Hole Taper Research Articles

Improving hole quality of thick CFRP laminates through a laser-mechanical compound drilling process

Conventional mechanical drilling of thick carbon fiber reinforced plastic (CFRP) composite laminates is prone to machining-induced defects such as burrs, delamination, and severe tool wear. However, pulsed laser drilling as an improved strategy results in hole taper and the formation of a heat-affected zone (HAZ). Herein, a new laser-mechanical composite drilling process is proposed, which combines the advantages of pulsed laser drilling for avoiding tool wear and twist drilling for achieving high dimensional accuracy, significantly improving the drilling quality of thick CFRP laminates. The evolution mechanism of the hole taper and HAZ with processing conditions in pulsed laser drilling is investigated. Furthermore, a theoretical model is established to reveal the material removal mechanism during the reaming process. The thrust force variation, drilling quality and tool wear are analyzed and verified by comparative experiments. The results show that due to the shielding effect from the surface materials, the maximum hole taper and HAZ at the hole exit reach up to 37.5° and 650 μm, respectively, which can be removed effectively by subsequent reaming operations. Due to its small amount of material removal, the peak thrust force and the average thrust force in laser-mechanical drilling are only 53.8 % and 37.6 % of the critical thrust force of delamination, respectively, which can effectively inhibit delamination. Compared with direct twist drilling, the average wear of the main cutting edge in laser-mechanical drilling is decreased by 60.87 %, which greatly reduces the size of the delamination by 55 %.

Femtosecond laser processing of controlled tapered micro-holes based on dynamic control of relative attitude

Femtosecond laser drilling of metal necessitates precise control over taper to ensure dimensional accuracy. However, conventional vertical incidence laser processing methods result in micro-holes with inherent taper and a beam waist at the midportion. To address this issue, this paper proposes a micro-hole machining method that involves adjusting the relative attitude between the laser beam and the workpiece, enabling controlled machining of micro-holes with varying tapers. The feasibility of the method is validated by simulating theoretical hole profile using an isophote model, which exhibit good agreement with experimental results. Experimental findings on nickel-based alloys demonstrate a linear correlation between the attitude angle and hole taper. By manipulating the attitude angle, it is possible to achieve controllable machining, ranging from positive taper to negative taper. This approach eliminates the waist within the micro-hole and enhances chip removal space, resulting in improved hole wall quality. Moreover, employing multi-attitude angle and dynamic attitude angle processing, in addition to single attitude angle control, effectively eliminates the core generated during drilling. This method prevents the exacerbation of multiple reflections caused by the core and the reduction of chip removal space, leading to enhanced energy coupling between the laser and the material in the ablation area. As a result, the maximum depth of the hole is increased, allowing for the realization of no tapered micro-holes on 5 mm thick nickel-based alloys. Furthermore, laser processing introduces a significant amount of dislocation structures in the microstructure near the hole wall. This study introduces a novel approach to achieve controllable taper in femtosecond laser drilling. It offers both theoretical and experimental support for understanding the hole shape evolution process in femtosecond laser drilling.

Experimental Investigation of the Machining Characteristics in Graphite-Powder-Mixed Electrochemical Discharge Machining of Microholes in Glass.

The effect of graphite powder on the machining characteristics in graphite-powder-mixed electrochemical discharge machining of microholes was still not clear. How the discharge mechanism changed with the addition of graphite powder into the electrolyte, which further led to changes in the morphology of the machined holes, remained to be revealed. In this study, a series of microhole machining experiments were conducted in glass. Comparisons of the discharge energy, microhole entrance diameter, hole taper, and tool electrode morphology after machining were made when machining in the electrolytes with and without graphite powder. Experimental results revealed that there were a lot of small pulse currents distributed on the current waveform when machining with the graphite-powder-mixed electrolyte. The average discharge energy of the small pulse current was 2.8 times as much as that of the general electrochemical discharge. After introducing graphite powder into the electrolyte, the entrance diameter of the hole became larger when the hole depth was deeper than 200 μm. The HAZ width increased with increasing hole depth at the voltage of 37-41 V, while it decreased at the voltage of 43 V. A reduction in hole taper angle with a range of 0.5° to 2.3° was achieved. In addition, after machining in electrolytes with and without graphite powder, the tool electrode surfaces showed different morphologies due to different discharges.

