Kerf Width Research Articles

INVESTIGATION OF THE EFFECT OF PROCESS PARAMETERS IN CO2 LASER CUTTING OF PMMA MATERIAL BY RESPONSE SURFACE METHOD

Recently, the studies on lightweighting have gained significant importance due to requirements such as energy efficiency and sustainability. Polymer materials are a group of materials that are frequently used for this purpose. This study investigated the effects of laser power, cutting speed and focal point on the kerf width, which are the most effective process parameters in laser cutting of Polymethylmethacrylate, a low-cost polymer material, using Response Surface Methodology and ANOVA. The results obtained from the data analysis show that the kerf width is seriously affected by the focal point depth as well as the speed and power.

A hybrid approach for machining optimization of the WEDM using grey-fuzzy with Metaphor-Less algorithms for Ti-3Al-2.5V

Purpose This paper aims to investigate the influence of “BroncoCut-X” (copper core-ZnCu50 coating) electrode on the machining of Ti-3Al-2.5V in view of its extensive use in aerospace and medical applications. The machining parameters are selected as Spark-off Time (SToff), Spark-on Time (STon), Wire-speed (Sw), Wire-Tension (WT) and Servo-Voltage (Sv) to explore the machining outcomes. The response characteristics are measured in terms of material removal rate (MRR), average kerf width (KW) and average-surface roughness (SA). Design/methodology/approach Taguchi’s approach is used to design the experiment. The “AC Progress V2 high precision CNC-WEDM” is used to conduct the experiments with ϕ 0.25 mm diameter wire electrode. The machining performance characteristics are examined using main effect plots and analysis of variance. The grey-relation analysis and fuzzy interference system techniques have been developed to combine (called grey-fuzzy reasoning grade) the experimental response while Rao-Algorithm is used to calculate the optimal performance. Findings The hybrid optimization result is obtained as SToff = 50µs, STon = 105µs, Sw = 7 m/min, WT = 12N and Sv=20V. Additionally, the result is compared with the firefly algorithm and improved gray-wolf optimizer to check the efficacy of the intended approach. The confirmatory test has been further conducted to verify optimization results and recorded 8.14% overall machinability enhancement. Moreover, the scanning electron microscopy analysis further demonstrated effectiveness in the WEDMed surface with a maximum 4.32 µm recast layer. Originality/value The adopted methodology helped to attain the highest machinability level. To the best of the authors’ knowledge, this work is the first investigation within the considered parametric range and adopted optimization technique for Ti-3Al-2.5V using the wire-electro discharge machining.

Experimental Investigation and Modeling of the Kerf Profile in Submerged Milling by Macro Abrasive Waterjet

Abstract Toward achieving control over the kerfing through macro abrasive waterjet submerged milling, there is a need (i) to understand the influence of the water column height on the kerf quality and (ii) to develop a model for the prediction of the kerf characteristics. This study performs detailed experimentation to assess the kerf quality enhancement in submerged milling relative to the in-air milling on Al-6061 alloy. From the modeling perspective, there are very limited efforts in developing a comprehensive model that includes both the jet flow dynamics and material removal models—this is the missing link. Toward this, a comprehensive model is proposed and validated for the prediction of kerf in in-air and submerged conditions by considering (i) jet dynamics and (ii) jet–material interaction. From the experimental results, it is observed that by adopting the submerged milling, the damaged region, top kerf width and edge radius got reduced by 20.3%, 13.53%, and 22.7%, respectively. However, this enhancement in the kerf quality is associated with a reduction in the centerline erosion depth (hmax) by 12.33% and a material removal rate by 24.52%. The material removal mechanism is more uniform and directed in the submerged milling, whereas in-air is random. The proposed model predicted the kerf cross-sectional profile in submerged milling and in-air with a mean absolute error of 60 µm and 57 µm, squared Pearson correlation coefficient of 0.97 and 0.99, and the hmax with a maximum error of 1.3% and 1.4%.

