Minimum lubrication in Al-Si drilling

Abstract

The high percentage of the refrigeration costs (17%) in the operational production costs, the ecological subjects, the lawlegal demands related to the preservation of the environment and the human health justify the recent researches about the restriction towards the use of abundant cutting fluid in machining processes. However, it is important to point out that the use of a minimal mist lubrication (mixture of air and oil) has been possible in production processes for machining, due to the technological development of tool materials and also machine-tools. The objective of this work is to test the minimum quantity of lubricant (MQL) technique (10 ml/h of oil) mixed in a flow of air in the drilling process of aluminum silicon alloy (SAE 323) with a solid carbide drill (K10). The input variables were drill diameter (and consequentelyconsequently, depth of cut) and cutting speed. The results showed that when high depth of cut and cutting speed are used, the operation using abundant fluid is not possible because the drill breaks after a few holes. Moreover, the quality of the holes obtained using MQL is not worse than that obtained for with smaller cutting speed and depth of cut.