OPTIMIZATION OF WELDING PARAMETER ON AA2014 IN GMAW

Transcription

1 OPTIMIZATION OF WELDING PARAMETER ON AA2014 IN GMAW P.Venkadeshwaran 1*, R.Sakthivel 1, R.Sridevi 1, R.Ahamed Meeran 1, K.Chandrasekaran 1 1 Department of Mechanical Engineering, Nadar Saraswathi College of Engineering and Technology, Theni, Tamilnadu, India. * Corresponding Author ID: venkadesh.sivam95@gmail.com ABSTRACT Welding is a permanent joining process used to join different materials like metals, alloys or plastics, together at their contacting surfaces by application of heat and or pressure. During welding, the work-pieces to be joined are melted at the interface and after solidification a permanent joint can be achieved. GMAW process a continuous and consumable wire electrode is used. A shielding gas generally argon or sometimes mixture of argon and carbon dioxide are blown through a welding gun to the weld zone. In this research work of Gas Metal Arc Welding (GMAW) show the effect of current (A), voltage (V), and gas flow rate (L/min) on Ultimate Tensile Strength (UTS) of aluminum alloy 2014 material, In this experiment we done experiment by using L9 Orthogonal Array to find out UTS and also perform confirmatory experiment to find out optimal run set of current, voltage and gas flow rate. Keywords MIG Welding - Aluminum alloy L9 Orthogonal Array - Tensile Strength - S/N ratio. 1. INTRODUCTION Welding is a permanent joining process used to join different materials like metals, alloys or plastics, together at their contacting surfaces by application of heat and or pressure. During welding, the work-pieces to be joined are melted at the interface and after solidification a permanent joint can be achieved [1].GMAW process a continuous and consumable wire electrode is used. A shielding gas generally argon or sometimes mixture of argon and carbon dioxide are blown through a welding gun to the weld zone. Electrode melts due to the heat and molten filler metal falls on the heated joint [2]. Machinability of aluminum alloy 2014 is very good. Typical applications of aluminum alloy 2014 are high strength components especially for use in the aerospace and marine industries.the aluminum alloys and copper are difficult to weld because of the high thermal conductivity, high thermal expansion and a tendency to give porous welds [3]. During a manual welding operation, the welder has to have control over the welding variables, which affect the weld penetration, bead geometry and the overall weld quality. A proper selection of welding variables will increase the chances of producing welds of a satisfactory quality [4]. 60

2 2. LITERATURE REVIEW Many of investigators have suggested various methods to explain the process parameters effecting on mechanical properties of weld metal of aluminum alloys. Oladele, et al.[5]worked on Wrought (6063) aluminum alloy for investigation using MIG welding.the current and voltage is used as parameters current and voltage on tensile strength, Since in arc welding is directly related voltage and current, the two conditions are applied i.e. at constant voltage the current was I1=75A & I2=100A and at constant current the welding voltage was varied as V1=25V & V2=30V.Tensile strength is more when current is at 100A.Toughness property is found to be good at V1=25V and other are nearer to it. Hardness is more at I1=75A & at V2=30V. Latfe, et al.[6] Perpetrated lap joint welding samples welded by seam welding method,2014 heat treatable aluminum alloy,the paper studied some groups at different variable welding,welding time was studied at electrode pressure 1,1.5 KN with thickness 1.5 mm and another group at 2 mm.after welding process shear strength,vickers hardness were tested at different variables. The paper stated the best shearing strength at 1.5mm thickness with 45 KA welding current at 1.5 KN electrode pressure. Patil et al. [7] Studied for the material AISI 1030 Mild steel and take input parameter as welding current, voltage, weld speed. The response was the signalto-noise (S\N) ratio and ANOVA (analysis of Variance) were used for optimization and It was found that tensile strength depends on welding speed. And the result show that by increasing the welding speed and decreasing the Fig 1: Schematic Diagram of GMAW System current increases the UTS of welded joint while voltage do not affect the weld strength. Anjanaya Prasad, et al.[8]the author has made comparison of mechanical properties on AA6061 by undergoing MIG and FSW processes. MIG welding produces more porosity due to solubility of hydrogen in the molten aluminum pool. The surface of MIG welding is same on both surface where it is Different in FSW.MIG welded element formed by columnar crystalline structure & FSW welded elements gives a fine microstructure at Nugget zone. And size of the weld nugget would generally be considered beneficial to the mechanical properties. Tensile strength of welded element is less in case of both welding comparing to base metal.but FSW shows stronger than MIG. Meshram, et al. [9] Used Taguchi optimization technique pair with grey relational analysis has been adopted for optimize parametric complex to carry out effect of process parameter on Penetration, Reinforcement and Bead width in GMAW welding process of stainless steel AISI410.The welding process parameters considered in this analysis are voltage, wire feed rate, Welding Speed, Nozzle to Plate Distance and Gas Flow. The Optimum welding Parameter combination was obtained by using analysis of signal to noise ratio. The S/N ratio calculated and used to obtain the optimum level for every input factor. Using ANOVA the adequacy of develop model is checked and significant coefficient for each input factor on weld bead geometry were determined. 61

