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Machinability Studies on Stainless steel by abrasive water jet -Review
Available online at www.sciencedirect.com
ScienceDirect Materials Today: Proceedings 5 (2018) 2871–2876
www.materialstoday.com/proceedings
ICAMA 2016
Machinability Studies on Stainless steel by abrasive water jet Review Supriya S Ba , S Srinivasa* a
Department of Mechanical Engineering, B.M.S College of Engineering, Bengaluru-560019, India
Abstract Stainless Steels are alloy steels with high resistance to corrosion and heat, strength, durability, low maintenance, fabrication flexibility and high hardness. Many studies have demonstrated the advantages of using Stainless Steels in the field of automotive and other industrial applications. Stainless steels are generally more challenging to machine due to high alloying content. The major problems with conventional machining of Stainless Steels are high work hardening, poor chip breaking, usage of various tools with different tool geometry, application of huge coolant supply during machining. These problems results in increased production time and cost. While machining Stainless Steels it is important to ensure that there is no machine vibration or tool chatter and conventional tools are prone to edge chipping. Because of these problems other alternate techniques are considered for machining of Stainless Steel. Abrasive Water Jet Machining (AWJM) is an effective method for machining, cutting and drilling of stainless steels. AWJ machining is a non-conventional machining process where material is removed by erosion of high velocity abrasives entrained in water jet. This paper discusses the machining studies on Stainless Steels by Abrasive Water Jet. © 2018 Published by Elsevier Ltd. Selection and Peer-review under responsibility of International Conference on Advanced Materials and Applications (ICAMA 2016). Keywords : Stainless Steel; Abrasive Water jet Machining
1. Introduction During 60’s the application of pure water for cutting was introduced. Water jet machining is a non-traditional machining process used to cut soft, metallic as well as non-metallic materials.
*Corresponding author. Tel.: +919964500251. E-mail address:[email protected]
2214-7853© 2018 Published by Elsevier Ltd. Selection and Peer-review under responsibility of International Conference on Advanced Materials and Applications (ICAMA 2016).
2872
Supriya S B and Srinivas S / Materials Today: Proceedings 5 (2018) 2871–2876
In water jet machining, a high velocity water jet is made to strike a work piece. During this process high pressure energy is converted to kinetic energy. Later on abrasives are added to high pressure water jet for cutting of high strength and hard materials. The water jet process provides many unique capacities and advantages to reduce cost. Water jet technology is the fastest growing and versatile process in the world. Toxic fumes, recast layers, slag and thermal stress are totally eliminated. Cutting forces are less and no heat affecting zone near cutting area. It has been proved that the materials which are machined by water jet simply cannot be machined more efficiently by any other technologies such as cutting thin details in stone, glass, and metals to rapid drilling of hole in titanium [1]. Main application of pure water jet machining includes cutting paper products, wood, clothes, plastics etc. Thus the abrasive water jet machine was made accessible to industries by 1980’s which could be used to machine hard materials. The growth of high performance material such as ceramics and composites has a range of manufacturing challenges. The high pressure water jet with abrasive additives such as silica, garnet, aluminum oxide, Silicon carbide etc are entrained in high speed water jet to erode materials from the surface of material. The material removal ensues by cutting wear and deformation wear, cutting wear defines erosion at smaller impact angle. Deformation wear occur by repeated attack of abrasives at larger impact angle. There are three area in abrasive water jet machined surface they are initial damage area, smooth cutting area and rough cutting area [2]. Water jet can be categorized under three criteria pressure, continuity and number of phases. Under pressure two types low pressure within 150 MPa range and high pressure ranges within 150 MPa - 550 MPa. Under continuity there are two types of water jet namely continuous and discontinuous water jets. Discontinuous water jet are obtained by means of mechanical mechanism or other kind of external mechanisms and the number of phases includes three phase jets formed from water, abrasive particles and air. Water jet results in passing water through a nozzle at high pressure about 100 - 400 MPa. Three zones are present in the structure of a high pressure water jet. Initial zone, the radial distribution of velocity is constant and the value is the same as those of exit from nozzle; the length of the zone depends on the pressure and diameter of the nozzle. Inside the principle zone the dynamic parameters of the jet varies on radial and axial directions. Disintegration zone starts from the point where core of the jet is not seen any more [3]. Abrasive water jet (AWJ) system contains components such as water purifier and storage system with high pressure generating system along with cutting head, abrasive delivery system and catcher tank as shown in figure 1. To supply pressure to ultrahigh pressure pump constantly water purifier and storage system is used. There are two different storage tanks in abrasive water jet system i) cutting tank and ii) cooling water tank , usually particle size having superior than 1µm needs to be separate from water because pump may fail to work and