RHEOLOGICAL AND TRIBOLOGICAL PERFORMANCE OF AN EXOPOLYSACCHARIDE USED AS CUTTING FLUID EXTRACTED FROM AN ALGAE
Daniel Osorio1; Kenny Díaz2; Natalia Jaramillo1; Lucia Atehortua2; Diana Lopez1; German Sierra1
1 Universidad Nacional De Colombia Sede Medellín; 2 Universidad De Antioquia
doi:10.20906/CPS/COB-2015-2241
Resumo
Cutting fluids are commonly used for improving the cutting conditions in metal machining operations, an evidence of this is present in materials such as austenitic stainless steel, that are considered a low machinability material. However, the use of cutting fluids presents relevant problems related with pollution of soils, water and health issues. In this study an exopolysaccharide from an algae is used as cutting fluid, thereby presenting an biodegradable alternative. For this purpose the variation in the rheological properties of bio-cutting fluid extracted from algae was analyzed using a rotational rheometer at steady state with 1° cone-plate geometry and 40 mm in diameter. Preliminary test were performed to determine the effect of shear stress on the viscosity of mixtures with different exopolysaccharide (EPS) concentration (4.5%, 2.5%,1%,0.2 % m/v). In addition, some rheological tests were carried out in 80°C, trying to simulate the temperature that achieves the tool under cutting conditions; as a result it was found that the concentration with 0,25% of EPS showed the best rheological performance. A tribological test that simulated the conditions of a cutting process was prepared, for this purpose austenitic stainless steel plates were machined using a drill of high speed steel lubricated with a solution of the EPS, and then the wear of the drill flanks was measured using image analysis. It was found that the EPS solution without any additive present an satisfactory performance respect to the commercial cutting fluid, so it could represent a viable alternative as a base for this kind of fluids in metalmechanic processes.
Palavras-chave: Cutting fluid; Exopolysaccharide; Rheology; Metals; Friction; Wear