Manufacturing Technology Today

P. Hema ¹, P. Yamini Priya ¹, M. Reddeiah ¹

Affiliations
1 Department of Mechanical Engineering, S.V.U College of Engineering, Tirupathi, Andhra Pradesh, IN

Abstract

Friction Stir weld joint exhibits better quality and properties compared to other fusion welding techniques. Dissimilar lap joining process is considered as a challenge when compared to welding of similar materials due to variations in the chemical composition and mechanical properties of the joining materials. In this project AA 6082-T6 and AA 5083-H111 are joined in lap joint configuration using H13 tool steel with taper threaded pin profile by FSLW as per Taguchi design. Process parameters considered are Tool Rotational Speed, Welding Speed and Tool Tilt Angle. FSLW is conducted on Knee Type Vertical Milling machine FN2V. Mechanical properties like Shear Strength, Peak Load and Elongation are measured by shear tensile test. Hardness at the weld zone is also determined by Vickers Hardness test. Multiple responses are optimized by using TOPSIS method and best Process Parameters are evaluated.

Keywords

Lap Joint, H13 Tool Steel, FSLW, Process Parameters, Shear Tensile Test, Hardness Test, TOPSIS.

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G. Evangelin Paul ¹, P. Hema ¹, K. Venkata Muni ¹, K. Aruna ¹

Affiliations
1 S. V. University College of Engineering, Tirupathi, IN

Abstract

The core and the heart of the battery industry is Grid. This paper discusses about the quality and productivity improvement by reducing the rejections in Grid casting section in one of the Battery manufacturing Multinational companies. The quality improvement would be attained by sigma methodology’s DMAIC approach. It depicts reducing rejections in Grids from grid casting machine. Data collection and Pareto analysis indicated the high rejections are due to flashes and wire miss. The ischolar_main causes are found out by six sigma using Variable search tool and validated by Better Vs Current Tool. By the results of DMAIC, Modifications are carried out in grid casting methodology and the process parameters optimized. This resulted in reducing the rejections from 9.5 % to 2.1 % and average improvement of grid caster’s productivity. To confirm whether Six Sigma implementation would be simplified, this paper highlights usage of Shainin DOE instead of Taguchi DOE.

Keywords

Six Sigma, DMAIC, Pareto Analysis, Shainin DOE, Variable Search, Better Vs Current Tool.

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K. Devisree ¹, K. Aruna ¹, K. Venkatamuni ², P. Hema ¹

Affiliations
1 Dept. of Mechanical Engineering, SVU College of Engineering, Tirupathi, IN
2 Batteries Organization, IN

Abstract

SMED (Single Minute Exchange of Die) is one of the many Lean production methods for reducing time in a manufacturing process. The present paper deals with reduction in tool change time in one of the prime automotive batteries industry using SMED technique which increases productivity of the industry. In this project first the problem is identified in SBD (Small Battery Division) Plant based on analysis of one month data of plant capacity. After analysis, the bottleneck is identified for production of the plant using Pareto Analysis which indicates that the maximum tool change time due to Calibration and Assembly. Next SMED Methodology implemented on major areas to reduce the tool change time. The causes for recursive activities searched and ideas implemented to eliminate them provided. After implementing SMED technique the total tool change time for Calibration from 2192 to 1194 seconds and Assembly from 42 to 24 minutes reduced.

Keywords

SMED (Single Minute Exchange of Die), Lean Production, SBD (Small Battery Division), Pareto Analysis, Calibration and Assembly.

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K. Aruna ¹, R. Bhargav ¹, P. Hema ¹

Affiliations
1 Department of Mechanical Engineering, S.V.U. College of Engineering, Tirupati, IN

Abstract

Electrical Discharge Machining has been playing an important role in manufacturing sector especially industries like aerospace, ordinance, automobile, general engineering, etc. Electrical Discharge Machining (EDM) is one of the important non-traditional machining processes which is used for machining of conductive and semi conductive materials and also difficult to machine materials like super alloys and composites materials. However, selection of process parameters for obtaining higher cutting efficiency or accuracy in EDM is still not fully solved, even with the most updated EDM machine. An attempt is made in the present work to develop a prototype of EDM consisting of different units namely, dielectric filtering and recirculation unit, pulse generation and control unit and tool-feed control unit. They describe the utilization of various units and their components of proto-type EDM. Orthogonal Array, Taguchi Experimental design is developed for experimentation. The process parameters such as voltage, duty cycle and sensor value are by considered during machining. The experiments are carried-out to produce holes on copper plate using EDM Machine. The experimental results are analyzed and the optimal combinations of influential parameters are determined using Grey Taguchi Analysis. The optimum size of hole is obtained as 2.030 mm, at 40V and 0% Duty Cycle. The analysis is carried-out using Mini TAB and GRA.

Keywords

Die-Sinking EDM, Dielectric Filtering, Voltage, Duty Cycle, Grey Taguchi Method.