to reduce the temperature of the oil pump , cooling water tank is used as shown in figure 2. High pressure generating system is fitted out with intensifier and accumulator to produce high pressure and for the storage of high pressure water. Intensifier is functioned by oil pressure which includes double acting reciprocating pump. Ultra high pressure pump contains two circuits to produce high pressure up to 600MPa and to reduce pressure loss in next stage the accumulators are used. By using water jet, the target material is being cut which contains enormous amount of energy needed to absorb before it can damage any part. Cather is used to gather the pressurized water after cutting. The high energy of water particle transfers to abrasive particle then mixer of water and abrasive pass through nozzle which act as saw to cut the material in the mixing chamber. In AWJ cutting, the surface roughness and the dimensional accuracy depend on process parameters such as feed rate, water pressure, traverse speed, and standoff distance, impact angle etc. As feed rate increased, the AWJ cuts narrower kerf. This is because fewer abrasives are made to strike on the target material and produces a finer slot [3]. The upper area of cut is having good surface texture compared to middle and lower area. As abrasive flow rate were increased surface roughness reduces gradually, roughness is less sensitive to change in the feed rate [4]. AWJ machining follows the theory of fluid mechanics, abrasive wear and damage mechanics. This mechanics gives a unique capability compared with conventional machining [5]. 2. Literature survey Y. B Gaidhani [6] investigated on Cutting of stainless steel plates in which there was a problem in making fixture part. It was a challenge to get a solution without losing its metallurgical properties for the purpose of making fixtures part. By the literature review it was found that AWJ technique is most suitable solution and suited best for the given practical problem.
Supriya S B and Srinivas S. / Materials Today: Proceedings 5 (2018) 2871–2876
2873
Abrasive water jet proposals potential for the improvement in cutting which is less sensitive to material properties has nearly no thermal effects and impose minimal stresses. Abrasive offer no thermal effects and impose nominal stresses as it is a cold cutting process and vertical thrust is less as the jet diameter is small.
Fig 1. Illustration of an abrasive water jet cutting process [7]
Fig 2. Process parameters influencing the AWJ cutting process [6]
The major part in this process is selection of various process parameters like impact angle, pumping system pressure, abrasive material, standoff distance, diameter of focusing tube, speed of nozzle, mass flow rate of abrasive and material properties of the target material for receiving the essential output like depth of cut and the cut quality. For cutting stainless steel 304 grade, the significant task is to find out a few parameters which influence more. With the assistance of analytical hierarchy process technique the selection of a few parameters are done which are more influencing.
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Supriya S B and Srinivas S / Materials Today: Proceedings 5 (2018) 2871–2876
The percentage of Standoff distance was 19%, nozzle feed rate 18%, and flow rate of abrasives and abrasive material with 17% weightage are the moderately important parameters which are used for additional investigation however the effect of pressure is not investigated [6]. M. Chithirai Pon Selvan et al. [7] focused on effect of process parameters on surface roughness and the depth of cut which were significant cutting performance measure in cutting of stainless steel by AWJ. His work depicts that the effects of various working parameters such as pressure, mass flow rate of abrasives, traverse speed and nozzle standoff distance on surface roughness and depth of cut have been studied. In his work grade 304 of stainless steel plates with a thickness of 150×100×60 mm dimension were used. The gravity type feed type of abrasive hopper were used for the continuous supply of abrasives to the cutting head. Pneumatically controlled valves with a work piece table of dimension of 3000mm×1500mm were used. Sapphire orifice with a carbide nozzle was used to convert high pressure water into a collimated jet and to form abrasive water jet. The work presents these process parameters have straight influence on depth of cut and surface roughness. It has been found that water jet pressure has the most effect on the surface roughness and depth of cut. Depth of cut is increased as water jet pressure is increased but surface roughness decreases gradually. These results indicate that the use of high water jet pressure is favored to obtain good cutting performance. Depth of cut regularly increases and surface roughness decreases as mass flow rate increases. It is suggested to use more mass flow rate to increase depth of cut and to decrease surface roughness. Among the process parameters measured here water pressure and abrasive mass flow rate have the related effect on depth of cut and surface roughness. As nozzle traverse speed increase, surface roughness increases but depth of cut decreases. It means more depth of cut and surface roughness is obtained only by low traverse speed but at the cost of sacrificing productivity. This investigational study has resulted that standoff distance has no apparent effect on depth of cut. However, surface smoothness increase as standoff distance decreases. Therefore to accomplish a complete cutting performance, low standoff distance should be selected. Author based his work on investigational results an empirical model for the estimate of depth of cut in AWJC