A simple strategy to tailor the microstructure and wear-resistance of sputtered WS₂ films

Sputtered WS₂ films can be modified by adding some amount of hetero-elements to overcome the porous columnar microstructure and thereby to enhance the wear resistance. However, the recession of tribological properties of WS₂-hetero-element composite films in low earth orbit environment would be a potential danger because most hetero-elements succumbed to oxidation by atomic oxygen. Herein, by altering deposition argon pressure to adjust the plasmas bombard function on growing WS₂ film, the characteristic porous microstructure disappeared. At the optimization condition, the sputtered WS₂ film exhibited a dense microstructure, high ratio of S to W, and thereby much better wear-resistance. However, the excessive bombardment would result in the prominent loss of S atoms in WS₂ film and the deterioration of tribological properties.