Kerf Taper Research Articles

A study on the machinability of DMLS In718 alloy using an electro-spark machining process

ABSTRACT The direct metal laser sintering process is used to develop the nickel base superalloy DMLS In718 for the experimentation. The DMLS In718 alloy is evaluated to ensure the metallurgical qualities and mechanical properties. Microstructure of the DMLS In718 alloy is anisotropic in nature and the hatch bands are clear to infer. The hardness of the DMLS In718 is 275 Hv which equivalent to the commercially available inconel718 material. the mechanical strength and density of the DMLS In718 alloy is justifiable to the commercial material. The machining studies are performed with electro spark erosion process to report on surface quality, kerf taper and material removal rate. the minimum pulse on time has produced a fine surface quality compared to the maximum process condition. The surface topography in terms of oxide scale and recast layers are identified during to inefficient process conditions. This paper was an opportunity to deliberate the machining quality of the wire electro spark process.

An experimental investigation into the potential of employing mixed eco-friendly abrasives during AWJ milling of nickel-based superalloy

Non-conventional machining processes are capable of achieving higher performance compared to conventional ones due to their inherent characteristics and higher amount of parameters which can be favorably regulated. Although the correlation between the most important process parameters and process outcome has been already established for a wide range of conditions and workpiece materials, the introduction of new considerations related to the three pillars of sustainability require further investigation on new means for the enhancement of AWJ milling process. As one of the most important parameters in AWJ milling is the abrasive material, the introduction of new materials may offer considerable advantages from different perspectives. Thus, in the present work, a comprehensive investigation on the efficiency of using eco-friendly, mixed abrasives is carried out under various conditions such as different traverse feed rate, abrasive mass flow rate, water jet pressure, jet impingement angle, and mixing ratio. The feasibility of using mixed abrasives is evaluated in terms of achievable depth of penetration, kerf width, kerf taper angle as well as material removal rate (MRR), and cutting efficiency. The findings indicate that among other factors, the mixing ratio plays a noticeable role especially regarding MRR and cutting efficiency and can offer an additional effective means to achieve the desired kerf characteristics in conjunction with other significant parameters such as water jet pressure.

Integrated error modeling for abrasive waterjet cutting at various nozzle tilt angle

The research investigates the specific impact of high-pressure abrasive waterjet (AWJ) on the cutting accuracy of circular trajectories. The coupling relationship between the kerf taper and the jet lag of the cutting front profiles is analyzed. Thus, an integrated error model for abrasive waterjet cutting of circular trajectories is innovatively established, which can predict the deformation of the circular arc trajectory not only at right angles but also at tilt angles. Cutting experiments at vertical angles were conducted, with a maximum prediction accuracy of 2.41%. Besides, arc trajectories with different diameters were conducted with a prediction accuracy of 2.26%. In order to reduce the deformation error of arc trajectories, compensation experiments for nozzle tilt ranging from 76° to 94° were carried out. The experimental results showed that when the nozzle was tilted in the direction opposite to the traverse speed up to half of the maximum deviation angle at the jet outlet point, the maximum deformation of arc trajectories was 1.218 mm, which was reduced by 0.532 mm compared to the case of vertical incidence, and the cylindricity increased by 31.74%. This adjustment can meet the precision requirements for cutting thick materials with abrasive waterjet.

Geometry accuracy control in abrasive water jet taper hole machining of ultra‐thick carbon fiber‐reinforced polymer (CFRP) laminates

