Comparação do desempenho de fluidos de corte de base vegetal e mineral no torneamento do aço ABNT 1050

Abstract

The main raw material for the manufacture of these cutting fluids is mineral-based oil, however, in the last few years vegetable-based cutting fluids have been increasingly used, due to the environmental appeal, and mainly to the more abundant amount of renewable raw material. In addition, vegetable-based oils have polar molecules which, when they come in contact with the metal, they align to the surface and form a lubricant film much more effective and capable to withstand large surface tensions. Despite these advantages, there are not so many works that compare the performance of vegetable-based cutting fluids with mineral-based fluids. The present work compares vegetable-based cutting fluids with an mineral-based cutting fluid applied by flooding, during the turning of ABNT 1050 steel with coated carbide tools, considering the following output parameters: tool life, machining forces, machining temperature and surface roughness. The performances of two vegetable-based metalworking fluids, an emulsion and a synthetic, were compared with a semi-synthetic mineral-based fluid and dry machining, in various combinations of cutting speed and feed rates. Additionally, some static tests were carried out in order to characterize the lubricant and cooling abilities, as well as the microbial contamination of the tested fluids. The vegetable-based fluids presented better performances in the tool life, surface roughness, microbiological growth, coefficient of heat exchange (cooling capacity) and wettability (lubricating capacity) tests. In the machining forces and temperature tests better results were obtained when machining with the mineral-based fluid.