Research on wear of CBN tool in precision machining of AISI M2 hard turning

Abstract In precision machining, tool wear deteriorates the surface quality of the workpiece and affects its surface integrity. Especially in hard turning precision machining, the tool is very prone to wear under the coupling load of large cutting force and high cutting heat. Therefore, tool wear has become one of the obstacles restricting the promotion of hard turning precision machining technology. This study investigates the effect of hard turning parameters on CBN tool wear using a single factor experimental method for dry hard turning AISI M2. The valuable research results are that: (1) The most prominent influence factor of CBN tool wear is cutting speed, and the increase of each processing parameter can aggravate tool wear; (2) The rake face, flank face and cutting edge of CBN tool are all worn, and their manifestations are crater, friction groove and micro chipping respectively; (3) The failure form of CBN tool is tool tip broken, including fatigue fracture caused by the decrease of tool tip strength and sudden fracture caused by large impact load; (4) The wear of CBN tool is resulted from mechanical friction, material adhesion and oxidation reaction, in which mechanical friction takes the main influence.