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B. Narayana Reddy ¹, P. Hema ¹, G. Padmanabhan ¹

Affiliations
1 Department of Mechanical Engineering, Sri Venkateswara University, Tirupati, IN

Abstract

Laser Beam Welding technique is applied to conduct experiments on joining of dissimilar metals, AISI 4130 and AISI 310 steels so as to study the influence of process parameters on mechanical properties of joints. Taguchi L₂₅ Orthogonal Array is selected to join 2mm thick dissimilar steels by varying Laser Power, Welding Speed, Beam Incident Angle, Focal Point Position and Focal Length. Output results of Ultimate Tensile Strength (UTS) and Impact Strength (IS) are measured. ANOVA is carried out to obtain the levels of influence of process parameters and statistical evolution of the results. TOPSIS optimization is applied to transmogrify a multi-criteria optimization problem into a single-criterion problem, so as to obtain optimal combination of process parameters of Laser Beam Welding. Then UTS and IS are maximised. Results have revealed that the proposed method is appropriate for solving multi-criteria optimization of process parameters.

Keywords

Laser Beam Welding, Ultimate Tensile Strength, Impact Strength, Analysis of Variance, TOPSIS.

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P. Hema ¹, M. Vinod ¹

Affiliations
1 S.V.U. College of Engineering, Tirupati, Andhra Pradesh, IN

Abstract

The Thermal Protection System (TPS) is a membrane used to avoid aerodynamic heating of metallic and plastic surfaces during flight of missile. Between a heat source and the protected entity, the thermal protection system is interposed. Although the Orbiter’s re-entry surface heating is primarily convective, ample energy in the air molecules disassociated from the shock layer and given the potential for additional heating. Various composite materials are used in thermal insulation systems to achieve higher backwall temperatures in order to maintain high temperatures and pressure upon re-entry. A Low-Density Ablative Material (LDAM) is prepared and coated using the High Velocity Low Pressure (HVLP) method of coating. The process of applying the chemical composition of the present invention shall ideally require spraying at room temperature, without the need to add heat to the treatment of the composition in order to affect the repair and to obtain the optimum dry film thickness specifications. In this present research, the configuration of the Taguchi experiments is considered and a series of experiments are carried out for the coating process using the L9 orthogonal array by varying the control factors such as air pressure, spray time and nozzle size (lock no.) and the performance parameters are optimized such as Dry Film Thickness (DFT) and Back Wall Temperature (BWT) using Taguchi optimization technique to get the optimal input levels. Finally, a validation test is carried out according to the optimal levels obtained from the optimization technique of Taguchi and the most influential parameters are found using ANOVA.

Keywords

Thermal Protection Systems, Low Density Ablative Material, High Velocity Low Pressure, Dry Film Thickness (DFT), Back Wall Temperature (BWT), Taguchi, ANOVA.

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P. Hema ¹, P. Susmitha ¹, A. K. Damodharam ²

Affiliations
1 SVU College of Engineering, Tirupati, Andhra Pradesh, IN
2 Sree Vidyanikethan Engineering College, Tirupati, Andhra Pradesh, IN

Abstract

Wire Electro Discharge Machining (WEDM) process parameters need to be optimized when new material is invented or even if some process variables changed Optimization of the WEDM process for machining of AISI 440C stainless steel using brass wire electrode was studied in this paper. In this work, based on Taguchi's (DOE), an orthogonal array L-12 is developed and experiments are conducted with eleven factors each at two levels. The experimental data is recorded for obtaining the response values of MRR and Kerf width. Grey relational analysis is done along with Taguchi to find the optimum set of input process parameters. The prediction of output values can be done using the Fuzzy logic approach. At last, a confirmation test is done to evaluate the exactness of the values between experimental and predicted, found that the prediction accuracy for MRR is about 94.92% and for Kerf Width is about 82.5%.

Keywords

Wire Electrical Discharge Machining (WEDM), Taguchi Technique, Design of Experiments (DOE), Grey Relational Analysis (GRA), Fuzzy Logic, Material Removal Rate (MRR).

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P. Hema ¹, G. Mahesh ¹, P. Akhila Swathanthra ¹

Affiliations
1 S. V. U. College of Engineering Tirupati, IN

Abstract

Polylactic acid (PLA), also known as polylactide, is a thermoplastic polyester that is commonly used in Fused deposition modeling (FDM) 3D printing and is considered one of the world's far more widely used bio-plastics. PLA is considered biodegradable and environmentally beneficial, unlike petrochemical-based polymers. This is a low-cost product that could be used in a variety of applications, including food packaging, tissue scaffolding, and biomedical devices. This proposed study is primarily concerned with an in-depth investigation of polylactic acid's mechanical strength and its optimization. The L-9 orthogonal array is adopted by utilizing the Taguchi design of experiments, with input characteristics such as Printing speed, Infill density, and Layer height for the fabrication of nine different sets of flexural and compressive specimens as per ASTM standards using FDM. The responses such as compressive strength and flexural strength are optimized using Taguchi Analysis – S/N Ratios and ANOVA. Similarly, this research reveals a statistical link between input elements and responses. According to the current study, the ideal parameter levels for Flexural and Compression strengths have been found and confirmation Tests have also been conducted according to the optimized process parameter levels as obtained in the Taguchi analysis.

Keywords

Polylactic Acid (PLA), 3D Printing, Fused Deposition Modeling (FDM), Additive Manufacturing (AM)

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