AbstractThe primary factors affecting the geometric accuracy of abrasive water jet (AWJ) machining of ultra‐thick carbon fiber‐reinforced polymer (CFRP) laminates are the cutting front drag and kerf width deviation caused by energy dissipation. Firstly, this study comprehensively analyzes the influence of the coupling relationship between cutting front drag and kerf width deviation on the geometric accuracy of hole machining. Secondly, a gradient distribution theory for jet traverse speed with cutting depth is proposed for taper hole machining characteristics. Finally, a general geometric error model applicable to both straight and taper hole machining of ultra‐thick CFRP laminates using AWJ is established, along with a geometric error compensation method. A series of experiments validate the accuracy of the proposed geometric error model and compensation method. The novelty of this research lies in unifying the geometric error models for straight and taper hole machining of ultra‐thick CFRP laminates by considering the gradient distribution of jet traverse speed. The proposed error compensation method reduces the high degree of freedom required for machine tools. This study provides a general geometric error model and compensation strategy for AWJ hole machining of ultra‐thick CFRP laminates, which has significant engineering value for achieving 3D controllable AWJ machining of complex ultra‐thick CFRP components.Highlights The high geometric precision taper holes machining technique is a necessary prerequisite for achieving precise machining of complex trajectories in ultra‐thick CFRP with abrasive water jet. The influence of the coupling relationship between cutting front drag and kerf taper on the geometric accuracy of hole processing is comprehensively analyzed. A model considering the gradient distribution of traverse speed during taper holes machining was established, and a geometric error model considering this gradient distribution of traverse speed was developed. A taper holes machining geometric error compensation method with high engineering applicability was proposed. Geometric error prediction experiments and error compensation experiments were conducted, and the results proved the accuracy of the geometric error model and error compensation method.

Abrasive waterjet cutting of r‐GO infused magnesium fiber metal laminates: Experimental investigations and optimization through gorilla troops algorithm

AbstractLaminated metal‐composite structures, known as fiber metal laminates (FMLs), are modern lightweight materials extensively utilized in diverse industries such as aerospace and automotive manufacturing. These materials offer enhanced impact and fatigue resistance, making them invaluable for various applications. However, machining FMLs poses a challenge due to the occurrence of delamination and heterogenous in nature during conventional methods. Therefore, this study aims to investigate the quality characteristics such as kerf width, surface roughness and kerf taper of Magnesium based FMLs processed with an unconventional machining process namely abrasive water jet cutting (AWJC). These FMLs comprise alternately stacked kevlar/carbon fibers adhesively bonded with epoxy resin matrix filled with varying wt% of reduced graphene oxide (r‐GO), combined with AZ31B alloy sheet as the skin material. AWJC experiments were performed by varying the process parameters including waterjet pressure (275–325 MPa), stand‐off distance (2.5–3.5 mm), and cutting speed (600–800 mm/min) based on the box–behnken experimental design. The findings from the statistical analysis underscore the significant influences of stand‐off distance and waterjet pressure on kerf characteristics, while the inclusion of r‐GO is observed to notably affect the surface quality. In pursuit of enhancing cut quality, a multi‐response optimization was conducted employing the Gorilla Troops Optimization (GTO) algorithm. Comparative analysis with established metaheuristics like the gray wolf algorithm, dragonfly algorithm, and harmony search algorithm reveals GTO's superior performance across various metrics, including rapid convergence, diversity, and spacing values. Further, the cutting‐induced damages such as matrix plowing, fiber‐metal debonding and composite delamination were observed through microstructure analysis.Highlights Magnesium (AZ31B) fiber metal laminate comprising with various wt% of reduced graphene oxide was fabricated. Abrasive waterjet cutting of FMLs were performed based on box–behnken design experimental approach. Statistical analysis and influence of process parameters on the kerf width, surface roughness and kerf taper were investigated. Multi‐response optimization was carried out using metaheuristic‐based gorilla troops algorithm.

