INTERNATIONAL JOURNAL OF DESIGN AND MANUFACTURING TECHNOLOGY (IJDMT)

Size: px

Start display at page:

Download "INTERNATIONAL JOURNAL OF DESIGN AND MANUFACTURING TECHNOLOGY (IJDMT)"

Lindsay Foster
5 years ago
Views:

1 INTERNATIONAL JOURNAL OF DESIGN AND MANUFACTURING TECHNOLOGY (IJDMT) Proceedings of the International Conference on Emerging Trends in Engineering and Management (ICETEM14) ISSN (Print) ISSN (Online) Volume 5, Issue 3, September - December (2014), pp IAEME: Journal Impact Factor (2014): (Calculated by GISI) IJDMT I A E M E EFFECT OF ROLLER BURNISHING PROCESS ON TOOL STEEL MATERIAL USING CNC LATHE JAYAKRISHNAN J 1, SURAJ R. 2 1 Asst.Professor, Department of Mechanical Engineering, SNGCE, Kerala, India, 2 Asst.Professor, Department of Mechanical Engineering, SNGCE, Kerala, India, ABSTRACT Roller burnishing is a technique used to super finish various components. In this technique, the type of contact between the workpiece and the tool is a line. The worpiece rotates on the chuck and the tool is held perpendicular to the length of the workpiece. Plastic deformation of the work piece surface occurs giving rise to a new topography. The effect of various operating parameters such as burnishing force, speed, feed, roller width, and number of pass are investigated for better surface finish. Workpeice material is HCHCr tool steel (35 HRC) and the burnishing tool material is tungsten carbide (69 HRC). The minimum surface roughness obtained was µm and the maximum micro hardness was 589 HV. Keywords: Roller Burnishing, Surface Roughness, Micro Vickers, Micro Hardness I. INTRODUCTION Burnishing is a cold working finishing process by which the surface undergoes plastic deformation to create a new topography. When the value of stress applied becomes more than the yield stress of the material, the surface roughness peaks flow towards the valley to fill them. As a result of grain reformation, the surface gets hardened during the process and improves the wear resistance as proved by various studies conducted. Burnishing can be considered to be of two types: ball burnishing and roller burnishing. The classification is based on the type of contact between the tool and the workpiece. In this study roller burnishing is used with a CNC Lathe on tool steel material of cylindrical shape. Hassan (1997) investigated the effects of different ball burnishing parameters on AI-Cu workpieces. [9] and studied the effect of ball and roller burnishing processes on non-ferrous materials.[10] Swirad (2011) studied the surface texture analysis after sliding burnishing with cylindrical element. During the experimental process, a minimum surface roughness of Ra = µm was achieved.[1]john and Vinayagam (2011) studied about roller burnishing process on tool steel material. They used response surface methodology for optimizing the operation parameters and studied their effect on surface roughness and hardness.[2] Hamadache et al. (2006) studied the characteristics of Rb40 steel superficial layer under ball and roller burnishing. According to the study, roller burnishing provides optimal roughness results, particularly when initial surface roughness is close to 3 µm. For better hardness, ball burnishing was found more suitable as per the study.[4]el-khabeery and El-Axir (2001) studied on 6061-T6 aluminum alloys on a milling machine[7] Murthy and Kotiveerachari (1981) studied about applications of burnishing process in various industrial fields.[8]dabeer&purohit (2010) investigated the ball burnishing process on surface roughness. A second order mathematical model correlating four predominant process parameters, like burnishing force, speed, ball diameter and number of tool pass with the surface roughness parameter had been obtained. The model can be used in selecting the optimum process parameters for obtaining a desired control surface finish.[5] 155

2 Yeldose and Ramamoorthy (2008) compared the effect of the uncoated and TiN coating by reactive magnetron sputtering on EN31 rollers in burnishing with varying process parameters such as burnishing force, feed, speed, number of passes upon surface roughness of EN24 steel work material.[6]grzesik and Zak (2012) investigated the surface finish produced by hard turning of a 41Cr4 low-alloy steel quenched to about 60 HRC hardness, using mixed Al2O3 TiC ceramic inserts, was subsequently modified by super finishing and mult ipass burnishing operations. It was documented that both super finishing and burnishing operations produced smoother surfaces with lower surface roughness.[3] Morimoto and Tamamura (1991) described in their study about ball burnishing process on steel bars and analysed various tool materials.[11] From the above literature review, it is shown that many researchers were using roller and ball burnishing process to super finish the material. In present study, roller burnishing process is used to super finish the tool steel material on CNC lathe. II. EXPERIMENTAL SETUP The workpiece material is high-carbon high-chromium tool steel (HCHCr). The chemical compositions are as follows: 2.03% C, 0.33 Mn, 12.01% Cr, 0.22% Si, 0.023% S and 0.02% P. The surface hardness is 35 HRC. The Jyoti Turning Centre DX200 CNC machine is used for machining. The work piece is turned to 27 mm diameter of 150 mm length and tool insert: TNMG Figure: 1.The schematic drawing of the workpiece The turning is done up to a length of mm. The remaining work piece area is used for chuck hold. The surface roughness and surface hardness after turning operation are 2.24 µm and 320 HV as obtained. The TR- 200 hand held surface roughness indicator is used to measure surface roughness and surface hardness is measured from Rockwell hardness testing machine. The surface roughness tester used has range of µm for Ra value. ISO 4288 and IS 1516 standards are used to measure roughness and Micro Vickers hardness respectively. Figure 2 shows the schematic drawing of the process. Figure 2.The schematic drawing of the burnishing process 156