process of stainless steel has been established using regression analysis. Also verification of the established model for using it as a practical guideline for selecting the parameters has been found to agree with the trials. Therefore the need for extensive investigational work in order to select the levels of the most significant abrasive water jet cutting parameters on depth of cut of stainless steel can be eradicated. Thrust force is identified as the major cause for delamination . The cutting experiment were done on rectangular block and not on trapezoidal target materials further full factorial experiment were not conducted to investigate the influence of pressure , mass flow rate and traverse speed on depth of cut [7]. M. Chithirai Pon Selvan et al. [8] carried out the work on the influence of process parameters on depth of cut which is an important cutting performance measure in abrasive water jet cutting of stainless steel. The process variables considered here include traverse speed, abrasive flow rate, standoff distance and water pressure. Experiments were conducted in varying these parameters for cutting stainless steel using abrasive water jet cutting process. In order to correctly select the process parameters, an empirical model for the prediction of depth of cut in abrasive water jet cutting of stainless steel is developed using regression analysis. This developed model has been verified with the experimental results that reveal a high applicability of the model within the experimental range used. In this full factorial experiments were not considered in this study [8]. Murugabalaji et al.[9] worked on experimental investigation on AWJM of Stainless steel 304 of thickness 40mm is supported using Response Surface Methodology (RSM) with Box-Behnken method. The stainless steel work piece is shown in figure 3 below. The input process parameters measured are pressure (P), traverse rate (TR) and mesh size (MS). Effects were investigated using a method named as Analysis of Variance (ANOVA) and response surfaces independently on depth of cut (DOC) and surface roughness (Ra).
Supriya S B and Srinivas S. / Materials Today: Proceedings 5 (2018) 2871–2876
2875
ANOVA and response surface analyses showed that combinations of process parameters such as high pressure (300 MPa), medium mesh size (# 100) and low traverse rate (30 mm/min) caused in higher DOC whereas lower Ra is obtained with combinations of pressure around (300 MPa), small mesh size (# 80) and less traverse rate (30 mm/min). Orthogonal array of experiments were conducted further full factorial experiments were not conducted to investigate the influence of pressure, mass flow rate, and traverse speed on depth of cut .[9].
Fig. 3 Photograph of the Stainless Steel work piece (Top surface) [9]
Chirag M Parmar et al. [10] presented work on AWJM using Taguchi method to optimize process parameters for commercially three different materials AL-6351, Fiber Reinforced Plastic and SS-316. Experimental investigations conducted to assess the influences of penetration on standoff distance, work feed rate and jet pressure. The output parameters to be studied were surface unevenness and MRR [10]. P. P Badgujar et al. [11] experimented the influence of process parameters pressure, abrasive material, grain size, standoff distance, nozzle speed and abrasive mass flow rate on surface roughness which is an important cutting performance measure in abrasive water jet cutting of stainless steel (SS304). The objective of this paper was to select the level of parameter one variable at a time analysis (OVAT). The input parameters were pressure, abrasive material grain size, standoff distance, nozzle speed and abrasive mass flow. Also the effect of input parameter on surface roughness was analyzed for machining Stainless steel (SS 304). It was observed that, higher levels of the process parameters excluding the abrasive size resulted in higher surface roughness in the work piece. The lower surface roughness was obtained when higher mesh size was used, while the higher roughness was achieved with an abrasive of smaller mesh size. As water jet nozzle speed was increased, surface roughness also increased. It was concluded that the higher standoff distance resulted in a constant increase in the surface roughness same result was observed for higher water jet pressure. The number of experiments conducted was six trials and however full factorial experiments were not conducted to investigate the influence of pressure, mass flow rate, and traverse speed on depth of cut. [11]. Ion Aurel perianu et al. [12] carried out research in the field of abrasive water jet cutting of materials which are hard to process by machining such as austenitic stainless steels, in this presented work, austenitic steel EN 1.4306 with a thickness of 20 mm and only three altered water pressure values with a range 3400 – 3800 bars was considered. The optimal cutting process parameters were selected based on technical, economic, type and thickness of the target material and also the physical and geometrical quality requirements. The abrasive used is Garnet of 80 mesh size. By measuring the surface roughness and hardness of the cut surface, estimation were made for the surface quality defining the optimal pressure values. Increase in water jet pressure resulted in increase of depth in the hardened layer and of maximum surface hardness.Independent of the water jet pressure, the cut surface roughness in the cut starting area is far better than the roughness in the lower cut ending area. SEM studies revealed that for all water jet pressure values the removal of material was unvarying at the top surface impact zones and irregular in the end final exit areas of the material [12].
