## 3 Machinability of AM Ti6 Al4V Alloy
### Material of a Cutting Tool  
The integrity of a cutting tool is primarily evaluated based on its ability to resist wear, particularly flank wear, which has a significant impact on tool edges and the dimensional accuracy of the workpiece. Tool materials can be classified according to their performance and durability. One commonly used coating material is titanium nitride (TiN), known for its excellent coating properties, which allow for increased cutting speeds and extended tool life; and coating material include titanium carbon nitride (TiCN), titanium aluminum nitride (TiAlN), and aluminum oxide (Al\({}_{2}\)O) [51]. The purpose of the coating is to protect the tool from being worn. The report shows that coated inserts yield good results at higher cutting speed, feed rate and a depth of cut 4 um thick [52] was chosen for the coating process with TiAlN during the cutting operation for titanium alloy parts [53]. This paper narrows its investigation to cutting speed, without exploring other critical parameters such as feed rate and depth of cut, both of which significantly impact surface integrity and \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline
**Element** & **Al** & **V** & **Fe** & **Cu** & **Cr** & **Ti** \\ \hline Composition (Wt. \%) & 5.7 & 4.2 & 0.15 & 0.003 & 0.0023 & 89.44 \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Chemical composition of titanium alloy [3; 6]. \begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline \multirow{2}{*}{**Property**} & \multicolumn{6}{c}{**Material**} \\ \cline{2-7}  & **Ti10V63 Al** & **Ti6 Al4V25n** & **Ti6 Al4V** & **Ti8V6C4** & **Inconel** & **Al** \\  & & **(g-alloy)** & **(\(\alpha\)-galloy)** & **(\(\alpha\)-g-alloy)** & **Mo4Z3 Al (g-alloy)** & **718** & **Al** \\ \hline Density (g/cm\({}^{3}\)) & 4.5 & 4.65 & 4.54 & 4.42 & 4.81 & 8.22 & 2.7 \\ Hardness (HRC) & 10–12 & 32 & 38 & 30–36 & 37–43 & 38–44 & 60 \\ Ultimate tensile & 220 & 970 & 1050 & 950 & 1250 & 1350 & 310 \\ strength (MPa) & 140 & 990 & 980 & 880 & 1150 & 1170 & 300 \\ Modulus of & 116 & 110 & 110 & 113.8 & 102 & 200 & 68.3 \\ elasticity (GPa) & 54 & 9 & 14 & 14 & 15 & 16 & 17 \\ Uncertainty (\%) & 70 & - & 60 & 75 & 65 & 96.4 & 29 \\ Thermal conductivity & 17 & 7.8 & 6.6 & 6.7 & 8.4 & 11.4 & 167 \\ Max. operating temperature (\({}^{\circ}\)C) & 150 & 315 & 315 & 315 & 315 & 650 & 170 \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Mechanical properties of Ti6 Al4V and other alloys [3; 44]. cutting force. Furthermore, it lacks attention to the lifecycle impact of titanium materials, an essential consideration for understanding their long-term performance and sustainability. The tungsten or cemented carbide WC+Co tools contain tungsten, carbon, and cobalt. They have 6% content of the Co element. These are the most used cutting tools in machining processes and include straight-grade tungsten carbide and cobalt grade. Carbide tools possess excellent wear resistance and toughness properties even at high cutting temperatures above 600 \({}^{\circ}\)C and a maximum cutting speed of 300 m/min. Delicate grain structures were reported to have performed better against grains with larger sizes or with high cobalt content (10% Co). Also, TiCN-coated tools performed significantly better than CrN-coated tools in turning titanium alloy [38]. The following describe the properties and characteristics of different cutting tools:  
* Carbon tool steel (0.6% to 1.5% C) having a maximum cutting speed of 5 m/min. * Satellites are tungsten, molybdenum, or molybdenum-cobalt base grades with a maximum cutting speed of 100 m/min. * High-speed steel (HSS) ratio 18:4:1 of W:Cr:V is the most applicable tool and possesses excellent toughness but low hardness among all types of cutting tools, with a maximum cutting speed of 33 m/min. * Ceramic tools contain aluminum oxide (Ai\({}_{2}\)O\({}_{3}\)), Cr\({}_{2}\)O\({}_{3}\), Zr\({}_{2}\)O, TiN, or silicon nitride. They are referred to as having less toughness compared to carbide tools. The maximum cutting speed is 650 m/min.