Abstract:A robotic belt grinding method for accurate control of the blade leading edge profile was proposed in this paper. The stress distribution in the contact area between the flexible abrasive tool and the leading edge of the blade was obtained by combining the semi-Hertzian contact theory and finite element simulation， and the material removal function was solved based on the Preston equation. The global material removal matrix was established by traversing the grinding depth of the control point. The resident time was set up to solve the nonlinear equations. Tikhonov regularization with a damping factor was used to eliminate the influence of a large sparse-ill-conditioned matrix on the fluctuation of solving accuracy， and then the desired dwell time was converted to the feed speed of the corresponding cutter point so as to generate the robot machining code. The grinding experiment results show that the robotic belt grinding method based on resident time control can achieve accurate machining of the leading edge profile of the blade within a given tolerance range， and the profile error can be controlled within 0.02 mm.

Abstract:To investigate the material removal mechanism and the subsurface damage evolution of monocrystalline gallium oxide， a systematic study was conducted by experimental methods. Firstly， the variable-depth nano-scratching test was used to simulate the material removal process of single grit and explore the material removal mechanism in the grinding process. Subsequently， the diamond grinding wheels with mesh sizes of SD600， SD1500， and SD5000 were used to carry out the grinding tests on the monocrystalline gallium oxide and to analyze the morphology of the ground surface and the evolution of subsurface damage. Scanning electron microscope and transmission electron microscope were used as the primary means of characterization， and the stress distribution during the scratching process was analyzed with the finite element method. The results indicate that the cross-acting slip band with multi-directions may lead to irregular fracture pits， and the orientation cracks were greatly affected by the （-3-10） plane of the monocrystalline gallium oxide. The grinding experiments reveal that the ground morphology， characterized by a brittle removal surface dominated by fracture pits and orientation cracks， gradually evolved into a completely plastic removal surface with the decrease of mesh sizes.

Abstract:Aiming at the problem of difficult machining of micro-structured surfaces of super-hard materials such as sapphire， a microstructure technology for grinding surfaces based on structured grinding wheels is proposed. In this paper， the surface of the grinding wheel is structured through Wire Electrical Discharge Machining（WEDM） technology， and the structurally dressed wheel was utilized to grind the microstructure of the sapphire surface. The influence law of structured wheel grinding speed， grinding depth， and feed rate on the surface roughness at the bottom of sapphire microgrooves in both down and up grinding modes was carried out. The results show that the microgroove morphology of the sapphire surface ground by the structured wheel is basically complete， the dimensional error is only 1.4 μm relative to the cutting depth of 120 μm， and the perpendicularity of the microgrooves is better， with a perpendicularity deviation of only 4.9°； The surface roughness at the bottom of the sapphire microgroove can be reduced by increasing the grinding speed and decreasing the grinding depth and feed rate in both down and up grinding modes； Compared with the up-grinding method， the micro-pits on the bottom surface of the micro-groove are smaller， and the bottom surface quality is better in the down-grinding method. The bottom surface roughness is reduced from 4.487 μm to 2.923 μm under the better machining parameters of grinding speed of 35 m/s， grinding depth of 1 μm， and workpiece feed speed of 200 mm/min.

Abstract:The kinematics of a single abrasive particle in three-dimensional Ultrasonic Vibration Assisted Grinding （UAG） was analyzed. The ultrasonic vibration assisted grinding experiment of zirconia ceramics was carried out with the self-built three-dimensional UAG system. By comparing the normal grinding force， surface roughness， and surface morphology of zirconia ceramics under different ultrasonic-assisted conditions， the influence of different processing parameters on the three-dimensional UAG process and the influence of three-dimensional ultrasound on the grinding process were studied. The experimental results show that the normal grinding force of zirconia ceramics decreases with the increase of ultrasonic assisted machining dimension. Three-dimensional UAG machining can effectively reduce the grinding load， and the influence of machining parameters on the reduction of normal grinding force is the smallest. The reduction of normal grinding force decreases with the increase of feed speed and cutting depth and increases with the increase of spindle speed. The surface roughness of zirconia ceramic workpieces decreases with the increase of ultrasonic assisted processing dimension， and the surface morphology gradually shows more plastic scratches. The influence of processing parameters on the surface roughness of three-dimensional UAG grinding is also the smallest. It can be seen that the increase of the cutting trajectory length of the single abrasive particle in the three-dimensional UAG machining is beneficial to the decrease of the cutting thickness， thus reducing the grinding force and improving the surface quality.

