Kerf Taper Ratio Research Articles

Effects of Abrasive Waterjet Machining on the Quality of the Surface Generated on a Carbon Fibre Reinforced Polymer Composite

The effect of the water pressure, traverse speed, and abrasive feed rate on the circularity, cylindricity, kerf taper, and surface roughness of holes produced by abrasive waterjet machining (AWJM) of a carbon-fibre-reinforced polymer (CFRP) composite was investigated in the current study. It was found that the circularity deviation decreased as the water pressure was increased. Cylindricity was affected by all three parameters, although the abrasive feed rate caused the largest deviations as it increased. The surface roughness was affected by all three, but a clear connection was not able to be concluded. The kerf taper ratio reduced with an increase in water pressure, while it increased with an increase in the abrasive feed rate and an increase in the traverse speed. To obtain optimum results, the water pressure should be increased, the traverse speed should be decreased, and the abrasive feed rate can remain constant but is recommended to be slightly reduced.

Experimental investigation of suspension-type abrasive water jet machining of nitrile rubber for positive displacement motor applications

The lightweight elastomers (such as nitrile rubber) frequently used in the Positive Displacement Motor (PDM) stator assembly are subjected to harsh environmental conditions. These elastomeric components are manufactured by primary casting/shaping methods, followed by secondary manufacturing/machining processes. The production of intricate shapes/sizes in single or batch-size elastomeric components using primary casting methods requires a customized mould to fulfil the requirement of sudden breakdown conditions, which is uneconomical. It necessitates an alternate production method that can satisfy the need for the elastomeric component at the stage of failure. The current research focuses on the possibility of producing nitrile rubber components using a non-conventional machining method, Suspension-type Abrasive Water Jet Machining (AWJM), suitable for batch production with better dimensional stability and versatility in shape/size. This work presents the experimental investigation of Suspension-type AWJM of nitrile rubber specimens (15 mm thick) using a custom-designed Tungsten Carbide (WC) nozzle under room-temperature condition. The top surface of the machined slot is analyzed to determine the mineral composition and abrasive particle embedding through Energy Dispersive Spectroscopy (EDX) and Backscatter Electron (BSE) detector. The Taguchi Orthogonal Array (OA) is employed to study the effect of the process parameters (Water Jet Pressure (WJP), Traverse rate (Vf), and Stand-Off Distance (SOD)) on the performance parameters (Kerf Taper Ratio (KTR), and Material Removal Rate (MRR)). The Analysis of Variance (ANOVA) is applied to check the statistical significance and percentage contribution of each process parameter on the performance of Suspension-type AWJM. The uniformity in the geometry of the machined slot is analyzed by the waviness patterns observed in the profile images of the cut specimen. The analysis of the EDX results reveals the presence of Manganese (Mn) and an increased percentage of Silicon (Si) particles near the top surface of the machined slot. The SOD influences KTR the most, whereas Vf highly influences MRR. It is observed that the waviness pattern is minimal at high WJP experimental runs. The outcome of this research work provides a quick and economical method of producing the PDM bushings instead of the casting/moulding method.

Investigation on Performance and Kerf Characteristics during Cryogenic-Assisted Suspension-Type Abrasive Water Jet Machining of Acrylonitrile Butadiene Rubber

The need for soft polymer (such as acrylonitrile butadiene rubber (ABR)) components in mating applications is increasing in several sectors, viz. automobile, mining, and marine, due to their viscoelastic nature with improved surface quality and tighter geometric tolerances. Therefore, this paper aims to compare the effect of cryogenic conditions on the performance parameters of the suspension-type abrasive water jet (S-AWJ) machining and investigate the kerf characteristics of the top and bottom surface by comparing the waviness of the cut profiles and abrasive contamination of the top surface near the vicinity of the slot under conventional (room temperature) and cryogenic (liquid nitrogen (LN2)) conditions. The study found that the use of LN2 positively affected the performance parameters (Kerf taper ratio (KTR) and material removal rate (MRR)) due to a sudden increase in Young’s modulus and a decrease in elasticity of the machining zone. The cryogenic-assisted S-AWJ at the highest water jet pressure (WJP) (250 bar) produced better kerf characteristics through uniform and waviness-free top and bottom kerf profiles than the other experimental sequences. The use of LN2 resulted in the embrittlement of ABR, due to which less garnet abrasive particle contamination was observed during cryogenic-assisted S-AWJ machining.

