The effects of cutting tool coatings on the surface roughness of AISI 1015 steel depending on cutting parameters

The effects of a number of cutting tool coating materials on the surface quality of workpieces, depending on various cutting parameters, were investigated. AISI 1015 steel was processed without cooling on a lathe using 4 different cemented carbide cutting tools, i.e. uncoated, coated with AlTiN and coated with TiAlN using the PVD technique, and one with 3-layer coatings (outermost being TiN) applied by the CVD technique. Among the cutting parameters, the depth of cut was kept constant (2.5 mm) while the cutting speed and feed rate were changed. Five cutting speeds (50, 73, 102, 145, 205 m/min) and 2 feed rates (0.24 and 0.32 mm/ rev) were used during the machining process. Coating type, feed rate and cutting speed have different effects on surface roughness. In the experiments, less average surface roughness was obtained by using a 3-layer coated tool coated outermost with TiN. The lessening of cutting speed by about 33% improves the surface roughness by about 26% increasing the cutting speed by about 310% resulted in an improvement of about 69%. cr Tübitak