MECHANICAL AND TRIBOLOGICAL PROPERTIES OF HARD ALUMINUM-CARBON MULTILAYER FILMS PREPARED BY THE LASER-ARC TECHNIQUE

The method of laser-induced vacuum are (Laser-Arc) combines the good c ontrollability of pulsed laser deposition with the high efficiency of a vacuum are technique. One advantage of this technique is the reducti on of droplets, allowing the deposition of high-quality amorphous carb on films. These hydrogen-free films, with a very high hardness, exhibi t excellent wear resistance and low friction. Multilayer films consist ing of aluminium and carbon were deposited on a metallic substrate (90 MnV8). A Rockwell C tester was used to assess and the adhesion of the coatings to the substrate. Young moduli of around 420 GPa were measure d by the non-destructive ultrasonic surface wave method (US-SAW). The coefficient of friction was investigated by using two different fretti ng wear tests with the same load but different frequencies and stroke lengths, and values between 0.1 and 0.25 were recorded against steel. The coatings showed an increase in adhesion and a decrease in the trib ological properties with increasing aluminium content. (C) 1998 Elsevi er Science S.A. All rights reserved.