EXPERIMENTAL STUDY OF ABRASIVE WATER JET MACHINING OF KEVLAR EPOXY COMPOSITE

Author(s):  
Puneet Kumar ◽  
Ravi Kant

The present paper describes an experimental study of abrasive water jet machining (AWJM) of Kevlar epoxy composite. Influence of process parameters namely stand-off distance, water pressure, traverse speed and abrasive mass flow rate on surface roughness and kerf taper is investigated. Taguchi orthogonal approach is applied to plan the design of experiments; and subsequent analysis of experimental data is done using analysis of variance (ANOVA). It is found that water pressure and traverse speed are most significant parameters followed by stand-off distance and abrasive mass flow rate influencing surface roughness and kerf taper. With increase in water pressure and decrease in traverse speed, kerf taper and surface roughness decreases.

2017 ◽  
Vol 51 (24) ◽  
pp. 3373-3390 ◽  
Author(s):  
Ajit Dhanawade ◽  
Shailendra Kumar

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.


2006 ◽  
Vol 304-305 ◽  
pp. 560-564 ◽  
Author(s):  
Chuan Zhen Huang ◽  
Rong Guo Hou ◽  
Jun Wang ◽  
Yan Xia Feng

The effect of cutting parameters such as water pressure, nozzle traverse speed and standoff distance on the granite cutting performance as characterized by kerf width, kerf taper, and striation drag angle are researched with a series of experiments using garnetabrasive and ultra high pressure abrasive water jet numerical control machine tool. The relationship between system pressure and abrasive mass flow rate is also studied. The research results show that the abrasive mass flow rate is only proportional to water pressure and the effect of other cutting parameters is not significant. It is found that an increase in water pressure is associated with an increased kerf width and a decreased kerf taper. The kerf width decreases with the enhancement of nozzle traverse speed, and resulting in a significant increase in kerf taper as the nozzle traverse speed increases. The kerf width increases with the enhancement of standoff distance, and hence it causes a significant increase in kerf taper at the standoff distance domain from 3mm to 4mm and then a little decrease in kerf taper at the standoff distance increasing from 4mm to 5mm. The striation drag angle decreases with an increase in water pressure and a decrease in nozzle traverse speed.


The main aim of this investigation is to study the surface roughness produced on abrasive water jet machining of the twill weaved carbon fibre reinforced epoxy composite. Abrasive water jet machining experiment was conducted as per L9 orthogonal array, by varying water pressure, transverse speed and SOD. The performance of the composite was analysed by measuring the surface roughness. Using Taguchi analysis, the influences of input parameter over the output response was analysed. It was found that the surface roughness is highly influenced by the transverse speed.


Author(s):  
Thobi Phokane ◽  
Kapil Gupta ◽  
Munish Kumar Gupta

Surface roughness parameters are important indicators for determining the operating performance, tribology behavior, wear and tear characteristics, and service life of engineered parts including gears. This article presents the investigation on surface roughness, and tribology and wear aspects of miniature brass gears manufactured by abrasive water jet machining. Experiments have been conducted based on Taguchi's robust design technique with L9 orthogonal array to machine external spur-type miniature gears of brass having 8.4 mm pitch diameter, 12 teeth, and 5 mm thickness. The effect of three important process parameters namely water jet pressure, abrasive mass flow rate, and stand-off distance on mean roughness depth of miniature gears are analyzed. Surface roughness is found to decrease with the increase in the water jet pressure and abrasive mass flow rate, and increases with the increase in the stand-off distance. Particle swarm optimization technique has been used for parametric optimization to minimize the surface roughness of miniature gears. Confirmation experiment conducted at optimized abrasive water jet machining parameters resulted in superfine surface finish with mean roughness depth value of 4.1 µm superior than the finish obtained by other advanced processes for brass gears. The investigated values of bearing area characteristics, skewness, kurtosis, and friction coefficient confirm the tribological fitness of the miniature brass gear machined at optimum abrasive water jet machining parameters.


2016 ◽  
Vol 66 (5) ◽  
pp. 522 ◽  
Author(s):  
Ajit Dhanawade ◽  
Shailendra Kumar ◽  
R. V. Kalmekar

An experimental study of abrasive water jet machining of carbon epoxy composite is presented. Process parameters namely hydraulic pressure, traverse rate, stand-off distance and abrasive mass flow rate are considered for this study. Taguchi approach and analysis of variance are used to study the influence of process parameters on response characteristics including surface roughness and kerf taper. It is found that hydraulic pressure and traverse rate are most significant parameters to control surface roughness and kerf taper. Microscopic features of the machined surfaces are evaluated using scanning electron microscope and compared with sample surfaces machined by conventional method using diamond edge cutter.A set of process parameters is optimised to achieve minimum surface roughness and kerf taper. Confirmation tests are performed to verify the optimum set of process parameters. Defects like delamination, fibre pull out and abrasive embedment are also studied using scanning electron microscope.


