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30120140505014

  1. 1. International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 – 6340(Print), ISSN 0976 – 6359(Online), Volume 5, Issue 5, May (2014), pp. 123-132 © IAEME 123 EXPERIMENTAL AND ANALYSIS OF FRICTION DRILLING ON ALUMINIUM AND COPPER T.PRABHU1 , Mr. A. ARULMURUGU2 1 PG Student Department of Mechanical Engineering, Regional centre Anna University of Technology, Coimbatore. 2 Assistant Professor Department of Mechanical, Regional centre Anna University of Technology, Coimbatore. ABSTRACT Friction drilling is a non-traditional hole making method that uses the heat generated from friction between a rotating conical tool and work piece to soften and penetrate the work material and generated a hole. Friction drilling is also called as thermal drilling, flow drilling, form drilling or friction stir drilling. High temperature and strain in friction drilling material properties and microstructure. The work piece enable softening, deformation and displacement of work material and creates a bushing surrounding the hole without generating chip or waste material. The research characterizes the experimental and analysis of friction drilling on the aluminium and copper alloy by HSS and Tungsten carbide tool. It is show that materials with different compositions and thermal properties affect the selection of friction drilling process parameters. So this research is to experimental and analysis the friction drilling process on the two material and study the behaviours of it. Keywords: Friction Drilling, Aluminium & Copper 1. INTRODUCTION Drilling is a process of producing round holes in a solid material or enlarging existing holes with the use of multi-tooth cutting tools called drills or drill bits Various cutting tools are available for drilling, but the most common is the twist drill. But here friction drilling is going to experiment in aluminum alloy and copper alloy by HSS and tungsten carbide tool. Friction drilling, also known as thermal drilling, flow drilling, form drilling, or friction stir drilling, is a nontraditional hole-making method. The heat generated from friction between a rotating conical tool and the work-piece is used INTERNATIONAL JOURNAL OF MECHANICAL ENGINEERING AND TECHNOLOGY (IJMET) ISSN 0976 – 6340 (Print) ISSN 0976 – 6359 (Online) Volume 5, Issue 5, May (2014), pp. 123-132 © IAEME: www.iaeme.com/ijmet.asp Journal Impact Factor (2014): 7.5377 (Calculated by GISI) www.jifactor.com IJMET © I A E M E
  2. 2. International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 – 6340(Print), ISSN 0976 – 6359(Online), Volume 5, Issue 5, May (2014), pp. 123-132 © IAEME 124 to soften the work-material and penetrate a hole. Figure.1 shows a schematic illustration of the five steps in friction drilling. The tip of the conical tool approaches and contacts the work-piece, as shown in Fig.1.1 (a). The tool tip, like the web center in twist drill, indents into the work-piece and supports the drill in both the radial and axial directions. Friction on the contact surface, created from axial force and relative angular velocity between tool and Work-piece, produces heat and softens the work-piece material. As the tool is extruded into the work-piece, as shown in Fig.1.1 (b), it initially pushes the softened work-material sideward and upward. With the work-piece material heated and softened the tool is able to pierce through the work-piece, as shown in Fig.1.1 (c). Once the tool penetrates the work-piece, as shown in Fig.1.1 (d), the tool moves further forward to push aside more work-piece material and form the bushing using the cylindrical part of the tool. As the process is completed, the shoulder of the tool may contact the work-piece to collar the back extruded burr on the bushing. Finally, the tool retracts and leaves a hole with a bushing on the work-piece as shown in the Fig.1.1 (e). Friction drilling is a technique to create a bushing on sheet metal, tubing, or thin walled profiles for joining devices in a simple, efficient way. The bushing created in the process is usually two to three times as thick as the original work-piece. This added thickness can be threaded, providing a more solid connection for attachment than attempting to thread the original sheet. Figure 1.2 shows a cross section of the bushing produced for a tapped and untapped hole. All work-material from the hole contributes to form the bushing. In addition, no cutting fluid or lubricant is necessary, which makes friction drilling a totally clean, environmentally friendly process. 