Abstract : This paper summarizes the research progress of laser heating assisted cutting technology in recent years. In the aspect of experimental research, the processing features of laser heating assisted turning, milling, drilling and grinding are summarized, and the effects of laser parameters and cutting parameters on the processing quality are described. Studies have shown that within a certain range, properly increase of the laser power, reduce the cutting rate, reduce the feed rate are conducive to the full softening of the material in the cutting zone, which can improve the machining of work piece materials, processing efficiency and processing quality. At present, the simulation research of laser heating assisted cutting mainly focuses on the simulation of cutting temperature field and cutting process. By establishing a temperature field model, it is possible to predict the optimum temperature range for material removal and optimize the processing parameters. The simulation of the cutting process explores the effects of physical quantities such as stress, strain, and temperature, providing a basis for controlling the surface quality of parts during actual machining. Follow-up work should further strengthen the research on processing mechanism, processing technology, simulation optimization and other aspects, establish a perfect laser heating auxiliary cutting processing database to promote the industrial application of the technology.In recent years, advanced engineering materials such as engineering ceramics, composite materials, high-temperature alloys, and titanium alloys have excellent properties such as high strength, wear resistance, corrosion resistance, and good thermal stability. They are used in machinery, chemical engineering, aerospace, and nuclear industries. The field has been widely used . When these materials are processed by conventional methods, due to the characteristics of high hardness, high strength and low plasticity, the cutting force and cutting temperature are very high, the tool wear is severe, the machining quality is poor, and the machining geometry is limited. Laser assisted machining (laser assisted machining, LAM) uses laser heating to soften the cutting zone material and use a tool for cutting. Compared with conventional machining, it reduces cutting force, prolongs tool life, improves machining quality and machining efficiency. Such aspects show many advantages, and provide an effective way to solve the processing of difficult materials . Therefore, laser heating assisted cutting technology has become one of the research hotspots in the field of machining in recent years.Laser heating assisted cutting technology has come a long way since its introduction in 1978, after decades of development. K?nig et al. took the lead in applying laser heated auxiliary turning technology to the machining of silicon nitride ceramic materials, improved the material processing performance, and obtained a machined surface with a surface roughness Ra of less than 0.5μm. Yang et al. conducted laser heating assisted milling experiments on silicon nitride ceramics. The results show that when the laser-assisted heating is used to increase the cutting zone temperature from 838℃ to 1319℃, the cutting force is reduced by nearly 50%, and the edge fractures. The phenomenon was significantly reduced and the quality of the machined surface was improved, demonstrating the feasibility of laser-assisted milling of ceramic materials. Anderson et al. laser-assisted turning of Inconel 718 material, compared with conventional machining (cutting energy required to remove the unit volume of material), reduced 25%, and tool life increased by 2~3 times. Dandekar et al. conducted a laser heating assisted turning experiment on the silicon nitride particle reinforced aluminum matrix composite A359/20SiCP. Compared with the conventional machining, the energy can be reduced by 12%, the tool life is improved by 1.7~2.35 times, and the surface roughness Ra is reduced. 37%. Wu Xuefeng et al found that when the high-temperature alloy GH4698 material was laser heated and assisted in milling, it could effectively reduce the material strength when the cutting zone temperature was 600℃. Compared with conventional milling, the cutting force was reduced by 35%, and the machining surface quality was better. Hedberg et al. carried out laser assisted milling experiments on titanium alloy material Ti6Al4V. Compared with conventional machining, the cutting force was reduced by 30% to 50%, the surface residual stress was reduced by 10%, and the processing cost was saved by 33%. This article reviews recent advances in laser heating-assisted turning, milling, drilling, and grinding, and looks forward to the future direction of laser heating-assisted cutting technology.1 laser heating auxiliary cutting principle1.1 Processing principlesLaser-heating-assisted cutting is the use of a high-energy laser beam to irradiate the surface to be machined. The material is heated to a certain temperature in a short time, softening occurs, and then the cutting process is performed. The basic principle of the machining is shown in Fig.1. The temperature has a significant effect on the processing performance of the material. By heating the material, the strength and hardness of the material can be reduced, the cutting force can be reduced, and the tool wear and vibration can be reduced, thereby improving the processing quality and improving the machining accuracy and processing efficiency. The effect of temperature on the tensile strength of different materials is shown in Fig. 2 .Fig. 1 Schematic diagram of laser assisted machiningFig. 