The Influence of the Tool Surface Texture on Friction and the Surface Layers Properties of Formed Component

Abstract

The morphological texturing of forming tool surfaces has a high potential to reduce friction and tool wear and also has an impact on the surface layers properties of formed material. In order to understand the effect of different types of tool textures, produced by nanosecond fibre laser, on the tribological conditions at the interface tool-formed material and on the integrity of formed part surface layers, the series of experimental investigations have been carried out. The coefficient of friction for different texture parameters (individual feature shape, including the depth profile of the cavities and orientation of the features relative to the material flow) was evaluated via a Ring Test and the surface layers integrity of the formed material (surface roughness and subsurface micro hardness) was also experimentally analysed. The results showed a positive effect of surface texturing on the friction coefficients and the strain hardening of test samples material. Application of surface texture consisting of dimple-like depressions arranged in radial layout contributed to the most significant friction reduction of about 40%. On the other hand, this surface texture contributed to the increase of surface roughness parameters, Ra parameter increased from 0.49 m to 2.19 m and the Rz parameter increased from 0.99 m to 16.79 m.