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Supriya S B and Srinivas S / Materials Today: Proceedings 5 (2018) 2871–2876
1. Conclusion • AWJ cutting is a significant technology used for cutting any intricate profile and drill holes in extensive range. It can be also be used for detailed machining. The efficient performance of abrasive water jet process depends on process parameters such as traverse speed, mass flow rate of abrasives, standoff distance, water jet pressure, abrasive mesh size etc. and material parameters like thickness, type of the material. • It was concluded from literature that hydraulic pressure and type of abrasive materials were considered as the most significant control factor in influencing surface roughness and depth of penetration. High traverse speed results in lower material removal rates in material. • Decrease in standoff distance and traverse speed leads to improve machining performance. • Proper selection of nozzle and orifice can improve quality of kerf. • There is a scope to investigate machinability studies on stainless steel by conducting full factorial experiments. Acknowledgement The authors would like to thank TEQIP, Center of Excellence, BMSCE Benguluru-560019, and the concerned faculty for providing the assistance in presenting this review. References [1] Abhishek Dixit , Vikas Dave , M. R Baid , Water jet machining – An advance manufacturing process,International Journal of Engineering Research and General Science , Volume 3, Issue 2, Part 2, March- April, 2015 [2] Sreekesh .K , Dr . Govindan .P, A Review on abrasive water jet cutting , International Journal of Recent Advances in Mechanical Engineering (IJMECH) Volume 3,No 3, August 2014 [3] Jignesh K Patel , Abdulhafiz,The influence of abrasive water jet machining parameters on various responses- review, International Journal of Mechanical Engineering and Robotics Reasearch ,ISSN 2278-0149 ,Volume 4,No.1,January 2015. [4] Cristian Birtu , Valeria Avramescu , Abrasive water jet cutting technique equipment performances ,Romanian Associate of Nonconventional technology,March 2012 [5] P. Jankovic ,T. Igic , D. Nikodijevic, Process parameters effect on material removal mechanism and cut quality of abrasive water jet machining,Volume 40, no.2,pp 277-291, Belgrade 2013* [6] Y. B Gaidhani, V. S Kalamani , Abrasive water jet review and parameter selection by AHP method, Procedia CIRP 6 (2013) 577-582. [7] M. Chithirai Pon Selvan. A Machinability Study of Stainless Steel Using Abrasive Waterjet Cutting Technology ,International Conference on Mechanical, Automobile and Robotics Engineering (ICMAR'2012) Penang. Malaysia [8] M. Chithirai Pon Selvan, Assessment of process parameters in abrasive waterjet cutting of stainless steel, International Journal of Advances in Engineering & Technology, July 2011, ©IJAET [9] Murugabalaji, A. Kannan , N. Nagarajan, Experimental investigation on abrasive water jet machining of stainless steel 304,IJMEIT , Volume.03,Issue 07 july, Page No 1446-1454,ISSN – 2348-196X, 2015 [10] Chirag .M . Parmar, Mr.Pratik . K. Yogi, Mr.Trilok D Parmar,Experimental investigation on abrasive water jet machine using taguchi techniques to optimize process parameter of various materials – a review, international journal for technogical research in engineering ,Volume 1,Issue 6, Febraury -2014. [11] P. P. Badgujar , M. G .Rathi, Anaysis of surface roughness in abrasive water jet cutting of stainless steel , international journal of engineering research and technology , ISSN :2278-0181,Volume 3, Issue 6, June- 2014 [12] Ion Aurel perianu, Researches regarding the effect of pressure on surface quality during abrasive waterjet cutting of austenitic steels, 15. - 17. 5. 2013, Brno, Czech Republic, EU
ScienceDirect Materials Today: Proceedings 5 (2018) 2871–2876
www.materialstoday.com/proceedings
ICAMA 2016
Machinability Studies on Stainless steel by abrasive water jet Review Supriya S Ba , S Srinivasa* a
Department of Mechanical Engineering, B.M.S College of Engineering, Bengaluru-560019, India
Abstract Stainless Steels are alloy steels with high resistance to corrosion and heat, strength, durability, low maintenance, fabrication flexibility and high hardness. Many studies have demonstrated the advantages of using Stainless Steels in the field of automotive and other industrial applications. Stainless steels are generally more challenging to machine due to high alloying content. The major problems with conventional machining of Stainless Steels are high work hardening, poor chip breaking, usage of various tools with different tool geometry, application of huge coolant supply during machining. These problems results in increased production time and cost. While machining Stainless Steels it is important to ensure that there is no machine vibration or tool chatter and conventional tools are prone to edge chipping. Because of these problems other alternate techniques are considered for machining of Stainless Steel. Abrasive Water Jet Machining (AWJM) is an effective method for machining, cutting and drilling of stainless steels. AWJ machining is a non-conventional machining process where material is removed by erosion of high velocity abrasives entrained in water jet. This paper discusses the machining studies on Stainless Steels by Abrasive Water Jet. © 2018 Published by Elsevier Ltd. Selection and Peer-review under responsibility of International Conference on Advanced Materials and Applications (ICAMA 2016). Keywords : Stainless Steel; Abrasive Water jet Machining
