Room-temperature Industrially-scaled Pulsed Laser Deposition of Coatings for Wear-protection, Low-friction and Decorative Applications
Publication from Materials
Proc. 49th Annual Technical Conference - Society of Vacuum Coaters, Washington D.C., pp. 50-54, 22.-27. Apr., 2006
Increasing demands on dimension accuracy and, thus, the minimization of distortion during coating – the final manufacturing step of many tools and machine components – as well as the increasing application of high-strength, but low temperature resistant materials – plastics, reinforced polymer compounds as well as light metals – require low-temperature vacuum coating techniques. However, many of the presently used techniques like sputtering, arc and electron beam evaporation, as well as the plasma-assisted CVD techniques are not able to provide coatings at low deposition temperatures (< 100°C) with properties of high- or medium-temperature deposited coatings. In the field of PVD techniques the Pulsed Laser Deposition (PLD) coating technique stands out against nearly all others by its unique feature of pulsed high- and low-energetic plasma flux, enabling even the deposition of tribological and decorative coatings at room temperature with properties, till now only known for elevated deposition temperatures (> 250°C). The present work emphasizes this feature of the PLD technique based on both scientific investigations of the adhesion strength (Rockwell indentation tests and scratch tests) and the tribological performance (pin-on-disc tests) as well as on the behavior of the coatings in selected industrial applications. The results show generally high critical loads (> 40 N) in scratch tests and adjustable tribological properties (friction coefficients between 0.05 and 1.0) depending on the coating type (TiN, TiCN, TiO2, CrN, CrCN, TiAlN, DLC, etc.). Due to the high wear resistance even in thin films, the room-temperature deposited PLD coatings are ideally for decorative applications of temperature-sensitive materials. Additionally to the development of tribological and decorative coatings, high efforts were taken in up-scaling of the PLD process from a laboratory coating technique to an industrial applicable one.