Análisis comparativo de la influencia del sistema de mínima cantidad de lubricación con aceite vegetal y sintético en operaciones de fresado CNC del acero AISI 4140.

Abstract

The present work studies the surface quality obtained in machining milling - 3D finishing of AISI 4140 steel, using synthetic and vegetable oil with a minimum amount of MQL lubrication system, with variations of 25 [ml/h] and 50 [ml/h] for machining on sloped surfaces, surface quality is analyzed by the use of roughness when measuring roughness. In the tests, cutting factors such as cutting speed (Vc) and feed per tooth (fz) are also varied according to the manufacturer's recommendations of the tool used for finishing, the spindle speed is kept constant at 6000 [rpm] and the cutting depth at 0.2 [mm]. The specimen for machining contains three earrings of 57, 63 and 70° designed in CAD, thus varying the effective cutting speed at the tip of the round cutter tool of diameter 14 [mm] with titanium nitride coating and titanium aluminum nitride, called FIREX. The methodology used is that proposed by Genichi Taguchi, a statistical methodology based on orthogonal arrangements that simplify the number of tests, in this case 27 experiments have been carried out, combining MQL factors, effective cutting speed and feed per tooth. CAD-designed specimens are machined in an EMCO CNC machining center to then measure surface roughness with an MITUTOYO SJ210 roughometer. With the results obtained an analysis is performed based on the statistical method ANOVA that allows to find a reliability interval of the tests, which allows to validate this work, it is also determined that for this study the best surface quality is achieved using in the MQL system vegetable oil with 50 [ml/h], cutting speed 220 [m/min] and feed per tooth of 0.05 [mm/z].