Laser dressing of diamond wheels is efficient and versatile, but the graphite layer formed on grains by thermal effects introduces uncertainty in its impact on grinding performance. In this study, a mathematical model of diamond-graphite coupled grinding force (DGCGF) was established to elucidate the grinding mechanism when graphite acts as an abrasive and to predict the resulting grinding force. The model calculates the critical penetration depth of graphite grain and introduces graphite layer thickness as a key variable. The presence of the graphite layer alters the grinding mode of the diamond abrasives, thereby affecting the critical depths for plowing and cutting. Subsequently, experimental validation was conducted, along with an in-depth analysis of the coupled grinding interaction between graphite and diamond. The results show that the model predictions align well with experimental results. The graphite layer is found to reduce the sharpness of the abrasive grains, leading to an increase in grinding force with greater graphite layer thickness. Moreover, the graphite layer significantly influenced workpiece surface quality at lower grinding depths, resulting in more pronounced cracks and surface pits. This study not only establishes a grinding model for understanding the grinding performance of laser-dressed diamond wheels, but also offers new insights into the grinding mechanisms of multi-material abrasive grains.

This study focuses on the challenges of profiling accuracy during the laser dressing process of formed grinding wheels. It particularly pays attention to addressing the impact of the interpolation trajectory in laser dressing on the Relative Contour Deviation (Rcd) of the final formed contour. A method of adaptive cutting depth based on the Laser Single-pass Ablation Depth (LSAD) was proposed, and a mathematical model for dynamically adjusting the cutting depth at different allowance positions was established for the first time. This provides a practical foundation for optimizing the profile accuracy in laser dressing. As the basic parameters of the model, the numerical simulations of the laser power and feed rate on the LSAD were studied. Single-factor experiments further verified the reliability of the numerical calculations. A concave-surface, coarse-grained diamond grinding wheel was used as a test case, and verification and comparison experiments of dressing with new models were carried out. The research results showed that the model can effectively compensate for the differences in laser ablation and achieve a flatter formed profile. The verification and comparison experiments demonstrated that under the specified contour requirements and laser parameters, the method ensured that the Rcd is within the controlled range of 7 μm, and ensured that the contour edges are smoother. Compared with the control group and EDM method, the edge flatness is improved by 38.94

The small arc-shaped CVD diamond roller wheel has broad application prospects in the preparation of micro-structured cutting tools. However, CVD diamond material has good wear resistance, which makes it extremely difficult to dress its small arc-shaped profile. In this work, the oblique line interpolation tangential envelope method is proposed to dress the small arc-shaped CVD diamond roller wheel. This method utilizes the squeezing contact points of two rotating wheels on the dressing path to form the required small arc-shaped profile. This can simultaneously avoid uneven loss of the tool wheel and interference with the installation accuracy of the machine tool, improving the dressing precision of arc-shaped profile. The profile errors caused by different machine tool motion axis are analyzed. The corresponding profile error prediction models have been established. In order to improve the truing accuracy of CVD diamond roller wheel, a segmented arc compensation method is proposed. Finally, femtosecond laser processing technology is used to achieve sharpening of CVD diamond roller wheel. The abrasive particles have a suitable blade height to facilitate the excellent grinding performance of the roller wheel.

Laser technology is increasingly being applied to the dressing of diamond wheels, not only enabling high profile accuracy but also enhancing its grinding performance. However, diamond wheel is a super-hard composite material, diamond exhibits significantly different thermophysical properties from the bond. This disparity introduces considerable uncertainties in the laser processing of diamond grinding wheels. In this study, the phenomenon of grain burial was first observed in a nanosecond laser sharpening bronze-bonded diamond wheel. Even with sufficient removal depth of the bronze bond, the diamond grains did not protrude as expected but instead ended up below the bond plane. It caused unstable grinding behavior, increased wheel clogging, and reduced grinding quality. Through detailed analysis of the changes in the wheel's surface morphology, the mechanism of laser sharpening was uncovered and the reason for grain burial was identified. This phenomenon is strongly influenced by the laser power input and the differences in thermophysical properties between diamond and bronze. Further increasing the laser power to 30 W, exceeding the theoretical value, effectively addressed the grain burial issue. At last, the subsequent strategy using a 5 W low-power laser cleaning was also proposed to mitigate the associated thermal effects resulting from high power.