1. Introduction During 60’s the application of pure water for cutting was introduced. Water jet machining is a non-traditional machining process used to cut soft, metallic as well as non-metallic materials.
*Corresponding author. Tel.: +919964500251. E-mail address:[email protected]
2214-7853© 2018 Published by Elsevier Ltd. Selection and Peer-review under responsibility of International Conference on Advanced Materials and Applications (ICAMA 2016).
2872
Supriya S B and Srinivas S / Materials Today: Proceedings 5 (2018) 2871–2876
In water jet machining, a high velocity water jet is made to strike a work piece. During this process high pressure energy is converted to kinetic energy. Later on abrasives are added to high pressure water jet for cutting of high strength and hard materials. The water jet process provides many unique capacities and advantages to reduce cost. Water jet technology is the fastest growing and versatile process in the world. Toxic fumes, recast layers, slag and thermal stress are totally eliminated. Cutting forces are less and no heat affecting zone near cutting area. It has been proved that the materials which are machined by water jet simply cannot be machined more efficiently by any other technologies such as cutting thin details in stone, glass, and metals to rapid drilling of hole in titanium [1]. Main application of pure water jet machining includes cutting paper products, wood, clothes, plastics etc. Thus the abrasive water jet machine was made accessible to industries by 1980’s which could be used to machine hard materials. The growth of high performance material such as ceramics and composites has a range of manufacturing challenges. The high pressure water jet with abrasive additives such as silica, garnet, aluminum oxide, Silicon carbide etc are entrained in high speed water jet to erode materials from the surface of material. The material removal ensues by cutting wear and deformation wear, cutting wear defines erosion at smaller impact angle. Deformation wear occur by repeated attack of abrasives at larger impact angle. There are three area in abrasive water jet machined surface they are initial damage area, smooth cutting area and rough cutting area [2]. Water jet can be categorized under three criteria pressure, continuity and number of phases. Under pressure two types low pressure within 150 MPa range and high pressure ranges within 150 MPa - 550 MPa. Under continuity there are two types of water jet namely continuous and discontinuous water jets. Discontinuous water jet are obtained by means of mechanical mechanism or other kind of external mechanisms and the number of phases includes three phase jets formed from water, abrasive particles and air. Water jet results in passing water through a nozzle at high pressure about 100 - 400 MPa. Three zones are present in the structure of a high pressure water jet. Initial zone, the radial distribution of velocity is constant and the value is the same as those of exit from nozzle; the length of the zone depends on the pressure and diameter of the nozzle. Inside the principle zone the dynamic parameters of the jet varies on radial and axial directions. Disintegration zone starts from the point where core of the jet is not seen any more [3]. Abrasive water jet (AWJ) system contains components such as water purifier and storage system with high pressure generating system along with cutting head, abrasive delivery system and catcher tank as shown in figure 1. To supply pressure to ultrahigh pressure pump constantly water purifier and storage system is used. There are two different storage tanks in abrasive water jet system i) cutting tank and ii) cooling water tank , usually particle size having superior than 1µm needs to be separate from water because pump may fail to work and to reduce the temperature of the oil pump , cooling water tank is used as shown in figure 2. High pressure generating system is fitted out with intensifier and accumulator to produce high pressure and for the storage of high pressure water. Intensifier is functioned by oil pressure which includes double acting reciprocating pump. Ultra high pressure pump contains two circuits to produce high pressure up to 600MPa and to reduce pressure loss in next stage the accumulators are used. By using water jet, the target material is being cut which contains enormous amount of energy needed to absorb before it can damage any part. Cather is used to gather the pressurized water after cutting. The high energy of water particle transfers to abrasive particle then mixer of water and abrasive pass through nozzle which act as saw to cut the material in the mixing chamber. In AWJ cutting, the surface roughness and the dimensional accuracy depend on process parameters such as feed rate, water pressure, traverse speed, and standoff distance, impact angle etc. As feed rate increased, the AWJ cuts narrower kerf. This is because fewer abrasives are made to strike on the target material and produces a finer slot [3]. The upper area of cut is having good surface texture compared to middle and lower area. As abrasive flow rate were increased surface roughness reduces gradually, roughness is less sensitive to change in the feed rate [4]. AWJ machining follows the theory of fluid mechanics, abrasive wear and damage mechanics. This mechanics gives a unique capability compared with conventional machining [5]. 