3 3. EXPERIMENTAL DETAILS For the research purpose on GMAW welding we have chosen the aluminum alloy material which is wrought and heat treatable alloy. We fabricate 20 pieces into a dimension of 150x50x6mm by hydraulic cutting machine. Then we have made all the work pieces in to flate plate standard form with angle of Then we had took two pieces and set it with maintaining a 1.5mm root gap and then we had started penetration process with desired or selected current, voltage, gas flow rate readings and done the experiment. In the present study, in order to identify the process parameters with the maximum stress distribution in the GMAW for aluminum alloy Factors affecting the GMAW welding and their levels are given in table 1 and the experimental layout using L9 orthogonal array are given in table 2. Table 1. Level of GMAW welding process variable variables Unit Level-1 Level-2 Level-3 Current (A) Voltage (B) Gas flow rate (C) Amp volt Lit/min Sample no Table 2. Experimental layout using L9 orthogonal array Current (A) Voltage (V) Gas flow rate (L/min) GMAW welding was used in experiments as it concentrates the heat in the welding area. ER 4043 electrodes of diameter 1.2 mm were taken as electrode for this experiment. For the first phase of experiment welding parameters selected are shown in table. Before performing the actual experiment a number of trial experiments have been performed to get the appropriate parameter range where welding could be possible and no observable defects like undercutting and porosity occurred. After performing the welding, welded specimens were cut in to I shape. Tensile test was performed with universal testing machine (UTN 40.SR NO.: 11/ ).The chemical composition of AA2014 and the filler material is given in table TAGUCHI'S DESIGN METHOD Dr. Taguchi of Nippon Telephones and Telegraph Company, Japan has established a method based on "orthogonal array" experiments which gives much reduced "variance" for the experiment with "optimum settings" of control variables. Thus the marriage of Design of Experiments with optimization of control parameters to find best results is attained in the Taguchi Method. Taguchi technique is used to increases the output and reduced the cost of the products. The Taguchi Design 62

4 is based on orthogonal array. Taguchi design recognizes the control factors to minimize the effect of Noise factor. Orthogonal array helps to reduced the time and cost of the Table 3. Chemical composition of base metal and filler wire used experiment. The Signal-to-Noise (S/N) Ratio which are log function of required output, which is the objective function to be optimized [10]. Material Cu Mg Mn Fe Si Zn Ti Cr Al AA REM Filler wire Cu Mg Mn Fe Si Zn Ti Br Al ER REM 4. RESULT AND DISCUSSION In this research work the effect of input parameters on the Tensile strength, Yield strength and Elongation were determined. The signal to noise ratio for all the response are given Table 4. The Taguchi analysis against the different factors is given in Table 5. It clearly shows that the optimum welding condition s for maximization of tensile strength is A1B3C1. Analysis of variance for tensile strength is given in Table 6. From this table gas flow is significally after the tensile strength following current and voltage. Similarly Yield strength and Elongation. The table 6 shows the analysis of variance for tensile strength. It clearly shows the gas flow rate is most significantly affect the TS with p value followed by Current with p value Table 4. Result for various parameters A B C TS SNRA1 YS SNRA4 EL SNRA Table 5. Taguchi Analysis: TS versus A, B, C Level A B C