2 Effect of temperature on ultimate tensile strength of various materials1.2 Laser heat sourceThe heating methods commonly used in various heating-assisted cutting processes include laser heating , electric heating , plasma arc heating , and oxyacetylene flame heating . In contrast, laser heating has the advantages of high power density, rapid temperature rise, good energy distribution and time controllability, and it has become an ideal heat source for auxiliary heating cutting.In a laser system commonly used for laser heating assisted cutting, a CO2 laser oscillates a 10.6 μm wavelength laser beam. Since the natural frequency of the free electrons on the metal surface is much larger than the laser beam in this band, most of the laser energy is reflected by the surface free electrons, resulting in a very high transmittance. Low, the laser can not be well absorbed by the metal, but the ceramic material can absorb the wavelength of the laser more than 85%, so the CO2 laser is often used as a heat source for processing ceramics and other non-metallic materials . The neodymium-doped aluminum pomegranate (Nd:YAG) laser oscillates a 1.064 μm wavelength laser, which facilitates the absorption of metallic materials and is suitable for mirror transmission and fiber optic cable transmission. It can be integrated with machine tools in complex machining systems . Semiconductor lasers have the advantages of small size, light weight, high efficiency, long working life, etc., and can be integrated with various optoelectronic devices, reducing the volume of lasers and peripheral devices, and the operating costs are relatively low . The quality of the beam emitted by the fiber laser is good and stable. Its integrated structure can solve the problems caused by contamination and position changes of the optical components in the cavity. The fiber is small in size, flexible and bendable, and it is convenient for laser transmission, which contributes to miniaturization of the mechanical system. Intensification .2 Laser heating assisted cutting experimental research progress2.1 Laser Heating Assisted TurningDue to the introduction of a laser heat source, laser heating assisted cutting differs from conventional machining in the selection of process parameters. The determination of processing parameters needs to be based on the principle of selection of the conventional cutting amount, and comprehensively consider the effect of laser thermal effect on the workpiece material and tool life. Reasonably choose the laser parameters and cutting parameters to achieve the purpose of improving the surface quality and improving the processing efficiency.Laser parameters including laser power, laser spot size, laser scanning rate, laser spot and tool tip distance, and laser emission angle have important influence on the temperature distribution in the cutting zone and the degree of material softening. Panjehpour et al. conducted experiments on laser heating assisted turning of AISI52100, and found that as the laser power increases, the heat penetration depth increases, the cutting zone material is sufficiently softened, the tool receives less resistance when cutting, and the tool wear decreases. When the laser power exceeds 425 W, the tool will overheat and the tool wear rate will increase. The optimal processing parameters obtained in the experiment were: laser power P=425 W, pulse frequency fp=120 Hz, cutting rate vc=70 m/min, feed rate f=0.08 mm/r, cutting depth ap=0.2 mm. With this combination of processing parameters, the surface roughness, Ra, is reduced by 18% compared to conventional machining and is 25% lower than cutting. Kannan et al. pointed out that laser heating assisted turning of alumina ceramics points out that as the laser scanning rate increases, the irradiation time of the material in the cutting zone is relatively reduced by the laser, and the softening degree of the material is reduced, resulting in an increase in cutting force. The optimal processing parameters obtained in the experiment are: laser power P=350 W, feed rate f=0.03 mm/r, depth of cut ap=0.3 mm, spot diameter d=2 mm, laser scanning rate v=35-55 mm /min. With this combination of machining parameters, cutting forces can be reduced by up to 80% compared to conventional machining and tool life is significantly increased. Navas et al. conducted a laser heating assisted turning experiment on Inconel718, and studied the effect of laser spot size and laser spot and tool tip distance on Inconel718 cutting performance. Experiments were conducted to compare the difference in power density, reaction time, and cutting force