Experimental Analysis of Kerf Characteristics of Carbon Fiber-Reinforced Polymer with Abrasive Water Jet Machining

<div>This research looks into how abrasive water jet machining (AWJM) can be used on carbon fiber-reinforced polymer (CFRP) materials, specifically how the kerf characteristics change with respect to change in process parameters. We carefully looked into four important process parameters: stand-off distance (SOD), water pressure (WP), traverse rate (TR), and abrasive mass flow rate (AMFR). The results showed that as SOD goes up, the kerf taper angle goes up because of jet dispersion, but as WP goes up, the angle goes down because jet kinetic energy goes up. The TR was directly related to the kerf taper angle, but it made the process less stable. The kerf drop angle was not greatly changed by AMFR. When it came to kerf top width, SOD made it wider, WP made it narrower, TR made it narrower, and AMFR made it a little wider. When the settings (SOD: 1 mm, WP: 210 MPa, TR: 150 mm/min, AMFR: 200 g/min) were optimized, the kerf taper angle and kerf top width were lowered. This improved the accuracy of the measurements and cut down on material waste in CFRP composite machining. These results make it clear how important parameter selection is in precision cutting.</div>

Evaluating the optimum abrasive water jet machinability for CARALL composites with various fiber orientations

AbstractCarbon Fiber Reinforced Aluminum Laminated (CARALL) composites are widely used in aircraft structures due to their ability to be produced in different shapes with desired properties and their high impact resistance properties. As with other layered composite materials, processing of CARALL composites by conventional manufacturing methods results in many damage mechanisms such as fiber breakage, deformation in the hole region, stress concentration, resin‐fiber separation and microcracks. One of the modern manufacturing methods, Abrasive Water Jet (AWJ), is a processing method in which the material is removed by abrasion and almost any material can be cut without thermal degradation. There are no experimental studies in the literature on the drilling of CARALL composites by modern manufacturing methods. The aim of this study is to investigate the impact of machining parameters on the output variables (kerf taper angle (K), roundness error (Re) and material removal rate (MRR)) as well as the effect of fiber orientation on the drilling of CARALL composites with different fiber orientations on an AWJ machine. PROMETHEE‐GAIA weighted by Entropy Weighting Method were used to ascertain the optimum levels of control factors. CARALL composites with different fiber orientations were drilled with an 8 mm diameter AWJ with three different water pressures, three different nozzle feed rates. With PROMETHEE‐GAIA multi‐criteria optimization method, the optimum levels of the factors that provide both minimum Re and K values and maximum MRR value were obtained with twill woven material, 1680 mm/min feed rate and 1680 bar water pressure.Highlights CARALL composite materials with two different fiber orientations (twill weave and UD) were used. CARALL composite materials were drilled at different machining parameters. Abrasive water jet was used in drilling experiments. Optimum drilling parameters were determined to achieve minimum roundness error, minimum kerf angle and maximum material removal rate. PROMETHEE‐GAIA was used as a multi‐criteria decision‐making method.

Abrasive waterjet machining of titanium alloy using an integrated approach of taguchi-based passing vehicle search algorithm

AbstractThe titanium alloy, Ti6Al4V, is a popularly used material in aerospace and medical applications due to its specific attributes, such as excellent strength-to-weight ratio and resistance to corrosion. Ti6Al4V is challenging to machine using conventional methods due to its poor thermal conductivity, which necessitates the use of unconventional machining methods like abrasive water jet machining (AWJM). In this work, AWJM was preferred for machining Ti6Al4V, considering three key process variables: nozzle traverse speed (Tv), abrasive flow rate (Af), and stand-off distance (Sd). The performance of the AWJM process was assessed using three main metrics: Material removal rate (MRR), Surface roughness (SR), and Kerf taper angle (θ), which were crucial for evaluating the effectiveness of the AWJM. Taguchi’s L9 array, a design of experiments method, was used to plan the experiments. The adequacy of the developed models was assessed by analysis of variance (ANOVA). ANOVA results have shown that Tv, Af, and Sd were found to have a significant effect on MRR, SR, θ with contributions of 73.15%, 49.72%, and 78.35% respectively. The Passing Vehicle Search algorithm was adopted to find the global optimal solution. Simultaneous optimization results using the PVS algorithm have shown the optimal MRR, SR, and θ values of 0.17 g/min, 3.28 μm, and 2.45, respectively, at Tv of 237 mm/min, Af of 450 g/min, and Sd of 2.0 mm. The optimization results with Pareto points will help to achieve desired outcomes by selecting appropriate input conditions.

