Abstract: The development in the manufacturing flied requires the continuous optimization using various methods. In order to minimize some technological output (such as surface roughness, tangential force, specific cutting force, and cutting power) characterizing material machinability, it is intended in the present paper to perform an optimizing approach of cutting parameters based on Taguchi method. Selected input cutting parameters are major cutting edge angle, cutting insert nose radius, cutting speed, feed rate, and depth of cut. The tests were performed on AISI D3 steel using mixed ceramic inserts under dry cutting conditions. A Taguchi L18 orthogonal array is used to design the optimization experiment. The analysis of variance (ANOVA) is exploited to evaluate the foremost effects on the output parameters. The results indicate that both feed rate and cutting insert nose radius are the mainly influencing factors on surface roughness while both tangential force and specific cutting force are affected principally by depth of cut followed by feed rate. The most significant parameter affecting cutting power is depth of cut followed by cutting speed and feed rate. Regression equations are formulated for estimating predicted values of technological parameters. Optimal cutting parameters are determined using the signal-to-noise (S/N) ratio which was calculated for the precited technological output according to the “the smaller-the-better” approach. Based on the confirmation experiments and laboratory results, it is concluded that the Taguchi method is successfully adapted to describe the optimization of cutting parameters (inputs) for improved technological ones (output).

Abstract: The turning process is one of the fundamental machining operations wherein optimization of parameters leads to better machining performance. This study has applied integrated Taguchi and Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) methods to determine the optimum process parameters in turning operation of EN25 steel using coated carbide tools. The process parameters considered are cutting speed, feed rate, and depth of cut. The objective is to minimize circularity and cylindricity simultaneously. An orthogonal array, Signal to Noise (S/N) ratio, and TOPSIS are employed to analyze the effects of input parameters on the output parameters. In this study, a decision matrix is formed using S/N ratios; then the TOPSIS method is used to transmogrify a multi-criteria optimization problem into a single-criterion problem. The result revealed that the proposed method is appropriate for solving multi-criteria optimization of process parameters. Results also showed that cutting spee...

Abstract: This paper presents a study of the Taguchi design application to optimize surface quality in a CNC end milling operation. The present study includes feed per tooth, cutting speed and radial depth of cut as control factors. An orthogonal array of L9 was used and the ANOVA analyses were carried out to identify the significant factors affecting the surface roughness. The optimal cutting combination was determined by seeking the best surface roughness (response) and signal-to-noise ratio. The study was carried-out by machining a hardened steel block (steel 1.2738) with tungsten carbide coated tools. The results led to the minimum of arithmetic mean surface roughness of 1.662 µm, being the radial depth of cut the most influent parameter, with 64% of contribution for the workpiece surface finishing.

Abstract: The effect of flux-cored arc welding (FCAW) process parameters on the quality of the super duplex stainless steel (SDSS) claddings can be studied using Taguchi L9 design of experiments. In this experimental investigation, deposits were made with 30 % bead overlap. Establishing the optimum combination of process parameters is required to ensure better bead geometry and desired properties. The above objectives can be achieved by identifying the significant input process parameters as input to the mathematical models like welding voltage (X 1), wire feed rate (X 2), welding speed (X 3), and nozzle-to-plate distance (X 4). The identified responses governing the bead geometry are bead width (W) and height of the reinforcement (H). The mathematical models were constructed using the data collected from the experiments based on Taguchi L9 orthogonal array. Then, the responses were optimized using non-traditional nature-inspired technique like genetic algorithm (GA).

Abstract: The electrochemical discharge machining is a highly stochastic process involving a number of complex parameters. Controlling of these process parameters simultaneously to fetch the best possible performance is a difficult task. Determining an optimal parametric combination has become complex owing to interdependency of the parameters. In this work, the authors have made an attempt to establish the optimal combination of control parameters for machining of micro-channels on quartz glass. Taguchi’s standard orthogonal array (L9) with Grey relational analysis (GRA) approach was used to establish the optimal parametric conditions for reducing the Width overcut (WOC) of micro-channels and increasing the Material removal rate (MRR). In order to optimize MRR and WOC together, the optimal combination of the selected control variables was obtained using the GRA. The experimental results showed the effectiveness of the adapted method to indicate the performance of the electrochemical discharge machining process.