2. WORKING PRINCIPLE Friction drilling is a process that uses friction to produce bushings in metal tubing and flat stock. The combined rotational and downward force of our special friction Drilling tool bit creates frictional heat. Temperatures can reach 900ºC for the tool, and 700ºC for the work piece. The material is transformed into a "super-plastic" state, allowing the tool to displace material and form a bushing. The height of the bushing is roughly 3 to 4 times the original metal thickness. These bushings are ideal for threaded applications, as the number and strength of threads is significantly increased. It is an excellent alternative to weld nuts or threaded inserts. The bushing can also be used as a support hole for welded, soldered or brazed connections as well as for a load-bearing surface. The Thermal Drilling System can be used in most ferrous and non-ferrous metals including mild steel, stainless steel, copper, brass and aluminum, with material thickness up to 12 mm. In general, all malleable materials can be thermal drilled. Standard drills are available in any size up to 25.4 mm. diameter. Larger drill sizes are available on request. No special equipment is required. A standard drill press, milling machine or CNC machining center is suitable. Thermal Drilling is also ideal for automation because it is a chip less process, produces accurate holes, and has a long tool life. Thermal Drilling is also well suited for short run or prototype work because of its ease of use. There is absolutely no cutting involved during the creation of the hole. Friction drilling is a non-traditional hole making method that uses the heat generated due to the friction between a rotating conical tool and the work piece to soften and penetrate the work- material and generate a hole in a sheet material and at the result a bushing forms. In friction drilling forms bushings from the sheet metal material, it is clean and chip less drilling method. The material Properties and microstructures are changed in friction drilling because of high temperature and strain. In machining and production methods these result soften unwanted but they are unavoidable and important to affect the quality of friction drilled holes. Contrary to the traditional drilling there is no chip and waste material, all extruded material contributes to form the bushing and it eliminates chip generation in friction drilling, therefore it can be called clean and chip less hole making process.
  3. 3. International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 – 6340(Print), ISSN 0976 – 6359(Online), Volume 5, Issue 5, May (2014), pp. 123-132 © IAEME 125 Tool life is increased, time of processing and cost of drilling is reduced, and bushing form is thicker than the work piece about three times, which provides longer contact area that fitted a shaft firmly. According to the tool geometry there are four steps in friction drilling. (i) First, the tip of the tool Approaches and penetrates the work piece. (ii) Second, the generated heat that softens the work material due to the friction on the contact surface which is between tool and work piece. (iii) Third, he softened Material is pushed sideward and tool moves forward to form the bushing using the cylindrical section of the tool. (iv) Fourth, the extruded burr on the boss pressed to the work piece surface by the shoulder of the tool and finally the tool retract and leave a hole with a bushing. The tool tip and the friction force On the contact area which is between the tool work piece interfaces, like the web centre of the twist drill deals into the work piece and support the drilling both radial and axial directions. The softened material pushed sideward by the tool which extruded and pierces through the work piece. The tool tip penetrates the work piece and tool waves further forward to push the softened material and form the bushing with using the cylindrical part of the tool. The purpose of the bushing is increased the thickness for threading and available clamp load. Friction drilling is suitable apply to ductile materials. The petals and cracks formations are generated at the bushing which obtained at the end of friction drilling of brittle cast metals. Petal formation generates a Bushing with limited load capability for thread fastening. The difference in brittle and ductile work pieces can be seen as the brittle work-material does not form a bushing with desired shape and ductile work-material has a smooth, cylindrical bushing with sufficient length. The ratio of work piece thickness (t), to tool diameter, (d), is an important parameter in friction drilling. The high of bushing contributed at high t/d represents that a relatively longer portion of material is displaced materials with higher strength requires more thrust force to be penetrated. The bushing shape, the cylindricality, petal formation, bushing wall thickness, and surface roughness are made to judge the friction drilled hole quality. The bushing shape, which becomes cylindrical, has less fracture as work piece temperature increases. At high spindle speed and pre-heating, the thrust force, torque, energy and power reduce for friction drilling of brittle cast metals. The thrust force and torque are reduced at higher feed rates and shorter cycle time for hole drilling. The bushing height is usually two to three times as thick as the original workpiece.The ductility of work piece material, which is extruded onto both the front and back sides of the material drilled, increases due to the frictional heat. The length the threaded section of the hole can increases about three to four times because of the added height of the bushing shape. The bushing shape is to increase thickness to threading and available clamp load the friction drilling tools geometry is important. The tool geometry becomes from five regions, which are called centre, conical, cylindrical, shoulder, and shank regions. The centre region, like the web of twist drill provides the support in the both