Materials optimization and preparation of WS_2 soft coated tools

Stresses due to thermal mismatch between substrate,interlayer and coating developed in WS2 soft coatings when cooled down to room temperature from deposition temperature.Two finite element models(FEM) were established to simulate and analyze thermal mismatch stress.Results show that mismatch of elastic modulus and coefficient of thermal expansion is significant to residual thermal stresses,while Poisson's ratio has little influence on them.WS2 coatings were deposited by medium-frequency magnetron sputtering technique,multi-arc ion plating technique and ion beam assisted deposition technique on the selected substrates and interlayers.The properties tested proved the analysis of FEM and found that residual thermal stress had great influence on the properties of WS2 soft coated tools.Another result is that Zr interlayer was proved to promote the growing of WS2 Ⅱ texture.