Abstract: Wire electric discharge machining (WEDM) is a nontraditional machining process for machining conductive materials with complex and intricate shapes with a high surface finish and dimensional accuracy. The decision making for the selection of the best set of combinations of input process parameters is a major challenge. Therefore a proper optimization tool should be used for the optimal selection of process parameters. The resent work deals with the comparative study of Preferential Selection Index (PSI) and Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) for the selection of process parameters during machining of EN31 tool steel. Four input parameters- Pulse on Time (Ton ), Pulse off Time (Toff ), Servo Voltage (SV) and the Wire tension (WT) are considered. Surface roughness and material removal rate are the measured output responses. Taguchi L9 orthogonal array is used for developing the experimental design. Three levels of each control factor are considered. The results show that a single parameter alone does not have a significant influence on the output responses. Thequality of the output responses depends on the combination of the various set of input parameters. The best set of combination suggested from the current input parameters for machining of EN31 Tool Steel by Wire EDM Process is found to be Pulse on Time (Ton )= 15μs, Pulse Off Time (Toff )=35μs, Servo Voltage (SV)=40V and the Wire tension (WT)=5kgf from both PSI as well as TOPSIS techniques. Confirmation experiments are performed to validate the optimal results.

Abstract: Inconel 718 is widely used in high-temperature environments, high-performance aircraft, and hypersonic missile weapon systems; however, it is very difficult to machine using conventional techniques. This study employed an L9 Taguchi orthogonal array for the analysis of wire electrical discharge machining parameters when used for the machining of Inconel 718. Our aim was to determine the optimal combination of parameters to minimize surface roughness while maximizing the material removal rate. The Taguchi method is widely applied in mechanical engineering with the aim of identifying the optimal combination of processing parameters as they pertain to single quality characteristics. Unfortunately, Taguchi analysis often leads to contradictory results when seeking to rectify multiple objectives. To resolve this issue, this study implemented gray relational analysis in conjunction with Taguchi method to obtain the optimal combination of parameters to deal specifically with multiple quality objectives. For the dual objectives of surface roughness and material removal rate, the optimal combination of parameters derived using gray relational analysis resulted in a mean surface roughness of 2.75 μm. In L9 orthogonal array experiments, run 1 produced the best gray relational grade with mean surface roughness of 2.80 μm, representing an improvement of 1.8%. The material removal rate achieved after the application of gray relational analysis was 0.00190 g/s, whereas the L9 experiment achieved a material removal rate of 0.00123 g/s, representing an improvement of 54.5%.

Abstract: We introduce systematic methods to create optimal designs for order-of-addition (OofA) experiments, those that study the order in which $m$ components are applied---for example, the order in which chemicals are added to a reaction or layers are added to a film. Full designs require $m!$ runs, so we investigate design fractions. Balance criteria for creating such designs employ an extension of orthogonal arrays (OA's) to OofA-OA's. A connection is made between $D$-efficient and OofA-OA designs. Necessary conditions are found for the number of runs needed to create OofA-OA's of strengths 2 and 3. We create a number of new, optimal, designs: 12-run OofA-OA's in 4 and 5 components, 24-run OofA-OA's in 5 and 6 components, and near OofA-OA's in 7 components. We extend these designs to include (a) process factors, and (b) the common case in which component orderings are restricted. We also suggest how such designs may be analyzed.

Abstract: In this research work, an effort has been made to study the influence of selected input parameters on the dimensional accuracy (linear as well as radial) and surface finish of polyurethane prototypes fabricated by vacuum casting (VC) process as a case study. The master pattern required for making a silicone mould has been fabricated by fused deposition modelling and its surface finish has been enhanced by chemical vapour smoothing process. Maximum shrinkage of 2.29 and 4.77% has been observed in the selected linear and radial dimension, respectively, after the VC process. Optimal parameter settings that were different for both the dimensions as well as surface finish have been obtained using Taguchi’s L18 orthogonal array. Finally, parameter setting that simultaneously minimizes the dimensional deviation and surface roughness has been found out using response optimization module of Minitab 17 software and the results obtained have been verified by performing the confirmation experiments. The tolerance grades for the selected dimension of the prototypes were found to be acceptable as per the ISO standard UNI EN 20286-I (1995) and DIN16901 for plastic materials. In addition, the C pk value greater than 1.3 indicated that the proposed process is highly capable. The surface finish and dimensional accuracy of prototypes are at par with the traditional moulding patterns, and hence, they can be used as end-products or plastic-based master patterns for investment casting applications.

