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Ef25803806

  1. 1. R. V. Shah, Prof. D. M. Patel / International Journal of Engineering Research and Applications (IJERA) ISSN: 2248-9622 www.ijera.com Vol. 2, Issue 5, September- October 2012, pp.803-806 Abrasive Water Jet Machining – The Review R. V. SHAH*, PROF. D. M. PATEL** *P. G. Student, U. V. Patel College of Engineering, Ganpat University, Kkerva, Mehsana, **Associate Professor, U. V. Patel College of Engineering, Ganpat University, Kkerva, MehsanaABSTRACTAbrasive water jet machining (AWJM) is a suitable for very soft, brittle and fibrous materials.relatively new machining technique. Abrasive This technology is less sensitive to materialWater Jet Machining is extensively used in many properties as it does not cause chatter. This process isindustrial applications. AWJM is a non- without much heat generation so machined surface isconventional machining process where material is free from heat affected zone and residual stresses.removed by impact erosion of high pressure high AWJM has high machining versatility and highvelocity of water and entrained high velocity of flexibility. The major drawback of this process is, itgrit abrasives on a work piece. There are so many generate loud noise and a messy workingprocess parameter affect quality of machined environment [1].surface cut by AWJM. Important processparameters which mainly affect the quality of AWJM have certain advantageouscutting are traverse speed, hydraulic pressure, characteristics, which helped to achieve significantstand of distance, abrasive flow rate and types of penetration into manufacturing industries. [3]abrasive. Important quality parameters in AWJM • Extremely fast set-up and programmingare Material Removal Rate (MRR), Surface • Very little fixturing for most partsRoughness (SR), kerf width, tapering of kerf. This • Machine virtually any 2D shape on any materialpaper reviews the research work carried out so • Very low side forces during the machiningfar in the area AWJM. • Almost no heat generated on the part • Machine thick platesKeywords: AWJM, Kerf width, MRR, surfaceroughness, traverse speed1. AWJM is normally used for Paint removal, Cutting soft materials, Cutting frozen meat, MassINTRODUCTION Immunization, Surgery, Cutting, Nuclear Plant AWJM is a well-established non-traditional Dismantling, Pocket Milling, Drilling, Turning,machining process. Abrasive water jet machining Textile, Leather industry.makes use of the principles of both abrasive jet Materials which are cut by AWJM are Steels, Non-machining and water jet machining. AWJM is a non- ferrous alloys, Ti alloys, Ni- alloys, Polymers,conventional machining process where material is Honeycombs, Metal Matrix Composite, Ceramicremoved by impact erosion of high pressure high Matrix Composite, Concrete, Stone – Granite, Wood,velocity of water and entrained high velocity of grit Reinforced plastics, Metal Polymer Laminates, Glassabrasives on a work piece [1]. Fibre Metal Laminates In the early 60s O. Imanaka, University of 2. LITERATURE SURVEYTokyo applied pure water for industrial machining. In H. Hocheng and K.R. Chang [4] hasthe late 60s R. Franz of University of Michigan, carried out work on the kerf formation of a ceramicexamine the cutting of wood with high velocity jets. plate cut by an abrasive water jet. There is a criticalThe first industrial application manufactured by combination of hydraulic pressure, abrasive flow rateMcCartney Manufacturing Company and installed in and traverse speed for through- out cut below whichAlto Boxboard in 1972. The invention of the abrasive it cannot be achieved for certain thickness. Awater jet in 1980 and in 1983 the first commercial sufficient supply of hydraulic energy, fine meshsystem with abrasive entrainment in the jet became abrasives at moderate speed gives smooth kerfavailable. The added abrasives increased the range of surface. By experiment they find kerf width increasesmaterials, which can be cut with a Watergate with pressure increase, traverse speed increase,drastically. [2] abrasive flow rate increase and abrasive size increase. Taper ratio increases with traverse speed increases This technology is most widely used and decreases with pressure increases and abrasivecompare to other non-conventional technology size increases. Taper ratio has no effect with increasebecause of its distinct advantages. It is used for in abrasive flow rate.cutting a wide variety of materials ranging from softto hard materials. This technique is especially 803 | P a g e
  2. 2. R. V. Shah, Prof. D. M. Patel / International Journal of Engineering Research and Applications (IJERA) ISSN: 2248-9622 www.ijera.com Vol. 2, Issue 5, September- October 2012, pp.803-806 attack; (3) a rough cutting region (RCR), which is the jet upward deflection zone. A.A. Khan, M.M. Hague [7] analyse the performance of different abrasive materials during abrasive water jet machining of glass. They make comparative analysis of the performance of garnet, aluminium oxide and silicon carbide abrasive in abrasive water-jet machining of glass. Their hardness of the abrasives was 1350, 2100 and 2500 knoops, respectively. Hardness is an important character ofTable 1: Comprehensive result of the present paper the abrasives that affect the cut geometry. The depth of penetration of the jet increases with the increase in M.A. Azmir, A.K. Ahsan [5] had done hardness of the abrasives. They compare the effect ofa practical for surface roughness