radial and axial directions. Conical region has sharper angle than the centre region. This region rubs against workpiece in the contact area which is between and Pushes the material sideward to shape the bushing. Shoulder region touch to the work piece to round the entry edge of the hole. Shank region grippes the tool to holder of the machine. The temperature in the work piece cause to undesired material damage and improper bushing Formation. In friction drilling of materials which thermal conductivities are high, a large portion of the heat is transferred into the work piece. Low Temperature causes insufficient ductility and softening resulting in high thrust force and improper Bushing formation. These effects removed with selection of low spindle speeds for materials which have low thermal conductivity coefficient and high spindle speeds for material which have high heat Conductivity coefficient. The low elongation of materials suggests the high fracture and petal Formation. The frictional heat which generated at the tool-work piece interface provides information about thermal properties. The high thermal
  4. 4. International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 – 6340(Print), ISSN 0976 – 6359(Online), Volume 5, Issue 5, May (2014), pp. 123-132 © IAEME 126 conductivity of the material cause to more heat transfer away from the tool-work piece interface quickly, which reduces the work piece temperature and ductility for bushing Formations. In friction drilling the work piece material melting temperature is important. The maximum temperature which is generated is about 1/2-2/3 of the work piece melting temperature. The material Plasticity is increased at elevated temperature which occurred at high rotational speed and pre-heating conditions. Most of the energy converts into heat and transfers to the work piece and tool. The tool surface temperature increases with increasing spindle speed and the more friction heat is generated. The friction coefficient, which is between the tool and work piece contact area, increases with increasing the number of holes drilled, thus raising the surface temperature. Lower thermal conductivity of the tool and work piece material causes to increase both tool surface temperature and the temperature, which is in Contact area between tool-work piece interfaces. The lower tool thermal conductivity resulted in less significant variation in axial thrust force produced and tool surface temperature. With increasing spindle speed the metal crystallization energy is increased and generated Uneven melting temperature, thus the surface roughness value is smaller. Large feed rates are caused to insignificant melting temperature and incomplete melting of the material. The material, which is incomplete melting, adhering on drill and therefore the surface roughness of the hole is Increased. Slow feed rates are caused to material melting temperature, which have different cooling Speeds. The upper material layer is cool down faster than the lower material layer. Thus the drill tool adhere the metal chip, and obtain a bad hole surface quality. The greater the number of hole drilled the Higher the tool surface temperature. This can be attributed to the greater surface roughness, as a result of adhesion tool to work piece. The purpose of this experimental study is investigated the friction drilling of aluminum alloys and copper alloy which have different thermal conductivity coefficient. It was analyzed the effect of the thermal conductivity on the surface roughness, bushing height and bushing wall thickness, depended on the spindle speeds and feed rates. (a) (b) (c) (d) (e) Figure 1. A schematic illustration of the five steps in friction drilling.
  5. 5. International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 – 6340(Print), ISSN 0976 – 6359(Online), Volume 5, Issue 5, May (2014), pp. 123-132 © IAEME 127 Figure 2. Resulting hole and bushing. Table No: 1 Tool style Short Short/Flat Long Long/Flat Description Short parallel sides behind the leading taper. This produces a short conical (tapered) bush and a rolled collar on top of the working surface. Short parallel sides behind the leading taper. Milling cutters are incorporated into the collar. This produces a short conical (tapered) bush and a flat surface on top of the working surface. Longer parallel-sided body that extends behind the leading taper. This produces a long cylindrical bush and a rolled collar on top of the working surface Longer parallel-sided body that extends behind the leading taper. Milling cutters are incorporated into the collar. This produces a long cylindrical bush and a flat surface on top of the working surface Hole Form Picture Today, the availability of this old technology is reliable and the process is fast, Friction Drilling is a process for generating bushings or holes in thin-walled sheet metal, metal tubes, or pipes without metal removal. A rotating, center punch type tool Center drill is forced into the material. The heat generated by the friction, heats the surrounding area and plasticizes the material. Without removing material, a hole is then formed by the entering tool, similar to a forging process. The excess material increases the wall thickness of the metal and provides an area of increased support.