Dimensional accuracy enhancement of machined-hole through UAECDM-process under the magnetic-field-assistance

ABSTRACT Electrochemical discharge machining (ECDM) is a micro-machining hybrid technique that utilizes electrical discharge and electrochemical machining principles. However, the issue of insufficient electrolyte in the hydrodynamic region hinders the continuation of the machining action. Although ultrasonic tool vibrations have been used to overcome this problem to some extent, the excessive mechanical energy produced by high-amplitude tool vibration may lead to surface crack formations. As a result, the present work employs two flushing improvement methods, namely the ultrasonic vibrations and magnetic filed assistances, in the ECDM process. A comparative study has been performed to identify the effect of the magnetic field on discharge quality. The material removal rate and depth of penetration were increased by 11% and 24%, respectively, and the observed reduction in hole overcut and taper angle was around 35% and 50%, respectively. Optical microscope images quantified improvement in dimensional accuracy and decreased HAZ area.

Reducing the taper and the heat-affected zone of CFRP plate by Micro fluid assisted laser induced plasma micro-drilling

Carbon Fiber Reinforced Plastics (CFRP) with superior mechanical properties are widely used in aerospace, automotive, and medical fields. The characteristics of CFRP with anisotropy and inhomogeneous result in poor machining performances by conventional drilling techniques. Laser drilling is a non-contact high precision machining technique without tool wear but leads to a large heat-affected zone (HAZ) and taper. Although underwater laser drilling could reduce thermal damage on CFRP surface, bubbles produced in the machining process severely affect the machining stability and surface quality. In this study, a micro fluid-assisted laser-induced plasma drilling (MFA-LIPMD) method was proposed to relieve the negative effect of bubbles as well as reduce the taper and HAZ. A comprehensive analysis of hole surface quality, HAZ, taper, and mechanical properties was conducted, and MFA-LIPMD performed more advantages over laser in the air (LIA) and laser-induced plasma drilling (LIPMD). It was found that the taper of micro-holes was reduced by 42.8%–51.78%, and the thermal damage rate of micro holes processed by the MFA-LIPMD process was reduced by 65.3%–68.1% compared with the LIPMD process, and the maximum tensile load of samples was increased by about 7.68%. Therefore, MFA-LIPMD has great potential for machining high-quality micro holes of CFRP plates.

Failure analysis and improvement of a 42CrMo crankshaft for a heavy-duty truck

The crankshaft of a heavy-duty truck engine fractured and failed. The failure occurred in the left crank web of the seventh main journal. To investigate the cause of the crankshaft fracture failure, macroscopic fracture and microscopic morphological analysis, chemical composition and mechanical properties testing, metallurgical examination and numerical simulation methods were used to analyse the failure of the fractured crankshafts and to propose improvement measures. The results show that the crack source was located at the junction of the threaded bottom hole column surface and taper surface, and the failure mechanism was high cycle fatigue fracture failure. The main reason for the failure was the stress concentration caused by the lack of an obvious transition fillet at the junction of the threaded bottom hole column surface and taper surface, with the maximum stress value of 486.9 MPa. In addition, the metallographic structure transformation of the surface layer of the bottom hole sidewall (maximum depth of about 22 μm) caused by the high machining temperature also had an important influence on the fracture. The proposed improvement scheme of increasing the transition fillet and using an internal cold machining tool was proposed, and the feasibility of the proposed scheme was verified by a fatigue bench test.

The Effect and Process Parameters During Conventional Drilling and Abrasive Water Jet Drilling

In Drilling is the important machining process in manufacturing industry. Optimization of process parameters during drilling operation has been key research in recent times. Over the years, many methods were proposed for optimization of process parameters during drilling which are aimed to get good surface finish, good quality hole, good material removal rate etc. In this regard the present work focuses on comparative study on effect of process parameters during conventional drilling and Abrasive water jet drilling. In this particular work different process parameters such as Material, thickness, speed is taken. Experiments are conducted according to L9 Orthogonal array both on conventional and Abrasive water jet drilling. The final results of Material Removal Rate and Hole taper are subjected to statistical analysis in Minitab19 software and Regression Analysis whose results are analyzed and compared to give conclusions.