Abstract:Thermal damage defects are prone to occur during the grinding process of superalloys， which seriously reduces the fatigue life of parts. To address this engineering issue， this paper uses zirconium corundum grinding wheels and microcrystalline corundum grinding wheels to carry out creep-deep grinding experiments on superalloys. The effects of grinding process parameters on grinding temperature， grinding force， surface morphology， and surface roughness were studied. The formation mechanisms and effective suppression measures of thermal damage in superalloy grinding were revealed. The influence of grinding thermal damages on surface integrity was compared and analyzed. The results indicate that the instantaneous high temperature in the processing arc zone is the essential cause of the thermal damage of superalloy grinding. Microcrystalline corundum grinder can suppress grinding thermal damages productively due to its self-sharpening advantage. The surface of superalloy alloy grinding with thermal damages exhibits oxidation discoloration， fish scale-like coating texture， decreased hardness， and residual tensile stress. An effective means to realize the thermal damage-free grinding of superalloys is to reduce the generation of grinding heat and strengthen the heat transfer in the machining arc region.

Abstract:In this study， an orthogonal experiment was designed by changing the preparation process parameters of bonded magnetic abrasives. Then， a series of magnetic abrasives with different specifications were prepared， and their morphology and composition were detected. Taking the 3D-printed AlSi10Mg plate as the processing object， the influence of the magnetic abrasive preparation process parameters on the polishing quality was revealed through the planar magnetic abrasive finishing experiment. A regression model between parameters and responses was established based on regression analysis， and the genetic algorithm optimized parameters. The results show that under the condition that SiC is 18~25 μm， the mass ratio of Fe to SiC is 4.7， the mass ratio of resin to curing agent is 2， the curing temperature is 100 °C， the material removal rate is 1.7 mg/min， and the surface roughness is reduced from the original 3.90 μm to 0.27 μm with a reduction of 93.1%.

Abstract:Considering the interaction between any adjacent abrasive grains during the grinding process， the orderly arrangement of a single abrasive grain is studied， and an orderly arrangement strategy that can control the spacing of any two abrasive grains is proposed. After arrangement， each abrasive grain acts as a separate cutting edge on the surface of the workpiece， and the material is cut off successively to form grooves. According to the arrangement strategy， three arrangement methods are designed. The spacing of any adjacent abrasive grains is -50 μm， 0 μm， and 50 μm， respectively， the arrangement template is prepared by electrochemical anode dissolution on the surface of the grinding wheel matrix， and the corresponding orderly arrangement of the grinding wheel is prepared by sanding electroplating， and thickening. At the same time， the grinding force and grinding temperature changes in grinding are calculated by grinding kinematic analysis， and the grinding force and grinding temperature in actual grinding are measured and analyzed by grinding experiment. The results show that under this test condition， the influence of feed speed on both is relatively independent： the grinding force is positively correlated with the feed speed， while the grinding temperature is negatively correlated with the feed speed. The grinding depth and the abrasive grain arrangement spacing comprehensively affect the changes in temperature and grinding force. When the abrasive spacing is small， the grinding temperature and force increase steadily with the increase of grinding depth； When the abrasive grain spacing is large， as the grinding depth increases， the two increase steadily and then slowly.

Abstract:To explore the cutting mechanism of cortical bone material during abrasive water jet cutting and improve the quality of cutting surfaces in the abrasive jet cutting process， sodium chloride and garnet were used as abrasives to cut cortical bone. The changes in surface roughness under different cutting directions and the microscopic scratch characteristics were compared. The experimental findings demonstrate a characteristic pattern in which the roughness values of the cutting section initially decrease and then increase. Based on these roughness values， the section can be divided into three distinct regions： initial region， smooth region， and rough region. When using sodium chloride as the abrasive， the average roughness values of the cutting surface in the direction perpendicular to the bone unit are 1.74 times and 1.70 times those in the directions parallel and traverse to the bone unit， respectively. When using garnet as the abrasive， the average roughness values of the cutting surface in the direction perpendicular to the bone unit are 1.41 times and 1.55 times those in the directions parallel and traverse to the bone unit， respectively. Numerous micrometer-scale scratches are formed on the cutting surface during the cutting process. The impact of sodium chloride and garnet abrasives on the scratch characteristics of the cutting surface was compared. Compared with garnet， when using sodium chloride as the abrasive， the dimensions of the cortical bone cutting surface scratches are too large， with similar length and width values； the range of scratch depth values is greater.

