Search

The thermal error is a significant factor that influences the machining accuracy of machine tools, and error compensation is an economical and effective method for enhancing the accuracy of machine tools. However, establishing a precise thermal error prediction model is crucial for thermal error compensation. In this paper, the subtraction-average-based optimizer-based CNN-GRU neural network (SABO-CNN-GRU) is applied to integrated thermal error modeling. Through conducting a thermal characteristic experiment, temperature rise data and thermal error data were collected from the linear feed system of LXK300X helical groove CNC machine tool. The fuzzy c-means clustering and grey correlation analysis are employed to identify temperature-sensitive points in the linear feed system. By utilizing the temperature rise data from these sensitive points along with feed shaft thermal errors as data samples, and using the SABO algorithm to optimize the CNN-GRU prediction model, the thermal error prediction model of SABO-CNN-GRU is established. To validate its superiority and practicality, a comparative analysis is conducted with traditional thermal error prediction models based on CNN-GRU and SO-ELM. The results demonstrate that SABO-CNN-GRU model outperforms both models in terms of mean absolute error (MAE), root mean square error (RMSE), remaining prediction deviation (RPD), mean square error (MSE), and determination coefficient (R2) in accurately predicting results. Building upon this achievement, this paper develops a real-time thermal error compensation system which effectively reduces maximum thermal errors from 80.5 to 17.6 μm after implementing compensation measures. Effectively reducing the influence of thermal errors and improving the machining accuracy of machine tools. [ABSTRACT FROM AUTHOR]

The analysis of the grinding mechanism of ITO conductive glass is particularly important for revealing material damage and chip formation. This article proposes the removal mechanism of brittle thin film materials during grinding based on the indentation model. And based on the thin film composite structure of ITO conductive glass, a material model in finite element simulation was established. The surface morphology and chip state of ITO conductive glass were studied through microscale grinding experiments. By comparing the simulation results, it has been proven that the ITO film is removed in a brittle fracture mode during the grinding process, while the removal mode of the glass substrate is influenced by the process parameters. The interlayer fracture between the film and substrate will affect the processing quality. [ABSTRACT FROM AUTHOR]

To investigate the machining mechanism of silicon carbide (SiC) ceramic materials, this study utilized sintered diamond tools to perform drilling and grinding simulations on the material and developed a drilling model for SiC ceramic materials. By analyzing parameters such as surface morphology, stress, and cutting force, the material removal mechanism of SiC ceramic materials was revealed, and the effects of drilling parameters on cutting force, torque, and residual stress were studied. Experimental results indicate that during the abrasive cutting process, the hard contact behavior of irregular abrasive grains significantly affects material removal, leading to failure forms such as chip collapse, hole and groove cracking, and crack propagation. With an increase in the feed rate of the abrasive grains, the drilling force shows a certain range of growth patterns. The axial force is positively correlated with spindle speed and feed rate, with the feed rate having a more significant impact on the magnitude of the axial force. Additionally, as the feed rate increases, the torque also increases. The radial residual stress mainly manifests as residual tensile stress. [ABSTRACT FROM AUTHOR]

The nano-cutting process of metallic glass (Zr52Cu20Ni16Ni12) processed at room temperature was studied by molecular dynamics simulation in this paper. At different cutting speeds, the microstructure of metallic glass, cutting force, strain morphology of cutting zone, temperature change of cutting zone and its influence on the quality of machined surface were analyzed. The simulation results show that the cutting speed has little effect on the content of Voronoi polyhedron in the cutting area of metallic glass. The cutting force increases significantly with the increase of cutting speed. The shape of strain deformation in the cutting zone of metallic glass material is significantly affected by the cutting speed, and the influence depth of strain is deepened with the increase of cutting speed. The increase of cutting speed has a significant effect on the temperature of the cutting zone of metallic glass, and the temperature of atoms in the cutting zone increases rapidly. The cutting speed has a significant impact on the surface quality of metal glass cutting. The surface quality of metal glass cutting becomes worse with the increase of cutting speed. In particular, the initial stage of plastic deformation in metal glass cutting process is simulated and analyzed, and the formation and evolution of its shear band and free volume are simulated and studied. [ABSTRACT FROM AUTHOR]

The nano cutting process of Zr-based amorphous alloy was simulated by molecular dynamics simulation in this paper. Through the research on the changing rule of cutting force in nano cutting of Zr-based amorphous alloy, it is found that the cutting force increases continuously, and the cutting rate is large at the initial stage of nano cutting, which may be related to the shear deformation of the atomic clusters or atomic clusters in the shear transition zone. The effect of cutting tool rake angle on nano cutting process for Zr-based amorphous alloy was studied. The simulation results show that the cutting force decreases with the increase of the rake angle of the cutting tool, and the friction coefficient between the rake face and the chip also decreases slightly. With the increase of the rake angle of the cutting tool, the pushing effect of the tool on the Zr-based amorphous alloy chip and the overall bending of the chip are weakened, leading to the increase of the chip height. The number of high-temperature atoms in the Zr-based amorphous alloy workpiece also decreases with the increase of the tool rake angle, and the cutting temperature distribution on the workpiece diffuses to the interior of the workpiece with the tool fillet as the center. [ABSTRACT FROM AUTHOR]