Parametric optimization of response parameter of Nd-YAG laser drilling for basalt-PTFE coated glass fibre using genetic algorithm

Composite materials are well-recognised in the automobile and aerospace industries due to their high strength-to-weight ratios. The orientation of fibres and anisotropic properties are gaining the attention of design engineers daily in different manufacturing industries. For stipulated requirements, hybrid composite materials can be developed. Hybrid composite materials have higher variations in the material; it’s difficult to machine using conventional methods. This manuscript reports the optimization of Nd: YAG drilling on basalt and PTFE-coated glass woven fibres hybrid composite material made with hand lay-up method using a genetic algorithm. The process control parameters considered for the laser drilling were lamp current, pulse width, stand-off distance and compressed air pressure. The average values of the top- and bottom-hole diameters were recorded to evaluate and optimise the hole taper. Optimized input parameters yielded were a lamp current of 180 A, a pulse width of 3 ms, a stand-off distance of 3 mm and compressed air pressure of 8 kg/cm2. The validation test of the optimized process yielded a hole taper angle of 0.00285°.

Ultrasonic-assisted electrochemical discharge grinding and broaching for machining quartz square microholes

A novel hybrid technology that ultrasonic-assisted electrochemical discharge grinding combined with in-situ ultrasonic broaching was used to process an array of square microholes on quartz glass. Diamond abrasive particles were directly added to the electrochemical discharge electrolyte to simultaneously perform electrochemical discharge machining and grinding. Because the diamond abrasive particles were added to the electrolyte, it could be used for both processes and replacing the slurry or electrode was unnecessary. This method removes material through simultaneous melting, etching, and impact grinding. The proposed method was successfully used to machine a 2 × 2 array of square microholes in quartz glass. The hole inlet size was 20 μm, and the difference between the maximum and minimum average size of the array holes was only 6 μm. After the final step of ultrasonic vibration broaching using the same electrolyte, the difference between the maximum and minimum average inlet size was reduced to 3 μm, and the hole taper angle was 1.77°.

Machining of Triangular Holes in D2 Steel by the Use of Non-Conventional Electrodes in Die-Sinking Electric Discharge Machining.

Electric discharge machining is relatively a slow process in terms of machining time and material removal rate. The presence of overcut and the hole taper angle caused by the excessive tool wear are other challenges in the electric discharge machining die-sinking process. The areas of focus to solve these challenges in the performance of electric discharge machines include increasing the rate of material removal, decreasing the rate of tool wear, and reducing the rate of hole taper angle and overcut. Triangular cross-sectional through-holes have been produced in D2 steel through die-sinking electric discharge machining (EDM). Conventionally, the electrode with uniform triangular cross-section throughout the electrode length is used to machine triangular holes. In this study, new designs of electrodes (non-conventional designs) are employed by introducing circular relief angles. For material removal rate (MRR), tool wear rate (TWR), overcut, taper angle, and surface roughness of the machined holes, the machining performance of conventional and unconventional electrode designs is compared. A significant improvement in MRR (32.6% increase) has been achieved by using non-conventional electrode designs. Similarly, the hole quality resulted by non-conventional electrodes is way better than hole quality corresponding to conventional electrode designs, especially in terms of overcut and hole taper angle. A reduction of 20.6% in overcut and a reduction of 72.5% in taper angle can be achieved through newly designed electrodes. Finally, one electrode design has been selected (electrode with 20 degree relief angle) as the most appropriate electrode resulting in better EDM performance in terms of MRR, TWR, overcut, taper angle, and surface roughness of triangular holes.

Research and Optimization of Machining Technology of Hammer Rod Subjected to Frequent Impact

In the oil exploration work, the hammer rod as the main component, due to the insufficient strength of the hammer rod, the hammer head falling off, the hammer body bending deformation and copper layer falling off and other problems often occur in the work, which not only affects the exploration progress but also causes huge economic losses. Aiming at the problem of insufficient strength of the hammer rod, through the analysis of the processing technology of the hammer rod and the working environment of the hammer rod, it is concluded that there are problems in the design of the hammer head, the material selection of the hammer body, and the processing technology of the copper layer. In this regard, the design of the hammer head is optimized, the depth of the inner hole of the hammer head is deepened, and the inner hole of the hammer head is changed to a taper hole; replace the 2CrMo alloy steel with higher strength as the main material of the hammer body, and add a heat treatment process after the rough turning to release the residual stress inside the hammer body; the processing process scheme for replacing the copper layer is attached to the surface of the hammer body by means of a hot-mounted copper sleeve. The improved hammer rod strength fully meets the needs of high-intensity impact work, shortens the exploration time, saves exploration costs, and makes great contributions to the exploration work.