ObjectivesIn today's information age, the semiconductor industry, as one of the core fields of modern science and technology, is booming at an astonishing speed. However, in the process of rapid development, a problem that can not be ignored has gradually emerged. That is, the processing technology and equipment of key wafer chamfering grinding wheels have been monopolized by foreign countries for a long time. This not only poses a major challenge to the independent development of Chinese semiconductor industry, but also limits the diversified development of the global semiconductor industry to a certain extent. The multi-micro-groove diamond grinding wheel has become the best choice for achieving high-quality wafer chamfering due to its excellent performance, which has high hardness, high wear resistance and high precision characteristics, and can achieve efficient and precise processing during wafer chamfering to ensure wafer quality and performance. However, the processing technology of multi-micro-groove forming diamond grinding wheel has always been a difficult problem in the industry, involving the complex material technology, the processing technology, the precision measurement technology and many other fields. To this end, the electrical discharge machining (EDM) finishing platform is set up, and the EDM finishing method is used to process the high-precision multi-micro-groove forming diamantine wafer chamfering wheel, and the finished wheel meeting the requirements is obtained.MethodsBy using the EDM dressing method, the influences of dressing factors such as voltage, discharge current and pulse width on the discharge rule are explored one by one. The orthogonal tests are carried out on their effects on the shape, contour accuracy and surface machining quality of the grinding wheel, and the combination of process electrical parameters for grinding wheel finishing is obtained and verified.ResultsThe optimized process parameter combination for grinding wheel dressing is the voltage of 50 V, the discharge current of 3 A and the pulse width of 40 μs. Under this combination of parameters, the surface of the grinding wheel finally obtains a qualified groove type with the groove depth of 596.35 μm, the circular arc radius of 178.72 μm and the groove angle of 44.25°. The smoothness of both sides of the groove is good, the edges are neat and clear, the scratches are fine and uniform, and there are no obvious burrs or edge breaks on the surface. Additionally, there are no cracks or thermal deformations on the grinding wheel surface.ConclusionsThis study provides theoretical basis and process test reference for EDM dressing of chamfered grinding wheel, and promotes higher quality and wider application of this method in the field of grinding wheel dressing. In addition, through the performance test of the graphite wafer chamfering grinding wheels after dressing, it is found that the high precision formed grinding wheel obtained by dressing has good practical value and application prospect.

This study investigates femtosecond laser helical drilling and milling of film cooling holes in nickel-based superalloy using a self-built optical platform. The multistep drilling method based on a single laser spot was proposed to fabricate small holes with a diameter of approximately 0.4 mm. Comparative experiments with conventional one-step drilling demonstrated the advantages of the multistep method: improved hole roundness, eliminated spatter and attachments, reduced ablation color zones, and yielded hole surfaces with continuous edges and no obvious recast layer, among other benefits. Key quality determinants include clearance hole diameter, single-step material removal thickness, and laser repetition frequency. When the laser repetition frequency is 100 kHz, the clearance hole diameter is 100 mu m, and the material removal thickness of the final step is approximately 20 mu m (equal to the laser spot diameter), the optimal microhole processing quality can be achieved. The multistep milling method based on a circular laser beam was proposed for milling large holes. The two-step method of layer-by-layer interpolation can achieve nearly the same processing quality as multistep drilling for a small hole. The interpolation trajectory and cutting width play a key role in the processing quality of the porthole and sidewall. The expansion allowance is set to slightly less than the diameter of the focus spot, approximately 0.02 mm, which can achieve dual improvements in processing efficiency and quality in the two-step method. The proposed methods and parameters for improving the quality of porthole and sidewall have important guiding significance for improving the service performance of turbine blades.