Formation mechanism and controlling technique for fabrication of extremely sharp diamond micro mills

The extreme sharpness for superhard micro mills is urgently needed to improve the surface quality, restrain size effect and suppress burr formation for the widely used miniature components. Therefore, laser cutting and precision grinding are coupled to form a hybrid method for the fabrication of diamond micro mills with extremely sharp edge. Firstly, the laser cutting simulation of polycrystalline diamond (PCD) based on various laser energy density and laser scanning speed was conducted to provide temperature distribution. Then the laser cutting experiments were conducted, and the influence of laser cutting parameters applied on the machining consequences (kerf width, cutting cycles, affected layer thickness, and surface roughness of cutting section) were analysed according to the simulation model. On this basis, the laser energy density and scanning speed were optimized as 175 J/cm2 and 0.2 mm/s respectively to obtain the smooth and uniformly graphitized surface. Moreover, the grinding experiments were conducted on the cutting section obtained by the optimized laser parameters, the impact of the abrasive grain size, grinding depth per path and feeding speed on the grinding results were studied, these grinding parameters were optimized as 1 μm, 1 μm, and 2 mm/min to realise the micro abrasion during grinding process. In this way, PCD micro end mills (PCDMs) with surface roughness Sa of 57.3 nm, effective length of 600 μm, diameter of 400 μm, and radius of cutting edge of 0.19 μm were fabricated. Finally, the micro-milling experiments with PCDMs were performed on the Ti-6Al-4V material, the micro slots and thin-walled structure were processed with almost no burrs being observed and the obtained surface roughness Sa of 18.3 nm. With the obtained machining results, the remarkable cutting performance of PCDM was validated.

On the Laser Micro Cutting: Experimentation and Mathematical Modeling based on RSM-CCD

The laser micro-cutting process is the most widely commonly applied machining process which can be applied to practically all metallic and non-metallic materials. While this had challenges in cutting quality criteria such as geometrical precision, surface quality and numerous others. This article investigates the laser micro-cutting of PEEK composite material using nano-fiber laser, due to their significant importunity and efficiency of laser in various manufacturing processes. Design of experiential tool based on Response Surface Methodology (RSM)-Central Composite Design (CCD) used to generate the statistical model. This method was employed to analysis the influence of parameters including laser speed, laser power, laser frequency and number of passes on the cutting characteristics -and geometrical. Cutting-geometry requirements are significant quality features since they are one of the metrics for the geometrical precision of micro-cutting proses it was concluded that higher laser power, slower speed, and more pass number result in a low kerf taper, these parameters have a significant impact on the other cutting characteristics, and geometrical. Whereas the frequency has the lowers impact on the cutting geometrical. Finally, the experiments show Maximum depth was 2000, width minimum top kerf width was 305.56 µm and the minimum angle of 2.8906.

Optimization and Prediction of Process Parameters during Abrasive Water Jet Machining of Hybrid Rice Straw and Furcraea foetida Fiber Reinforced Polymer Composite

In the last few decades, natural composite materials have been considered one of the highly sustainable ecological alternatives for reducing the consumption of synthetic materials. Today, research on natural fiber composites is the main thrust for their use in various industrial applications. Further, continuous research works are being carried out to utilize natural composites as an alternative to synthetic materials. However, the inhomogeneity of composites, delamination, fiber pullout, higher surface roughness (SR) and dimensional inaccuracy under traditional machining have led the attention towards non-traditional machining, such as abrasive water jet machining, to achieve high-quality components. Hence, in this study, an experimental analysis based on the design of experiments is conducted on the machinability of a hybrid rice straw/Furcraea foetida composite under abrasive water jet machining (AWJM). Further, the concentration of the rice straw and the AWJ process parameters are varied, and their effects on the quality of machining is evaluated. The experimental trials are designed based on the Taguchi L27 orthogonal array, followed by an analysis of variance (ANOVA). From extensive experimentations, the concentration of rice straw is observed to be the most contributing (93.5%) factor to the SR. The traverse speed (TS) shows the highest percentage contributions of 93.13%, 55.50 and 55.70% to the material removal rate (MRR) and the top (TKW) and bottom kerf widths (BKW), respectively. However, the interaction between the fiber concentration and traverse speed gives the maximum contribution (35.04%) to the kerf taper (KT). A second-order response surface model is generated to study the effects of the process parameters on the SR, MRR, TKW, BKW and KT in any experimental domain. Finally, the microstructural characteristics of the machined surfaces, such as micro-cracks, debonding, and fiber pullout, are discussed.