Effect of copper, tungsten copper and tungsten carbide tools on micro-electric discharge drilling of Ti–6Al–4V alloy

Achieving microholes with dimensionally higher accuracy on the Ti-6Al-4V alloy using traditional machining techniques is challenging. Micro-electric discharge drilling (μEDD) has become a prominent machining technique in fabricating microholes. Though there are extensive applications of μEDD in producing microholes in difficult-to-cut materials, the appropriate tool materials and process parameters determine the process characteristics and accuracy. Because of the uneven machining and inadequate debris flushing, the technique is less productive and results in high overcut (OC) and hole taper (HT) for the microholes as well as poor material removal rate (MRR). Additionally, the rate of electrode wear affects hole precision. To address these issues, a rotating tool electrode set-up was used to drill microholes in Ti–6Al–4V alloy. The impact of three distinct electrode materials, copper (Cu), tungsten copper (WCu), and tungsten carbide (WC), as well as various process parameters, was investigated. The μEDD was accomplished by changing input process parameters, viz. voltage (V), capacitance (C) and tool rotation speed (TRS) and using Cu, WCu and WC tool electrodes to examine their influence on the process response variables such as MRR, TWR, OC, and HT. The experiments for each electrode were designed using a Taguchi-based L9 array, and the results were examined using Analysis of Variance (ANOVA). Capacitance was found to be the most significant electrical parameter in the μEDD of the titanium alloy. At 10,000 pF capacitance, the WCu electrode showed the highest MRR 0.009247 mm3/min, which was 6.11% and 21.92% higher than the Cu and WC electrodes. In contrast, the WCu electrode had the lowest tool wear rate (TWR) of 0.002033 mm3/min, which was 280.61% and 61.61% less than the Cu and WC electrodes, respectively. The WC electrode exhibited more accuracy by reducing the OC and HT compared to the Cu and WCu electrodes. The Cu tool electrode owing to its lower melting point and high thermal conductivity ensued in higher TWR than the WCu and WC electrodes. The used of rotary tool enabled a steady machining and proper flushing of debris. The impact of the tool materials and process variables on the surface quality of manufactured micro-holes was also explored using scanning electron microscopy (SEM) and energy-dispersive X-ray analysis (EDX). The WCu electrode showed higher carbon deposition on the hole surface than the Cu and WC electrodes.

A study of laser machining combined with dynamic chemical etching in micro‐hole drilling of 2.5D SiCf/SiC composites

AbstractIn this study, we used a novel method of laser machining combined with dynamic chemical liquid etching (LMDCE) to drill holes in 2.5D SiCf/SiC ceramic matrix composites (CMC‐SiC). A chemical solution that could quickly remove the recast layer without damaging the substrate was selected. Severe recast layer and microcrack defects were observed when laser machining was performed in the air. The surface of the material was highly carbonized due to the thermal effect of the laser. The effect of different defocus amounts and scanning speeds on the hole taper was studied. A lower scanning speed can ensure that a smaller taper is obtained by the microhole. The bore diameter of the holes processed with a defocusing amount of 0 or −1 mm is more uniform. The results show that with the assistance of a dynamic chemical solution, the fibers break neatly into needle‐like shapes, the thermal effect of the laser on the ceramic substrate is significantly weakened, the microhole shows good roundness, and there are no recast layers and oxides on the sample surface. In addition, microcracks are significantly reduced, and high‐quality microholes without a heat‐affected zone (HAZ) are machined. The method provides a new idea on how to eliminate machining defects and achieve higher‐quality micromachining for ceramic matrix composites.

Experimental Study on Coaxial Waterjet-Assisted Laser Scanning Machining of Nickel-Based Special Alloy