  6. 6. International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 – 6340(Print), ISSN 0976 – 6359(Online), Volume 5, Issue 5, May (2014), pp. 123-132 © IAEME 128 This eliminates additional welded bracing or the insertion of plugs. Friction drilling is an excellent process to create reliable, stronger connections or bushings. Fig 3 Key dimensions of the friction drilling tool h: The length of the tool cylindrical region (mm) hl: The length of the tool conical region (mm) hn : The length of the tool tip region (mm) ß: Tool conical angle a: Tool tip angle d: Hole diameter (mm) ØD1: Tool shoulder diameter (mm) ØD: Tool shank diameter (mm) T: Material thickness (mm) ha: Bushing height (mm) L: Tool handle region (mm) T: Tool shoulder region (mm) 3. APPLICATIONS Potential automotive applications for friction drilling are shown in Fig. 1.2. These include seat frame, exhaust system parts, fuel rail, seat handle, foot pedal, oxygen sensor, and castings. It is believed that the friction drilling technique can be applied on a broader scale in automotive industry. Potential for substitution of a friction drilling fastening process will need to be evaluated on a case- by-case basis. Aluminum and magnesium castings require bolt bosses and thick flanges to accommodate fastening. In hydro formed components, punching holes and attaching weld nuts and clinch nuts are very difficult and/or expensive to accomplish. In certain cases, it appears that sheet metal components are made thicker than necessary for the sole purpose of providing more thread engagement for fasteners. In other cases a threaded hole is needed for attachment of an electrical ground, which requires little load carrying capability.
  7. 7. International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 – 6340(Print), ISSN 0976 – 6359(Online), Volume 5, Issue 5, May (2014), pp. 123-132 © IAEME 129 Figure 4. Automotive applications of friction drilling including (a) seat frame, (b) exhaust O2 sensor boss, (c) exhaust part, (d) seat handle, (e) foot pedal, and (f)oxygen sensor 4. ADVANTAGES Advantages of the friction drilling System are: 1. Very fast process 2. Stronger joints 3. Cost-effective 4. No special machines needed 5. Small investment 6. High quality 7. No additional components 8. Less production steps 9. Clean workspace 10. Chip less process 11. The process reshapes all material so that no material is lost. The sleeve that is about 3 times longer than the original diameter of the target material makes it possible to make very strong bolt joints in thin material. 12. Moreover, it is a clean process, because no litter (particles) is produced
  8. 8. International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 – 6340(Print), ISSN 0976 – 6359(Online), Volume 5, Issue 5, May (2014), pp. 123-132 © IAEME 130 5. OBJECTIVE 1. To Experiment the friction drilling on the material and identify the different parameters like temperature, stress, strain 2. To design the friction drill tool 3. To study about the material properties of and tool properties 4. To identify the stress and strain in the tool by analysising 5. To identify the mach inability of the material(Aluminum and copper ) 6. To analysis the microstructure of the material before and after drilling 7. To analysis stress /strain of work piece and tool by ansys software 6. FRICTION DRILLING TOOL The Thermal Drilling System can be used in most ferrous and non-ferrous metals including mild steel, stainless steel, copper, brass and aluminum, with material thickness Thermal drilling is a process that uses friction to produce bushings in metal tubing and flat stock. The combined rotational and downward force of our special Thermal Drilling tool bit creates frictional heat. Temperatures can reach 900 C for the tool, and 700 C for the work piece. The material is transformed into a "super-plastic" state, allowing the tool to displace material and form a bushing. The height of the bushing is roughly 3 to 4 times the original metal thickness. These bushings are ideal for threaded applications, as the number and strength of threads is significantly increased. It is an excellent alternative to weld nuts or threaded inserts. The bushing can also be used as a support hole for welded, soldered or brazed connections as well as for a load- bearingsurface.Up to 12 mm. In general, all malleable materials can be thermal drilled. Standard drills are available in any size up to 25.4 mm. diameter. Larger drill sizes are available on request. No special equipment is required. A standard drill press, milling machine or CNC machining center is suitable. Thermal Drilling is also ideal for automation because it is a chip less process, produces accurate holes, and has a long tool life. Thermal Drilling