Influence of minimum quantity lubrication in the surface quality of milled maraging steel

The use of large amount of cutting fluid in machining process represents a great environmental and economic issue. Minimum quantity lubrication (MQL) seems to be a feasible alternative to flood application as it reduces drastically the volume cutting fluid used in machining process. This paper investigated the relationship between cutting parameters and machined surface quality in the end milling of maraging 300 steel when flood and MQL methods were used. A full factorial design setting feed per tooth, cutting speed cutting depth, and fluid application technique was performed. Then, the effects of these parameters on machining forces, surface roughness, and residual stresses were studied by analysis of variance (ANOVA). The analysis of variance showed that the most important milling parameter regarding results of both surface roughness and residual stresses was the feed per tooth. Minimum quantity lubrication system was able to reduce machining forces for most of tested conditions, and surface roughness (Ra) was reduce in approximately 10%. Residual stress results showed that MQL is able to produce better results than flood method when low feed rate is used. It was found that the use of MQL technique is advantageous in the milling of maraging steel.