Manufacturing Technology Today

B. V. S. Rao ¹, G. Chandra Mohan Reddy ¹, G. Krishna Mohan Rao ², P. V. R. Ravindra Reddy ¹

Affiliations
1 Department of Mechanical Engg., CBIT, Gandipet, Hyderabad, IN
2 Department of Mechanical Engg., JNTU College of Engg., Hyderabad, IN

Abstract

Deep drawing is the process of converting a blank into cup shaped articles like kitchen sinks, utensils, fountain pen caps etc. Wrinkles and fracture are the major defects in deep drawn products. Wrinkles occur at flange as well as the sidewalls of a deep drawn cup. The main reason for wrinkles is inadequate blank holding force. However excessive blank holding force results in fracture. The aim of this work is to arrive at optimum blank holding force in order to produce wrinkle free products. In this work numerical simulations are conducted by considering five different parameters namely punch radius, die radius, clearance, coefficient of friction and Punch diameter using finite element explicit solver LSDYNA. Modeling of the set up is done using hyper mesh. In this work simulations are carried out as per L-27 orthogonal array suggested by Taguchi. A combination of finite element method and Taguchi analysis is used to determine the influence of process parameters in deep drawing.

Keywords

Deep Drawing, Blank Holding Force, Wrinkling, Taguchi Approach, LSDYNA.

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P. V. R. Ravindra Reddy ¹, P. Radhakrishna Prasad ¹, A. A. Sriramakrishna ¹, P. Prabhakar Reddy ¹, N. V. Srinivasulu ¹

Affiliations
1 Department of Mechanical Engineering, CBIT, Gandipet, Hyderabad, IN

Abstract

Tungsten Inert Gas (TIG) welding is commonly used to weld thin sections of stainless steel and non-ferrous metals such as Aluminium, Magnesium, and Copper alloys. Stainless steels are widely used by many manufacturing industries for automobile parts, pressure vessels etc, due to their good corrosion resistance properties. TIG welding process grants the operator greater control over the weld than competing processes allowing for stronger, higher quality welds. Literature survey indicates that the flow rate of the inert gas, ischolar_main gap and the current are the control factors for the required bead geometry. In this work, the effect of flow rate and current on bead geometry of AISI 304 weldments is studied. The most influencing parameters are determined by the experiments carried out using L-9 orthogonal array. Results are analysed using ANOVA. Radiography is carried out, tensile and hardness test is conducted on defect free samples and the optimum parameters are obtained.

Keywords

TIG, Orthogonal Arrays, Taguchi, ANOVA.

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P. V. R. Ravindra Reddy ¹, B. Chenna Kesava Rao ¹, A. A. Sriramakrishna ¹, Poojita Kotha ¹, D. Amani Reddy ¹

Affiliations
1 Dept. of Mech Engg., CBIT, Gandipet, Hyderabad, IN

Abstract

Tungsten inert gas (TIG) welding is commonly used to weld thin sections of stainless steel and non-ferrous metals such as Aluminium, Magnesium, and Copper alloys. The process grants the operator greater control over the weld than competing processes allowing for stronger, higher quality welds. Literature survey indicates that the flow rate of the inert gas and the current are the control factors for the required bead geometry. In this work, the effect of flow rate and current on bead geometry of mild steel weldments is studied. The most influencing parameters are determined by the experiments carried out using L-9 orthogonal array. Results are analysed using column effect method and S/N analysis.

Keywords

TIG, Orthogonal Arrays, Taguchi, S/N Analysis, Column Effect Method.

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P. V. R. Ravindra Reddy ¹, P. Radhakrishna Prasad ¹, G. Chandra Mohan Reddy ¹, A. Sarotham Reddy ¹, K. Srikanth ¹

Affiliations
1 Dept. of Mechanical Engg., CBIT, Gandipet, Hyderabad, IN

Abstract

Friction Stir Welding (FSW) is a solid state welding process in which the heat for welding is produced by the relative motion between the tool and the two interfaces being joined. In this present study, AA-6082 alloy is friction stir welded for different combination of tool rotation speed and tool feed. Here a cylindrical tapered tool along with a profiled probe is rotated and fed at a constant traverse rate in to the joint. Taguchi technique is used to design the experiments. Total four experiments are conducted. The UTS and hardness for all four welded parts are measured by UTM and Vickers hardness tester respectively. Analysis is done and the optimum parameters are obtained and presented.

Keywords

Friction Stir Welding, Orthogonal Arrays, Taguchi, ANOVA, AA-6082.