Determination and prediction of surface and kerf properties in abrasive water jet machining of Fe-Cr-C based hardfacing wear plates

Improving and maintaining the sustainability, profitability and efficiency of sectors such as manufacturing, mining and agriculture are the most important goals for industries. It is therefore quite common to apply hardfacing method to products and equipment created to achieve these goals. However, machining of the workpiece is necessary to ensure dimensional accuracy as a result of hardfacing production. In the processing of hardfacing materials with traditional machining methods, negative factors such as tool wear and thermal effects occur. For this reason, the cutting performance of hardfacing wear plate with abrasive water jet, which is one of the unconventional manufacturing processes, was investigated in this study. Tests were realized in regard to the full factorial experimental design, which includes the changes in the levels of material alignment direction, abrasive mass flow rate and traverse speed parameters. The influences of the test parameters on the surface roughness and kerf taper angle constituting the cutting performance were determined by analysis of variance (ANOVA). In addition, the effects of changes in parameter levels were investigated. Material alignment direction was found to be the most effective test parameter for surface roughness and kerf taper angle. The influences of parameter and parameter levels on the formation of surface conditions were determined with surface images. Thus, machining mechanisms and surface morphologies were explained by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). Optimal levels of test parameters were achieved by performing multiple-response optimization with equal importance. Finally, the estimated results of cutting performances were found by general linear model, and all results were confirmed by regression analysis.

An integrated CRITIC-COPRAS approach for multi-response optimization on AWJM of hybrid filler–reinforced polymer composite and its surface integrity

Composites have gained acceptance in an extensive range of applications owing to their unique characteristics. But, machining of these materials is often challenging due to improved bonding between matrix and fibre when fillers are added. Since the machinability is an important aspect for any material for its successful utilization, it is essential to analyse the effect of secondary phase on machinability. However, investigations on the effect of fillers on machinability of polymer composites are minimal. In this research, hybrid fillers, namely boron nitride (BN) and montmorillonite (MMT) nanoclay, were added to epoxy/glass fibre composite through compression moulding, in which quantity of MMT is fixed and BN is varied from 2 to 6 wt%. Abrasive water jet machining (AWJM) is a leading method for machining polymer composites in which transverse speed, stand-off distance, pump pressure and filler percentage are key factors and are considered as input variables. To assess the machinability, material removal rate (MRR), surface roughness (Ra) and kerf taper (Kt) are chosen as response variables. Experimental planning is done through Taguchi method, and Criteria Importance Through Intercriteria Correlation (CRITIC)-weighted Complex Proportional Assessment (COPRAS) technique is utilized for optimization. The results revealed that addition of BN reduces the MRR while it improves the surface finish and reduces the Kt. Transverse speed has the most influence over all the considered output responses, stand-off distance and water pressure mainly affect the MRR and Ra while filler addition mainly affects the Kt. The hybrid CRITIC-COPRAS approach–recommended optimal control factors resulted in 16.20 mm3/min MRR with 0.29° Kt and 3.86 µm Ra. The recommended optical condition can be utilized for effective machining of polymer composite with MMT/BN fillers.Graphical abstract

Improving surface striation and kerf taper of hybrid Al/CFRP stacks using dual-pass abrasive waterjet slotting strategy

Improving surface striation and kerf taper of hybrid Al/CFRP stacks using dual-pass abrasive waterjet slotting strategy

A Statistical and Optimization Study on the Influence of Different Abrasive Types on Kerf Quality and Productivity during Abrasive Waterjet (AWJ) Milling of Ti-4Al-6V.