2. Literature survey Y. B Gaidhani [6] investigated on Cutting of stainless steel plates in which there was a problem in making fixture part. It was a challenge to get a solution without losing its metallurgical properties for the purpose of making fixtures part. By the literature review it was found that AWJ technique is most suitable solution and suited best for the given practical problem.
Supriya S B and Srinivas S. / Materials Today: Proceedings 5 (2018) 2871–2876
2873
Abrasive water jet proposals potential for the improvement in cutting which is less sensitive to material properties has nearly no thermal effects and impose minimal stresses. Abrasive offer no thermal effects and impose nominal stresses as it is a cold cutting process and vertical thrust is less as the jet diameter is small.
Fig 1. Illustration of an abrasive water jet cutting process [7]
Fig 2. Process parameters influencing the AWJ cutting process [6]
The major part in this process is selection of various process parameters like impact angle, pumping system pressure, abrasive material, standoff distance, diameter of focusing tube, speed of nozzle, mass flow rate of abrasive and material properties of the target material for receiving the essential output like depth of cut and the cut quality. For cutting stainless steel 304 grade, the significant task is to find out a few parameters which influence more. With the assistance of analytical hierarchy process technique the selection of a few parameters are done which are more influencing.
2874
Supriya S B and Srinivas S / Materials Today: Proceedings 5 (2018) 2871–2876
The percentage of Standoff distance was 19%, nozzle feed rate 18%, and flow rate of abrasives and abrasive material with 17% weightage are the moderately important parameters which are used for additional investigation however the effect of pressure is not investigated [6]. M. Chithirai Pon Selvan et al. [7] focused on effect of process parameters on surface roughness and the depth of cut which were significant cutting performance measure in cutting of stainless steel by AWJ. His work depicts that the effects of various working parameters such as pressure, mass flow rate of abrasives, traverse speed and nozzle standoff distance on surface roughness and depth of cut have been studied. In his work grade 304 of stainless steel plates with a thickness of 150×100×60 mm dimension were used. The gravity type feed type of abrasive hopper were used for the continuous supply of abrasives to the cutting head. Pneumatically controlled valves with a work piece table of dimension of 3000mm×1500mm were used. Sapphire orifice with a carbide nozzle was used to convert high pressure water into a collimated jet and to form abrasive water jet. The work presents these process parameters have straight influence on depth of cut and surface roughness. It has been found that water jet pressure has the most effect on the surface roughness and depth of cut. Depth of cut is increased as water jet pressure is increased but surface roughness decreases gradually. These results indicate that the use of high water jet pressure is favored to obtain good cutting performance. Depth of cut regularly increases and surface roughness decreases as mass flow rate increases. It is suggested to use more mass flow rate to increase depth of cut and to decrease surface roughness. Among the process parameters measured here water pressure and abrasive mass flow rate have the related effect on depth of cut and surface roughness. As nozzle traverse speed increase, surface roughness increases but depth of cut decreases. It means more depth of cut and surface roughness is obtained only by low traverse speed but at the cost of sacrificing productivity. This investigational study has resulted that standoff distance has no apparent effect on depth of cut. However, surface smoothness increase as standoff distance decreases. Therefore to accomplish a complete cutting performance, low standoff distance should be selected. Author based his work on investigational results an empirical model for the estimate of depth of cut in AWJC process of stainless steel has been established using regression analysis. Also verification of the established model for using it as a practical guideline for selecting the parameters has been found to agree with the trials. Therefore the need for extensive investigational work in order to select the levels of the most significant abrasive water jet cutting parameters on depth of cut of stainless steel can be eradicated. Thrust force is identified as the major cause for delamination . The cutting experiment were done on rectangular block and not on