# Construction of a Cutting-Tool Wear Prediction Model through Ensemble Learning
## 1 Introduction
The results showed that the average cutting forces along the feed and longitudinal direction, the maximum and average cutting temperature and the mean values of 3D surface roughness, Sa and Sq, all exhibited reductions from a specific percentage to a larger extent, respectively, as the ultrasonic amplitude increased from 0 to 6 \(\upmu\)m. These are attributed to the increased amplitude, which increased the separation distance between the cutting-tool and the workpiece, with friction constraint and contact time between them being thus reduced. A literature review on laser-assisted milling examines the effect of thermal preheating on cutting performance. [PERSON] and [PERSON] [8] compared the advantages of laser-assisted micro milling on process responses, such as material removal rates, cutting-tool wear, cutting force, and surface finish. They utilized TiAlN-coated tungsten carbide end mills to perform micro slot milling experiments on A2 tool steel (62 HRC), with and without laser assistance, under a proper micro milling condition. The results showed an average reduction in cutting force of up to 69% with laser assistance. They also indicated that cutting-tool wear is significantly less with laser assistance, even when the material removal rates are increased by six times higher than the cutting conditions recommended by the tool manufacturer. Through the proper selection of cutting-tool diameter relative to laser spot size to handle the proper laser thermal preheating, better surface roughness and reduced cutting-tool wear can be obtained due to reduced burr height formation. [PERSON] et al. [9] studied the impact of laser-assisted milling on advanced materials' cutting forces and tool flank wear without cooling lubricants. They proposed an innovative laser-assisted equipment that guides the laser beam through an HSK tool interface, directing irradiation onto the cutting surface of the workpiece in the machining area. The milling experiments were conducted on Inconel 718, using cemented carbide end mills with TiAlN coatings on a 5-axis machining center. The results showed that the cutting forces along F\({}_{\rm x}\), F\({}_{\rm y}\), and F\({}_{\rm z}\) directions were reduced by 40%, 60%, and 60%, respectively, for the local plastification of workpiece material in laser assistance. Laser assistance may effectively reduce the cutting forces and flank wear with optimized laser parameters. [PERSON] and [PERSON] [10] studied the machining characteristics of laser-assisted milling on cylindrical shape workpieces, focusing on AISI 1045 and Inconel 718. They proposed a method for three-dimensional laser-assisted milling suitable for cylindrical workpieces and investigated its effects on surface roughness and cutting forces. Firstly, finite element analysis was conducted for both materials to determine the proper preheating temperature and effective cutting depth. Subsequently, milling experiments were performed, comparing them with conventional milling to observe variations in surface roughness and cutting forces. The results showed that finite element analysis for thermal analysis was effective in similar machining processes. Compared to conventional methods, laser-assisted milling significantly reduced cutting forces and surface roughness by some specific extent for AISI 1045 and Inconel 718. Additionally, as the milling position angle increased, both cutting forces and surface roughness increased. It was suggested to rotate the workpiece clockwise to decrease the angle or utilize tool edge machining to improve surface roughness and tool life. For AISI 1045, cutting forces decreased and surface roughness improved with three-dimensional laser assistance, while for Inconel 718, down milling demonstrated better results. In their related literature review on high-speed milling, [PERSON] et al. [11] utilized the split Hopkinson pressure bar technique to obtain stress-strain curves under high temperature and high strain-rate conditions.