5 Delta Rank Table 6. Analysis of Variance for TS, using Adjusted SS for Tests Delta Rank Source DF Seq Adj Adj F P SS SS MS A B C Error Total S = R-Sq = 91.64% R-Sq (adj) = 66.57% The Taguchi analysis against the different factors are given in Table 7.It clearly shows that the optimum welding condition s for maximization of tensile strength is A1B3C1. Analysis of variance for tensile strength is given in Table 8.Similarly Yield strength and the table 8 shows the analysis of variance for Yield strength. It clearly shows the gas flow rate is most significantly affect the YS with p value followed by current with p Table 7. Taguchi Analysis: YS versus A, B, C Level A B C Value Table 8. Analysis of Variance for YS, using Adjusted SS for Tests Source DF Seq Adj Adj F P SS SS MS A B C Error Total S = R-Sq = 79.40% R-Sq (adj) = 17.59% The Taguchi analysis against the different factors are given in Table 9.It clearly shows that the optimum welding condition s for maximization of tensile strength is A1B3C1. Analysis of variance for tensile strength is given in Table 10.Similarly Yield strength and the table 10 shows the analysis of variance for Elongation. It clearly shows the gas flow rate is most significantly affect the EL with p value followed by current with p value Table 9. Taguchi Analysis: EL versus A, B, C Level A B C Delta Rank Table 10. Analysis of Variance for EL, using Adjusted SS for Tests Source DF Seq Adj Adj F P SS SS MS A B C Error Total S = R-Sq = 68.35% R-Sq (adj) = 0.00% The main effect plot for SN ratio in Tensile strength, Yield strength and Elongation are graph in figure 2, 3, 4 64

6 Fig 2: main effect plot for TS Fig 3: main effect plot for YS 65

7 Fig 4: main effect plot for EL 5. CONCLUSION The present focus on MIG welding parameter on AA2014 under different welding condition the following on the outcome of this research. 1.Optimum welding condition for maximization is current set as 180 A, voltage set as 28 V, gas flow rate set as 17 L/min for tensile strength. 2.Optimum welding condition for maximization is current set as 180 A, voltage set as 28 V, gas flow rate set as 17 L/min for yield strength. 3.Optimum welding condition for maximization is current set as 180 A, voltage set as 24 V, gas flow rate set as 17 L/min for elongation. 6. REFERENCES [1] Bolten, W Engineering Material Technology, prentice hall. [2] Kulekci, M Metallurgy, vol.44, No.3. [3] Aluminum welding guide, [4] Ramanaiah, N International Symposium of Research Students on Materials Science and Engineering December 20-22, Chennai, India Department of Metallurgical and Materials Engineering, Indian Institute of Technology Madras. [5] Oladele, I.O., Omotoyimbo, Adewuyi. 2009Study of the effect of welded joints on the mechanical properties of Wrought (6063) aluminum alloy, The Pacific journal of science and Technology, Vol 10 (Nov 2009) pp [6] Latfe, Y., Ahmed Hassn.2010 state some mechanical properties for al- alloy welded by seam welding technique, Vol. 03, No. 01, pp (June 2010). [7] Patil, S. R. 2013optimization of mig welding parameters for improving strength of welded joints", International Journal of Advanced Engineering Research and Studies (July-Sept 2013) [8] Anjanaya Prasad., Prassana, B. 2013Experimental Comparison of the MIG and Friction stir welding processes for AA6061(Al Mg Si Cu) Aluminum alloy,international Journal of Mining, Metallurgy & Mechanical Engineering (IJMMME) Vol 1,Issue 2(2013) pp [9] Meshram., Pohokar, S.R Optimization of Process Parameter of Gas Metal Arc Welding to Improve the Quality of Weld Bead Geometry, International Journal of Engineering, Business and Enterprise Application,5 (1)( June-August 2013), pp [10] Utkarsh, S., Neel, P., Mahajan, T Experimental Investigation of MIG Welding for ST-37 Using Design of Experiment. International Journal of Science and Research Publications, Volume 4, Issue 5, (May 2014) ISSN