Papers by Keyword: Surface Stains

Abstract: The basic principles of the cold and foil aluminium rolling technology used in most rolling plants today have been around for many years with the major flatness control developments taking place 30 years ago. A crucial component of this technology is the coolant and lubricant fluid used for this process. In cold and foil rolling, kerosene is used as a coolant for the work rolls and as a lubricant for the rolling process, with the aid of specific additives. A lot of alternatives have been tested in the past but the kerosene medium has remained as the industry standard. An overview of the alternative technologies is discussed.

Abstract: This paper reports the investigation of a root cause of stain formation on the surfaces of diamond-like carbon (DLC) films. The DLC thin films are prepared using a radio-frequency plasma enhance chemical vapor deposition (RF-PECVD) technique with C₂H₄ as a carbon precursor gas. We have observed water spot-like stains on the DLC surfaces after treating the films with a dilute solution of dipropylene glycol monomethyl ether (DPGME). Low voltage-scanning electron microscopy (SEM) is employed to examine the thin layer of agglomerated stains on the surfaces. The results from capacitance-voltage (C-V) measurements show that as-deposited films inherit some trapped charge accumulations within the structure, thereby resulting in the pronounced shift in the flat-band voltage. These trapped charges make the films prone to surface stain formation. Post-annealing of the DLC films at 200 °C in N₂ for 1 h has proven to reduce the trapped charge density, and therefore prevent stain formation on the DLC films.