Effect of standoff distance on the kerf characteristic during abrasive water jet machining

The aim of this research is to elucidate the effects of the standoff distance (SOD) in abrasive water jet machining (AWJ) on mild steel. Nine different standoff distances (z) of 5, 8, 10, 11, 15, 18, 20 and 25mm AISI 1090 steel samples were used in this study. Following the test, the kerf width and kerf taper ratio were measured. The surface morphology characteristics of the machined surface were investigated using a scanning electron microscope (SEM). The results revealed that the ratio of kerf taper increased as the standoff distance and kerf width increased. Compared to the 15mm standoff distance, 8 mm at the jet entry and exit exhibited more uniformity in kerf appearance. Both 8 and 15mm standoff distances showed that the surface roughness gradually became rougher towards the jet exit.

Eksperimentalno istraživanje kriogeno potpomognute obrade čelika za kalupe abrazivnim vodenim mlazom

This paper reports the investigation on parametric optimization of the abrasive aqua jet (AAJ) and cryogenic assisted abrasive aqua jet (CAAAJ) processes for cutting AISI D2 steel using multi objective TOPSIS approach. The input parameters considered were aqua jet pressure, abrasive grit size and jet impingement angle. In this study, depth of penetration, metal removal rate, kerf taper ratio and average roughness were taken as the performance characteristics. The results showed that the CAAAJ process exhibited better performance characteristics than the AAJ process. The AAJ machining process with an inclined jet impact angle influences the output responses, which is evident from an optimal selection of parameters. Besides, the influencing process variables were determined by using the analysis of variance. The overall machining performance of the AAJ and CAAAJ processes were improved by using the optimum process variables through the TOPSIS method.

Performance Analysis of Abrasive Waterjet Machining Process at Low Pressure

Normally, a commercial waterjet cutting machine can generate water pressure up to 600 MPa. This range of pressure is used to machine a wide variety of materials. Hence, the price of waterjet cutting machine is expensive. Therefore, there is a need to develop a low cost waterjet machine in order to make the technology more accessible for the masses. Due to its low cost, such machines may only be able to generate water pressure at a much reduced rate. The present study attempts to investigate the performance of abrasive water jet machining process at low cutting pressure using self-developed low cost waterjet machine. It aims to study the feasibility of machining various materials at low pressure which later can aid in further development of an effective low cost water jet machine. A total of three different materials were machined at a low pressure of 34 MPa. The materials are mild steel, aluminium alloy 6061 and plastics Delrin®. Furthermore, a traverse rate was varied between 1 to 3 mm/min. The study on cutting performance at low pressure for different materials was conducted in terms of depth penetration, kerf taper ratio and surface roughness. It was found that all samples were able to be machined at low cutting pressure with varied qualities. Also, the depth of penetration decreases with an increase in the traverse rate. Meanwhile, the surface roughness and kerf taper ratio increase with an increase in the traverse rate. It can be concluded that a low cost waterjet machine with a much reduced rate of water pressure can be successfully used for machining certain materials with acceptable qualities.

Experimental Investigations on Multiple Responses in Abrasive Waterjet Machining of Ti-6Al-4V Alloy

In general, Ti-6Al-4V alloys are one of the challenging materials to machine using conventional machining process. Due to its high strength to weight ratio, good thermal stable property and exceptional corrosion resistance, Ti-6Al-4V became an attention-grabbing material to propose a proper modeling and machining for various types of applications. In this research study, Ti-6Al-4V was machined using Abrasive Waterjet Machining under different process parameters such as mesh size, abrasive flow rate, pressure and traverse speed. The Machining approach is based on the Box Behnken method to enhance the Abrasive waterjet machining process parameter for effective machining of Ti-6Al-4V. Then multiple responses were carried out such as kerf taper geometries (θ), surface roughness (Ra) and material removal rate (MRR). The structures of various machining surface regions were examined using Scanning electron microscopy (SEM). The experimental results specify that high pressure, low traverse speed, low abrasive mesh size and high abrasive flow rate were resulted in lower surface roughness in Ti-6Al-4V. And it was found that high pressure, high mesh size leads to minimum kerf taper ratio and whereas high traverse speed produce a maximum kerf taper. It was also evident that high abrasive flow rate, standard traverse speed and low pressure provide high MRR in selected conditions.