trapezoidal target materials further full factorial experiment were not conducted to investigate the influence of pressure , mass flow rate and traverse speed on depth of cut [7]. M. Chithirai Pon Selvan et al. [8] carried out the work on the influence of process parameters on depth of cut which is an important cutting performance measure in abrasive water jet cutting of stainless steel. The process variables considered here include traverse speed, abrasive flow rate, standoff distance and water pressure. Experiments were conducted in varying these parameters for cutting stainless steel using abrasive water jet cutting process. In order to correctly select the process parameters, an empirical model for the prediction of depth of cut in abrasive water jet cutting of stainless steel is developed using regression analysis. This developed model has been verified with the experimental results that reveal a high applicability of the model within the experimental range used. In this full factorial experiments were not considered in this study [8]. Murugabalaji et al.[9] worked on experimental investigation on AWJM of Stainless steel 304 of thickness 40mm is supported using Response Surface Methodology (RSM) with Box-Behnken method. The stainless steel work piece is shown in figure 3 below. The input process parameters measured are pressure (P), traverse rate (TR) and mesh size (MS). Effects were investigated using a method named as Analysis of Variance (ANOVA) and response surfaces independently on depth of cut (DOC) and surface roughness (Ra).
Supriya S B and Srinivas S. / Materials Today: Proceedings 5 (2018) 2871–2876
2875
ANOVA and response surface analyses showed that combinations of process parameters such as high pressure (300 MPa), medium mesh size (# 100) and low traverse rate (30 mm/min) caused in higher DOC whereas lower Ra is obtained with combinations of pressure around (300 MPa), small mesh size (# 80) and less traverse rate (30 mm/min). Orthogonal array of experiments were conducted further full factorial experiments were not conducted to investigate the influence of pressure, mass flow rate, and traverse speed on depth of cut .[9].
Fig. 3 Photograph of the Stainless Steel work piece (Top surface) [9]
Chirag M Parmar et al. [10] presented work on AWJM using Taguchi method to optimize process parameters for commercially three different materials AL-6351, Fiber Reinforced Plastic and SS-316. Experimental investigations conducted to assess the influences of penetration on standoff distance, work feed rate and jet pressure. The output parameters to be studied were surface unevenness and MRR [10]. P. P Badgujar et al. [11] experimented the influence of process parameters pressure, abrasive material, grain size, standoff distance, nozzle speed and abrasive mass flow rate on surface roughness which is an important cutting performance measure in abrasive water jet cutting of stainless steel (SS304). The objective of this paper was to select the level of parameter one variable at a time analysis (OVAT). The input parameters were pressure, abrasive material grain size, standoff distance, nozzle speed and abrasive mass flow. Also the effect of input parameter on surface roughness was analyzed for machining Stainless steel (SS 304). It was observed that, higher levels of the process parameters excluding the abrasive size resulted in higher surface roughness in the work piece. The lower surface roughness was obtained when higher mesh size was used, while the higher roughness was achieved with an abrasive of smaller mesh size. As water jet nozzle speed was increased, surface roughness also increased. It was concluded that the higher standoff distance resulted in a constant increase in the surface roughness same result was observed for higher water jet pressure. The number of experiments conducted was six trials and however full factorial experiments were not conducted to investigate the influence of pressure, mass flow rate, and traverse speed on depth of cut. [11]. Ion Aurel perianu et al. [12] carried out research in the field of abrasive water jet cutting of materials which are hard to process by machining such as austenitic stainless steels, in this presented work, austenitic steel EN 1.4306 with a thickness of 20 mm and only three altered water pressure values with a range 3400 – 3800 bars was considered. The optimal cutting process parameters were selected based on technical, economic, type and thickness of the target material and also the physical and geometrical quality requirements. The abrasive used is Garnet of 80 mesh size. By measuring the surface roughness and hardness of the cut surface, estimation were made for the surface quality defining the optimal pressure values. Increase in water jet pressure resulted in increase of depth in the hardened layer and of maximum surface hardness.Independent of the water jet pressure, the cut surface roughness in the cut starting area is far better than the roughness in the lower cut ending area. SEM studies revealed that for all water jet pressure values the removal of material was unvarying at the top surface impact zones and irregular in the end final exit areas of the material [12].