2021 ◽  
Author(s):  
Isam Qasem ◽  
Ahmed Hussien ◽  
Pramodkumar S. Kataraki ◽  
Ayub Ahmed Janvekar

Abstract Advanced machining techniques are extensively being adopted for machining of high strength materials such as stainless steels. However, these materials are difficult to be machined out due to properties such as high work hardening rate and low thermal conductivity, work hardening and poor machinability. The manufacturing requirements such as production of high precision and surface finished components has led the researchers to study abrasive water jet (AWJ) machining and its applications in industrial sectors. As the AWJ is multi-operational and can produce high precision components. The carried-out work mainly intended to involve technical parameters such as water pressure, cutting speed, abrasive flow. These parameters were analyzed with respect to kerf taper and surface roughness on 304 stainless steel. Two critical variables namely cutting speed and outlet pressure were varied from 100 to 200 mm /min and 100 to 200 MPa, respectively. In additional based on the setup flow rate was altered from 360 to 540 g/min. The experimental results indicate kerf taper and surface roughness were strongly deflect by varying cutting rate, water pressure, and flow rate. Optimization of process parameter was performed by adopting response surface methodology as well as central composite design method. Finally, mathematical models and set of contour graphs for tested surface quality along the kerf taper angle was carried out using ANOVA analysis.


Author(s):  
Ehsan Shakouri ◽  
Mohammad Abbasi

The abrasive water jet machining is known as a cold cutting process and can be effective for developing cut in the bone in orthopedic surgery to prevent thermal necrosis. This research examined surface roughness and cutting quality of bovine femur bone using abrasive water jet machining. Furthermore, the effect of three parameters was studied including water pressure, traverse speed, and the type of abrasive particles. The feed rate of the abrasive particles was considered 100 g/min, and the levels obtained from pure water jet cutting, bone powder abrasive water jet machining, and sugar abrasive water jet machining were compared with each other. Application of bone powder as an abrasive particle caused improved cutting quality, when compared with pure water jet, and in the best case, it resulted Ra and Rz values of 7.36 and 54.76 μm, respectively at the pressure of 3500 bar and traverse speed of 50 mm/min. The minimum surface roughness was obtained using sugar abrasive particles at the pressure of 3500 bar and traverse speed of 50 mm/min. The values of Ra and Rz parameters measured at the most desirable state were 3.87 and 19.72 μm, respectively. The results suggested that use of sugar as an abrasive material, in comparison with pure water jet and bone powder water jet, resulted in improved cutting quality. Furthermore, elevation of water pressure and reduction of traverse speed had a significant effect on improving surface roughness.


2018 ◽  
Vol 53 (20) ◽  
pp. 2909-2924 ◽  
Author(s):  
Ajit Dhanawade ◽  
Shailendra Kumar

Traditional machining of carbon epoxy composite material is difficult due to excessive tool wear, excessive stresses and heat generation, delamination, high surface waviness, etc. In the present paper, research work involved in the experimental study of abrasive water jet machining of carbon epoxy composite material is described. The aim of present work is to improve surface finish and studying defects in machined samples. Taguchi's orthogonal array approach is used to design experiments. Process parameters namely hydraulic pressure, traverse rate, stand-off distance and abrasive mass flow rate are considered for this study. Analysis of machined surfaces and kerf quality is carried out using scanning electron microscope to evaluate microscopic features. Further, the effect of machining parameters on surface roughness is investigated using analysis of variance approach. It is found that traverse rate and pressure are most significant parameters to control surface roughness. Optimization of process parameters is performed using grey relational analysis. Thereafter, confirmation tests are carried out to verify the improvement in the surface quality with optimum set of process parameters. It is found that surface finish of machined samples is improved by 10.75% with optimum levels of process parameters. Defects like delamination, fiber pull-out and abrasive embedment are also studied using SEM. It is observed that delamination and fiber pull-out are prominent in samples machined at low pressure and high traverse rate.


2019 ◽  
Vol 895 ◽  
pp. 301-306
Author(s):  
Keshav Kashyap ◽  
S. Srinivas

This study evaluates the effect of process parameters on depth of penetration and surface roughness in abrasive waterjet (AWJ) cutting of copper. Full factorial experiments are carried out on trapezoidal blocks for each of the three abrasive particle sizes used. Experimental parameters - abrasive mass flow rate, water jet pressure and traverse speed are varied at three levels. Main effects and contributions of process parameters to depth of penetration and surface roughness is calculated. From the data, it is observed that, high abrasive mass flow rate, high water jet pressure and low traverse speed resulted in higher depth of penetration and a high abrasive mass flow rate, high water jet pressure and low traverse speed resulted in lesser Ra value. Using experimental data a statistical model for predicting depth of penetration & surface roughness is developed. Error between experimental and statistical values are compared to validate the statistical model. The maximum DOP of 49.32mm was observed at AMFR=405.4 g/min, P=300 MPa, TS=60 mm/min, MS=60 Mesh and minimum DOP of 4.27mm was observed at AMFR=200 g/min, P=100 MPa, TS=90 mm/min, MS=80 Mesh.


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