and kerf taper ratio different of abrasive on taper of cut by varyingof glass/epoxy composite laminate machined by cutting parameter standoff distance, work feed rate,AWJM. They considered six process parameters of pressure. It is found that the garnet abrasivesdifferent level and use Taguchi method and ANOVA produced the largest taper of cut followed by(analysis of variance) for optimization. Parameter aluminium oxide and silicon carbide abrasives. Forused are abrasive types (two-level), hydraulic all kinds of abrasives, the taper of cut increases withpressure (three-level), standoff distance (three-level), SOD. For all the types of abrasives used taper of cutabrasive flow rate (three-level), traverse rate (three- decreases with increase in jet pressure. Taper of cut islevel) , cutting orientation (three-level). Kerf taper smaller for silicon carbide abrasives followed byratio is the ratio of top kerf width to bottom kerf aluminium oxide and garnet.width. Types of abrasives and traverse rate areinsignificant for surface roughness while hydraulic J. John Rozario Jegaraj, N. Ramesh Babupressure is most significant for that. Standoff [8] had worked on strategy for efficient and qualitydistance, cutting orientation and abrasive mass flow cutting of materials with abrasive water jetsrate is equally significant for surface roughness. For considering the variation in orifice and focusingkerf taper ratio hydraulic pressure, abrasive mass nozzle diameter in cutting 6063-T6 aluminium alloy.flow rate and cutting orientation are insignificant. They found the effect of orifice size and focusingTypes of abrasives are most significant for kerf taper nozzle diameter on depth of cut, material removalratio while Standoff distance and traverse rate are rate, cutting efficiency, kerf geometry and surfacealmost equally significant for that. By increasing the roughness. The ratio of 3:1 between focusing nozzlekinetic energy of AWJM process better quality of cut diameter to orifice size was suggested as the bestproduce. suited combination out of several combinations of focusing nozzle to orifice size in order to achieve the Ahmet Hascalik, Ulas Aydas, Hakan maximum depth of cut in cutting they suggest theGurun [6] has carried out study on effect of ratio of 5:1 and beyond cause ineffective entrainmenttraverse speed on abrasive water jet machining of Ti– of abrasives in cutting head. It is noticed that6Al–4V alloy. They perform practical by varying with an increase in hydraulic pressure for differenttraverse speeds of 60, 80, 120, 150, 200, and 250 combinations of orifice and focusing nozzle size themm/min by abrasive water jet (AWJ) machining. depth of cut increased. The material removedThey studied the effect of traverse speed on the increased with an increase in the size of focusingprofiles of machined surfaces, kerf geometries and nozzle up to 1.2 mm diameter but with furthermicrostructure features of the machined surfaces. The increase it is reduced. The abrasive flow rate is foundtraverse speed of the jet is a significant parameter on to be less significant on kerf width. This studythe surface morphology. The features of different suggests maintaining the orifice size and focusingregions and widths in the cutting surface change with nozzle size within certain limits say 0.25–0.3 mm andthe change in traverse speed. They also found that 1.2 mm, respectively, for maintaining less taper onkerf taper ratio and surface roughness increase with kerf. Any increase in the size of orifice and focusingtraverse speed increase in chosen condition. This is nozzle is not much effect the surface quality butbecause the traverse speed of abrasive water jet larger size of orifice produce a better surface finishallows fewer abrasives to strike on the jet target and on cut surfacehence generates a narrower slot. They identify threedifferent zone in cutting surfaces of samples are (1) J. Wang, W.C.K. Wong [9] had done studyan initial damage region (IDR), which is cutting zone of abrasive water jet cutting of metallic coated sheetat shallow angles of attack; (2) a smooth cutting steels based on a statistically designed experiment.region (SCR), which is cutting zone at large angles of They discussed relationships between kerf characteristics and process parameters. They produce 804 | P a g e
  3. 3. R. V. Shah, Prof. D. M. Patel / International Journal of Engineering Research and Applications (IJERA) ISSN: 2248-9622 www.ijera.com Vol. 2, Issue 5, September- October 2012, pp.803-806empirical models for kerf geometry and quality for decreased as SOD increases. They introduced athe prediction and optimization of AWJ cutting material removal factor (MRF). MRF is a non-performance. They perform three-level four-factor dimensional parameter and it gives the weight offull factorial designed experiment. Process parameter material removed per gram of abrasive particles.used are water jet pressure, traverse speed, abrasive MRF decreases with increase in pressure that meansflow rate and standoff distance. The top and bottom the quantity of material removed per gram ofkerf widths increase as the water pressure increase. abrasives at a lower pressure is higher than theThe top and bottom kerf widths increase as the quantity of material removed per gram of abrasives atstandoff distance increase but the rate of increase for a higher pressure. This is happened because at higherthe bottom kerf width is smaller. The traverse speed air pressure more number of abrasive particles areproduces