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1. Conclusion • AWJ cutting is a significant technology used for cutting any intricate profile and drill holes in extensive range. It can be also be used for detailed machining. The efficient performance of abrasive water jet process depends on process parameters such as traverse speed, mass flow rate of abrasives, standoff distance, water jet pressure, abrasive mesh size etc. and material parameters like thickness, type of the material. • It was concluded from literature that hydraulic pressure and type of abrasive materials were considered as the most significant control factor in influencing surface roughness and depth of penetration. High traverse speed results in lower material removal rates in material. • Decrease in standoff distance and traverse speed leads to improve machining performance. • Proper selection of nozzle and orifice can improve quality of kerf. • There is a scope to investigate machinability studies on stainless steel by conducting full factorial experiments. Acknowledgement The authors would like to thank TEQIP, Center of Excellence, BMSCE Benguluru-560019, and the concerned faculty for providing the assistance in presenting this review. References [1] Abhishek Dixit , Vikas Dave , M. R Baid , Water jet machining – An advance manufacturing process,International Journal of Engineering Research and General Science , Volume 3, Issue 2, Part 2, March- April, 2015 [2] Sreekesh .K , Dr . Govindan .P, A Review on abrasive water jet cutting , International Journal of Recent Advances in Mechanical Engineering (IJMECH) Volume 3,No 3, August 2014 [3] Jignesh K Patel , Abdulhafiz,The influence of abrasive water jet machining parameters on various responses- review, International Journal of Mechanical Engineering and Robotics Reasearch ,ISSN 2278-0149 ,Volume 4,No.1,January 2015. [4] Cristian Birtu , Valeria Avramescu , Abrasive water jet cutting technique equipment performances ,Romanian Associate of Nonconventional technology,March 2012 [5] P. Jankovic ,T. Igic , D. Nikodijevic, Process parameters effect on material removal mechanism and cut quality of abrasive water jet machining,Volume 40, no.2,pp 277-291, Belgrade 2013* [6] Y. B Gaidhani, V. S Kalamani , Abrasive water jet review and parameter selection by AHP method, Procedia CIRP 6 (2013) 577-582. [7] M. Chithirai Pon Selvan. A Machinability Study of Stainless Steel Using Abrasive Waterjet Cutting Technology ,International Conference on Mechanical, Automobile and Robotics Engineering (ICMAR'2012) Penang. Malaysia [8] M. Chithirai Pon Selvan, Assessment of process parameters in abrasive waterjet cutting of stainless steel, International Journal of Advances in Engineering & Technology, July 2011, ©IJAET [9] Murugabalaji, A. Kannan , N. Nagarajan, Experimental investigation on abrasive water jet machining of stainless steel 304,IJMEIT , Volume.03,Issue 07 july, Page No 1446-1454,ISSN – 2348-196X, 2015 [10] Chirag .M . Parmar, Mr.Pratik . K. Yogi, Mr.Trilok D Parmar,Experimental investigation on abrasive water jet machine using taguchi techniques to optimize process parameter of various materials – a review, international journal for technogical research in engineering ,Volume 1,Issue 6, Febraury -2014. [11] P. P. Badgujar , M. G .Rathi, Anaysis of surface roughness in abrasive water jet cutting of stainless steel , international journal of engineering research and technology , ISSN :2278-0181,Volume 3, Issue 6, June- 2014 [12] Ion Aurel perianu, Researches regarding the effect of pressure on surface quality during abrasive waterjet cutting of austenitic steels, 15. - 17. 5. 2013, Brno, Czech Republic, EU