between a square spot of 1.25 mm×1.25 mm, an elliptical spot of 1.6 mm×1.3 mm, and a round spot of 2 mm in diameter. The power density of the square spot was high, and the elliptical spot reaction was observed. For a long period of time, the circular spot has a moderate power density and reaction time, which is more pronounced in reducing the cutting force. With the increase of the spot diameter, the irradiation area is enlarged, but the laser power density is reduced, and the unit area of the workpiece is reduced by the irradiation energy, resulting in a reduction in the heating softening effect. The center of the laser spot and the tip of the laser should be kept at an appropriate distance, not only to achieve the effect of laser-assisted heating, but also to prevent the cutter from overheating damage or melting of the chip splashed on the processed surface to affect the processing quality.鄢銼 et al. laser-heat assisted turning of alumina ceramics. The laser beam was tangentially incident at the Brewster incidence angle. The spot was elliptical, although the laser power density was reduced relative to vertical irradiation. As the area is enlarged, the material in the cutting zone is heated more evenly, which is more conducive to improving the processing quality. Ding et al. used two lasers to perform laser turning experiments on the AMS5704 nickel-base superalloy, which caused the CO2 laser beam to vertically illuminate the workpiece surface to be machined, and the Nd:YAG laser beam tilted to irradiate the workpiece transition surface. The cutting area is heated more evenly. Compared with the conventional machining, the cutting area is reduced by 20%, the tool life is increased by 50%, and the surface roughness Ra is reduced by 200% to 300%.Cutting parameters such as feed rate, cutting rate and cutting depth have a very important influence on the machining quality, processing efficiency and processing cost. Kim et al. conducted experiments on the heated auxiliary turning of silicon nitride ceramics and found that as the feed amount increases, the average heating temperature in the cutting zone decreases, resulting in an increase in cutting force and a decrease in tool life. As the depth of cut increases, the depth of softening of the deep material is small, resulting in increased cutting force and tool wear. The depth of cut of the silicon nitride ceramic material is a maximum of 3 mm. Xavierarockiaraj et al. conducted laser heating assisted turning experiments on SKD11 tool steel and analyzed the influence of cutting parameters on cutting force, surface roughness, and tool wear. As the feed rate increases, cutting force, tool wear, and surface roughness increase, a smaller feed rate should be used to increase the material’s heat softening time. With the increase of cutting rate, the average heating temperature in the cutting zone decreases, the tool wear increases, and the surface roughness increases. The optimum cutting rate is vc=100 m/min. With a laser power of P=1000 W, a cutting rate of vc=100 m/min and a feed of f=0.03 mm/r, a minimum cutting force can be obtained. Rashid used Nd:YAG laser to perform the heat assisted turning experiment on Ti6Cr5Mo5V4Al alloy. The recommended processing parameters ranged from: laser power P=1200 W, feed rate f = 0.15~0 . 25 mm/r, Cutting rate vc = 25~100m/min. When the feed rate f<0.15 mm/r, the machining efficiency is low; when the feed rate f>0.25 mm/r, the heating softening degree of the cutting zone material is low, which will aggravate the tool wear. Cutting rate vc<25 m/min.When the workpiece is heated for a long time, overheating causes the tool to wear and reduce the quality of the machined surface. When the cutting rate vc>100 m/min, the workpiece cutting area by the laser heating time is reduced, the material can not be fully softened, resulting in serious tool wear. Tadavani et al conducted laser heating assisted turning on Inconel 718. The orthogonal experimental design, signal-to-noise ratio and variance analysis determined that the optimal processing parameters were: laser power P = 400 W, pulse frequency fp = 80 Hz, Heating temperature T = 540 ℃, cutting rate vc = 24 m/min, feed rate f = 0.052 mm/r. With this combination of processing parameters, the surface roughness, Ra, is reduced by 22% compared to conventional machining, 35% lower than cutting, and tool wear is reduced by 23%.In addition, Mohammadi et al. also investigated the effect of tool geometry on the surface quality of laser-assisted turning of silicon wafers. In laser power P=20 W, spindle speed n=2000 r/min, feed rate f=0.001 mm/r, and cutting depth ap=0.005 mm, when the tool rake angle is γ0=?45°, The surface roughness Ra is 9.8 nm. When the rake angle is γ0 = -25°, the resulting surface roughness Ra is 3.2 nm.2.2 Laser Heating Assisted MillingMilling refers to the use of a rotating multi-blade tool to cut a workpiece. It can not only machine flats, grooves, gear teeth, but also complex surfaces. Since milling is a multi-blade interrupted cutting, the cutting thickness of each tooth during the cutting process is changed, and the impact load is large and vibration