a negative effect on both the top and bottom carried through the nozzle so more number of interkerf widths but the kerf taper increase as the traverse particle collisions and hence more loss of energy.speed increase. The surface roughness decreases withan increase in the abrasive flow rate. They show theburr height steadily decreases with a decrease in thetraverse speed.Table 2: Kerf characteristics in terms of processparameters Figure 1: MRR vs pressure at grain size 120 micron Mahabalesh Palleda [10] investigated theeffects of the different chemical environments likeacetone, phosphoric acid and polymer(polyacrylamide) in the ratio of 30% with 70% ofwater and stand off distance on the taper angles andmaterial removal rates of drilled holes in the abrasivewater jet machining process. Material removal ishighest when slurry added with polymer compare tothree slurries. MRR increase with increase of standoff distance because momentum of impactingabrasive particles on the work surface creating cratersof more depth. Taper holes of drilled holes reduce asthe stand off distance increase. Taper holes observedless in case of phosphoric acid combination withslurry than the plain water slurry and the slurry withacetone combination. Taper observed in case ofpolymer is almost nil. The material removal rate is Figure 2: MRR vs SODincreasing with increase of chemical concentration ofacetone and phosphoric acid in the slurry up to a 3. SUMMARYcertain level and then reducing. In case of polymer So many investigations had done on AWJMwith the slurry in material removal increases process. MRR or production is improved bycontinuously. the taper of the hole is less in improving the traverse speed but major problem withphosphoric acid combination compare to acetone increasing traverse speed is that surface roughnesscombination. In polymer combination taper of the and kerf quality are decreased. Types of abrasive andhole is very less or almost nil. abrasive flow rate are also affect the MRR. By increasing abrasive flow rate MRR is increased but it P K Ray and Dr A K Paul [11] had decrease the surface roughness.investigated that the MRR increases with increase ofair pressure, grain size and with increase in nozzlediameter. MRR increases with increase in stand off 4. CONCLUSIONdistance (SOD) at a particular pressure. They found Quality of cutting surface in AWJM isafter work that initially MRR increases and then it is depending on so many process parameters. Processalmost constant for small range and after that MRR parameter which affect less or more on quality of 805 | P a g e
  4. 4. R. V. Shah, Prof. D. M. Patel / International Journal of Engineering Research and Applications (IJERA) ISSN: 2248-9622 www.ijera.com Vol. 2, Issue 5, September- October 2012, pp.803-806cutting in AWJM are hydraulic pressure, Stand off glass/epoxy composite laminate “Journal ofdistance, types of abrasive, size of abrasives, abrasive Materials Processing Technology 209flow rate, nozzle diameter, orifice size, and traverse (2009) 6168–6173speed. Quality of cutting surface is measured by [6] Ahmet Hascalik, Ulas C aydas, Hakanmaterial removal rate, surface roughness, kerf width, Guru “Effect of traverse speed on abrasivekerf taper ratio. From the literature review compare water jet machining of Ti–6Al–4V alloy, ”to above all mentioned parameter traverse speed is Materials and Design 28 (2007) 1953–1957most effective parameter for MRR. Abrasive flow [7] A.A. Khan, M.M. Hague,” Performance ofrate is also an important parameter for increasing different abrasive material during abrasiveMRR. But beyond some limit with increase in water jet machining of glass ” Journal ofabrasive flow rate and traverse speed the surface Materials Processing Technology 191roughness decreases. Increasing traverse speed also (2007) 404–407increase the kerf geometry. So it is required to find [8] J. John Rozario Jegaraj, N. Ramesh Babu “Aoptimum condition for process parameter to give strategy for efficient and quality cutting ofbetter quality of cutting surface. Traverse speed is materials with abrasive waterjetsdirectly proportional to productivity and should be considering the variation in orifice andselected as high as possible without compromising focusing nozzle diameter” Internationalkerf quality and surface roughness. Journal of Machine Tools & Manufacture 45 (2005) 1443–1450REFERANCES [9] J. Wang, W.C.K. Wong, “A study of [1] P.K. Mishra; Non-conventional machining, abrasive water jet cutting of metallic coated Narosa publishing house, Third reprint- sheet steels” International Journal of 2005. Machine Tools & Manufacture 39 (1999) [2] http://lyle.smu.edurcamresearchwaterjetwj2. 855–870 html updated on 8th December 2009 [10] Mahabalesh Palleda, “A study of taper [3] Module 9, lesson 37, non-conventional angles and material removal rates of drilled machining, version 2 ME, IIT Kharagpur holes in the abrasive water jet machining [4] Hocheng and K.R. Chang, “Material process “Journal of Materials Processing removal analysis in abrasive water jet Technology 18 (2007) 292–295 cutting of ceramic plates “Journal of [11] Some Studies on Abrasive Jet Machining by Materials Processing Technology, 40(1994) P K Ray, Member A K Paul, Fellow 287-304 Department of Mechanical Engineering [5] M.A. Azmir , A.K. Ahsan, “A study of Regional Engineering College Rourkela abrasive water jet machining process on UDC 621.921 page no 27 to 29. 806 | P a g e

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