Studies on effect of wire EDM process parameters on machining characteristics of Inconel 825 plate

Wire-cut Electrical Discharge Machining (WEDM) is an emerging engineering process in the field of micro parts manufacturing to fabricate the complex shapes of micro products. This machining method has been magnificently employed in machining various materials starting from Al metal, a highly ductile material to a very high hard material like ceramics and Inconel’s. Inconel and Ti-based alloys treasure trove wider applications in these present industries. Those parts are producing difficulty in several machining processes and create difficult interactions with machining process parameters. Inconel 825 is a Ni-based strength metal and temperature resistant. Conventional machining of these results in large amounts of cutting forces, more strain-hardened and toughened chips, and extreme tool wear. In this work, an effort is made to study the influence of WEDM process parameters such as Ton, Toff and WF on the output variables such as the Cutting Width of Wire-cut EDM for Inconel 825. Preliminary trials were conducted by varying the process parameters in order to design a process parameter window. Factorial design matrix has been developed with L9 numbers of experiments and the corresponding output/responses such as Kerf Width and surface roughness (Ra) were measured and recorded. The responses have been used to measure the Ra and kerf values of all the specimens after cutting by Wire cut EDM machine. Use of ANOVA using identifies the influenced process parameter on machining (cutting) Inconel 825 output responses Kerf Width and surface roughness.

Influence of Ceramic Particles Additives on the Mechanical Properties and Machinability of Carbon Fiber/Polymer Composites

Hybrid polymer composites have become the interest of the world, especially in mechanical and electronic applications. Recently, advanced machining techniques such as abrasive water jet machining of hybrid polymer composites have been used to solve many problems including the ability to form complex shapes, high performance, better surface features, and high levels of accuracy. In this study, the effect of ceramic particle (SiC and Al2O3) constituents on the mechanical properties and machinability of the hybrid polymer composites was investigated. The results of mechanical tests showed that an improvement in the tensile and flexural properties appeared using a hybrid polymer constituent (70 wt% Epoxy + 15 wt% CF + 10 wt% Sic + 5 wt% Al2O3). However, this hybrid polymer constituent includes the lowest value of impact strength. Also, the morphological analysis indicated the uniform distribution of particles, the best defect-free surface, and the bonding strength between the reinforcement and the epoxy matrix can be obtained using this constituent which has contributed to the improvement of the mechanical properties. The abrasive water jet automation process was also performed based on the design of experiment (Taguchi L18 design) to study the machinability the hybrid polymer composites in terms of surface roughness, hardness, and kerf width. The analysis of variance concluded that the constituent (70 wt% Epoxy + 15 wt% CF + 10 wt% Sic + 5 wt% Al2O3) has the most influential factor on the machinability of the hybrid polymer composite followed by traverse velocity, and then stand of distance that used during abrasive water jet machining. Moreover, the grey relational analysis was beneficially used to determine the multi-optimization of abrasive water jet machining parameters.

Exploring the potential of the fabrication of large-size mirror facet for semiconductor laser bar utilizing mechanical cleavage

While mechanical cleavage technology is an ideal alternative approach to fabricate large-size mirror facets for high-power laser bar, there has been little scientific understanding of mechanical cleavage mechanisms. To fill this gap, cleavage experiments were designed according to the Taguchi method for analyzing the main effects of three parameters. Surface and subsurface cracks and cleavage plane morphology are analyzed as well. The results show that scribing load has significant impact on the scratch morphology as compared with other parameters, and quadratic polynomial models are formulated to predict kerf width and maximum damage width values. For scribing along the [0−1−1] direction on the (100) GaAs wafer, the subsurface cracks are TLC and LC which propagate along [0-11] direction and MC which propagates along [100] direction. The achieved optimal combination of parameters are scribing load of 10 g, scribing speed of 20 mm/s and scribing length of 0.6 mm. The undamaged length of cleaved planes can reach 11.77 mm. Our results demonstrate that mechanical cleavage is a powerful technique which could guide actual production and manufacturing field of high-power GaAs-based laser bars.

