Influence of Silver Incorporation on Toughness Improvement of Diamond-Like Carbon Film Prepared by Ion Beam Assisted Deposition

Abstract

Six silver-containing diamond-like carbon films (Ag-DLC), each with a particular content of Ag, were deposited on M2 high speed steel substrates in an ion beam assisted deposition (IBAD) system. Systematic investigation of the influence of the incorporation of Ag on the adhesion and impact-resistant properties of Ag-DLC films was conducted, and the toughness of individual films was revealed. Results verified that the doping of silver distinctly influenced the toughness of Ag-DLC films. Typically: (i) the variation of Ag contents and nanocrystallites dispersed in the DLC matrix tended to induce change of film toughness as a result of changing the film adhesion and impact-resistance behaviors; (ii) the evidence of improvement in the toughness of the film (especially for the film containing 15.2% silver) could be clearly seen by the larger critical adhesion forces, and the better adhesion performance and impact-resistant properties. The failure mechanism of both scratch and impact tests served to reveal how the toughness of the Ag-DLC films was affected by Ag content.