Non-conventional machining processes offer significant advantages over conventional ones, especially in terms of the productivity, cost, and surface integrity of the produced parts due to their higher flexibility. Abrasive waterjet machining, in particular, constitutes an ecologically friendly process with a negligible thermal impact on a workpiece, and it has considerable capabilities for obtaining the desired outcome by regulating some of its numerous parameters. Among these parameters, the abrasive type is particularly important due to its hardness, mesh size, and shape, which lead to considerable deviations on the obtained depth, kerf characteristics, and productivity. Thus, in this work, a comprehensive comparison is conducted on the use of garnet and silicon carbide particles for the slot milling of the Ti-6Al-4V alloy under different conditions. The capabilities of both abrasive materials are evaluated by statistical analysis regarding the depth of penetration, kerf width, kerf taper angle, and material removal rate (MRR), which are obtained under the same process conditions. Finally, a multi-objective optimization based on grey relational analysis (GRA) is performed for several different practical cases. It was found that, although silicon carbide is more efficient in optimizing individual process outputs, the use of a garnet abrasive can lead to considerably better trade-offs between two or more objectives of the machining process.

Influence of material thickness and hatching strategies on laser cutting of epoxy mold composites

Glass-filled composites are used for overmolding of electrical components due to their good electrical isolation properties. Laser cutting is a preferred technology to remove excess mold material to achieve a low surface roughness and reduce tool wear. Hatching strategies improve the laser-cutting process of carbon fiber-reinforced polymers toward lower cutting times and a more homogeneous cut surface. The impact of hatching strategies on epoxy mold compounds has been so far unknown as the laser-cutting strategy was based on multiple single passes in previous studies. This work investigates the effects of hatching strategies such as perpendicular hatching, parallel hatching, and a single line, including the influence of material thickness and filler content regarding the cutting time, kerf taper angle, and heat-affected zone, using a 50 W short-pulsed fiber laser for different highly filled epoxy mold compounds. Results show that the use of a hatching strategy is required to cut workpieces at thicknesses of 4 mm or higher due to the sieving size of the filler. Perpendicular hatching needs to be chosen when the aim is a minimal cutting time. The kerf taper angle at the top of the cut is below 4° while hatching leads to a more pronounced kink of up to 25° occurring toward the bottom of the cut. Meanwhile, an increase in filler concentration leads to an increase in cutting time, because of higher thermal conduction, while no effect on the kerf taper angle or the heat-affected zone can be identified.

Multi-objective optimization of fiber laser cutting quality characteristics of glass fiber reinforced plastic (GFRP) materials

Laser cutting can achieve ultra-precision cutting of materials by using appropriate parameters. In order to optimize processing parameters and obtain better processing quality, conducted experimental research on laser cutting of Glass fiber reinforced plastic (GFRP). In this study, the impact of four process parameters (laser power, cutting speed, assistant gas pressure and focus position) on quality characteristics (kerf width, kerf taper and kerf section roughness) was evaluated through analysis of variance (ANOVA), the regression relationship between laser processing parameters and quality characteristics was analyzed. And an integrative model for predicting and optimizing the quality characteristics of fiber laser cutting was constructed. In the proposed integrative model, Back-Propagation Neural Network (BPNN) was used to build a prediction model for quality characteristics. Through Non-dominated Sorting Genetic Algorithm (NSGAII) optimizes and outputs the complete optimal solution set of processing parameters, and finally realizes the nonlinear optimization of multi-objective parameters. The fitness value of BPNN model can reach 97.814%, and the maximum prediction relative error is 8.614%. And the set of suggested optimal solutions can be used as most of them are showing certain improvements in the quality characteristics. The results indicate that the integrative modeling strategy has the ability to predict and optimize laser cutting of composite materials.

A Study on Processing Defects and Parameter Optimization in Abrasive Suspension Jet Cutting of Carbon-Fiber-Reinforced Plastics.