Performance Evaluation of Input Power of Diode Laser on Machined Leather Specimen in Laser Beam Cutting Process

Numerous industries, including footwear, handicrafts, and the automobile industry, utilize leather materials. The main goal of this study was to investigate the effect of input power of the diode laser in laser cutting on vegetable chrome tanned buffalo leather to enhance the cutting process. In the present investigation, carbonization, kerf width, and material removal rate (MRR) were taken as performance measures. The diode-based laser beam machining was designed and fabricated with 2.5 W, 5.5 W, and 20 W diode laser to cut vegetable chrome tanned leather. The high-intensity 20 W diode laser produced lower carbonization, lower kerf width, and higher material removal rate compared with the 2.5 W and 5.5 W diodes. This improved performance was due to the adjustable features associated with this diode laser actuation in the form of circular shape with adjustable diameter. A high power with a lower spot size under pulsed mode can produce higher power density. Since a higher power density can establish less interaction time, it produces lower carbonization. Due to the ability of the 20 W diode laser driver to control the beam shape and size, it could produce a lower kerf width and higher MRR. The optimal parameters for cutting chrome vegetable tanned cow leather were a standoff distance of 18 mm, feed rate of 200 mm/min, and duty cycle of 70%.

Experimental evaluation of cut quality and temperature field in fiber laser cutting of AZ31B magnesium alloy using response surface methodology

Fiber laser cutting of AZ31B magnesium alloy was studied to assess the effect of laser cutting process parameters on the resultant cutting temperature near the cut kerf and the resultant cut quality. To systematically analyze the effect of parameters on the temperature variation and cutting edge surface roughness during the cutting process of the AZ31B magnesium alloy, the Response Surface Methodology (RSM) was utilized to fit a quadratic polynomial model through the experiments. The influence of three main factors including speed of cutting, power of laser and nozzle distance on the major responses of temperature near the cut kerf, average surface roughness of the cutting edge and the cut kerf quality was then evaluated.Changes in the cutting speed had no serious impact on the quality of the cut kerf.Laser power levels from 800 to 1000 W were suitable for laser cutting of magnesium alloy sheets. The results showed thatvariations in the nozzle distance and laser emitted power had a remarkable effect on the temperature variation around the cut kerf width. Changing the nozzle distance and thereby creating different laser beam diameter had a more significant influence on the temperature variation rate (about 15 %), in comparison to the laser power. The nozzle distance had a huge effect on the cutting edge surface roughness due to the significant variation of laser beam energy density and beam diameter and hence, the cut kerf dimensional changes.The optimal cutting condition was obtained at the minimum roughness according to the investigated parameters levels, which included the cutting speed of 6 m/min, the power level of 1000 W and the nozzle distance of 0.8 mm. The SEM images from the top surface of the cut kerf implied the existence of oxidation in the magnesium alloy kerf edges.

Experimental investigation of cutting parameters during laser beam machining of aluminum alloy 7075

In today’s manufacturing sector, importance of application of lightweight aluminum alloys for construction of structural equipment in automotive, aerospace and aircraft industry is immense. In this study processing of this kind of aluminum alloy, i.e.aluminum 7075 alloy with low power laser beam has been investigated in terms of parametric effect. Influence of laser power, pulse frequency and assist gas pressure has been studied on kerf width and heat affected zone. Response surface methodology is used here to design the experimental run. ANOVA results indicate at the adequacy of developed model as well as the statistical significance of the process parameters. It has been observed that pulse frequency is the main governing factor for kerf width whereas assist gas pressure for HAZ width.

Experimental investigation on WEDM parameters of Ni-rich nitinol plate

Wire Electro discharge machining (WEDM) process is extensively employed to fabricate miniaturized products. Ni-Ti shape memory alloy (Nitinol) finds its primary application in many significant engineering areas and biomedical fields because of its inherent properties, like shape recovery, superior biocompatibility, and elasticity. The current research investigates the shape recoverability characteristics of WEDM machined nitinol. WEDM Experiments were conducted through DOE with significant input factors like the current (I), pulse on time (Ton), and Wire Feed (f). The responses recorded are material removal rate (MRR), wire wear rate (WWR), percentage of shape recovery (R), kerf width (w), and surface roughness (Ra). The mathematical model developed was to predict the response for corresponding input factors, and the variances of the model are analyzed. Significant contributors are identified from ANOVA, and surface plots are drawn to show the interaction effects. The morphological behavior of the surface was analyzed by FESEM and compositional analysis by EDAX. Surface topography is analyzed in surface roughness, and microhardness was measured to understand the process relevant to shape recoverability better. The results reveal that current and pulse on time affect the microhardness and surface roughness, altering the machined alloy’s shape recoverability.