The demand for modern lightweight design has increased the need for variable cross-section holes in functional components. However, conventional mechanical drilling and two-dimensional or 3D dynamic-focusing galvanometer scanning drilling, are difficult to process such holes in carbon fiber-reinforced plastic (CFRP) laminates due to tool-geometry constraints and the fixed laser angle of incidence (AOI). Herein, this study introduced a novel femtosecond laser-based method for fabricating stepped holes in CFRP laminates by utilizing a five-axis galvanometer system capable of dynamic incident-angle adjustment. A critical laser fluence distribution mechanism was demonstrated both theoretically and experimentally, showing that increasing the laser angle of incidence (AOI) from 1 degrees to 9 degrees enhances the deep-hole laser fluence by 157.84%. This significant increase directly counteracts the occlusion effect of the sidewall taper, fundamentally explaining factor that a five-axis galvanometer system is able to reduce the sidewall taper from 38.3 degrees to 1 degrees. Furthermore, the transition from thermal ablation to thermo-mechanical removal is also governed by laser fluence. In the thermo-mechanical removal process, the ejection speed of fibers and particles reaches 34.83 m/s, which subsequently affects the uniform distribution of spot energy. As the laser spot diffuses along the hole depth, the fluence decreases to 93.03% of its initial surface value at a depth of 1.5 mm, resulting in taper accumulation. These lead to a gradient spot energy distribution, which in turn induces the formation of a gradient sidewall microstructure, and this structure is further influenced by the fiber orientation. It can be addressed by increasing the AOI to improve the effective energy distribution and maintain uniform removal. These findings demonstrate that dynamic AOI control can adjust the laser fluence distribution to overcome geometric constraints and material heterogeneity, offering a promising approach for the high-quality laser machining of stepped hole in CFRP laminates.

This paper presents a deep learning method for real-time detection of key parameters in bevel grinding wheels, capable of fitting the required curves based on the keypoints and directly providing the key parameter values. Grinding wheel profile images were captured using a custom-developed grinding wheel dressing machine and the Grinding-Pose dataset was created. To improve the accuracy of keypoint annotation, we designed the MAF module, KPSEF module and QLIoU loss function, tailored to the specific characteristics of the grinding wheel, and integrated them into the network. Experimental results demonstrate that YOLO-QLPose significantly outperforms state-of-the-art methods in keypoint detection. Furthermore, it can generate an evaluation result for a grinding wheel in just 11 s, far faster than the industry-standard GGPD method which requires 6 min. The lightweight architecture and robustness of YOLO-QLPose make it ideal for deployment in complex industrial environments, particularly in high-end manufacturing sectors where high-precision, rapid response for grinding wheel key parameters is essential. The related code is available at https://github.com/meihuoAI/YOLO-QLPose.git.

In laser dressing of grinding wheels, the laser "tool tip" position, instantaneous efficiency, and accuracy represent the key control factors (KCFs) for achieving automated dressing and high-precision compensation, significantly influencing both real-time process response and final grinding performance. However, elucidating the underlying relationships between these factors and the dressing process remains a formidable challenge in contemporary research endeavors. To this end, a novel hybrid-driven surrogate framework has been developed, integrating a data-driven pathway, a knowledge-driven pathway, and a feature fusion-output module. The data-driven pathway was constructed based on laser dressing experiments, with the process parameters defined according to the most commonly adopted manual compensation strategy-machine tool motion. Moreover, a high-precision machine vision system was employed to quantitatively characterize KCFs, including the depth of laser single-pass ablation (D-LSA), rate of laser single-pass ablation (R-LSA), and width of contour fluctuation zone (W-CFZ). The knowledge-driven pathway was established through computer simulations of laser ablation thermodynamics and calculations of spot overlap ratios. Subsequently, a methodology for multimodal and hierarchical feature fusion was proposed. To optimize the output strategy, ablation experiments were conducted based on various traditional machine learning (ML) models: SVR, BPNN, XGBoost, large language models (LLMs): GPT-4o, DeepSeek-R1, as well as driving mechanisms. The results indicate that hybrid-driven traditional models exhibit the most competitive performance in terms of prediction accuracy. This is evidenced by the fact that the optimal R-2 values for each KCF (R-2 > 0.988 for both D-LSA and R-LSA, and R-2 = 0.898 for WCFZ) were all achieved within the hybrid-driven groups. The integration of LLM with traditional models further enables semantic interpretation of process modeling, with minimal compromise in predictive accuracy. Finally, this study demonstrates that information fused from fundamental physical mechanisms and process regularities exhibits strong adaptability to ML models when predicting KCFs in laser dressing, along with excellent generalizability across wheels of different specifications (bronze bond, 70# 100 %, 140# 125 %, and 200# 100 %), thereby establishing a robust foundation for process planning based on material response and for extending classical Computer Aided Manufacturing (CAM) theory into the field of laser dressing.

