Multi-objective optimization of minimum quantity lubrication in end milling of aluminum alloy AA6061T6

Abstract

The purpose of this research is to optimize the process of minimum quantity lubrication (MQL) in the end milling of AA6061T6 using multi-objective genetic algorithm approach. Response surface methodology coupled with a central composite design of experiments is used for modeling. Data is collected from a vertical CNC milling center and the input parameters are cutting speed, table feed rate, axial depth of cut and the minimum quantity lubrication flow rate. Analysis of variance at a 95% confidence level is implemented to identify the most significant input variables on the CNC end milling process. Optimization of the responses is done using a multi-objective genetic algorithm. A multi-criteria decision making utility is used to find among the feasible range of optimum designs for the operating parameters and the responses. An iterative multi-criteria decision making algorithm is used to find the best design among those obtained from multiobjective optimization with respect to the given conditions. The best design obtained for the equal weightage case is the design at 5252 rpm, with a feed rate of 311 mm/min, a depth of cut of 3.47 mm and MQL flow rate at 0.44 ml/min.

Experimental investigation on the performance of the TiO2 and ZnO hybrid nanocoolant in ethylene glycol mixture towards AA6061-T6 machining

“…Figures 5-6 show the comparison between dry, MQL and hybrid nanofluids in terms of surface roughness and material removal rate at different cutting speed, depth of cut and feed rate values. Hybrid nanofluids show a slight improvement in enhancing surface roughness compared to the dry and MQL technique due to the lesser effect of the cooling function of the cutting fluid, which is significantly effective as a lubricant more than its function as a coolant [20]. The surface roughness value is increasing at a high speed and feed for dry and lubricated surfaces and the improvement in surface roughness can be attributed to the reduction in the material transfer onto the machined surface [42].…”

“…The principal wear mechanisms in aluminium alloys machining are the burr formation, built-up-edge as well as surface roughness. The surface finish and Experimental investigation on the performance of the TiO2 and ZnO hybrid nanocoolant in ethylene glycol mixture towards AA6061-T6 machining 3914 burr formation in aluminium alloy machining are mainly used as tool life criteria as it is difficult to observe tool wear in aluminium alloys [19][20][21][22]. The minimum quantity lubrication has been proved to be an effective near dry machining technique as well as an efficient alternative to completely dry and wet cutting conditions from the viewpoint of cost, ecological and human health issues and machining process performance [23][24][25][26][27][28].…”

Analysis and study of the influence of the geometrical parameters of mini unmanned quad-rotor helicopters to optimise energy saving

“…Experiment results ( Figure 5) were approximated using non-linear regression analysis software [37]. Lifting force dependency on the propeller rotation speed can be expressed as follows:…”

Effects of sintering schedule on the characteristics of Fe-based powder compacts formed through warm compaction route

“…The bending strength shown in Figure 5 is almost the inverse of the density changes (Figure 3) for the sample sintered at 750°C, where the highest strength was obtained by the sample sintered at 900°C for 60 mins, which yielded a strength of 34.55 MPa, and which also shows a lower density change ( Figure 4) and volumetric expansion (Figure 2). Referring to the SEM image (Figure 6), it can be seen that the grains are closely packed together with fewer voids [31,32]. Close-packed grains might produce larger grain boundaries, which would further enhance the strength of the material.…”