Investigation on surface roughness and kerf analysis in abrasive water jet machining of silicon carbide

Machining silicon carbide (SiC) is challenging due to its brittle and maximum tensile nature. Lapping or laser beam are done with a high cost of manufacturing and low material removal rates. Water abrasive jet cutting is a promising candidate since the machining temperatures and processing force of ceramics are extremely low. Investigation into the abrasive water jet machining of silicon carbide is carried out in the present work.The variations in traverse speed while abrasive water jet cutting of silicon carbide and its effect on the surface roughness and kerf characteristics are studied. Silicon Carbide abrasive material is used as garnet consisting of 80 mesh. The surface roughness was calculated along with the depth of the cut made during the processing.The outcomes demonstrated that the traverse speed is more effective upon the surface roughness and is an important factor that damages the top kerf width and the kerf taper angle.Based on the hardness and thickness of the SiC plate, the taper angle is high, and for a feed rate of 10 mm/min, the surface roughness is low. Less thickness of the SiC plate could have a lower taper angle than with high thickness. The erosive force is provided by abrasive material along with the jet stream.Water abrasive fine jet could effectively machinate silicon carbide ceramic material with a better surface finish accurately. Suitable surface roughness with higher productivity can be attained with medium traverse speed.The effect of process parameters on kerf taper angle and top kerf width in the abrasive water jet machining of silicon carbide is explored, considering surface roughness as an important output parameter.

Gaussian distribution-based modeling of cutting depth predictions of kerf profiles for ductile materials machined by abrasive waterjet

This study proposes a model for the erosion cutting profile to predict the cutting depth under different process parameters for abrasive waterjet (AWJ) cutting. The model follows the Gaussian distribution and is experimentally validated. Additionally, the effects of the dimensional characteristics and process parameters on the kerf geometry were analyzed. It was found that the water pressure, abrasive flow rate, and focusing tube traverse speed changed the slope of the kerf wall without changing the kerf width. However, the standoff distance (SOD) changes the kerf width, whereas the slope of the kerf wall induces minor changes. Furthermore, based on the first-order derivation of the extracted kerf profile, the relationship between jet energy, cutting depth, and kerf width was analyzed. The experimental results revealed that: 1) the relationship between the reduction in the jet energy distribution and cutting depth is non-linear; 2) the jet energy distribution is smallest at the kerf top edge and bottom section. The predictive cutting depth model and jet energy distribution will enable the subsequent optimization of process parameters in the AWJ process.

Investigation of wire EDM process parameter on kerf width for high chromium high carbon steel by response surface methodology

The current work focused on studying the effect of process parameter on kerf width in Wire EDM using molybdenum wire electrode. Pulse on time, pulse off time, Servo voltage and wire feed were selected as a process parameter for design the DoE in Response Surface Methodology. It was observed that electrical parameters chosen had a significant impact on the Kerf Width. Pulse on time is the most important electrical characteristic for Kerf Width. Higher duration of the spark causes the job to shift dimensions. Utilizing Design Expert's point prediction functionality, model validation was carried out.

Achieving controlled topography and wettability through laser surface texturing of Ti6Al4V for bioengineering applications

The global rise of dental and orthopedic implant treatments in the twenty-first-century appeals to researchers for further investigations. The situation is worsening as the rate of failure and revision treatments are considerable. Inadequate osseointegration and infections are the significant causes of the problem. To address the issue laser surface texturing is proficient to modulate surface topography, morphology, wettability, and chemical characteristics. To date, the implant surface features are not configured to receive an optimal response for early bone healing through cell adhesion and proliferation. Experimental design to investigate optimal responses of Ti6Al4V surface by texturing it with nanosecond Nd: YAG 1064 nm laser is carried out. The evolved research surface methodology model resulted in an efficient parametric relationship with 98.5%, 98.87%, and 96.99% R2 values for ‘kerf width’, ‘Rz’, and ‘kerf width to Rz’ ANOVA analysis respectively. The ANN approach shows more accuracy than the RSM approach for the prediction of ‘kerf width’, ‘Rz’, and ‘kerf width to Rz’. The experiment was performed to attain control in the range of water contact angle 40° to 119° as hydrophilic (ϴ ≤ 90) nature is prominently favorable for cell adhesion and proliferation. The Lower ‘kerf width to Rz ratio’ and higher Rz inclined towards hydrophobicity. An increment in carbon content also assists in rising contact angle. LST improves the Ti oxide layer which is considered a more corrosion-resistive and biocompatible layer. This study will certainly help to develop improved stability and life of dental and orthopedic implant surfaces.

