In this study, the abrasive grains of a brazed diamond wheel were the first to undergo pulsed laser texturing experiments, successfully fabricating low-damage, regularly arranged surface textures on the grain surfaces. Subsequently, a theoretical model of single grain cutting thickness (agmax) for textured abrasive wheels was established, elucidating the variation patterns of two distinct agmax with grinding parameters. Finally, experiments involving the grinding of WC/6Co were carried out. The impact of these textured patterns on the wear characteristics of textured grains and the grinding surface of WC/6Co was analyzed. The material removal mechanism of WC/6Co grinding was revealed, and the effect of grain texture types on surface roughness was clarified. The results demonstrate that texturing the abrasive grains of the brazed diamond wheel significantly improves the material removal mode for WC/6Co, inducing a transition from the brittle removal to the ductile removal. The ranking of surface roughness (Ra) values for wheels with different textures was: non-texture > square texture > 45°texture > 0°texture > wave texture > rhombus texture. The significance of this study lies in designing and fabricating micro-textures on abrasive grains, so as to facilitate the plastic removal of cemented carbide materials and improve ground surface quality.

In response to the escalating demand for functional surfaces in marine applications and aerospace, this study investigates the precision fabrication of microstructured surfaces on TC6 using structured diamond grit tools. A novel kinematic model is developed to reveal the formation mechanisms of microstructures, integrating numerical simulations and experimental validation to optimize critical cutting parameters. The simulations reveal that increasing the tool-workpiece speed ratio enhances periodicity and reduces the overlapping effects of microstructures. Controlled feed speeds (20–100 rpm) ensure uniform separation distances between microstructures. Experimental results demonstrate that the distribution of microstructures is determined by the interplay between speed ratio ( v s / v w ) and feed speed ( f ). And their topographies are dominated by the dynamic morphology of the diamond grit. Notably, the proposed methodology contributed to the fabrication of microstructured arrays with controlled depths (7–15 μm) and good consistency. This work deepens the understanding of the distribution of microstructures and provides a scalable solution for fabricating arrayed structured surfaces.

Structured wheels exhibit significant potential for surface microstructuring while reducing grinding forces and temperature. Due to theheterogeneity and high hardness of the CBN wheel, achieving efficient and precise microstructures remains a significant challenge. In this paper, a temperature-dependent material removal model combined with experiments was executed to explore the nanosecond laser ablation mechanism of CBN wheel microstructuring, where the heat diffusion, the temperature-dependent material removal, the spatial distribution, and the composition of the CBN wheel are taken into consideration. The CBN wheel, comprising grits, ceramic binder, and inherent voids, was reconstructed by 3D convolution based on the measured 3D topography, and the spatial variation characteristics of material properties were explicitly explained. A series of laser ablation experiments was then undertaken. The surface topographies of the CBN wheel predicted by the theoretical model are consistent with the experiments. The structured strategy was formulated by keeping the consistency of energy density and radiation temperature to fabricate different microstructures. The shapes of lines, rectangles, trapezoids, hexagons, circles, and ellipses were of high accuracy and good consistency, where clear geometric textures of sharp edges were achieved.

Titanium alloys are widely employed in aerospace and medical applications due to their excellent mechanical properties. Surface microstructuring has been demonstrated as an effective approach to enhance its functional performance. Fabrication of microstructure surfaces on TC6 alloy remains challenging due to the limitations in efficiency and precision. In this work, surface micro-structuring of TC6 based on laser structured wheel was proposed to address the problems. Initially, a nanosecond pulsed laser was employed to precisely fabricate the abrasive units on the CBN wheel. Subsequently, a microstructure simulation model integrating the topographies of laser structured wheel and dynamic contact mechanics was developed to simulate the generated surface morphologies and grinding forces. In the theoretical model, the wheel topography was reconstructed by convolution operations to account for grain randomness and wear evolution, and the grain-workpiece interactions, including rubbing, plowing, chip formation and pile-up effects were further analyzed to achieve accurate prediction of microstructure topographies and grinding forces. Finally, the wear of the structured wheel and its influence were quantitatively investigated. The theoretical model and experimental results provide guidelines for designing structured wheels and optimizing grinding parameters in high efficiency and precision manufacturing of microstructures.