is also well suited for short run or prototype work because of its ease of use. Temperature distribution The temperatures involved in the friction drilling process are measured using an infrared thermometer. Fig 4 depicts the temperature involved in the friction drilling process for various speeds. Friction drilling of aluminum, brass and stainless steel attained a maximum temperature of 164, 252 and 468o C respectively. Higher can increase the frictional heat transfer between the tool and the work piece. Heat flux involved in the Process of friction drilling is dependent on the speed of the friction drill tool. Since the speed is increased, frictional heat flux and heat transfer is increased which in turn increases the temperature of the work piece. At the final stages of the tool penetration, higher temperature is involved and the temperatures gradually reduce at of the tool from the work Process parameters Frictional heat and feed pressure produce the material deformation and displacement. The frictional heat is generated through the rotational speed, the corresponding axial force (contact pressure) and feed rate. This means that, independently of the core hole size, the drill unit to be used must be capable of a speed of up to 500 rpm, a machine output of up to 5 KW, and a feed rate of up to 1000 mm/min. The right combination of feed rate and speed depends on the type (stainless steels, steel, or non-ferrous metals) and thickness of the material. For optimized results, the material must retain the correct temperature during forming and must not cool down too rapidly. Data listed later in this document are intended as reference values only and can vary significantly for different material grades and thicknesses.
  9. 9. International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 – 6340(Print), ISSN 0976 – 6359(Online), Volume 5, Issue 5, May (2014), pp. 123-132 © IAEME 131 7. AXIAL FORCE The required axial force at the start of the flow punch forming process is very high and decreases towards the end of the process when the core hole is fully formed. When processing thin materials, relining may be necessary to prevent deflection. 8. ROTATIONAL SPEED RPM The normal speed for small core hole diameters is relatively high, at approx. 3000 rpm, and can be as high as 4500 rpm for non-ferrous metals. For larger core hole diameters such as M20, the necessary speed is only approx. 1000 rpm. Stainless steel, with a lower thermal conductivity, can be processed at speeds up to 20% lower. For working with center drill and centertap the following safety rules should be obeyed: • Always wear safety goggles. • When working with the flat flow punch formers that are used to remove the collar, proper protective clothing and safety goggles should be worn if no safety guard is installed on the machine to protect against flying chips. • The flow punch former is glowing hot initially after use and should not be touched without proper safety gloves or before it has cooled down. • The work part gets very hot and should not be touched without proper safety gloves or before it has cooled down. • The safety instructions for the recommended parting medium should be obeyed. The safety data sheets will be supplied if needed. • At the start of the flow punch forming process, the collet chuck should be tightened after 5 to 10 forming operations to prevent the part from slipping or falling out. 9. CONCLUSION Comparison with Conventional Drilling Process In friction drilling tool wear is very minimal in comparison with twist drill. Also the unwanted chips are not produced and the walls of the hole drilled are stronger in grain orientation in comparison with twist drill where holes are made by cutting the grains abruptly. Only concern of friction drilling is the higher thrust force, clamping force and elevated temperature which were within tolerable level in this experimentation. It can be observed from Table 4 that the roundness errors are higher in comparison with twist drill but it is of non significant order when comparing the severity of the friction drilling process. 10. ACKNOWLEDGEMENT • Behind every achievement lies an unfathomable sea of gratitude to those who actuated it, without them it would never have into existence. To them we lay the word of gratitude imprinted within us. • First and foremost, I am grateful to God for giving me good health throughout the period I was working on my project. • I owe my thanks to the Dean Dr.M.SARAVANA KUMAR., M.B.A., Ph.D. for providing with all facilities to work on my project successfully. • Also, I take this opportunity to convey my sincere thanks to the Head of the Department Dr. M. SAKTHIVEL M.E., Ph.D., without whom this project would have been a distant reality.