Optimization of WEDM Process Parameters on Multiple Responses in Cutting of Ti-6Al-4V

Ti-6Al-4V alloys are one of the toughest materials to machine using conventional machining process due to its high too wear ratio and high elevating cutting temperature. Owing to its fatigue resistance, excellent corrosion resistance, high strength to weight ratio and good thermal behavior, Ti-6Al-4V became a most important material to propose a proper modeling and machining for different types of applications. In this research study, Ti-6Al-4V was machined using Wire Electrical Discharge Machining under various process parameters like pulse on time TON, pulse off time TOFF, Wire feed, Servo Gap voltage and cutting speed. The approach is based on the Box Behnken method to optimize the WEDM process parameter for efficient machining. After the machining, multiple responses were examined such as kerf taper geometries (θ) and material removal rate (MRR). The topographies of different cutting surface regions were analyzed using SEM (Scanning electron microscopy investigation). The experimental results indicate that pulse on time, wire feed and servo gap voltage increases to increase the kerf taper ratio in Ti-6Al-4V machining. It was also observed that MRR increase with high pulse on time TON, low pulse off time TOFF and low servo voltage in the selected environmental conditions. By those multiple responses, it was evident that quality of cutting surface of Ti-6Al-4V at optimum condition obviously depends on different process parameter significantly.

Study and evaluation of abrasive water jet cutting performance on AA5083-H32 aluminum alloy by varying the jet impingement angles with different abrasive mesh sizes

ABSTRACTThis article describes the experimental investigation of abrasive water jet (AWJ) cutting on AA5083-H32 aluminum alloy. In this study, the influence of varying the jet impingement angles and abrasive mesh sizes with different water jet pressures, on the output parameters for the AWJ cutting of the aluminum alloy, was analyzed. The experimental results found that the output parameters, namely, the depth of penetration, top kerf width, kerf taper ratio, surface roughness, and abrasive contaminations, were strongly influenced by the combined effect of oblique jet impingement angles and abrasive mesh sizes on AWJ. Also, it is noticed that oblique jet impingement angles have more influence on the output cutting responses than the normal jet impingement angle, and consequently, each abrasive mesh size has an influence on the different output responses for the AWJ cutting of AA5083-H32. Scanning electron microscope and microhardness tester were used to examine the different cutting regions of the kerf wall surfaces. The Energy-dispersive X-ray spectroscopy analysis was used to confirm the amount of silicon particles embedded in the AWJ cut surfaces. The adequacy checking of the experimental data for the AWJ cutting performance models has been analyzed through the residual plots using the statistical software.

Experimental study of delamination and kerf geometry of carbon epoxy composite machined by abrasive water jet

The present article focuses on mechanism of delamination and kerf geometry in abrasive water jet machining of carbon epoxy composite. In the present study, four process parameters of abrasive water jet machining namely hydraulic pressure, traverse rate, stand-off distance, and abrasive mass flow rate are considered. The experiments are performed on the basis of response surface methodology as a statistical design of experiment approach. Delamination in machined samples is observed by using scanning electron microscope. Analysis of variance is performed in order to investigate the influence of process parameters on delamination, kerf taper ratio, and kerf top width. It is found that delamination decreases with increase in pressure and abrasive mass flow rate and decrease in stand-off distance and traverse rate. Kerf taper ratio decreases with increase in pressure and decrease in traverse rate and stand-off distance. Kerf top width decreases with decrease in stand-off distance and increase in traverse rate. Based on analysis, mathematical models are developed to predict the maximum delamination length, kerf taper ratio, and kerf top width. Further, a multi-response optimization is performed on the basis of desirability function to minimize delamination, kerf taper ratio, and kerf top width.

Surface quality of marble machined by abrasive water jet

AbstractThis paper presents a study conducted to examine the effect of cutting parameters, namely standoff distance, nozzle traverse speed (TS), abrasive flow rate (AFR), and material type on cutting performance for two types of marble workpieces, Carrara white and Indian green. Statistical analysis was undertaken to assess the influence of the cutting parameters on the process performances in terms of surface roughness, surface waviness, and Kerf taper ratio. The results showed that the TS and material type were the most significant factors that affected surface roughness and Kerf taper ratio. Also, although AFR was found to have significant effect on surface waviness, it had no noticeable influence on surface roughness nor Kerf taper ratio.