Abrasive suspension jet (ASJ), an accurate cold-cutting technology, can address traditional processing issues relating to carbon-fiber-reinforced plastics (CFRPs) like tool wear, interlayer delamination, large heat-affected zone, and low surface roughness. This study employed the use of an ASJ to cut CFRPs and an ultra-depth optical microscope to scan the cut surface to analyze interlayer delamination, surface roughness, kerf taper, and shoulder damage. Regression analysis was conducted to establish a prediction model for cutting quality based on surface roughness, kerf taper, and shoulder damage. Various types of CFRP cutting quality were analyzed using jet parameters. It was found that the use of ASJ to process CFRP results in the following defects: The range of surface roughness variation is from 0.112 μm to 0.144 μm. Surface roughness is most influenced by stand-off distance, followed by traverse speed and jet pressure. The range of kerf taper variation is from 4.737° to 10.1°. Kerf taper is most influenced by stand-off distance, followed by jet pressure and traverse speed. The range of shoulder damage variation is from 3.384 μm2 to 10 μm2. Shoulder damage is most influenced by jet pressure, followed by traverse speed and stand-off distance. A prediction model for cutting quality was developed based on surface roughness, kerf taper, and shoulder damage, providing data support for ASJ cutting of CFRPs. The optimal parameter combination is a stand-off distance of 1 mm, a jet pressure of 30 MPa, and a traverse speed of 30 mm/min.

Evaluation of Geometric Defects Produced in Abrasive Water Jet Drilling of Steel S275JR

Drilling of metal alloys is an operation that is still performed today in many industrial sectors such as aeronautics, automotive or civil engineering. This is mainly due to the high number of mechanical joints that must be made in structural elements. However, it is known that conventional drilling operations can generate defects on the machined surface mainly due to the effect of temperature on the tool and the material. For this reason, a non conventional process such as abrasive water jet machining (AWJM) is ideal for this type of operation. The decrease in temperature along the process minimizes the defects generated while keeping a high surface finish on the machined part. Therefore, this research has been carried out, where a 2 mm thick S275JR steel has been drilled by abrasive water jet. An experimental methodology has been developed to carry out the drilling. The input parameters include hydraulic pressure (P), stand of distance (SOD), abrasive flow rate (AMF) and traverse speed of the tool head (TS). In order to carry out the experiment satisfactorily, micro-drilling trials have been carried out leaving the TS parameter fixed in order to know the behavior of the material against the kinetic energy presented by the water jet equipment. These holes have been analyzed by means of the geometrical defects obtained in the form of diameter and kerf taper angle. Finally, the most relevant conclusions of the research have been developed, where it is emphasized that kerf taper (KT) angle increases drastically with the increase in SOD, giving greater results in area and with a greater amount of deformations and projections.

Multi-performance optimization for AWJ drilling process in cutting of ceramic tile: BBD with EOBL-GOA algorithm

PurposeThe goal of this study is to determine the values of the process parameters that should be used during the machining of ceramic tile using the abrasive water jet (AWJ) process in order to achieve the lowest possible values for surface roughness and kerf taper angle.Design/methodology/approachIn the present work, ceramic tile is processed by the AWJ process and experimental data were recorded using the RSM approach based Box–Behnken design matrix. The input process factors were water jet pressure, jet traverse speed, abrasive flow rate and standoff distance, to determine the surface roughness and kerf taper angle. ANOVA was used to check the adequacy of model and significance of process parameters. Further, the elite opposition-based learning grasshopper optimization (EOBL-GOA) algorithm was implemented to identify the simultaneous optimization of multiple responses of surface roughness and kerf taper angle in AWJ.FindingsThe suggested EOBL-GOA algorithm is suitable for AWJ of ceramic tile, as evidenced by the error rate of ±2 percent between experimental and predicted solutions. The surfaces were evaluated with an SEM to assess the quality of the surface generated with the optimal settings. As compared with initial setting of the SEM image, it was noticed that the bottom cut surface was nearly smooth, with less cracks, striations and pits in the improved optimal results of the SEM image. The results of the analysis can be used to control machining parameters and increase the accuracy of AWJed components.Originality/valueThe findings of this study present an innovative method for assessing the characteristics of the nontraditional machining processes that are most suited for use in industrial and commercial applications.