The high-pressure phase transformation behavior of monocrystalline silicon is extensively investigated, with the resulting amorphous phase enabling plastic processing. However, the microscopic mechanisms of its plastic deformation under cyclic loading remain poorly understood. Through systematic cyclic nanoindentation experiments, we find that cyclic loading raises the critical load for the transition from Si-II phase to Si-III/XII phases, thereby promoting continuous amorphous phase accumulation in the indentation zone. This shift in the phase transformation pathway leads to an increase in free volume within the amorphous phase, facilitating the formation of shear bands and enabling coordinated shear deformation. Ultimately, the rearrangement of atomic bonding induces pronounced plastic flow beneath the indenter. Our work reveals an amorphous-phase-mediated plastic deformation mechanism in monocrystalline silicon under cyclic loading, linking microscopic phase evolution to macroscopic deformation, and offers a theoretical basis for understanding its plastic behavior in ultra-precision machining.

In micro-cutting, microstructure induced anisotropic properties highly affect the machinability of materials because the removal amount is almost on same level as the size of microstructures such as grains and phases. In this paper, cutting force fluctuation induced by different phases is theoretically and experimentally investigated in the micro-cutting of dual-phase Ti6Al4V alloy. Particularly, a significant change of cutting force was observed as the tool traverses phase boundaries. Furthermore, the mechanism of the variation of cutting forces is discussed from perspectives of crystallographic orientation, critical resolved shear stresses and slip systems. Constitutive model and geometrical relationship between the tool and workpiece are also proposed to analyzed the resolved shear stresses of phases with different crystallographic orientations. The results agree well with experimental data, indicating that activation of various slip systems is directly determined by the values of corresponding resolved shear stresses. Additionally, cutting force fluctuation is primarily attributed to the change of slip systems at phase boundaries in the micro-cutting. The main findings of this study present the significant role of crystallographic orientations and slip systems in governing cutting force fluctuations at phases and phase boundaries, which provide valuable insights for optimization of cutting parameters in machining of titanium alloys.

Precise photolithographic patterning on titanium alloy is critical for functional microstructures via etching in aerospace and biomedical applications. However, achieving high fidelity is challenged by complex parameter interactions. To address this gap, this study proposes an intelligent framework for optimizing photolithography parameters on Ti6Al4V alloy surface. The study employs an integrated data-driven approach combining orthogonal experimental design, Spearman's rank correlation coefficient, and support vector machine (SVM) modeling. Analysis of four key parameters revealed that exposure time was the dominant factor positively influencing pattern fidelity, followed by development time, which also showed a significant positive effect. In contrast, prebake temperature exhibited a weak negative correlation, while spin-coating speed demonstrated a minimal positive influence. A K-fold cross-validation optimized SVM model achieved high prediction accuracy, with 91% on the training set and 90% on the test set, for development state classification. This machine learning framework enables intelligent parameter optimization. By accurately predicting pattern states and pinpointing key controls, it provides a robust foundation for subsequent precision microstructure fabrication, enhancing reliability and yield in critical industries.

The complex coupling effects between the microscopic phase microstructures of dual phase titanium alloys severely restrict their processing efficiency and performance of high-precision components. Currently, there is still a lack of quantitative research on the correlation mechanism between material characteristics such as dual phase fractions and surface integrity. Therefore, this study aims to regulate the dual phase composition of Ti6Al4V alloy through heat treatment processes and explore the influence of different phase fractions on the surface integrity of workpieces in ultra-precision diamond turning. The results show that the microstructural characteristics of the materials highly affect their macroscopic turning performance. In detail, the standard deviation of cutting force fluctuations significantly increases as the content of (3 phase increases. Surface integrity characterization reveals that the surface integrity decreases with the increase of (3 phase content, manifested by degraded machined surface quality, increased surface roughness, and reduced microhardness. Besides, a physics-based constitutive model incorporating dual phase characteristics is proposed which successfully simulates machining dynamics, achieving favorable consistency of 94 % with experimental cutting forces. The findings establish dual phase composition as a critical parameter for surface quality optimization, which provide theoretical foundations for high-precision titanium manufacturing and enable customized machining strategies through microstructural engineering.

