Electron microscopy of pulsed-laser-deposited thin films for tribological applications

Abstract

Pulsed laser deposition (PLD) is a novel thin film deposition technique which has recently been applied to tribological materials with great success. PLD has several inherent advantages over conventional deposition techniques, including excellent film adhesion, replication of target chemistry, and low film deposition temperature. Because load-bearing materials are typically hardened, heat treated alloys, these properties of PLD are ideally suited for tribological applications. In addition to being a relatively simple deposition technique, considerable processing flexibility is inherent with PLD. Dense, nonporous, stoichiometric films of solid lubricants, such as MoS2, have been grown having long wear lives with low coefficients of friction. Hard coating materials, such as TiC, have been grown at room temperature that were polycrystalline and had excellent wear properties.A significant feature of pulsed laser deposited (PLD) thin films is the incorporation of spherical particles within the films. Figure 1 shows these particles embedded in a film of PLD MoS2 deposited at room temperature.