The helical drilling process exhibits significant potential for applications in the drilling of high-temperature alloys and carbon fiber reinforced plastic (CFRP) laminates. However, due to the limitations of the optical modulation, the current helical drilling technique is exclusively applicable for small-hole machining with diameters less than 1 mm. Given this, an eccentric helical drilling process for machining large holes in CFRP laminate has been proposed. High-quality 10 mm diameter holes with an average hole taper of less than 0.6 degrees have been successfully drilled in 6.2 mm-thick CFRP laminates. The integrated theoretical and experimental analysis revealed the formation mechanisms of hole taper and heat-affected zone (HAZ), and their correlations with microscopic morphology and fiber-orientation dependent quality under different laser deflection angles and helical rotary speeds. Results show that increasing the deflection angle to 3 degrees enhances laser fluence by 78.15 % compared to 0.5 degrees, effectively mitigating taper and HAZ caused by hole sidewall obstruction. At 7000 rpm and 3 degrees deflection, rotary speed has limited effect on taper reduction but enables rapid material removal and suppresses heat accumulation, reducing HAZ by 49.33 % at the entrance and 82.14 % at the exit. Larger deflection angles reduce sidewall defects (e.g., adhesive resin, interface cracking, fiber fractures), while higher rotary speeds improve kerf uniformity through enhanced polarization consistency and geometric independence of the laser beam. These advantages highlight the potential of the eccentric helical process for drilling large holes in CFRP laminates.

Laser etching technology has the advantages of high efficiency and high precision, and can be used to etch micro textures on the surface of PCD materials. However, nanosecond laser etching has serious thermal damage defects, significantly reducing tool durability. In this work, spray assisted laser etching is regarded as a promising new method. The objective of this study is to investigate experimentally the groove morphology of PCD materials under different laser pulse energies and input energy densities. Firstly, the spray assisted laser etching technology is theoretically analyzed, and its processing advantages are shown from the material removal mechanism. Then, the influence of average power, repetition rate, scanning speed, scanning frequency, and pumping water volume on the groove morphology was studied through single factor experiments. By combining appropriate process parameters, a substantial amount of material with thermal damage should be removed. In addition, it is found that spray assisted laser etching effectively inhibits the formation of recast layer, reduces the disorder structure of graphite, and significantly improves the processing quality. Finally, based on the above optimized process parameters, a variety of micro textures without recast layer and with complete structure were successfully obtained by using this new technology. The above research results indicate that the spray assisted laser etching technology can effectively reduce or eliminate the thermal damage defects on the surface of PCD materials.