Performance evaluation of cryogenic treated and untreated brass electrode in wire-EDM

ABSTRACT WEDM is regarded as a specialized thermo electric cutting process for precise machining in a wide range of materials with varied hardness and complex geometries that curtails utilization of conventional machining methods. The technology of WEDM process requires electricity to penetrate through a material with a thin conductive wire electrode as the tool. In this study, an untreated and deep cryogenic treated (196°C) brass wires are used to experiment with different machining variables such as peak current (IP), tension in the wire, pulse on time (TON), servo feed rate (SF), and pulse off time (TOFF). Monel 400 alloy, a work material that has high mechanical strength and corrosion-resistant properties, for which the output responses such as Surface Roughness (SR) and Material Removal Rate (MRR) are investigated. Taguchi L27 orthogonal array was selected to formulate the design of experiments and to inquire the response of each variable from the output responses. The most influencing parameters such as pulse-on time on MRR, pulse-off time as contributing parameter in surface roughness and wire tension playing a vital role in kerf width were determined by the analysis of variance. MRR is greater with untreated brass wire than cryogenic treated brass wire. Cryogenically treated brass wire provides leverage over untreated brass wire in Surface Roughness and Kerf width. Surface morphological study proves that workpiece machined by deep cryogenic treated wire electrode provides better surface finish over untreated wire electrode which has large pores, voids, and unevenly distributed re-solidified particles. Experimental results are provided to verify this approach, and conclusion is to be drawn on the wire electrode with most phenomenal aspects.

Multi-Objective Optimization of Fiber Laser Cutting of Stainless-Steel Plates Using Taguchi-Based Grey Relational Analysis

Stainless-steel has become a widely preferred material type in the marine, aerospace, sanitary, industrial equipment, and construction industries due to its superior corrosion resistance, high mechanic properties, high strength, formability, and thermal and electrical conductivity. In this study, a multi-objective optimization method based on grey relational analysis was employed to optimize the fiber laser-cutting parameters of cutting speed, focal position, frequency, and duty cycle. Surface roughness and kerf width, which are the two most important parameters that determine laser-cutting quality, were simultaneously optimized. In order to assign the optimum level of each parameter individually, the Taguchi technique was applied. The cutting surface morphology was examined according to the grey relational grade with a 3D optical profilometer, and maps of the cutting surfaces were created. According to the results achieved using Analysis of Variance (ANOVA), it was seen that the parameters that affected surface roughness and kerf width the most were duty cycle, with a contribution rate of 49.01%, and frequency, with a contribution rate of 31.2%. Frequency was the most important parameter in terms of multiple responses, with a contribution rate of 18.55%. Duty cycle and focal position were the second and third most effective parameters, respectively. It was determined that the optimum parameter values for minimum surface roughness and minimum kerf width that could be obtained with the fiber laser cutting of 20 mm thick AISI 304L (DIN EN 1.4301) material were 310 mm/min cutting speed, −11 mm focal position, 105 Hz frequency, and 60% duty cycle.

Micro-mechanism study on tissue removal behavior under medical waterjet impact using coupled SPH-FEM.

To fully grasp the numerical characteristics of the interaction process between medical waterjet and soft tissue, the smoothed particle hydrodynamics (SPH)-finite element method (FEM) was used in the simulation of this complex process to avoid the unstable error caused by indirect measurement in experiments. The SPH was applied to the numerical simulation of medical waterjet, and a three-dimensional model of gelatin sample was proposed with the FEM. The impact process between two extremely deformed materials was reproduced, and the established model was verified by comparison with experimental data; the comparison showed relatively consistent results. The separation effect under three operating modes was deduced with the stress and strain range. For the vertical impact condition, the higher the waterjet impact pressure is, the higher the biological tissue deformation bulge height is. For oblique intrusion, the longitudinal separation rate decreases and the kerf width increases with the increase of the incident angle. For the moving impact condition, with the increase of the waterjet moving speed, the longitudinal high-stress distribution range of the impact object decreases slightly.