is likely to occur. The use of laser-assisted milling can reduce the chatter of the milling cutter during cutting, reduce cutting forces, increase tool life, and improve machining surface quality.Kumar et al. found that in the laser heated auxiliary milling of A2 tool steel, the material removal rate was increased by 6 times, the cutting force was reduced by 69%, and the milling burr was reduced compared to conventional machining.The damage is significantly reduced. Woo et al. used laser heating to assist milling of spherical surfaces and found that the cutting forces of AISI1045 and Inconel718 were reduced by 82% and 38%, respectively, and the surface roughness Ra was reduced by 53% and 74%, respectively, compared to conventional machining. Tool vibration was reduced small. Kim et al. conducted laser heating assisted milling experiments on AISI1045, Inconel718, and titanium alloy spherical workpieces. Compared to conventional machining, the milling forces of AISI1045, Inconel718, and titanium alloys decreased by 2.1% to 8.6% and 3.7%, respectively. ~12.3%, 0.8%~21.2%, surface roughness Ra decreased by 14.5%~59.1%, 19.9%~32.4%, and 15.7%~36%, respectively, and the processing efficiency increased significantly.In laser heating-assisted milling, due to the high temperature in the cutting zone, it is easy to cause the tool to wear or diffuse wear. In severe cases, it may cause plastic deformation of the tool and change the geometric parameters of the tool. Reasonable choice of cutting fluid can effectively reduce the friction between the tool and the workpiece, the tool and the chip, reduce the cutting temperature, and increase the tool durability and processing quality. Bermingham et al. found that at a lower cutting rate, using a small amount of lubrication to cool the tool can reduce the cutting temperature and delay the occurrence of tiny nicks or flaking off of the Ti6Al4V. The tool life is increased by more than 5 times. At higher cutting rates, the use of cutting fluids can result in thermal shock or thermal fatigue of the workpiece and tool.2.3 Laser Heat Aided DrillingDrilling is widely used in processing various types of machine parts. When conventional drilling is used to process forged blanks, difficult-to-machine materials, or hardened parts, due to high hardness, strength, irregular surface shapes, etc., It is easy to lead to biased drilling, large axial drilling force, and serious drill wear . Laser-heating-assisted drilling is the use of a laser to heat the drilled area of the workpiece, softening the surface layer material, and then turning off the laser and rapidly drilling the heated area . The use of laser-assisted heating method for drilling, can make the drill positioning accuracy, avoid bias, reduce drilling resistance and bit wear, and then improve the processing accuracy and processing efficiency.At present, research on laser-assisted drilling is far less than laser-assisted turning and milling, but it has also made some progress. Jen et al. conducted laser heating assisted drilling of carbon steel materials. During the experiment, the CO2 laser spot was adjusted to a ring shape to drill the middle of the irradiation to obtain the laser power and laser spot size for the heating temperature. Influence laws, improve drilling quality and efficiency. Zheng et al. used laser heating assisted drilling technology to conduct an experimental study on the drilling of key automotive parts. Compared with conventional drilling, 40Cr, 45 steel, and stainless steel increased by 50.5, respectively, in the diameter of the drilled hole. %, 52.2%, 51.4%; in terms of drilling efficiency, QT600, 45 steel, and stainless steel increased by 19.3%, 16.3%, and 39.9%, respectively. Similarly, Zhang et al. conducted experiments on laser-assisted drilling of 41Cr4, C45E4, stainless steel, and cast iron. Compared with conventional drilling, it was found that 41Cr4, C45E4, and stainless steel increased in terms of entry diameter. 122.7%, 85.9%, 140.7%; in terms of drilling efficiency, cast iron, C45E4, and stainless steel increased by 18.6%, 16.3%, and 39.9%, respectively. Choubey et al. used Nd:YAG laser assisted heating method to drill marble and found that it can effectively reduce the stress concentration on the marble surface, improve the surface integrity, reduce the processing cost, and improve the processing efficiency.In the laser heating assisted drilling process, the laser can only quickly heat and soften the surface material of the workpiece, which is conducive to rapid drilling; however, as the drilling depth increases, the laser cannot heat the material in the hole. Can not further improve the processing efficiency. At present, there are few reports on the drilling force, tool wear, hole roundness and surface roughness in the laser heating assisted drilling process, and the research work in these areas needs to be further strengthened.2.4 Laser Heating Assisted GrindingEngineering ceramic materials such as silicon nitride, aluminum oxide, and zirconium oxide have been used in mechanical, automotive, aerospace and other fields for more and more applications due to their high