This study focuses on the challenges of improving profile accuracy and surface quality during the laser ablation profiling of formed grinding wheels. A holistic strategy for laser profiling based on multi-mode active compensation is proposed, which breaks through the accuracy limits of traditional constant-speed laser scanning in grinding wheel dressing. It provides an in-depth analysis of the dynamic nonlinear processes during laser scanning and proposes a set of scanning speed compensation equations. It also identifies the phenomenon of differential accumulation of the metamorphic layer following nonlinear scanning and proposes a comprehensive compensation model that integrates deep-cutting with trajectory deformation. This strategy simultaneously resolves a fundamental theoretical flaw inherent in conventional scanning processes. The proposed strategy enhances the edge profile accuracy, reduces the contour wave band width (B), minimizes the metamorphic layer, and increases the chip space on the wheel surface. For the first time, a mathematical model for dynamically adjusting the scanning speed is established, alongside a trajectory deformation equation to correct for inherent path inaccuracies. Additionally, a novel framework is proposed for the comprehensive characterization of grinding wheel profile fidelity, addressing both global and local accuracy. Preliminary tests on a coarse-grained diamond flat wheel validated the method's effectiveness. Comparative experiments using a concave-profile wheel were conducted, analyzing the material ablation process and theoretical limitations of tangential paths. The study investigated factors affecting the single-pass ablation depth (Dls) and the growth inhibition of the wave band width. Results indicate that the feed rate compensates for Dls, while defocus amount and cutting depth strongly inhibit wave band growth. The deformed laser scanning strategy effectively removes the surface metamorphic layer while sharpening the wheel surface, improving abrasive protrusion. Quantitative validation experiments demonstrate that the novel MMAC-based truing strategy achieves superior contour accuracy under optimized parameters. Specifically, the Relative Contour Deviation (Rcd) is maintained below 4 mu m, while the Contour Similarity Loss (Lcs) is restricted to within 1 mu m. This represents a substantial improvement over conventional methods in both local surface profile fidelity and global geometric conformity. The wave band width was reduced to below 5 mu m, a 28.95% reduction, indicating effective growth suppression. Nominal dimension errors were within 3%, and surface observations confirmed increased binder exposure and abrasive protrusion, reducing chip space occupation. This study demonstrates significant advantages in laser active compensation, providing a critical reference for high-precision, high-quality dressing processes. The strategy is extendable to general laser profiling applications.

AISI 4340 alloy steel is widely used in critical aerospace components due to its high strength, yet achieving superior surface integrity during high-efficiency grinding remains a challenge. This study systematically investigates the formation mechanisms of microscopic defects (including micro-cracks, pits, and regional burns) and their suppression strategies in high-speed grinding. Using a #100 grit CBN wheel, the evolution of surface roughness (Ra), micro-morphology, and residual stress was analyzed across a speed range of 40–150 m/s. Results demonstrate that at vs ≥100 m/s, the material removal transitions to a stable regime where Ra stabilizes within 0.38–0.54 μm. Residual stress analysis reveals a consistent compressive state, which is fundamentally governed by a synergistic thermomechanical balance: the “thermal lag effect” at ultra-high speeds restricts intense heat to a shallow surface layer, allowing mechanical reinforcement to dominate. Furthermore, the specialized fully synthetic fluid effectively suppresses Fe2O3 oxidation by breaking the aerodynamic airflow barrier. Based on these mechanistic insights, an integrated control strategy (vs>100 m/s, f ≤ 400 mm/min) is proposed. This research provides a robust scientific basis for the precision grinding of high-strength alloys, ensuring defect-free surfaces while maintaining high removal efficiency.

Laser profiling has become the mainstream technology for high-precision dressing of formed grinding wheels. However, the widely used Tangential Scanning Model (T-SM) suffers from inherent flaws caused by the coupled mechanism of trajectory distortion, laser energy attenuation and forming deviation, limiting profile accuracy enhancement and resulting in insufficient abrasive grain protrusion. To tackle these issues, this paper systematically explores the influence mechanism of laser scanning direction on profiling performance, and proposes a novel Deforming-Contour Scanning Model (Dc-SM) through theoretical modeling, numerical simulation and experimental verification. This work first reveals the inherent defects of conventional tangential truing trajectories, and clarifies the governing laws of cutting depth angle and defocus distance on material removal and abrasive grain protrusion during laser ablation. A mathematical model and general compensation equation for hyperbolic profile distortion are established, realizing synchronous one-step truing and dressing. Results show that a deep cutting depth angle significantly increases abrasive grain protrusion height and optimizes wheel chip space, and the compensation equation effectively offsets laser energy attenuation to achieve uniform material removal. Comparative experiments confirm that Dc-SM outperforms T-SM in profile accuracy, with straightness and roundness stably within 5 μm. For 45° bevel profiles, Dc-SM yields an angle error of only −0.084°, a maximum 89.84% improvement in angle accuracy. The modified layer coverage of Dc-SM dressed wheels is comparable to conventional processes, with a gradient abrasive grain-binder interface. Its effectiveness is validated via flat wheel tests and industrial V-shaped concave chamfered wheel experiments. The proposed method shows outstanding advantages in accuracy control, efficiency improvement and surface optimization, providing a theoretical reference and engineering solution for high-precision laser profiling of formed grinding wheels, and enriching laser truing theory to promote the industrial application of high-end precision form grinding.

