Energy Mapping and Optimization in Rough Machining of Impellers

In this paper, energy mapping and optimization in rough machining of impellers was investigated. Experiments were first designed based on the response surface methodology (RSM) to minimize operation specific energy consumption in machining through selection of machining parameters (spindle speed, cutting depth, and feed rate) in the Siemens NX computer aided manufacturing (CAM) simulation. With the simulated machining solution and G-code, experiments were conducted on the CNC lathe and mill to cut Al 6061 impellers. The machine energy consumption was measured using a power meter. The operation specific energy was analyzed in analysis of variance (ANOVA), regression models, and desirability functions. The minimum specific energy in the rough and semi-finish turning process is 0.16 J/mm³ and 0.23 J/mm³ respectively. The minimum specific energy in the blades milling process with 6mm ball mill or 3mm ball mill is 0.08 J/mm³ and 0.42 J/mm³ respectively. In the experiment settings, it identified that cutting depth is the most critical factor to affect the specific energy consumption in impeller machining. The empirical equations between the specific energy and material removal rate (MRR) concluded that specific energy is proportional to the inverse of MRR. From the study, it would suggest that in order to minimize the specific energy in machining of impellers, it should selected the MRR as large as possible.