Process parameters optimization in machining of monel 400 alloy using abrasive water jet machining

This research examines the optimum machining features for abrasive water jet cutting of Monel 400 alloy. This alloy system faces significant challenges in conventional machining and can be surpassed by using the coolest machining technology, such as AWJM. In this experimental investigation, the water beam jet pressure (AP), the nozzle jet traverse speed (NS), and the abrasive flow rate (AMF) were used to explore the kerf taper angle (Kta) and surface roughness (Ra) response variables. The experimental L-9 layout (Taguchi's/L-9(−|-) standard orthogonal array) was used to run the experiment. The S/N ratios for each experimental run were determined using a mono-output response optimization technique. The input characteristics, such as water beam jet pressure (AP) and abrasive flow rate (AMF), were determined to have the most substantial effects on kerf taper angle (Kta) and surface roughness (Ra). While increased water pressure (AP) caused a narrowed jet, reducing the kerf taper angle (Kta) and surface roughness (Ra). Its simultaneous abrasive mass flow rate (AMF) increase causes constant erosion on the cutting front, resulting in a smooth surface roughness (Ra) and less kerf taper angle (Kta). Confirmation tests were carried out using the optimal input parameter combinations found by the statistical program to establish effective solutions to the machining.

Performance evaluation of abrasive water jet machining on spent garnet reinforced hybrid composite

In recent years, garnet from abrasive water jet machining has been used for cutting-edge technologies. Specifically, spent garnet abrasive particles posses significant strength in nature and have been used for strengthening polymer composites for new applications such as aero blade rotors and the construction industry. The spent garnet received from the abrasive water jet machine (AWJM) has been fed to 30 mesh size using a sieve shaker, which is used to reinforce the glass fiber polymer composite. The hybrid polymer composite was fabricated using a wet hand lay-up technique, and AWJM was used to cut the polymer composite. The machining output responses of surface roughness (Ra) was measured using an SJ-210 m, and kerf was measured using a video measurement system (VMS). Kerf taper (KT) and surface roughness (Ra) were measured by changing the machining inputs of AWJM. The KT and Ra were controlled by varying the input parameters. Moreover, it was found that the kerf was influenced by the amount of spent garnet reinforced in the glass fiber, which ranged from the range of 5% to 15%. Subsequently, cut surface smoothness was predominantly affected by the addition of spent garnet more than 10%. Increasing water jet pressure mainly improves the surface quality and reduces the kerf width. The abrasive flow rate mainly affects the Ra and is just the reverse of water jet pressure. The selection of optimal AWJM parameters is desirable for hybrid composite machining.

Modeling and multi-objective optimization of abrasive water jet machining process of composite laminates using a hybrid approach based on neural networks and metaheuristic algorithm

Although the abrasive water jet (AWJ) has proven to be a suitable process for machining composite materials, it has some limitations related to dimensional inaccuracy and surface defects. As the performance of the AWJ process mainly depends on the machining parameters, an optimal selection of them is crucial to achieving an improved quality of cut. In this context, the present study reports an experimental investigation to assess the influence of AWJ machining parameters on kerf taper angle (θ) and surface roughness ( Ra) of E glass/Vinylester 411 resin laminates. The experiments are carried out using a full factorial design by varying the water pressure, traverse speed, abrasive flow rate, and standoff distance. A first-ever attempt is made in this paper to optimize the AWJ process using a hybrid approach combining artificial neural networks (ANNs) with a recently proposed metaheuristic algorithm known as multi-objective bonobo optimizer (MOBO). The results show that standoff distance and abrasive flow rate were the most significant control factors in influencing θ and Ra, respectively. The developed ANN models are capable to predict the output responses with high accuracy and the solutions from the Pareto front provide a sufficient performance with a trade-off between θ and Ra. The corresponding levels of the optimal process parameters are 430 g/min for the abrasive flow rate, the range of 140–180 mm/min for the traverse speed, 280 MPa for the pressure, and 1.5 mm for the standoff distance.