  10. 10. International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 – 6340(Print), ISSN 0976 – 6359(Online), Volume 5, Issue 5, May (2014), pp. 123-132 © IAEME 132 • I would like to express my warm acknowledgement and my sincere thanks to my Guide Mr. A. ARULMURUGU M.E., Regional Centre of Anna University, Coimbatore for his encouragement, support and time for guiding me throughout this project. I am very much grateful to him for his constructive criticism and suggestions throughout the duration of my project. • Also I would like to thank all the staffs who either have directly or indirectly given his or her suggestions and supports throughout this project and my respects and love to my parents and all other family members and friends for their love and encouragement. 11. REFERENCES 1. Scott F.Miller, Peter J Blau, Albert J Shih,Microstructural Alterations Associated With friction drilling of steel,Aluminium and Titanium(2005) 2. Scott F.Miller, Peter J Blau, Albert J Shih, Tool wear in friction drilling (2006) 3. Cebeliozek, ZulkufDemir, Investigate the effect of tool conical angle on the bushing height, wall thickness and forming in friction drilling of A7075-T651 aluminum alloy(2013) 4. P.V.Gopal Krishna, K.Kishore and V.V.Sathyanarayana some investigations in friction drilling AA6351 using high speed steel (2010) 5. Pantawane.P.D, AhujaB.B Experimental investigation and multi-objective optimization of friction drilling process on AISI 1015(2011) Volume 2 ISSN 0976-59 6. S.Indumathi, V.Diwakar Reddy, G.Krishnaiah Grey relational analysis to determine optimum process parameters for thermo mechanical form drilling-riveting (2013) Volume 1 Issue 3 July 7. B.PadmaRaju, M.KumaraSwamy Effect of tool material in friction drilling a case study (2012) volume 2 8. B.PadmaRaju, M.KumaraSwamy, Finite element simulation of a friction drilling process using Deform-3D (2012) 9. Cebeliozek, ZulkufDemir Investigate the surface roughness and bushing shape in friction drilling of A7075-T651 and St37 Steel (2013 10. Wei-Liangku, Ching-lien hung, Shin-min lee, Optimization in thermal friction drilling for SUS 304 Stainless steel (2010) 11. G.Somasundaram,S.RajendraBoopathy and K.Palanikumar Modeling and analysis of roundness error in friction drilling of aluminum silicon carbide metal matrix composite(2011) 12. L.Francis Xavier D.Elangovan, Effective parameters for improving deep hole drilling process by conventional method (2013) volume 2 13. S.Madhavan, S.Balasivanadha prabu Experimental investigation and analysis of thrust force in drilling of carbon fiber reinforced plastic composites using response surface methodology(2012) vol 2 Issue 4 july 14. Somasundaam G, Rajendra Boopathy S, Fabrication and friction drilling of aluminum silicon carbide metal matrix composite (2010) volume 1 15. J.Pradeep Kumar, P.Packiaraj, Effect of drilling parameters on surface roughness, tool wear, material removal rate and hole diameter error in drilling of ohns (2012) 16. P. Govinda Rao, Dr. C L V R S V Prasad, Dr.D.Sreeramulu, Dr.V. Chitti Babu and M.Vykunta Rao, “Determination of Residual Stresses of Welded Joints Prepared Under The Influence of Mechanical Vibrations By Hole Drilling Method and Compared By Finite Element Analysis” International Journal of Mechanical Engineering & Technology (IJMET), Volume 4, Issue 2, 2013, pp. 542 - 553, ISSN Print: 0976 – 6340, ISSN Online: 0976 – 6359.

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