strength, high hardness, and corrosion resistance. Grinding is the main processing method of engineering ceramics. Due to the high hardness and high brittleness of ceramic materials, it results in large cutting force, severe tool wear, low material removal rate, and easy surface subsurface damage . In addition, due to the poor thermal conductivity of ceramics, the heat generated in the grinding process accumulates on the surface of the workpiece, causing a very high temperature gradient on the surface of the workpiece. This can easily lead to thermal damage to the surface of the material and even cracks. Laser-heating-assisted grinding uses laser to pre-heat the surface of the workpiece, which can significantly reduce the hardness and brittleness of the material, reduce the grinding force, reduce the generation of sub-surface damage, and improve the quality of the grinding surface .Chang et al. used laser-assisted assisted grinding to machine silicon nitride ceramic materials. Compared with conventional grinding, laser heating assisted the machining process is more stable, the surface integrity is better, and there is no obvious microstructure change and crack. Kumar et al. performed laser-assisted grinding on silicon nitride ceramics. The results show that the cutting force is reduced by 43.2%, tool wear is reduced, and the material removal rate is improved compared to conventional grinding. Kizaki et al. conducted laser heating assisted grinding experiments on yttria-stabilized tetragonal zirconia polycrystalline ceramics (Y-TZP). The results show that the suitable grinding temperature for Y-TZP materials is around 490 ℃. At temperature, the fracture toughness of Y-TZP is 5.3 MPa·m1/2, which is far less than 9.1 MPa·m1/2 at room temperature. Compared with conventional processing, laser-assisted grinding can reduce material hardness, reduce grinding force and tool wear, and improve processing quality and efficiency.2.5 Laser Heating Aid Milling ProcessingTurning milling is an advanced cutting method that uses milling cutters. The combined motion of rotation and workpiece rotation for machining . Turning and milling machining includes four basic movements of workpiece rotation, milling cutter rotation, milling cutter axial and radial feed. The processing methods are divided into two major categories of orthogonal turning and milling and axial turning and milling, among which the application of orthogonal turning and milling More extensive. As a relatively new composite machining method, the characteristics of turning and milling are mainly: excellent intermittent machinability, large metal removal rate.It has good processing capability for special-shaped rotating parts. Laser heating assisted turning and milling can further reduce cutting force to extend tool life, improve complex profile parts, fine shaft zero. The processing quality of the pieces. Chio et al. developed a set of C++-based applications that can convert CAD graphic files into NC code, enabling automatic programming of rectangular and four-leaf section workpieces.The program was successfully applied to a 5-axis machining center. Kim et al. conducted laser heating assisted milling and milling machining experiments on the SM45C material. Compared with conventional turning and milling machining, the tool vibration during cutting was reduced and cut. The cutting process is more stable, the axial and radial forces of the rectangular section workpiece are reduced by 10.4% and 13.5%, respectively, and the four-leaf section workpiece is axial. The force and radial forces were reduced by 10.6% and 8.9%, respectively. The surface roughness Ra of the rectangular cross-section and the four-leaflet-shaped workpiece was reduced by 39.9% and 37.1%, respectively. Cha et al used the Taguchi method to optimize the processing parameters of the laser heating assisted turning and milling silicon nitride ceramics. The results showed that the significant degree of influence on the surface roughness was the cutting depth, laser power and cutting rate.The laser heating assisted milling and milling process has certain advantages in reducing cutting force, prolonging tool life, and improving machining efficiency. However, there are still many deficiencies in machine tool stability and machining shape error, and further research and improvement are still needed. 2.6 Other laser heating auxiliary cutting processing methodsLaser-assisted heating can also be applied to other processing methods such as planing, polishing, turning and finishing. Chang et al. found that when laser heating assists in planing alumina ceramics, the axial force is reduced by 20% and the radial force is reduced by 22% compared to conventional planing.The degree of Ra is reduced by more than 50% and the surface integrity is better. Tian et al. conducted laser heating assisted polishing tests on the AISI4140 and MP35N materials. The results show that the tool wear is significantly reduced and the machining surface integrity is better than that of the conventional polishing process, but the surface residue is better.Stress has increased. For high hardness abrasive wheel, dressing