To investigate the effect of microscale grinding on the quality of ITO conductive glass, this paper conducted microscale grinding experiments on ITO conductive glass. The influence of process parameters on machining quality was analyzed using microgrinding force, surface roughness, and sheet resistance as indicators. Meanwhile, soda-lime glass was set as the control group to analyze the effect of ITO film. The results indicate that brittle fracture is the main removal method for ITO films, and the glass substrate exhibits two different removal methods, brittle and ductile, depending on the process parameters. The ITO thin film layer suppresses the sheet deformation of the glass substrate, increasing the grinding force and reducing the processing quality. Increasing the spindle speed, reducing the feed speed, and reducing the cutting depth can improve the machining quality. The spindle speed has a significant impact on surface roughness, while the cutting depth has a significant impact on the sheet resistance of the thin film. In addition, soda-lime glass chips mainly appear in powder and granular form, while ITO conductive glass also has flaky thin film chips generated by interlayer fracture. [ABSTRACT FROM AUTHOR]

Zr-based bulk metallic glass is an amorphous alloy. In order to study the burr problem in the groove milling process of Zr-based bulk metallic glass, the milling force in the process is studied experimentally. Then the effect of milling parameters on the burr of Zr-based bulk metallic glass was studied, and the relationship between milling force and burr was analyzed. In order to further study the milling burr of amorphous alloy, under the same test parameters, the single crystal alloy material (nickel base single crystal superalloy DD5) and the traditional polycrystalline metal material (304 stainless steel) were selected for comparative test and analysis. The results show that Zr-based bulk metallic glass has good groove milling machinability. The test results provide some experimental basis for groove milling of Zr-based bulk metallic glass. [ABSTRACT FROM AUTHOR]

In order to study the milling machinability of Zr-based bulk metallic glass, a comparative experimental study on the surface roughness of the milling groove bottom surface for Zr-based bulk metallic glass was carried out in this paper. Through different processing materials, milling tools with different coatings, milling tools with different geometric parameters, and different processing conditions, a large number of comparative tests were carried out on the surface roughness of the milling groove bottom surface for Zr-based bulk metallic glass. The surface roughness values of the milling groove bottom surface are compared, studied, and analyzed from many angles (surface roughness Sa, Sq, Sz, Ssk, and Sku). The test results show that Zr-based bulk metallic glass has good milling machinability. It can obtain a low surface roughness value through the processing conditions and methods used in the test. The research content of this paper provides experimental basis for groove milling of Zr-based bulk metallic glass. At the same time, it also provides a strong test basis for the manufacture of Zr-based bulk metallic glass parts. [ABSTRACT FROM AUTHOR]

The effect of milling parameters on chip shape and chip morphology for Zr-based bulk metallic glass was studied in this paper. The milling groove experiments of Zr-based bulk metallic glass (Zr-based BMG) (Zr52Cu17.5Ti16Ni12Nb2.5) were conducted by using a JX-1A ultra-precision machine tool. In order to study the milling quality and milling characteristics of Zr-based bulk metallic glass, it is very important to study the chip shape and chip morphology. In this paper, firstly, the temperature field distribution of Zr-based bulk metallic glass in milling process was simulated by finite element method, and the milling temperature and its distribution at different cutting speeds were obtained. Then the effect of different milling parameters on chip shape and chip morphology was studied, and the reason of the change was analyzed. Then the influence of milling cutters with different geometric parameters on the chip shape and chip morphology of Zr-based bulk metallic glass was also studied. At last, under the same milling conditions, the chip shape and chip morphology of traditional polycrystalline metal materials, monocrystalline metal alloy materials, high-entropy alloy which is in amorphous system, and Zr-based bulk metallic glass were compared. It provides theoretical and experimental basis for the groove milling technology of Zr-based bulk metallic glass. [ABSTRACT FROM AUTHOR]

In order to meet the maintenance requirements of ship shell plant, the old polyurethane paint needs to be removed from the ship shell plant. The experiment of repeated cleaning on the surface of polyurethane paint ship shell plate using pulse fiber laser is conducted by the large-scale laser cleaning system which was independently developed. The mechanism of twice repeated pulse fiber laser cleaning method was clarified. In this experiment, the effect of pulsed fiber laser power on surface roughness value was studied. The surface roughness of ship shell plate under different pulsed fiber laser power was obtained. The surface topography of two-dimensional and three-dimensional ship shell plate with different laser power was measured. The results showed that process parameters changed surface topography of ship shell plant by changing laser power. The cross-section profiles of the ship shell plate surface under different laser power are obtained. It is found that the surface height of ship shell plate decreases with the increase of pulsed fiber laser power. The relationship among the pulsed fiber laser power, the surface roughness, and the surface topography was analyzed. The surface topography of ship shell plate obtained by once pulse fiber laser cleaning was compared with that obtained by twice repeated laser cleaning. The experimental results show that twice repeated laser cleaning has a very significant cleaning effect on the removal of polyurethane paint which is on the ship shell plant. The experimental results are of practical significance to the production process of pules fiber laser cleaning for ship shell plate. [ABSTRACT FROM AUTHOR]

The milling groove experiments of Zr-based bulk metallic glass (Zr-based BMG) (Zr52Cu17.5Ti16Ni12Nb2.5) are conducted by using an ultra-precision lathe. In order to study the milling groove flank contour accuracy in mesoscale groove milling for Zr-based bulk metallic glass component, the milling force and the flank contour shape were investigated by single-factor experiment. The effect of milling process parameters of Zr-based bulk metallic glass materials on the milling force and the flank contour profile of milling groove were obtained, and the relationship between flank contour profile of milling groove and milling force was also obtained. The flank contour profile of milling groove for Zr-based bulk metallic glass is analyzed theoretically. The effect of milling experimental parameters on the deviation between the actual flank contour profile of milling groove and the theoretical flank contour profile of milling groove is analyzed and summarized through the experiment. [ABSTRACT FROM AUTHOR]