International Journal of Research and Innovation (IJRI)
International Journal of Research and Innovation (IJRI) 1401-1402
RESEARCH AND ANALYSIS OF FSW TO SUGGEST OPTIMUM TOOL SHAPE
G. Ragni 1, S.V.S Rama Krishnam Raju2, G Nagendra Krishna3, Godi Subba Rao4, 1 2 3 4
Research Scholar, Department of Mechanical Engineering, Hyderabad Institute of Technology and Management, Hyderabad, India Professor , Department of Mechanical Engineering, Hyderabad Institute of Technology and Management, Hyderabad, India Assistant professor , Department of Mechanical Engineering, Hyderabad Institute of Technology and Management,Hyderabad,India professor , Department of Mechanical Engineering, Hyderabad Institute of Technology and Management,Hyderabad,India
Abstract A319 Aluminum alloy has gathered wide acceptance in the fabrication of light weight structures required a high strength to weight ratio. Compared to fusion welding processes that are routinely used for joining structural aluminum alloys, friction stir welding process is an emerging solid state joining process in which the material that is being welded does not melt and recast. This process uses non-consumable tool to generate frictional heat in the butting surfaces. The welding parameters tool pin profile plays a major role in deciding welding quality. In this project an attempt is made to understand the effect of welding speed and tool pin profile on FSP zone formation in A319 alloy. Four different tool pin profiles are used to fabric the welding joints. Those profiles are 1.Stright cylindrical,2.Tapered cylindrical,3.Thread, 4.Hexagonal.In this project we are also doing coupled field analysis for both cutting toolsand welding plates. We are also doing experimental work by using CNC milling machine. In that we are preparing fixture, cutting tools and plates. We are conducting this experimental work for 4 different tools. For modeling we are using Pro/Engineer software, for analysis ANSYS.
*Corresponding Author: G. Ragni , Research Scholar, Department 0f Mechanical Engineering, Hyderabad Institute of Technology and Management, Hyderabad,India Published: July 04, 2015 Review Type: peer reviewed Volume: II, Issue : IV
Citation: G.Ragni,Research Scholar (2015) RESEARCH AND ANALYSIS OF FSW TO SUGGEST OPTIMUM TOOL SHAPE
INTRODUCTION TO EDM
FRICTION STIR WELDING
Friction stir welding has enjoyed worldwide interest since its inception because of its advantages over traditional joining techniques. A rotating tool with pin and shoulder is inserted in the material to be treated, and traversed along the line of interest (Figure 2.1). During FSW, the area to be processed and the tool are moved relative to each other such that the tool traverses with overlapping passes until the entire selected area is processed to a fine grain size. The rotating tool provides a continual hot working action, plasticizing metal within a narrow zone while transporting metal from the leading face of the pin to its trailing edge. The processed zone cools without solidification, as there is no liquid a defect-free re- crystallized fine grain microstructure is formed.
Although weldingisa promising joiningprocess in terms of fabricationcost, the traditionalarcweldingmethodsarenotcapableof producing soundwelds due toMetallurgical problems.However,FSW process which was recently invented enables the welding of high performanceAlalloysthatarecustomarily usedinaircraftstructures.This chapterdealswithdesignationofAluminum alloys, description of welding, descriptionofFSW process,description ofcommercialFEA software’sand previouswork on simulationof FSW.
CLASSIFICATION OF WELDING: (a) Arc welding (b) Gas Welding (c) Resistance Welding (d) Thermit Welding (e) Solid State Welding (f) Newer Welding (g) Related Process
Fig: Schematicoffrictionstirwelding Essentially, FSW is a local thermo-mechanical metal working process with additional adiabatic heating from metal deformation that changes the local properties without influencing properties in the remainder of the structure. A processed zone is produced by movement of material from the front of the pin to the back of the pin. As mentioned later, the pin and shoulder of the tool can be 143
International Journal of Research and Innovation (IJRI)
modified in a number to ways to influence material flow and micro-structural evolution. Friction Stir welding has opened up a new process for inducing directed, localized, and controlled materials properties in any arbitrary location and pattern to achieve revolutionary capability in high value-added components. Friction stirwelding provides the ability to thermo-mechanically process selective locations on the structure’s surface and to some considerable depth (>25mm) to enhance specific properties. Research is being increasingly focused on this aspect of the technology for use with automotive alloys. For example, Cast aluminum alloys, such as A319, are used for suspension and drive line components in automobiles. Materialunderthe toolshoulderelevatesthestrengthof thematerial decreases.
