## 3 Machinability of AM Ti6 Al4V Alloy
### Energy Consumption  
The estimated power can be divided into air cut (P\({}_{\text{I}}\)) and actual or total cut (P\({}_{\text{T}}\)) powers. It was reported that energy and power consumption could be investigated using a quality analyzer (CA8331) manufactured by Chauvin Arnoux (Asnieres-sur-Seine, France) to measure and control the energy consumed during the machining process [81]. The mathematical difference between P\({}_{\text{A}}\) and P\({}_{\text{T}}\) will determine the cutting power (P\({}_{\text{C}}\)) needed for material removal during the cycle, as shown in Equation (12) [62]. Power cut represents the energy consumed by machine tools to achieve a workpiece's final surface finish [82]. Modern manufacturing requires reducing the electrical energy consumption of machine tool operations to achieve cleaner and more efficient production [82; 83]. Manufacturing equipment widely used in the industry includes machine tools, which share a significant part of the energy consumed [84; 85]. As the machining process progresses, the primary reason for tool wear is seen in the variation of the specific cutting energy. Tool life is also affected by increased cutting speed and the feed rate [62]. It was reported that the up-milling machining process consumes more energy than the down-milling process, which is 8.5% on average [86]. [PERSON] employed multi-response optimization to investigate energy consumption during dry milling. The results indicate that a reduction in cutting forces also leads to a decrease in SCE [77]. However, this paper neglects to address tool wear and tool life, and it fails to incorporate other cooling strategies, such as oil-based cooling or hybrid cooling. This oversight may overlook significant variables that influence machining efficiency and surface integrity. Accurately selecting cutting parameters reduces energy consumption to an optimum level with high surface quality [87; 88]. SCE and MRR were observed to be reduced by 16% and 127%, respectively, at a higher cutting speed of 125 m/min [3]. As the cutting condition increases, the energy efficiency is reported to increase during milling operation. As such, most of the energy was consumed by the supporting system [86]. The power of machine tool feature transitions was reduced by 28.60% [83]. According to some reports, the world economy depends mainly on energy savings because the sector that consumes energy is the manufacturing industry [2; 89; 90]. Cryogenic machining has been reported to have reduced the energy consumption of a machine tool by 80% at a cutting speed of 200 m/min [91]. It was reported that tool life increased by 28.9% and 38.6% in the dry cutting environment and deep cryogenically treated WC tools, respectively [40]. The main reasons for the energy consumption during machining processes is resistance to the cutting forces and movement of the spindle, as well as adjusting the speed up or down. To determine the required energy consumed during the cutting process or chip removal, it is vital to consider the different power dissipated during air cutting (P\({}_{\text{I}}\)), cutting process (P\({}_{\text{C}}\)), and total energy (P\({}_{\text{T}}\)) from Equation (11):  
\[P_{Total}=\sqrt{3}VICos\sigma \tag{11}\]  
where \(V\) is the CNC vertical operating voltage in (\(V\))  
\(I\) = the current indicated by the ammeter in (\(A\))  
\(Cos\sigma\) is the phase angle. Equation (12) determines the cutting power during chip removal by subtracting the idle power from the actual power dissipated [92]. \[P_{Cutting}=P_{Total}-P_{Iddle} \tag{12}\]  
\(P_{Cutting}\) is an essential factor affecting cutting force, tool wear, surface roughness, and chip formation [89]. \[SEC\left(\frac{J}{mm^{3}}\right)=\frac{P_{Total}}{MRR}\ \left(\frac{KW}{\frac{ mm^{3}}{s}}\right) \tag{13}\]  
Energy map development in machining refers to the graphical representation of energy consumption into low, medium, and high levels to identify the safe zone in the machining process.