The brazed diamond grinding wheel with orderly arranged grains exhibits excellent performance in efficiently processing hard and brittle difficult-to-machine materials owing to its high exposure height, holding strength, and grinding ratio. However, there are many challenges in achieving high efficiency and precision dressing of brazed diamond grinding wheels and improving the grinding surface quality of hard and brittle materials. In this study, firstly, laser trimming experiments were conducted on a brazed diamond grinding wheel, and an evaluation method for abrasive high equivalence of the grinding wheel was proposed based on the global data acquisition and image processing, the exposure height distribution of abrasive grains of the brazed grinding wheel was analysed comprehensively. Subsequently, pulsed laser texturing experiments were performed on the diamond abrasive grains of the brazed diamond grinding wheel. By optimising the laser scanning trajectory, a low damage and uniformly arranged surface texture was fabricated on the abrasive grains. Finally, grinding experiments was conducted on WC/6Co cemented carbide using the abrasive textured brazed diamond grinding wheel, where the wear characteristics of the abrasive textured brazed diamond grinding wheel were investigated and the influence of different abrasive texture types on the grinding surface quality and grinding force of WC/ 6Co cemented carbide was compared and analysed. In this study, low-damage textures were fabricated on the surface of large-grain brazed diamond grinding wheels to regulate the material removal mechanism in WC/6Co cemented carbide, providing valuable insights for grinding efficiency and accuracy.

Ultrasonic vibration-assisted grinding (UVAG) has made significant progress in improving the surface integrity of hard and brittle materials. However, the influence of ultrasonic overlap effect and ultrasonic motion trajectory on material removal mechanisms in monocrystalline silicon remains to be further understood, especially in microgrinding of through-silicon vias (TSVs). In this work, the ultrasonic overlap effect and ultrasonic motion trajectory on the damage inhibition mechanisms during ultrasonic vibration-assisted scratching (UVAS) of monocrystalline silicon is investigated, combined with Smoothed Particle Hydrodynamics (SPH) simulation. The average error of the normal force and tangential force of UVAS between simulation and test is 10.6 % and 13.2 %, which verifies the validity of the scratch simulation model. Subsurface damage and stress field analysis reveal that a high ultrasonic overlapping rate results in significant interference and overlap of ultrasonic stress waves, effectively suppressing the propagation of median cracks and reducing the depth of subsurface damage. Additionally, the ultrasonic overlap effect suppresses the offset of the stress field at the vibration angle of 0, thereby reducing the length of lateral cracks and improving edge damage. The achieved results provide valuable insights into the ultrasonic vibration-assisted machining of hard and brittle materials and offer significant implications for the machining processes of micro-holes.

GH4169 superalloy is widely used in the aerospace industry due to its high specific strength, excellent hightemperature oxidation resistance, good fatigue resistance, and superior creep strength. However, its high strength and low thermal conductivity result in severe tool wear and chip-breaking difficulties during the turning process. This leads to degradation in surface quality and a significant decrease in fatigue resistance. Highpressure cooling lubrication-assisted machining technology can enhance the machinability of this superalloy. In this work, finite element simulation is used to analyze the influence of various high-pressure cooling parameters (injection diameter, angle, and pressure) on chip formation, burr morphology, and tool wear during turning with a polycrystalline cubic boron nitride (PCBN) tool. Comparative experiments are conducted to investigate tool wear, chip morphology, and burr formation under dry and high-pressure cooling conditions, verifying simulation accuracy. The results indicate that dry turning produces long spiral chips and significant tool wear. In contrast, high-pressure cooling changes chip morphology from long to short spirals, reduces burr formation, and decreases tool wear. Optimal parameters include an injection pressure of 50 bar, an angle of 0 degrees, and a diameter of 1.6 mm, which lead to extended tool life, well-formed chips, and reduced burrs.

In this study, a prediction model of the surface texture of a single crystalline diamond ablated by infrared pulsed laser was established. Firstly, the laser ablation threshold of diamond was obtained through an experiment, and the energy accumulation effect of pulsed laser processing was analysed and simulated. By analysing the time distribution function and defocusing variation function of pulsed laser and by considering the height gradient change of laser energy density caused by the ablation curved surface, the surface morphology change function of diamond pulsed laser ablation was obtained, and the numerical simulation results of the surface texture of linear groove array, square groove array, rhombus groove array, wave groove array and circular groove array were realised. Results showed the groove depth and width, and the average relative error of the two were 12 % and 11.8 %, respectively, which were obtained by comparing the diamond ablation groove experiment with the simulation results. These results indicate that the numerical simulation can achieve a good prediction of the ablation groove profile and realise the surface texture processing with regular groove edges and consistent crosssection profiles.

