Evaluation of the feasibility and machining performance of internal cooling grinding Inconel 718 superalloy

Abstract

Inconel 718 superalloy generates a large amount of grinding heat in the grinding process, posing challenges in its effective control through cooling techniques. Proposing a phyllotaxy arrangement internal cooling grinding wheel (ICGW) for grinding processing and using water-based ILs-MWCNTs/MoS2 composite nanofluid as a coolant can improve this situation. The thermal physical properties and contact angles of composite nanofluids at variable temperatures were measured to investigate the heat transfer capability and lubrication of coolant in the grinding area and compare them with conventional coolant. The CFD and CFX methods were used to optimize the abrasive cluster and to study the effects of the flow ability of the two coolants in the grinding area and the heat transfer properties, respectively, and grinding experiments were conducted. The simulation results showed that the coolant had better flow properties when phyllotaxy coefficient k is 1.186 and abrasive cluster diameters d is 1.5. The composite nanofluid obtained a lower surface temperature of the abrasive cluster than the conventional coolant. The thermal conductivity of the composite nanofluid exhibited a significant enhancement of 37.3 % and a substantial decrease of 45.9 % in viscosity at elevated temperatures, as demonstrated by the characterization experiments, in contrast to the conventional coolant. The machining experiments revealed a decrease in the grinding temperature by approximately 11.2 % to 25.6 %. The surface roughness value improved by 15.7 %–22.3 %, and the maximum reduction of workpiece surface microhardness increased by about 7.2 %. The workpiece surface exhibited superior quality compared to the conventional coolant.