Deposition of diamond-like carbon films on aluminium substrates by RF-PECVD technique: influence of process parameters

Abstract

The properties of diamond-like carbon (DLC) films are influenced by both the process parameters and the properties of the substrate on which they are deposited. Deposition of DLC films on aluminium and its alloys has drawn increasing attention owing to its potential applications as wear resistant coatings in automobile pistons, bores, VCR heads, copier machine drums and textile components. In the present study, DLC films have been deposited on commercial pure aluminium (98.9% purity) in a 200 kHz RF glow discharge sustained by methane gas in an asymmetric and capacitively coupled deposition system. Influence of various process parameters such as power density or bias voltage, methane gas pressure and flow rate on deposition kinetics, hardness and elastic modulus of the films has been assessed. Interrelationships between independent process variables like power density, methane gas pressure and flow rate, and dependent process variables like bias voltage and temperature have also been evaluated on the basis of available models.