High temperature superlubricity behaviors achieved by AlSiN coatings against WS2 coatings at 600 °C

Abstract

In this paper, AlSi coatings and AlSiN coatings on 22MB5 high strength steel and MoS2 coatings on the die steel were prepared by magnetron sputtering respectively. The tribological properties of the coatings were studied from room temperature to 800 °C. The hardness and the bond strength between the coatings and the substrate were also investigated. The experimental results show that AlSi coatings have poor anti-friction behaviors comparing with the steel, and coefficient of friction (CoF) is as 0.2 at room temperature, but 0.8 at 600 °C. The N element was doped into AlSi coatings with FeAl transition layers to improve the tribological performances of the coatings at high temperature. CoF of AlSiN coatings and H13 steel is high. However, AlSiN coatings have excellent wear-resistance. WS2 coatings were prepared on the surface of the die steel to improve high temperature anti-friction behaviors of AlSiN coatings and H13 steel pin. The experimental results show that WS2 coatings exhibit good high temperature anti-friction behaviors. Super low friction about 0.003 is achieved at 600 °C. High temperature superlubricity mechanisms of AlSiN coatings and WS2 coatings are discussed systematically.