difficulty, low efficiency of trimming, Zhang et al conducted laser heating assisted turning trimming experiment on the metal bond CBN grinding wheel. Compared with the traditional diamond tool dressing method, the laser heating assisted on the premise of ensuring the dressing quality. Turning and dressing can greatly shorten the dressing time, improve the dressing efficiency, and extend the service life of the dressing tool.In summary, laser heating assisted turning, milling, drilling, grinding and other processing methods have obvious advantages over conventional machining in reducing cutting force, improving tool life, improving processing quality, and saving cost, but in laser heating. There are some deficiencies in the research of auxiliary cutting process, tool wear mechanism, etc. Laser heating auxiliary processing technology still has a lot of room for development.3 laser heating assisted cutting simulation research progress3.1 Temperature Field Simulation StudyIn the laser heating auxiliary cutting processing, the cutting zone temperature and distribution are one of the key factors that affect the tool life and processing quality. Excessively high temperatures in the cutting zone can cause thermal damage to the material or wear of the tool, affecting the quality of the machined surface, and too low a temperature can weaken the laser-assisted heating effect. The method of temperature field simulation can reflect the actual cutting temperature field distribution more intuitively and accurately. By establishing the temperature field simulation model under different process parameters, predicting the optimum removal temperature range of the material and optimizing the processing parameters, the actual measurement cost can be greatly saved. In the field of temperature field simulation research, many numerical simulation methods that are currently used include finite element method, finite volume method, and the like.Cha et al. established a three-dimensional transient temperature field model of silicon nitride ceramics for laser heating-assisted milling and milling processing using finite element method. The simulated and measured average temperature error under different laser power heating is 1.5%~6.2%. Roostaei et al. established a three-dimensional finite element model of a fused silica ceramic (SCFS) temperature field and compared the simulation results with the pyrometer measurement results. When the heating time is between 25 s and 43 s, the two are basically consistent. . When the heating time is less than 25 s or greater than 43 s, the error between the two increases, and the maximum temperature error is 40 K. Kim et al. conducted finite element simulation and experimental study on the temperature field of the laser heating-assisted turning and milling machining of the SM45C. The results showed that the SM45C had a rectangular cut-off.The prediction error of the average heating temperature of the surface and four-leaf clover cross-section workpieces was 8.7% and 6.4%, respectively. The effective depths and widths of the workpieces with rectangular cross-sections were 0.34 mm and 2.26 mm, respectively, and the effective depths and widths of the four-leaf workpieces were 0.45 mm and 2.89 mm, respectively.Rozzi et al studied the temperature field of laser-assisted turning of silicon nitride ceramics using the finite volume method and analyzed the effects of laser heat flux, surface convection, heat conduction and heat radiation on the surface temperature, and simulated different cutting parameters. The temperature field distribution under the laser parameters and the temperature field simulation results are basically consistent with the experimental results. In addition, Zhang et al established a quasi-steady-state heat transfer model for laser-heat assisted cutting of alumina ceramics using the finite difference method, and simulated the effects of different laser power, laser scanning rate, and laser spot radius on the temperature field distribution. Studies have shown that using a lower laser scan rate, higher laser power, and a smaller radius of the laser spot is more conducive to softening the material in the cutting zone and thus achieving an ideal depth of cut. Kashani et al. established a numerical model of the temperature field of laser heating assisted cutting carbon steel by analytical method. The pyrometer was used to measure the temperature field distribution of the workpiece. The error between the simulation results and the measured results was within 10%. Chang et al. applied the lattice Boltzmann method (LBM) to the temperature field of laser-heat assisted cutting of alumina ceramics, and the temperature field distribution obtained was in good agreement with the experimental results.3.2 Simulation Research of Cutting ProcessBy laser heating assisted cutting process simulation can obtain cutting stress, strain, temperature and other physical variables, in order to reduce the damage of the machining surface and provide the basis for optimizing the processing parameters. The methods applied to the simulation of cutting process include finite element method, discrete