribological properties. Recent systematic studies of DLC films have confirmed that the presence or absence of certain elemental species such as hydrogen, nitrogen, sulfur, silicon, tungsten, titanium, and fluorine in their microstructure can also play significant roles in their properties. The main goal of this review is to highlight the most recent developments in tribological applications of DLC films. We will also discuss the progress made in understanding the fundamental mechanisms that control their very unique friction and wear behaviors. Novel design concepts and the principles of superlubricity in DLC films are also presented.