CO2 laser cut quality of Inconel 718 nickel – based superalloy

This paper experimentally investigates the cut quality of laser cutting for the age hardened Inconel 718 nickel based super alloy, with the use of a continuous CO2 4.0kW laser cutting system. The quality of the cut has been monitored by measuring the kerf taper ratio, the recast layer thickness and the surface roughness of the cut specimens. The effects of processing parameters, such as the laser power, the cutting speed and the assisting gas pressure were evaluated. Scanning electron microscopy (SEM), Energy Dispersive Spectrography (EDS), X–Ray Diffraction (XRD), Atomic Force Microscopy (AFM) and Knoop hardness tests are carried out to examine the cutting defects, the kerf size variation and formed carbide on the surfaces. A statistical analysis of the results has been performed in order for the effect of each parameter on the cutting quality to be determined. The regression analysis has been used for the development of empirical models able to describe the effect of the process parameters on the quality of laser cutting.

Effect of Traverse Speed on Abrasive Waterjet Machining of Age Hardened Inconel 718 Nickel-Based Superalloy

In this study, the effect of traverse speed on abrasive waterjet machining (AWJM) of Inconel 718 nickel-based superalloy was experimentally investigated. In the experiments, six different traverse speeds of 80, 130, 180, 230, 280, and 330 mm/min were employed. Following the tests, the surface roughness of the machined job, the kerf taper ratio, and kerf wideness were measured. The characteristics of machined surface were also investigated using scanning electron microscope (SEM) and atomic force microscope (AFM). As a consequence, it is observed that the surface roughness and kerf taper ratio tended to increase with traverse speed, while kerf wideness decreased.

A study of abrasive water jet machining process on glass/epoxy composite laminate

Surface roughness ( R a ) and kerf taper ratio ( T R ) characteristics of an abrasive water jet machined surfaces of glass/epoxy composite laminate were studied. Taguchi's design of experiments and analysis of variance were used to determine the effect of machining parameters on R a and T R . Hydraulic pressure and type of abrasive materials were considered as the most significant control factor in influencing R a and T R , respectively. Due to hardness of aluminium oxide type of abrasive materials, it performs better than garnet in terms of both machining characteristics. Increasing the hydraulic pressure and abrasive mass flow rate may result in a better machining performance for both criteria. Meanwhile, decreasing the standoff distance and traverse rate may improve both criteria of machining performance. Cutting orientation does not influence the machining performance in both cases. So, it was confirmed that increasing the kinetic energy of abrasive water jet machining (AWJM) process may produce a better quality of cuts.

Effect of abrasive water jet machining parameters on aramid fibre reinforced plastics composite

This paper presents a study on the effect of abrasive water jet machining (AWJM) process parameters on surface roughness (Ra) and kerf taper ratio (TR) of aramid fibre reinforced plastics (AFRP) composite. Taguchi’s design of experiment was used as the experimental approach. Through analysis of variance (ANOVA), it was found that the traverse rate was considered to be the most significant factor in both Ra and TR quality criteria. Ra and TR were reduced as increasing the hydraulic pressure and reducing the standoff distance and traverse rate. However, there was no clear pattern for abrasive mass flow rate on both Ra and TR. Therefore, it was confirmed that increasing the kinetic energy of water jet may produce a better quality of cuts. Mathematical models were also developed using multiple linear regression analysis to predict the performance of Ra and TR in terms of AWJM process parameters. Considerably, the models are useful in predicting Ra and TR in AWJM of AFRP laminate as shown in present study.

Effect of traverse speed on abrasive waterjet machining of Ti–6Al–4V alloy

In the presented study, Ti–6Al–4V alloy, known as one of the difficult-to-machine materials using conventional machining processes, was machined under varying traverse speeds of 60, 80, 120, 150, 200, and 250 mm/min by abrasive waterjet (AWJ) machining. After machining, the profiles of machined surfaces, kerf geometries and microstructural features of the machined surfaces were examined using surface profilometry and scanning electron microscopy (SEM). The experimental results indicate that the traverse speed of the jet is a significant parameter on the surface morphology, and the widths and features of different regions formed in the cutting surface change according to the traverse speed. It was also observed that the kerf taper ratio and surface roughness increase with increasing traverse speed in chosen conditions.