3. Veryfine grainsize inthe stirredregion. 4. Randomdisorientation ofgrain boundariesinstirredregion. 5. Mechanicalmixing of thesurfacelayer. 6. Controlledflow of material. 7. Highjointefficiencies(competitive withriveting andbonding) 8. Excellent mechanical properties as demonstrated by fatigue,tensile and bend tests. 9. Robustprocess 10. Environmentally friendly process 11. Nofumes, No porosity 12. One tool can typically be used for upto 1000m of joint length 13. Nofiller wire 14. No gasshielding 15. No grinding,brushing or pickling required in mass production.
APPLICATIONS Shipbuilding and MarineIndustries The ship building and marine industries are two of the first industry sectors which have adopted the process for commercial applications. The process is suitable for the following applications: Figure1.1frictionstirweldingprocess: (a)rotatingtoolprior tocontact withtheplate; (b)toolpincontactsplatecreatingheat; (c)Shoulderoftool contactsplaterestrictingfurtherpenetrationwhileexpandingthehotzone; (d)platemovesrelativetorotatingtoolcreatingafullyre-crystallized,fine grainmicrostructure. Oneofthekey elementsintheFSW processistheheatgeneratedat theinterfacebetweenthetoolandtheworkpiecewhichisthedrivingforce tomake theFSW processsuccessful. The heatfluxmustbe keptmaximum suchthatthe temperature intheworkpieceishighenough, sothatthe materialissufficiently softfor the pintostirbutlowenoughsothatthe materialdoesnotmelt. The maximum temperature created by FSW processrangesfrom 80% to 90% of the melting temperatureof the workpiece material, as measured by Tangetal. andColegroveetal.,so that welding defects and large distortion commonly associated with fusion welding are minimized or avoided. The heat fluxinfriction stir processing isprimarily generated by the friction and the deformation process. Thisheatisconductedtoboththe tooland thework piece.Theamount of the heatconductedinto the work piece dictatesa successful process which is defined by the quality, shape and microstructure of the processed zone,as well as theresidualstressand the distortion of the work piece.The amount of the heat gone to the tool dictates the life of the tool and the capability of the tool to produce agood processed zone. For instance, insufficient heat from the friction could lead to breakage of the pin of the tool since thematerial is not soft enough. Therefore, understanding the heat transfer aspect of the friction stir welding is extremely important, not only for the science but also for improving the process.
• • • •
Panels for decks, sides, bulkheads and floors Hulls and superstructures Helicopter landing platforms Marine and transport structure
Aerospace industry At present the aerospace industry uses FSW for welding prototype and production parts. Opportunities exist to weld skins to spars, ribs, and stringers for use in military and civilian aircraft. The Eclipse 500 aircraft, in which 60% of the rivets are replaced by friction stir welding, is now in production. The friction stir welding process can therefore be considered for: • • • •
Wings, fuselages, empennages Cryogenic fuel tanks for space vehicles Aviation fuel tanks Repair of faulty MIG welds
PART MODELING IN PRO/ENGINEER Circular tool
ADVANTAGESOFFRICTIONSTIRWELDING The followingaretheunique featuresof frictionstir welding. 1. Lowamountof heatgenerated. 2. Extensive plastic flowofmaterial. 144
International Journal of Research and Innovation (IJRI)
HEXAGONAL TOOL
Contact area: Cylindrical = 117.8m2 Tapered = 102.22 m2 hexagon = 118.6 m2 Threaded = 158.69 m2 1.HEAT FLUX for circular : Heat flux = q = KA(∆T )/d ∆T = change in temperature T2 = 973 T1 = 323 ∆T =650K q = 26×117.8×650/85.75=1990820/85.75=23216.559 heat flux = q/A=23216.559/5133.57=4522.497 W
TAPPERD CYLENDER TOOL
2.HEAT FLUX for tapered cylinder Heat flow = q= KA(∆T )/d ∆T=650 q = 26×102.22×650/85.75=20145.982 heat flux = q/A=20145.982/5117.63=3936.584 W 3.HEAT FLUX for hexagon Heat flow = q= KA(∆T )/d q = 26×118.6×650/85.75=23374.22741 heat flux = q/A=23374.2274/5151.84=4537 W
CERCULER WITH THREADS TOOL
4.HEAT FLUX for threaded Heat flow = q= KA(∆T )/d q = 26×158.69×650/85.75=31275.346 heat flux = q/A=31275.346/5185.58=6031.214W A= contact area ∆T = temperature difference D = distance of heat flow
COUPLED FIELD ANALYSIS OF STRAIGHT CYLINDRICAL
ASSEMBLY
The above image shows imported model