Pure copper is widely used in motor windings, heat exchangers and aerospace engines because of its high electrical and thermal conductivity. High-strength laser powder bed fusion (HS-LPBF) not only allows rapid production of components with complex geometry and high spatial resolution, but also offers various advantages such as small focal spot diameter, fine powder, and small layer thickness, providing advantages for forming complex structural parts in fields such as engines and heat exchangers. A single factor single layer experiment was performed by varying the hatch spacing (H), and the range of hatch spacing was determined according to the overlap rate. The degree of influence of process parameters on the relative density of pure copper specimens was analyzed using an orthogonal experiment, and a comparative study of the phase composition, microstructure and mechanical properties of pure copper specimens was carried out by varying the laser power. The characteristics of pure copper formed by HS-LPBF were analyzed. In addition, the effect of heat treatment on the microstructure and mechanical properties of pure copper specimens was investigated, and the fracture morphology of the specimens was observed comparatively. The results show that the HS-LPBF technique can effectively increase the energy density and improve the specific surface area of the powder and the laser absorptivity due to its small focal spot diameter, fine powder and layer thickness, thus reducing the minimum energy required to melt pure copper powder. The optimum process parameters were obtained by orthogonal experiment with a relative density of 98.1 % of the specimen. The highest hardness, ultimate tensile strength and elongation were obtained at a laser power of 260 W with 84 HV, 320 MPa and 17.8 %, respectively. This ultimate tensile strength is 18 % higher than the highest ultimate tensile strength that has been reported so far. In addition, the average grain size of the optimal specimens was 3.6 mu m. Mechanical properties such as hardness, tensile strength and elongation of pure copper parts can be significantly improved by precisely controlling the process parameters, in particular laser power and hatch spacing.

With the increasing demand for complex, functionally formed parts, there is an increasing demand for processing tools with complex shapes. However, the conventional dressing of shaped grinding wheels to create irregularly shaped parts is still expensive and inefficient. Therefore, a systematic study was conducted on the trimming of shaped ceramic diamond wheels using a laser with a large deflection angle (> 5°). The effects of different laser power and defocus on the ablation of ceramics and diamond were studied by simulation. The effects of different cutting depth and deflection angle on the dressing error and efficiency were studied. The simulation results show that the laser power cannot but the defocus can improve the removal difference between diamond and ceramic binder. With the increase of cutting depth, the dressing efficiency increases, and the quality of the trimmed surface decreases. The reason for the difference in precision between large and small cutting depth is attributed to changes in defocus, so the large-cutting-depth laser trimming with high efficiency can be used in the rough dressing stage. With the increase of deflection angle, the processing efficiency of the laser trimming bevel wheel increases, but the contour PV value increases. Therefore, a large deflection angle can be used for semi-precision dressing of the shaped wheel, and a suitable small deflection angle can be used for precision dressing. The best PV value of the straight contour of the shaped wheel was 10.3 µm using the method; the size error of the large arc contour was 24 µm; and the size error of the small arc contour was 17 µm. The total time required for laser dressing was approximately 3.6 h.

