Research in surface roughness for laser cladding coatings

Abstract

In the present research the laser cladding process, as one of the most effective ways to improve surface characteristics, namely corrosion resistance, wear resistance, heat resistance etc., was investigated. Samples with high-speed tool steel coatings, cladded on spring steel substrate by the laser cladding method using different cladding regimes and cladding directions have been analysed. For this reason the main goal was to find the relation between the direction of flat grinding of the coatings and the direction of laser cladding in cases when the sample has been grinded in a parallel way to the cladded beads and perpendicularly to them. For the roughness analysis of laser cladding coatings the modern 3D measuring system Taylor Hobson Talysurf Intra 50 has been used, by the help of which 3D and 2D surface roughness parameters were determined. When comparing the roughness parameters of both sample series separately it was found that laser cladding regimes, particularly laser focus, have influence on the surface roughness spacing parameters and correlation of the surface ordinates, what is of importance for friction and wear calculations. Whereas by comparing the sample surfaces grinded perpendicularly to the cladding direction and parallel to it, it was discovered that the values of roughness parameters did not differ essentially, pointing to the fact that the mechanical treatment direction towards the direction of laser scanning does not affect surface roughness.