FSW tools Circular/cylindrical S.A =5133.57 sq mm. Tapered cylinder S.A = 5117.84 Sq mm. hexagon S.A = 5151.84 sq mm. Threaded S.A = 5185.58 sq mm. HEAT FLUX = q/A=(heat flow)/(surface area)=W/m2 Thermal gradient ∆T = ∂T/∂x Cutting tool temperature = 973K Atmosphere temperature = 500C = 327K Thermal conductivity = 26 W/mk Heat flow = Q =KA∆T K = thermal conductivity w/mk Q = rate of heat flow watts
The above image shows meshed model
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International Journal of Research and Innovation (IJRI)
The above imageshows temperature
The above imageshows total heat flux
The above imageshows thermal error
The above image shows stress
MODEL ANALYSIS OF STRAIGHT CYLINDRICAL
The above image shows total deformation mode 1
COUPLED FIELD ANALYSIS OF TAPERED CYLINDRICAL
The above image shows total deformation The above imageshows temperature
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International Journal of Research and Innovation (IJRI)
COUPLED FIELD ANALYSIS OF STRAIGHT SLOT
The above imageshows total heat flux
MODEL ANALYSIS OF TAPERED CYLINDRICAL
The above imageshows temperature
The above imageshows total heat flux The above image shows total deformation mode 1
COUPLED FIELD ANALYSIS OF HEXAGONAL SHAPE
COUPLED FIELD ANALYSIS OF THREAD CYLINDRICAL
The above imageshows temperature
The above imageshows total heat flux
The above imageshows temperature
The above imageshows total heat flux
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International Journal of Research and Innovation (IJRI)
GRAPHS AND RESULT TABLES
The above graph shows Total heat flux
The above graph shows Stress
The above graph shows Total deformation COUPLED FIELD ANALYSIS STRAIGHT CYLINDRICAL
TAPERED CYLINDRICAL
THREAD CYLINDRICAL
S T R A I G H T HEXAGONAL SLOT SHAPE
OCTAGON SHAPE
Temperature
983.69
1059.3
1003.2
1013.2
1001.7
1001.4
Total heat flux
39.509
51.602
208.59
114.45
39.42
43.291
Thermal error
4.33E+6
1.16E+7
2.70E+7
5.92E+6
1.55E+7
7.85E+6
Total deformation
0.192
0.193
0.195
0.190
0.191
0.190
Stress
3068.6
3452.1
20441
5160.3
3016.4
2999.9
Strain
0.043
0.041
0.120
0.044
0.043
0.043
Model analysis Total deformation mode 1HZ
6973.9
6921.8
6564.6
6832.6
6974
7041.2
Total deformation mode 2 HZ
7089.7
7016.8
6867.2
6936.8
7087.7
7146.8
Total deformation mode 3 HZ
10745
10593
10433
10409
10629
10959
Total deformation mode 4 HZ
16532
16391
15308
15821
16516
16913
Total deformation mode 5 HZ
17116
16818
16086
16311
17058
17452
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International Journal of Research and Innovation (IJRI)
REFERENCES
AUTHOR
1.Mechanical properties of the friction stir welded dissimilar aluminium alloy joints international journal of mechanical and production engineering, 2.Friction stir welding of al 6061 alloy 3.Friction stir welds (fsw) of aluminium alloy aw6082-t6 4.Analysis of fsw welds made of aluminium alloy aw6082-t6 Archives of materials science and engineering 5. Design and development of fixture for friction stir welding Innovative systems design and engineering
G. Ragni, Research Scholar, Department of Mechanical Engineering, Hyderabad Institute of Technology and Management, Hyderabad,India
6.Friction stir welding of austenitic stainless steels 7.An analysis to optimize the process parameters of friction stir welded low alloy steel plates international journal of engineering, science and technology 8.Friction stir welding – process and its variables international journal of emerging technology and advanced engineering 9.Analysis and design of friction stir welding 10.Effect of friction stir welding parameters (rotation and transverse) speed on the transient temperature distribution in friction stir welding of aa 7020-t53 arpn journal of engineering and applied sciences
S.V.S Rama Krishnam Raju, Professor, Department of Mechanical Engineering, Hyderabad Institute of Technology and Management, Hyderabad,India
11.Effect of tool geometries on thermal history of fsw of a1100 sponsored by the american welding society and the welding research council
G Nagendra Krishna, Assistant professor,Department of Mechanical Enineering, Hyderabad Institute of Technology and Management, Hyderabad, India
Godi Subba Rao, Professor, Department of Mechanical Engineering, Hyderabad Institute of Technology and Management, Hyderabad,India
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