###### Abstract
Additionally, cryogenic methods reduced energy consumption and improved wear characteristics, highlighting their sustainability advantages for titanium alloy machining [24]. Researchers conducted another study on micro-milling Inconel 600 super alloy, commonly used in aerospace and high-temperature applications. They found that cryogenic cooling yielded the best surface roughness and extended tool life, making it a valuable cooling method for machining super alloys [25]. Researchers conducted a study on milling Inconel 718 at conventional speeds, comparing uncoated and coated tools. Uncoated and AlTiN-coated tools had lower tool wear, while TiSiN-coated tools resulted in higher surface roughness and burr formation. The optimal conditions reduced surface roughness and tool wear by 18% and 20%, respectively, using an AlTiN-coated tool at specific machining parameters [26]. Recently, many studies have been carried out in the micro-milling domain. The study by [PERSON] et al. [27] examined how microstructural anisotropy in Ti-6 Al-4V alloy produced through selective laser melting (SLM) affects micro-milling. Orthogonal milling tests were performed on different surfaces of SLMed specimens, and various parameters were evaluated. The research revealed the influence of grain orientation on cutting forces, surface quality, and chip formation, highlighting the importance of selecting appropriate machining methods for precision processing. In another study, researchers explored micro-milling of tough cemented carbides with a focus on enhancing surface quality and dimensional accuracy. Their investigation delved into surface and chip formation, assessing the impact of cutting parameters and tool selection. The results unveiled various surface damage mechanisms and confirmed a ductile cutting regime for these hard materials, offering valuable insights for precise micro-milling [28]. In one study, researchers explore the micro-milling of FeCo-2V soft magnetic alloys to improve their magnetic properties and geometric finish. They optimize the process by varying machining parameters, and additionally describe a complementary electro polishing process to eliminate burrs and milling residuals. This work showcases the potential of micro-milling for fabricating precise micro-assemblies in MEMS, with a focus on improving surface quality and deburring [29]. In a related study, researchers aimed to improve tool wear measurement in micro-milling, especially in the presence of challenging burrs in Inconel 718. By employing abrasive deburring, they reduced burr heights by around 99%, leading to more accurate tool wear assessments based on slot geometry, which is a valuable alternative to direct measurements. This method enhances the precision of micromachining processes [30]. This research aims to target research goals of enhanced productivity and higher sustainability achieved by the improved machinability of titanium grade 9, which would benefit precision manufacturing, especially in aerospace, biomedical engineering, and electronics applications. Initially, the output responses are analyzed by drawing the main effects plots, which highlights the effects of input variables. Then, the significance and influence of each input is determined in terms of its \(p\)-value and contribution ratio. Validation of the work is conducted by confirmatory experiments at best and worst-state conditions, as identified from the main effects plots. The envisioned output of the current work is closely aligned with the United Nations' Sustainable Development Goals (SDGs) [31; 32]. Productivity is improved through optimizing vital indices, including surface roughness and burr formation, which represents product quality. Similarly, tool wear is minimized, which in turn improves process economy, thereby promoting sustainability. It is foreseenthat the adoption of such practices will add to the optimization of manufacturing output while serving the globally applicable UN SDGs.