This study presents a comprehensive multi-objective optimization of a diamond-based U-type counter-flow manifold microchannel heat sink (U-type CMMC) for ultra-high heat flux applications. A systematic optimization framework integrating Sobol sensitivity analysis, surrogate modeling, and NSGA-II algorithm was developed to simultaneously optimize thermal resistance, pumping power, and entropy generation. Analysis of five key geometric parameters revealed that fin width dominated thermal resistance (71.49 %), while microchannel width exhibited the strongest influence on entropy generation (75.24 %) and pumping power (52.18 %). The established BP neural network surrogate model achieved prediction accuracy exceeding 99 %. The tri-objective optimization incorporating entropy generation achieved 46.7 % reduction in thermal resistance and 25.2 % decrease in entropy generation compared to the initial design, while the bi-objective optimization scheme reduced thermal resistance by 44.1 % with only 13.3 % increase in pumping power. Temperature uniformity analysis showed that the optimized design significantly improved temperature distribution, with non-uniformity reduced by 34.82 %. This study provides valuable insights into the design optimization of high-performance microchannel heat sinks and establishes a robust methodology for multi-objective thermal management optimization.

This study numerically investigates the thermal performance of multi-stage Tesla valve microchannels (TVM) and a symmetric variant (SYMTVM) using single-phase deionized water, with mass flow rates ranging from 0.5459 to 1.6377 g/s. Both designs, particularly under reverse flow, exhibit lower peak temperatures and reduced temperature gradients compared to forward flow. The SYMTVM, characterized by its increased vortices and bifurcations, periodically disrupts and redevelops the thermal boundary layer, enhancing heat transfer efficiency. The TVM exhibits a significantly higher pressure drop than the SYMTVM across all flow conditions, with the reverse flow in TVM reaching up to 2.48 times that of forward flow and exceeding SYMTVM, especially at a peak flow rate of 1.6377 g/s. The performance evaluation criteria (PEC) and thermal resistance criteria (PECTR) demonstrate the superior performance of SYMTVM, with a reduced connection angle between the trunk and helix regions enhancing thermal efficiency. Furthermore, the SYMTVM-Reverse structure with a 30 degrees interconnection angle demonstrates superior performance compared to the conventional rectangular microchannel (RM), achieving a Nusselt number (Nu) that is five times higher than that of the RM and an overall performance up to 2.59 times greater. These results indicate the SYMTVM-Reverse's high heat transfer efficiency and its capacity to effectively balance thermo-hydraulic performance, even with increased power dissipation.

Objective CVD diamond is a hard and brittle material of wide applications,but the disordered arrangement of coarse grains in polycrystalline CVD diamond leads to uneven surface.The commonly used methods for CVD diamond processing are ultra-precision grinding and chemical-mechanical polishing,but generally of low efficiency and tool life.The efficiency of laser ablation depends on the optical and thermal properties of the laser,which provides a highly directional and localised energy source for diamond processing.Therefore,laser proessing is suitable for CVD diamonds with high hardness and wear resistance.It is necessary to study the influence of laser parameters on the surface morphology and surface damage to achieve the parameters optimization for nanosecond laser polishing of CVD diamond. Methods In this study,the surface generation process of laser ablated CVD diamond was firstly investigated by finite element simulation,and then the influence of laser processing parameter on the surface roughness and surface topographic characteristics of CVD diamond was investigated by single factor experiment.The surface roughness was measured using a 3D laser confocal microscope,and the surface topographic features of the workpieces were examined using a scanning electron microscope.The effects of laser incidence angle,laser power,laser scanning speed and scanning times on the surface roughness and surface topographic features of CVD diamond were achieved(Fig.6,Fig.11,Fig.14). Results and Discussions The results of finite element simulation(Fig.4)show that the incidence angles of the laser affect the polished surface,and the greater laser incidence angle,the smaller removal depth of the material.The laser polishing of CVD diamond were carried out with different laser incidence angles and powers,and the experimental results(Fig.6)were consistent with FEM.When the laser power is higher,the surface roughness of the material decreases with increasing incident angle,while the effect of the laser incident angle on the surface roughness drops significantly when the laser power is lower.The laser polishing of CVD diamond under different laser scanning speeds(Fig.11)shows that the surface roughness of the material decreases firstly and then increases with the growth of laser scanning speed.When the scanning speed was lower,the a great number of larger-size graphite grains and grooves formed(Fig.13),and when the scanning speed was higher,the surface turned to be relatively flat but with a lot of small cracks among the graphite grains.Finally,different laser scanning times of CVD diamond(Fig.14)show that the surface roughness of the material firstly decreases and then increases with the increase of the number of laser scanning times.A growing number of laser scanning times leads to a number of cracks on the diamond surface,which worsens the surface roughness(Fig.16). Conclusions In this study,the surface generation process of laser ablation of CVD diamond is investigated by finite element simulation and experiments,and the influence law of nanosecond laser processing parameters on the surface morphology and surface damage of CVD diamond is explored to achieve the optimization of nanosecond laser polishing parameters.The experimental results show that the increase of the laser incident angle can weaken the trapped light effect on the material surface,which can effectively improve the surface roughness of the material,and the greater laser incident inclination angle,the lower processing depth of the material surface.After nanosecond laser processing,a graphite layer is formed on the surface of CVD diamond,and surface grooves grooves and other damages appears when the laser power is higher,which can be suppressed by increasing the laser incident angle.The cracks on the surface of the material are attributed to the tensile stress in the graphite layer after cooling,and the size and number of cracks can be reduced by increasing laser incidence angle and decreasing laser power.Finally,the surface roughness(Sa)of CVD diamond dropped to be 1.3 μm by controlling the parameters,including laser incidence angle,laser power and laser scanning speed.

