Influência de fluidos de corte no fresamento do aço nb 8640

Abstract

The application of conventional milky soluble oil at 5% concentration, semi-synthetic cutting fluid also at 5% concentration and synthetic cutting fluid at 5% and 10% concentration, when face milling AISI 8640 steels with triplo-coated (TiN-TiC-TiN) ISO - P45 cemented Carbide tools was investigated. Dry cut was also used for comparisons. Tool lives power consuption and surface finish were the main parameters considered. In order to study the tool lives, Expanded Taylor’s Equations were determined using a method that optimises the number of tests needed to obtain the coefficients with reliability. After these tests wom tools were analysed within the SEM. To classify the cooling ability of the cutting fluids the chip-tool thermocouple method was used when tuming AISI 1020 steels with uncoated klO cemented Carbide tools. Generally, the cutting temperature was higher for the dry cut followed by the use of synthetic 5%, synthetic 10%, soluble oil and semi-synthetic fluids. An inverse order was found for the power consuption, that is the higher the cutting temperature the lower the power consuption. Tool life tests showed that dry cut outperformed the application of the cutting fluids at all cutting fluids better results were presented when applying the synthetic than when the semi-synthetic was used. At low cutting speeds the soluble oil presented lower tool lives but at high cutting speeds this fluid outperformed the others. Generally, dry cut has presented the best surface finish among all cooling/lubricant condition tested.