Characterization of wear hss drills with coated alcrn and uncoated in testsof drilling in machining of ductile cast iron GGG DIN 50

Abstract

The use of coatings when drilling cast iron has the pot ential to increase the tool wear resistance at higher temperatures and enables the reduction or elimina tion of the use of coolants , lubricants means reducing the environmental impact with the nonapp lication thereof. The objective of th is study is to evaluate the perfor- mance of high speed steel drills coated AISI M2 AlCrN by PVD process in drilling process in full. For this as- says were performed as drilling evaluating wear quanti zation parameter, the value of VBmáx (maximum flank wear) for coated and uncoated drill, hol es of diameter measur ement performed along the tool life and surface roughness of machined surfaces. 12 trials we re performed for each type of dril l, all dry. The material used for drilling tests was the ductile cast iron GGG 50 DIN in form ats plates 48 x 400 x 500 mm. According to the di- mensions of the plate characterized as deep holes, given that the drill has a diameter of 8 mm, with L/d>5. The cutting parameters were worked out: cutting speed (25 and 35 m / min) and feed rate (0.15 to 0.25 mm / rev.) We evaluated the resistance to abrasion and yield in length machined, comparing the drills with and without coating. The results show the influence of cutting sp eed drills coated in VBmáx maximum flank wear. SEM and EDS analysis revealed the presence of adhesive wear c ontributing a small portion to the tool wear occurred..