Análise do desempenho da furação do aço SAE 1012 com broca de metal-duro sem revestimento e com fluídos semissintéticos

Abstract

The drills performance at the drilling process depends on the combination of a series of factors like the material of the piece to be drilled, the material of the drill and the use of overlaying, conditions and cut fluids used, amongst others. Based on these variables this study has the goal of analysing the hard metal drills without covering performance at the SAE 1012 steel drilling, using two semisynthetic cut fluids. Drilling tests were performed, with the tool breaking being the end of life criteria used. The tests were repeated on both fluids using three different cutting speeds. The speeds adopted were the minimum and maximum recommended for the drill in addition to a third medium speed between the previous values. To each speed and fluid three series of tests were performed. The results were statistically evaluated showing that there was no difference between the fluids regarding the total number of holes created. Comparing the speeds, regardless of the fluid used, the lower cutting speed resulted in higher performance when compared to the other conditions applied. During the interaction between the fluid and the speed it was demonstrated that the result for each fluid depends on the speed as well as the result for each speed depending on the fluid used. The main wear mechanism was the adherence with posterior edge chipping which resulted in the destruction of the drill edge shape. The abrasion mechanism was also observed, although, it did not directly affect the results.