This study addresses the challenges associated with internal dimension and profile accuracy in the profiling of concave-surface coarse-grained diamond grinding tools, with a particular focus on solving the problems of thermal damage during laser truing and the significant wear and inefficiency associated with rotary dressing. A novel combination method of non-deflection laser rough truing, deflection laser semi-precision truing and rotary precision dressing was proposed. A mathematical model for deflection laser truing has been established for the first time, which is crucial for understanding and optimizing the truing process. Utilizing a grinding wheel intended for oil pipeline cutting tools as a test case, a combination experiment of laser truing and rotary dressing was conducted. The material removal and wear mechanisms were thoroughly investigated. The findings indicate that the thickness of the diamond's graphite layer and the thermal damage layer of the bronze bond is less than 5 mu m under the specified laser truing parameters, according to the analysis of the surface and subsurface materials. And rotary dressing effectively removes the thermal damage layer and the graphite layer when adjusted to varying dressing depths. The mathematical model confirms that the deflection laser is effective in compensating the power density loss caused by the contour changes of the grinding wheel. The combination experiment demonstrates that the laser can achieve a controlled material allowance of approximately 10 mu m. The thermal damage on the wheel can be eliminated by a rotary dressing allowance of 10 mu m. The combination method of laser truing and rotary dressing significantly minimizes tool wear and offers substantial advantages in terms of truing efficiency and dressing accuracy.

With the increasing industrial demand for the mechanical properties of SS316L formed parts, metal matrix composites have been widely used for their excellent mechanical properties. This study investigates the effects of SiC particle reinforcement (0-4 vol%) on high-precision laser powder bed fusion (HP-LPBF)-formed SiC/SS316L composites under optimized process parameters (laser power: 80 W, scanning speed: 751 mm/s, hatch spacing: 63 mu m). The surface morphology, phase composition, microstructure, mechanical properties, hardness, and laser absorptivity were systematically analyzed. The addition of 1 vol% SiC yielded an ultimate tensile strength of 650 +/- 11 MPa, representing a notable improvement over the unreinforced SS316L (515 +/- 4.5 MPa), while hardness values rose from 225 +/- 2.3 HV for pure SS316L to 271.6 +/- 12.1 HV at 4 vol% SiC. However, elongation decreased from 43 +/- 1.86 % to 21.8 +/- 2.5 % with 1 vol% SiC, reflecting a trade-off between strength and ductility. Laser absorptivity of the composite powder increased by 9.03 % compared to pure SS316L, enhancing energy utilization during processing. Microstructural analysis revealed substantial grain refinement, with average grain size reduced from 5.88 mu m (unreinforced) to 3.54 mu m (1 vol% SiC), accompanied by a marked rise in high-angle grain boundaries (M1 = 59.4 %, M0 = 38.5 %). These improvements stemmed from SiC-induced Zener pinning and heterogeneous nucleation. Notably, higher SiC content (>2 vol%) intensified defects, including a 35 % increase in pore density and elevated surface roughness (Ra = 43.27 +/- 1.4 mu m at 4 vol% SiC), which detrimentally affected tensile performance. The strengthening mechanism of SiC particles is due to their intrinsic physical properties and the alteration of the microstructure of the metal matrix. This work provides quantitative insights into optimizing SiC/SS316L composites for high-performance applications requiring tailored strength-hardness trade-offs.

Carbon fiber-reinforced plastics (CFRP) are widely used in the aerospace and other industries due to the exceptional mechanical properties. However, the outstanding properties in-reverse bring challenges in conventional drilling processes, such as rapid wear rate, burr formation. As an alternative processing method, laser drilling shows promise for machining CFRP efficiently while avoiding the aforementioned defects. In this review, the state-of-the-art techniques on the laser drilling of CFRP laminates are reported, and fundamental mechanisms in the material removal process, including the influence of energy input on machining precision, photothermal and photochemical ablation, the formation of thermal defects, and dynamic material expulsion processes, are comprehensively introduced. Furthermore, relevant achievements of theoretical modeling and numerical simulation are reviewed. These key findings indicate that adjusting the laser incidence angle eliminates hole taper, while lower power, higher scan speed, optimized spot spacing, and external cooling suppress heat-affected zone defects. Theoretical modeling and simulation offer unique visualizations of defect mechanisms and temperature distribution in laser drilling of CFRP laminates. This study also outlines potential scopes and future work, focusing on optimizing and balancing improved drilling efficiency with the limitation of the heat-affected zone.