Abstract:This study proposes a novel degradable soft abrasive for abrasive water jet cleaning technology and analyzes and compares the cleaning performance and surface damage patterns of remanufactured components treated with the abrasive water jet of varying hardness. Furthermore， the study conducts comparative experiments on the cleaning of component dirt using three different jet methods： garnet hard abrasive water jet， walnut shell soft abrasive water jet， and pure water jet. The study analyzes the differences in cleaning rate， specific energy consumption， surface roughness after cleaning， and maximum pit depth among different cleaning methods， and investigates the matrix damage under different cleaning modes from both macro and micro perspectives. The results show that the walnut shell soft abrasive demonstrates superior cleaning efficacy， reduced specific energy consumption， improved cleaning speed， and negligible substrate surface damage. Consequently， the walnut shell soft abrasive is regarded as an ideal cleaning choice in remanufacturing industries or for applications that demand high surface roughness standards.

Abstract:To meet the demand for high-precision and high-integrity surface machining of tungsten alloy parts， this paper carries out systematic research to achieve the control of tungsten alloy grinding quality and the optimization of the machining process. The impact of grinding wheel grit type and bond type on the form of grinding wheel wear was analyzed， and the advantages of super-hard abrasive in tungsten alloy grinding processing were clarified. The influence law of abrasive grain size and grinding parameters on the quality of tungsten alloy grinding processing was investigated， which provided a basis for the development of a reasonable grinding process. Finally， the high-precision and high-integrity surface grinding process of tungsten alloy was obtained through the grinding test. The results show that the grinding wheel of tungsten alloy is easy to wear during the grinding process， and the super-hard abrasive grinding wheel is more suitable for the grinding processing of tungsten alloy. Metal-bonded diamond wheels showed superiority in the comprehensive consideration of surface quality and machining accuracy of tungsten alloy grinding processing. By improving the grinding parameters， a surface roughness of 18.9 nm after precision grinding of tungsten alloy was realized， and a mirror grinding effect was achieved.

Abstract:In this paper， a chemical magnetorheological polishing method based on the Halbach magnetic field array is utilized to enhance the precision and efficiency of polishing medical titanium alloy （TC4）. Strengthening the magnetic field strength is used for the Halbach magnetic field array， and hydrogen peroxide solution is incorporated as an oxidant in the polishing process. Firstly， the Halbach magnetic field array is compared with the conventional N-S magnetic field array through simulation. Subsequently， the activity of carbonyl iron powder is adjusted to verify the experimental feasibility. The effects of working gap， main shaft speed， and abrasive particle size on surface roughness and contact angle of workpiece surface are then investigated. The results demonstrate that the Halbach magnetic field array exhibits higher magnetic-field strength than the conventional N-S magnetic field array. Moreover， the surface roughness of the medical titanium alloy polished using this method is 80% lower than that achieved through single pure magnetorheological polishing. Optimal smoothing of the workpiece surface is achieved at a working gap of 0.8 mm， a main shaft speed of 400 rad/min， and an abrasive particle size of 1 μm， resulting in an optimal Ra value of 15.5 nm. The surface contact angle measurements indicate that the majority of contact angle values for the titanium alloy surface in the experimental group are less than 90°. In conclusion， the application of this method for polishing medical titanium alloy yields an ultra-smooth surface and enhances its hydrophilicity， thereby meeting the standards required for medical titanium alloys.