This paper investigates the material removal behavior of diamond/Cu composites by multi-passes infrared nanosecond pulsed laser ablation, focusing on the formed surface cracks, periodic ripples, profile evolution and deposition. Combining nanosecond laser ablation experiments with simulations based on thermophysical properties is then undertaken to effectively reduce the maximum thermal stress and inhibit crack initiation and propagation. Three types of cracks were identified in nanosecond laser ablation, which were influenced by the diverse thermophysical properties of the material and the temperature gradient. The periodic ripples of 300-1800 nm on the sidewalls of the machined groove on diamond grains were induced when the laser fluence approached the ablation threshold, which did not even appear on the copper matrix as the thermal effects dominate. The groove profile showed a limited change as the ablation passes further increase to be over 40 due to the plasma shielding effect inside the groove, the laser defocusing phenomenon and the increased difficulty of sputtering the molten material. In addition, the different ablation mechanisms of diamond and copper resulted in the formation of overlapping deposition layers with changed surface characteristics at varying laser energy densities. The uneven island-like recast layer affected the uniformity of the ablated grooves, which was dependent on the material microstructure and accumulated laser energy.

For the light weight and chemical stability, Ti-6Al-4V titanium alloy microchannel is an ideal element for fluids controlling, transporting and manipulating, which has been widely used in the aerospace field. However, the poor surface quality of machined microchannels and tool wear pose challenges to performance improvement. In this study, ultrasonic vibration-assisted milling (UVAM) of titanium alloy microchannels was investigated, comparing the effects of ultrasonic vibration amplitude, spindle speed, feed rate, and cutting depth on surface morphology, surface roughness, sidewall verticality, and tool wear with conventional milling (CM) processes. The results demonstrated that axial ultrasonic vibration can effectively improve the machined surface uniformity and reduce tool wear, resulting in a 29.06 % decrease in microchannel surface roughness and a 7.76 % increase in sidewall perpendicularity. This study lays the foundation for manufacturing high-quality Ti-6Al-4V titanium alloy microchannels and also expands the application of ultrasonic-assisted machining techniques in the field of microchannel manufacturing.

Monocrystalline silicon is the most widely used material in microchips, microsensors and photovoltaic systems, where ultrashort pulse laser has been applied in grooving and holing. This paper investigates the ablation mechanism of monocrystalline silicon by picosecond laser, where a TTM-MD (Two-temperature model-Molecular dynamics) model was established based on the interaction theory between ultrashort pulse laser and Si. The effects of plasma shielding and surface reflectivity on the laser irradiation energy are investigated to analyze the variation of carrier temperature, lattice temperature and carrier density on the monocrystalline silicon surface. The occurrence of material melting, bubble nucleation and phase explosion are simulated to explore the material removal mechanism and the effect of laser fluence on the ablation behavior. The simulation model was finally verified by the ablation threshold experiments where a high-speed camera was applied to monitor the ablation process.