The influence of the cooling conditions on the cutting tool wear and the chip formation mechanism

The paper presents the influence of the cutting zone cooling method on the wear of a cutting tool made of sintered carbide P25 during the process of turning AISI 1045 steel. The following cooling variants have been considered: dry machining, MQCL method and MQCL + EP/AW. The tests have been performed with different cutting speeds. This work also emphasizes the influence of the cutting tool wear on the chip shape and the indices of the chip formation zone: the chip thickening coefficient and the friction coefficient on the rake face. It has been found that during MQCL + EP/AW cooling, the tool wear decreases by 20% at the lowest cutting speed to 51% at the highest cutting speeds as compared to dry machining. Application of the EP/AW additive also results in a reduction of the friction coefficient on the rake face. In consequence it advantageously influences the chip shape. In a scanning analysis of the tool point, it has been found that a thin layer of a tribofilm is formed on the wedge surfaces, which results in an improvement of the machining process conditions.