Abstract:A deep learning-based recognition and classification model named Tenon Grinding Burn Net （TenonGBNet） is proposed to address the issues of misdiagnosis and missed detection in visual inspection of grinding burns on nickel-based Superalloy blades. The K4125 nickel-based superalloy blades are chosen as the target， and through grinding burn tests and specimen organization inspection， a set of classification standards and corresponding image collection for different degrees of blade tenon grinding burns are obtained. Then， ODConv dynamic convolution is employed to fuse Inception V2 modules and the Coordinate Attention mechanism to enhance the model's feature extraction capability while ensuring the model is lightweight. Finally， a fully connected layer is employed for identification and classification. Experimental results indicate that， compared with four other classical classification models， TenonGBNet achieves an average classification accuracy of 96.50% while maintaining a minor model complexity and parameter count. Additionally， the classification accuracy for each burn level exceeds 95%.

Abstract:Based on the geometric relationship between the steel rail and the abrasive belt， a calculation model for the grinding depth and profile of the contact area is established to clarify the influence of grinding process parameters on the contact area parameters. As the grinding radius of the abrasive belt increases， the contact area of different steel rail profiles increases logarithmically， and the position of the axis length radius of the contact area changes on different cross-sections. Based on the characteristics of the rail abrasive belt grinding process， a calculation model for heat flux density in the contact area was solved and theoretically verified. Based on the contact area grinding depth and profile calculation， and regional heat flux density calculation model solved above， the instantaneous point heat source temperature field， continuous point heat source temperature field， and continuous action moving point heat source temperature field were applied to discretize the temperature field of the continuous action moving surface heat source in the contact area. Research shows that under the set grinding process parameters， the simulation and theoretical temperature changes on the surface of rail grinding are similar and almost reach the maximum temperature at the same time. The relative error between the simulation and theoretical maximum temperature is 6.14%， which verifies the correctness of the above theoretical model and simulation.

Abstract:Because of the lack of an accurate mathematical model of oxide scale removal and process parameters in slurry blasting， the oxide scale of the Q235 hot rolled strip is taken as the research object in this article. According to the energy conservation principle， the kinetic energy change law of the mixed slurry of abrasive particles and water in the slurry blasting process during the impact was analyzed. The strain energy change law of the oxide scale on the surface of the matrix after the slurry blast was analyzed based on the strain energy theory， the mathematical model between the oxide scale removal amount and the slurry blasting process parameters was established， and the finite element ANSYS/ AUTODYN module and smooth particle hydrodynamics are used to simulate the process of oxide scale and matrix deformation during the slurry blasting process. Finally， the integrated descaling test platform is used to carry out the slurry descaling test. The results show that the oxide scale cracks and peels off when the oxide scale strain on the substrate surface is higher than the critical strain， the ratio of the influence of abrasive particle size on the increase rate of impact range to the impact velocity is 105.35%∶24.14%， the ratio of the influence of abrasive particle size on the increase rate of impact depth to the impact velocity is 233.67%∶5.86%， the maximum deviation rate between the finite element calculation and experimental results in the impact range is 8.71%， and the maximum deviation rate of impact depth is 8.55%. The finite element calculation results are consistent with the experimental results， and the model applicability is verified by the results of 304 stainless steel and 45 steel slurry descaling tests.

Abstract:Aiming at the environmental pollution of the polishing solution in chemical mechanical polishing， a single-crystal SiC chemical mechanical polishing method based on metal electrochemical corrosion is proposed. The Si surface of single-crystal SiC corrosion performance and wear performance of electrochemically corroded were investigated by corrosion experiments and wear experiments. By comparing the corrosion performance of Al， Cu， and Fe metals on the Si face in a Na2SO4 electrolyte solution， it was found that only Al can generate a noticeable corrosion layer. The EDS and XPS analyses of the Si face confirmed that the corrosion is due to the formation of the SiO2 layer. Frictional wear experiments were conducted to investigate the influence of solution composition on the wear behavior of Si face. Increasing the concentration of the Na2SO4 electrolyte solution resulted in higher wear， with a maximum wear value of 7.19 μm2 obtained in 1.00 mol/L Na2SO4 electrolyte solution. In an acidic corrosive solution， the Si face exhibited the highest material removal， with a wear value of 11.97 μm2 achieved at pH=3. The material removal mechanism of single-crystal SiC via metal electrochemical corrosion involved the corrosive reaction involving Al at the cathode， which generated a corrosion current， and the subsequent oxidation of the SiC surface at the anode， thereby forming a SiO2 oxide layer leading to material removal.