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P. V. R. Ravindra Reddy ¹, G. Chandra Mohan Reddy ², Shiva Shankar Reddy ¹, L. Suresh Kumar ¹

Affiliations
1 Dept of Mech. Engg., CBIT, Gandipet, Hyderabad, IN
2 Mahatma Gandhi Institute of Technology, Gandipet, Hyderabad, IN

Abstract

Cast iron can be used to produce varied products ranging from basic components in daily life to complex engine blocks of automobiles. This flexibility is achieved in cast iron by the process of alloying, where the properties of cast iron changes tremendously with addition of alloys. In this work, the significance and contribution of the effect of copper and silicon on mechanical properties of grey cast iron is studied using Taguchi method. An L-4 orthogonal array is selected for design of experiments and ANOVA is carried out to find out relative significance of copper and silicon on mechanical properties. The micro structural examination is also done to support the results obtained from ANOVA.

Keywords

Orthogonal Arrays, Taguchi, ANOVA, Cast Iron.

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M. Sailender ¹, G. Chandra Mohan Reddy ², Sriram Venkatesh ³, P. V. R. Ravindra Reddy ¹

Affiliations
1 Dept. of Mechanical Engg., Chaitanya Bharathi Institute of Technology (CBIT), Gandipet, Hyderabad, IN
2 Mahatma Gandhi Institute of Technology, Gandipet, Hyderabad, IN
3 Dept. of Mechanical Engg, Osmania University College of Engg., Osmania University, Hyderabad, IN

Abstract

Submerged arc welding (SAW) is one of the important welding processes used for welding thick blocks. Since arc in this welding is submerged under the blanket of granular fusible flux, the bead cannot be seen while welding. Hence all parameters such as arc voltage, welding current, carrier speed, electrode feed rate, nozzle to plate distance and the gap between plates etc. are to be preset. So, the effect of the parameters on the bead geometry is to be found out for which a number of experiments are to be carried out. Hence, in this work, to reduce the number of experiments a screening test is initially conducted, using Taguchi Technique. Open circuit voltage (OCV), wire feed rate (WFR), carrier speed (CS) and nozzle to plate distance (NPD) are chosen as input parameters and the reinforcement, width and penetration of the weld bead are taken as output parameters. L8 orthogonal array is selected, the factors are assigned and experiments are carried out. Column effect method is used to find the most effective parameters on bead characteristics.

Keywords

Submerged Arc Welding, Weld Bead, Orthogonal Array (OA), Column Effect Method.

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G. Haragopal ¹, P. V. R. Ravindra Reddy ¹, G. Chandra Mohan Reddy ², V. V. Satyanarayna ³, J. V. Subrahmanyam ⁴

Affiliations
1 Dept. of Mechanical Engg., CBIT, Gandipet, Hyderabad, IN
2 Mahatma Gandhi Institute of Technology, Gandipet, Hyderabad, IN
3 Sagar Institute of Technology, Chevella, Hyderabad, IN
4 Vasavi College of Engg., Ibrahimbagh, Hyderabad, IN

Abstract

Al-65032 is an Aluminum alloy used for construction of aerospace structures such as wings. This alloy can be welded by Tungsten Inert Gas (TIG) or Metal Inert Gas (MIG) welding. Hence establishment of welding parameters and their optimization for good quality weld is utmost important factor. In this work; Taguchi parameter design is used to design the process parameters that optimise the mechanical properties of weld specimen. The process parameters of the TIG welding setup considered are gas pressure, current, groove angle and pre-heat. Assigning the process parameters to L-9 orthogonal array, experiments are conducted and the optimization condition is obtained along with the identification of most influencing parameters using S/N analysis and mean response analysis. ANOVA is also carried out to reaffirm the same. A confirmation test is conducted to ascertain the optimized condition.

Keywords

Al 65032, TIG, Taguchi, Orthogonal Arrays, S/N Analysis, ANOVA.

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P. V. R. Ravindra Reddy ¹, Chandra Mohan Reddy ², T. A. Janardhan Reddy ³

Affiliations
1 CBIT, Gandipet, Hyderabad, IN
2 Dept. of Mech. Engg, CBIT, Gandipet, Hyderabad, IN
3 Dept. of Mech. Engg, O.U College of Engg., Hyderabad, IN

Abstract

Deep drawing is a complex process that is influenced by various parameters like tooling configurations, blank configurations, material properties, and forming conditions. Limit Drawing Ratio is one of the parameters that indicate the drawability of material. There is lot of research on the effect of material parameters on LDR, but a little work is done on tooling and process parameters. In this paper, the effect of various tooling and process parameters like die profile, punch profile, clearance, friction factor, punch diameter on limit drawing ratio is investigated and presented using an explicit finite element code LSDYNA 3D. The model is validated by comparing force obtained in experiment with the one obtained in simulation. A screening test is conducted to fin d out the most infuencing parameters and their interactions using L8 orthogonal array. Column effect method and plotting method are used for the analysis. After identifying the most effective parameters , their affect on the LDR is studied and presented in the paper.

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