The problems of the recast layer, oxide layer, and heat-affected zone (HAZ) in conventional laser machining seriously impact material properties. Coaxial waterjet-assisted laser scanning machining (CWALSM) can reduce the conduction and accumulation of heat in laser machining by the high specific heat capacity of water and can realize the machining of nickel-based special alloy with almost no thermal damage. With the developed experimental setup, the laser ablation threshold and drilling experiments of the K4002 nickel-based special alloy were carried out. The effects of various factors on the thermal damage thickness were studied with an orthogonal experiment. Experimental results have indicated that the ablation threshold of K4002 nickel-based special alloy by a single pulse is 4.15 J/cm2. The orthogonal experiment results have shown that the effects of each factor on the thermal damage thickness are in the order of laser pulse frequency, waterjet speed, pulse overlap rate, laser pulse energy, and focal plane position. When the laser pulse energy is 0.21 mJ, the laser pulse frequency is 1 kHz, the pulse overlap is 55%, the focal plane position is 1 mm, and the waterjet speed is 6.98 m/s, no thermal damage machining can be achieved. In addition, a comparative experiment with laser drilling in the air was carried out under the same conditions. The results have shown that compared with laser machining in the air, the thermal damage thickness of CWALSM is smaller than 1 μm, and the hole taper is reduced by 106%. There is no accumulation and burr around the hole entrance, and the thermal damage thickness range is 0-0.996 μm. Furthermore, the thermal damage thickness range of laser machining in the air is 0.499-2.394 μm. It has also been found that the thermal damage thickness is greatest at the entrance to the hole, decreasing as the distance from the entrance increases.

Multi-performance characteristics optimization in near-dry rotary EDM of AlSiC by weighted principal component analysis

In the current study, electrical discharge machining of particle reinforced aluminium matrix composite (AlSiC) using near-dry conditions is investigated. The investigation has been carried out by using de-ionized water as liquid phase and air as gaseous phase of a two-phase dielectric fluid. The gap between the work material and the tool is supplied with a little amount of de-ionized water droplets at a slow, steady pace using a minimum quantity lubrication (MQL) device. The process parameters included in the study are peak current, duty cycle, pulse-on time, tool rotation and air pressure. MRR (Material removal rate), TWR (Tool wear rate) and HT (Hole Taper) were selected as evaluation criteria. L27 (313) orthogonal array was used to conduct the experiments. The experimental results obtained were used in principal component analysis (PCA). The MPI (multi-response performance index), which combines these principal components and weighted principal component analysis (WPCA), is calculated as overall performance index. The approach is capable of forecasting optimal levels of machining factors. Significant factors and their contribution is determined by ANOVA performed for MPI. To validate the optimum parametric settings confirmatory experiment was conducted. Experimental results show that the responses in near dry rotary EDM process can be successfully improved using the suggested method.

EFFECT OF STAND-OFF DISTANCE ON ABRASIVE WATER JET PIERCING OF CERAMIC-COATED SUPERALLOY

The drilling of film cooling holes on gas turbine blades made out of ceramic-coated superalloy improves the efficiency of the gas turbine and prolongs the life of the turbine blade. The purpose of this study was to investigate the effects of different stand-off distances (SODs) on abrasive water jet (AWJ)-pierced holes, in which the machining time, entry and exit hole diameters, overcut, hole taper, and surface morphology were studied. In this study, the water jet pressure (WJP) of 275[Formula: see text]MPa, piercing angle of [Formula: see text], dwell time of 0.2[Formula: see text]s, and abrasive flow rates (AFRs) of 350[Formula: see text]g/min and 400[Formula: see text]g/min were considered for the AWJ piercing operations. The entry and exit hole diameters and overcut linearly increased with an increase of SOD with different abrasive flow rates. And hole taper was observed at the coating and substrate sections in which it decreased with an increase of SOD up to 2[Formula: see text]mm, and a further increase of SOD increased the hole taper. Besides, the drilled holes were found to have an absence of delamination, cracks, and thermal defects. It was also noted that there is a transformation from a brittle to a ductile mode of erosion that may occur in the high-erosion kinetic energy impact region in the YSZ material section. Based on the experimental results, it is confirmed that SOD of 2[Formula: see text]mm became an influencing factor in AWJ for piercing quality holes in the YSZ-coated superalloy.