element method, and smooth particle fluid dynamics method.Tian et al. used the finite element method to simulate the machining process of laser and auxiliary cutting silicon nitride ceramics. The results show that under the action of the load, the crystallized glass phase will generate micro-cracks and the micro-cracks will expand. Eventually a macroscopic crack is formed in the shear zone, and slipping occurs to generate discontinuous chips. The simulated chip thickness is about 15μm, which is slightly smaller than the experimental result. The cutting force error is 10% to 15%. The simulated value of surface residual stress is basically consistent with the experimental value, which proves the effectiveness of the simulation model. Liu et al carried out the finite element simulation of the laser heating assisted milling process for Ti6Al4V materials. Based on the temperature field model, the milling model was added using the method of sequential thermal coupling, and the variation law of cutting force and the distribution of tool temperature field were obtained. The error between the simulated and experimental values of the cutting force was 11.8%.Shen et al. used discrete element method (DEM) to simulate the process of laser heating assisted milling of silicon nitride ceramics. The dispersed particle clusters represent the structure of silicon nitride ceramic materials, and the fracture of the bonding unit was used to simulate the processing process. The formation and expansion of cracks. Through comparison of simulation and experimental results, it is found that applying DEM method to cutting process simulation can predict the subsurface damage of materials under different processing conditions; the removal mechanism of ceramic material is mainly brittle fracture; the greater the depth of cut, the greater the cutting force of the tool. The more fragmented the workpiece is, the more the cutting force has an important effect on the formation and propagation of cracks. Balbaa et al. used the smooth particle hydrodynamics (SPH) method to simulate the cutting process of Inconel 718 material. It was found that the laser heating softening effect of the tool front is the main factor causing the residual stress. The laser heating assisted cutting mainly produces the surface along the cutting direction. Residual tensile stress, while conventional cutting mainly produces surface residual compressive stress. In addition, Nasr et al. used the finite element method.Similar conclusions have been obtained when the AISI 4340 steel was subjected to a simulation study of the cutting process.4 ConclusionThis article reviews the latest research progress of laser heating assisted cutting technology in recent years. In terms of processing methods, laser heating auxiliary turning, milling, drilling, grinding and other technologies continue to develop and innovate, reducing cutting forces, improving processing quality, and improving processing efficiency. To solve engineering ceramics, composite materials, high-temperature alloys, titanium The machining of hard-to-machine materials such as alloys provides a viable method. Through the simulation study of the temperature field and cutting process, the prediction of the optimum removal temperature range of the material and the optimization of the processing parameters can be realized, providing the basis for the actual processing. Although laser heating assisted cutting technology has achieved a series of research results, there are still some problems in the processing mechanism, processing technology and industrial applications. With reference to the development trend at home and abroad, the following research work still needs to be done:(1) Strengthen the research on the processing conditions and removal mechanism of difficult-to-machine materials, and solve the problems such as the adhesive wear of the tools, the difficulty in separating the tool and the chips, the tool cooling, etc., which may occur during the laser heating auxiliary cutting process.(2) Strengthen the study of laser heating auxiliary cutting simulation, establish accurate and rapid temperature field and cutting process simulation model, and improve the speed and accuracy of the simulation model. Optimize the laser parameters, cutting parameters and other process parameters, establish a perfect laser heating auxiliary cutting database, provide a theoretical basis for reasonable choice of processing parameters.(3) Strengthen the research on industrialized laser heating auxiliary cutting system, improve the production R&D and supporting capabilities of laser heating auxiliary cutting system, and enhance the integration, stability, and accuracy of laser heating auxiliary cutting system to promote laser The actual production application of heating assisted cutting technology.With the continuous advancement of laser technology, cutting processing technology and material technology, laser heating auxiliary cutting processing technology will have a broader development prospect in the areas of difficult-to-process material processing, micro-machining and other fields.
Ngu?n: Meeyou cacbua