3 Optimum parameters are determined as follows for the experiment: Burnishing force : 1000 N Burnishing speed : 250 r.p.m. Burnishing feed : 0.06 rev/sec No: Of Passes : 5 Roller Width : 2 mm Figure 3shows the Micro Vickers Hardness Tester, which is used to measure the micro hardness of the workpiece material. It is non-destructive type of testing in which the machine applies loads of range kg on the material surface. The load is applied using pyramidal shaped indenter with an angle of 136 between opposite faces. III. RESULTS AND DISCUSSIONS Figure 3 Photographic view of the Micro Vickers Hardness Tester Figure 3shows the effect of burnishing force on the surface roughness and micro hardness. When burnishing force is increasing, surface roughness is decreasing and correspondingly surface hardness is increasing. When burnishing force is increasing, the deformation action on the top layer of the surface is increasing. Therefore, the surface roughness is decreasing and surface hardness is increasing. When more force is applied on the surface, the deformation action on the peak valleys of the surface is more. Hence, surface roughness is decreasing and surface hardness is increasing. Figure 4.Effect of burnishing force on surface roughness and micro hardness. Figure 4shows the effect of burnishing speed on surface roughness and micro hardness. When burnishing speed is increasing the area of contact between the tool and the workpiece gets reduced. This leads to a situation in which the amount of deformation reduces. As a result, surface roughness increases and micro hardness reduces. 157

4 Figure 4 Effect of burnishing speed on surface roughness and micro hardness. Figure 5shows the effect of burnishing feed on the surface roughness and surface hardness when burnishing force is 1000 N. At lower feed, contact time between tool and work piece is more. Therefore, deformation action is more on the top surface. As feed increases, contact reduces between the tool and the workpiece surface causing the roughness to increase as no deformation takes place. Meanwhile, the micro hardness keeps reducing as the feed increases. Figure 5 Effect of burnishing feed on surface roughness and micro hardness. Figure 6shows that the effect of number of pass. For the number of pass 2 to 4, the deformation action on the top layer is less compared to number of pass 1 to 2. This is because the top layer hardens when the tool moves on the surface from first pass to second pass. Therefore, the rate of improvement in the surface finish is more compared to number of pass 2 to 4. Figure 6. Effect of number of passes on surface roughness and micro hardness. 158

5 Figure 7 shows the effect of roller width of the burnishing tool on the surface roughness and micro hardness. As in the figure, roughness value increases as the roller width increases, this is due to the fact that as roller contact area increases the stress applied gets reduced below the yield stress of the material. This causes lesser deformation to take place on the workpiece causing the surface roughness to increase. Since the surface doesn t get deformation under the load, the micro hardness gets reduced. IV. CONCLUSION Figure 7.Effect of roller width on surface roughness and micro hardness. The study was done as per the parameters obtained using the response surface optimization method. The values of surface roughness and micro hardness varied as a result of the various operating conditions. The minimum value of surface roughness obtained was µm and micro hardness obtained was 589 HV.It was seen that the Roller burnishing proved to be a more suited finishing process which improves the surface finish and also increses the micro hardness with minimum changes to orginalworkpiece geometry. REFERENCES 1. S.Swirad, The surface texture analysis after sliding burnishing with cylindrical elements, Wear,Volume 271,pages (2011) 2. M. R. Stalin John and B. K. Vinayagam, Optimization of roller burnishing process on tool steel material using response surface methodology,journal of Machining and Forming Technologies,Volume 3, Issue 3-4, pages 1 18 (2011) 3. Wit Grzesik, Krzysztof Zak, Modification of surface finish produced by hard turning using super finishing and burnishing operations, Journal of Materials Processing Technology, Volume 212, pages (2012) 4. Hamadache, L.Laouar, N.E.Zeghib and K. Chaoui, Characteristics of Rb40 steel superficial layer under ball and roller burnishing, Journal of Materials Processing Technology, Volume 180, pages (2006) 5. Dabeer P.S. and PurohitG. K., Effect of ball burnishing parameters on surface roughness using surface roughness methodology, Advances in Production Engineering & Management Volume 5, pages (2010) 6. Binu C. Yeldose and B. Ramamoorthy, An investigation into the high performance of Ti-N coated rollers in burnishing process, International Journal of Material Processing and Technology Journal of Materials Processing Technology, Volume 207, Issues 1-3, pages (2008) 7. M.M. El-Khabeery, M.H. El-Axir, Experimental techniques for studying the effects of milling roller-burnishing parameters on surface integrity,international Journal of Machine Tools & Manufacture, Volume 41,pages (2001) 8. R.L. Murthy and B. Kotiveerachari, Burnishing of metallic surfaces, Precision Engineering, Volume /81/030, pages (1981) 9. MahmoodHassan, An investigation into the surface characteristics of burnished cast Al-Cu alloys,international Journal of Machine Tools and Manufacturing, Volume 37,pages (1997) 10. Adel MahmoodHassan, The effects of ball- and roller-burnishing on the surface roughness and hardness of some non-ferrous metals, Journal of Materials Processing Technology, Volume 72,pages (1997) 11. Tokio Morimoto and Kentaro Tamamura, Burnishing process using a rotating ball-tool - effect of tool material on the burnishing process, Wear, Volume 147,pages (1991) 159

An Experimental Work on Multi-Roller Burnishing Process on Difficult to Cut Material Titanium Alloy

An Experimental Work on Multi-Roller Burnishing Process on Difficult to Cut Material Titanium Alloy S.Thamizhmanii * and S.Hassan Faculty of Mechanical and Manufacturing Engineering, Universiti Tun Hussein