Investigation of precession laser machining of microholes in aerospace material

Sidewall tapering is one of the main limitations in ultrashort pulse (USP) laser machining and is associated with the beam shape and self-limiting effect. Laser processing with a precession beam is a potential solution to overcome this limitation. A study into the effects of precession parameters on the taper angle in microhole drilling of a nickel alloy is reported in this paper. The effects of three key precession parameters, i.e., incident angle, relative distance between the focuses of the precession and individual beams, and scanning speed, have been investigated in detail. Experiments were performed to drill through holes with aspect ratios up to 20:1 and diameters ranging from 100 to 500 μm over 0.6–2 mm thick nickel alloy substrates. Experiment results showed that all the considered parameters/factors were significant and affected the hole tapering in different ways. In addition, there were important interaction effects between two of the factors, i.e., incident angle and focus position, in some cases. The optimal parameters to minimize the tapering effect are suggested, and the mechanism is discussed in detail. The precession laser machining showed clear advantages in overcoming the limitations to associated with conventional USP laser machining. Fabricating microholes with high geometrical accuracy, i.e., with straight side walls and zero taper angles, is feasible with the use of a precession beam. The results clearly show the potential of precession laser processing and the capabilities that the technology can offer for a range of laser micromachining applications in different industries, such as microelectronics, automotive, and aerospace.

Experimental Characterization of Laser Trepanned Microholes in Superalloy GH4220 with Water-Based Assistance.

An experiment using water-assisted millisecond laser trepanning on superalloy GH4220 was carried out, and the effects of pulse energy on the hole entrance morphology, diameter, roundness, cross-section morphology, taper angle, sidewall roughness, and recast layer in air and with water-based assistance were compared and analyzed. The results show that, compared with the air condition, the water-based assistance improved the material removal rate and hole quality, increased the diameter of the hole entrance and exit, increased the hole roundness, decreased the hole taper angle, decreased the hole sidewall roughness, and reduced the recast layer thickness. In addition, under the combined action of water and steam inside the hole, the sidewall surface morphology quality was improved. Compared with the air condition, the spatter around the hole entrance was reduced, but the oxidation phenomenon formed by the thermal effect surrounding the hole entrance with water-based assistance was more obvious. The research provided technical support for the industrial application of millisecond laser drilling.

Laser microdrilling of CFRP with a nanosecond-pulsed high-power laser

The global demand for air travel and air transport is expected to further increase in the next couple of years, and so the environmental protection will also increasingly come into focus again. In the aviation sector, this means not only saving fuel and reducing emissions but also reducing the noise pollution caused by aircrafts. For this purpose, sound-absorbing acoustic liners are used, which consist of a sandwich structure with one perforated skin layer. To reduce weight, these outer layers are often made of carbon fiber-reinforced plastic (CFRP). For manufacturing these CFRP skin layers, laser drilling offers specific benefits, but when it comes to industrial applications, further process improvements are necessary. Although laser microdrilling is a well-known process in laser materials’ processing, it has not yet been sufficiently investigated for the processing of carbon fiber-reinforced plastics. This study investigates the quality and efficiency of laser microdrilling with a 1.5 kW nanosecond-pulsed high-power laser for percussion drilling and helical drilling of thin CFRP laminates. The efficiency was evaluated in terms of drilling depth, the amount of energy required to remove a specific volume of material, and the time required to remove a specific volume of the material. The quality evaluation focused on the heat-affected zone and the hole taper. The efficiency and quality results were set in relation to higher-level parameters such as energy fluence in the laser spot, pulse overlap, or total energy applied. This facilitates future transferability to similar laser processes that may use laser machines and system technology with deviating specifications.

Investigation on Ablation Characteristics and Material Removal Mechanism of Si3N4 Ceramics by a New Type of Coupled Laser Beam

Due to the excellent comprehensive properties, Si3N4 ceramics have been widely studied and applied in the field of engineering structures. Conventional processing of Si3N4 ceramics faces a series of challenges, and laser processing has become an effective processing technology for hard and brittle materials. In this paper, a new type of dual-beam coupled nanosecond pulsed laser was used to carry out a series of ablation experiments on Si3N4 ceramic at various powers, and the laser ablation mechanism was analyzed. The equivalent diameter method and the equivalent area method were used to calculate the corresponding laser ablation threshold, and influence of laser power on surface roughness of the ablation hole edge, hole depth, removal volume and hole taper were explored. The results show that when the repetition frequency f = 10 kHz, wavelength λ = 532 nm and ablation time t = 6 s, the laser ablation thresholds of Si3N4 ceramic calculated by the equivalent diameter method and the equivalent area method are 0.55 J/cm2 and 0.59 J/cm2, respectively. In a certain power range, surface roughness of the ablation hole edge, hole depth and removal volume increase with the increase of laser power, while the ablation hole taper decreases with the increasing laser power. This innovative work is helpful to expand the scope of laser processing technology for hard and brittle materials, and has guiding significance for the optimization of laser processing technology parameters of Si3N4 ceramics.