Abstract:In the laser additive manufacturing process of superhard tools， diamonds are highly susceptible to the direct irradiation of laser beams and the influence of high-temperature melt pools， leading to phenomena such as graphitization and other thermal damage. A typical metal bonding agent CuSn10 powder for diamond abrasives is selected， and the Powder Bed Fusion-laser Beam （PBF-LB） technology is used to prepare CuSn10-diamond composites in this study. Focusing on two key factors affecting the performance of diamond particles in the manufacturing process， high-energy laser beams and high-temperature melt pools， individual diamond particles are selected as the research subject. A finite element simulation analysis is conducted to construct a temperature field model of diamond particles， reflecting the thermal evolution process of diamond particles in PBF-LB. The study elucidates the thermal damage mechanism of diamonds during the PBF-LB process， revealing that the graphitization transformation of diamonds is not caused by direct laser irradiation but is induced by the thermal effects of high-temperature melt pools. The critical temperature for graphitization of CuSn10-diamond composite material in the PBF-LB process is 1 491.6 °C. Furthermore， a quantitative relationship is established among the PBF-LB process-diamond particle temperature-degree of graphitization-frictional wear performance， demonstrating that with the increase of diamond particle temperature， the degree of graphitization increases， seriously damaging the friction and wear performance of the composite material.

Abstract:The material characteristics of silicon carbide substrate， which are difficult to machine， coupled with its amplification effect of large-sized and ultra-thinned， pose a huge challenge to existing processing technologies. Consequently， the processing technology of high efficiency and high quality for silicon carbide substrate has become a current research focus. In this paper， the research progress of mechanical and chemical grinding and polishing technology for silicon carbide substrates is reviewed. The characteristics of various grinding and polishing technologies are compared. The challenge and development trend of grinding and polishing technologies of silicon carbide substrate is pointed out to provide new ideas and methods for high quality， high efficiency， and low-cost processing of large-size silicon carbide substrate.

Abstract:The structural deformation generated by multi-source heterogeneous decommissioned 3C products in the service stage may cause the failure of automatic disassembly equipment. The performance drift failure will also disturb the disassembly process planning and production scheduling. Taking the decommissioned 3C product mixed-flow disassembly line as the research object， this study investigates the insertion order scheduling problem caused by decommissioned product disassembly failure in decommissioned products. An AND/OR node network model is constructed to quantify uncertain disassembly sequence and depth. With the optimization goal of maximizing workstation utilization and the variable of disassembly fault product buffering and transfer threshold， a mixed manual-automatic line reordering schedule model is established. Then， it is encoded by two-dimensional real-number coding and solved by a genetic algorithm. Finally， data instances of 58 varieties of decommissioned smartphones with mixed manual-automatic disassembly lines are selected for verification. The results show that the established manual-automatic hybrid line scheduling model can effectively develop the threshold scheduling scheme of maximum workstation utilization. The optimized maximum utilization rates of the three types of mixed-flow disassembly lines in the example clustering are 80.3%， 73.2%， and 81.3%， respectively.

Abstract:Aiming at the uncertainty of disassembly processes and logistics， an optimization method for the production and logistics integrated scheduling in a disassembly workshop is proposed to cooperatively optimize efficiency and cost. Firstly， the interaction factors between reverse production and reverse logistics in end-of-life product disassembly workshops are analyzed. A multi-objective scheduling model of the workshop is constructed， aiming at optimizing the maximum completion time and the advanced/delayed costs in reverse production and workshops logistics processes. Secondly， based on the logistics route decision， a mutation operator with gene repair is designed to improve the mutation accuracy of the NSGA-Ⅱ algorithm and enhances the solution effectiveness of the algorithm. Finally， taking a company's mobile phone disassembly line as an example， the multi-size production and logistics examples are analyzed. The results show that as the number of adaptive guided vehicles increases， the delay cost of large and small size examples are reduced by 57.1% and 58.3%， respectively， verifying the effectiveness of the model.