PERFORMANCE OF SYNTHETIC AND MINERAL SOLUBLE OIL WHEN TURNING AISI-8640 STEEL

The present work shows a comparative study of the application of synth etic and semisynthetic, mineral soluble oil (at concentrations of 3 an d 10 percent) as well as dry cut when turning AISI 8640 steel bars wit h triple coated (TiC,Al2O3,TiN) P35 grade of cemented carbide tools. T ool lives, cutting forces, cutting temperatures and surface roughness were considered to evaluate the cutting fluids. Generally, the semi-sy nthetic gave longer tool life based on flank wear parameter VB. The su rface roughness was not sensitive to the lubrication quality, if wear effects are not considered. Mean tool-chip interface temperature was l ower with the synthetic fluid, followed by the semisynthetic, mineral soluble oils and dry cutting, respectively. The inverse of this order was true for the cutting forces.