Abstract: The present work aims to determine an appropriate setting of process parameters (viz. gap voltage, peak discharge current, pulse-on time, duty factor and flushing pressure) for achieving optimal machining performance during electro-discharge machining of super alloy Inconel 718 by using copper tool electrode. Experiments have been performed based on \(L_{25}\) orthogonal array design of experiment by varying each of the aforesaid process parameter at five different levels. The machining performances have been evaluated in terms of material removal rate, electrode wear rate, surface roughness (\(R_{\mathrm{a}})\), surface crack density, white layer thickness, and micro-hardness of the EDMed Inconel 718 end product. In this paper, a novel optimization route (combining satisfaction function, distance measure approach in conjugation with Taguchi’s philosophy) has been introduced. Application feasibility of the aforementioned approach has been compared to that of obtained through exploration of principal component analysis and combined quality loss concept integrated with Taguchi method. Additionally, morphology of the EDMed work surface of Inconel 718 has been investigated through scanning electron microscopy.

Abstract: SummaryOrthogonal Latin hypercubes provide a class of useful designs for computer experiments. Among the available methods for constructing such designs, the method of rotation is particularly prominent due to its theoretical appeal as well as its space-filling properties. This paper presents a general method of rotation for constructing orthogonal Latin hypercubes, making the rotation idea applicable to many more situations than the original method allows. In addition to general theoretical results, many new orthogonal Latin hypercubes are obtained and tabulated.

Abstract: This article presents a method of constructing a rich class of orthogonal designs that include orthogonal Latin hypercubes as special cases. Two prominent features of the method are its simplicity and generality. In addition to orthogonality, the resulting designs enjoy some attractive space-filling properties, making them very suitable for computer experiments.

Abstract: A new robust optimal design methodology has been developed and applied to the design of plastic injection molding products Taguchi’s robust design method and an optimal design search algorithm are integrated with a commercial CAE simulation tool A direct search-based optimization procedure is implemented with the considerations of process variations as well as uncontrollable noise variables The Interactive Design Space Reduction Method (IDSRM) based on orthogonal arrays for design of experiments is developed as a general optimization tool Using the system, designers can interactively adjust the design space during the searching process for the optimal solution based on the outcomes of the experiments The developed methodology is applied to an industrial application: a molding process design of an automobile front bumper to minimize the weldline, a form defect of plastic parts Compared with the initial design solution, the optimized design aided by the proposed methodology shows a more efficient and better result in terms of design robustness against process variations

Abstract: This paper investigates the application of Taguchi method with fuzzy logic for multi objective optimization of roughness parameters in electro discharge coating process of Al-6351 alloy with powder metallurgical compacted SiC/Cu tool. A Taguchi L16 orthogonal array was employed to investigate the roughness parameters by varying tool parameters like composition and compaction load and electro discharge machining parameters like pulse-on time and peak current. Crucial roughness parameters like Centre line average roughness, Average maximum height of the profile and Mean spacing of local peaks of the profile were measured on the coated specimen. The signal to noise ratios were fuzzified to optimize the roughness parameters through a single comprehensive output measure (COM). Best COM obtained with lower values of compaction load, pulse-on time and current and 30:70 (SiC:Cu) composition of tool. Analysis of variance is carried out and a significant COM model is observed with peak current yielding highest contribution followed by pulse-on time, compaction load and composition. The deposited layer is characterised by X-Ray Diffraction analysis which confirmed the presence of tool materials on the work piece surface.

Abstract: Weld quality is a very important working aspect of the manufacturing and construction industries In this research work, an attempt has been made to optimize the parameters of activated tungsten inert gas (A-TIG) welding of sintered hot-forged AISI 4135 steel produced through the powder metallurgy route Experiments were performed based on Taguchi L9 orthogonal array Response surface methodology was used to create regression equations, and process parameters were optimized using genetic algorithm (GA) and simulated annealing (SA) Process parameter optimization is multi-input to single output (tensile strength), in which the quality of output depends upon input parameters like current, voltage, welding speed, and gas flow rate The present study was conducted to maximize the output of the A-TIG welding of sintered hot-forged AISI 4135 steel and fix the input parameters The results indicate that the voltage and current have a maximum influence on tensile strength in A-TIG-welded joint Confirmation experiments have also been conducted to validate the optimized parameters

Abstract: The present work studies the effect of three variables (spindle speed, feed rate, and depth of cut) towards surface roughness by adopting orthogonal design and surrogate model. Experiment in hard turning of AISI 1045 steel with YT5 tool were carried out. The analysis of variance (ANOVA) and the regression model suggest that the feed rate has great effect on the surface roughness compared to the other two variables. The contour plot and the surface plot based on the regression model show the correlation between the response (surface roughness) and all possible pairwise combinations of the three variables. In order to get the desired surface roughness, the optimum cutting parameters are obtained by developing an optimization method.

Abstract: This paper presents the application of Taguchi method (TM) to design optimization of non-uniform circular antenna array (CAA) for suppression of sidelobe levels (SLLs). TM, a robust design approach, takes signal-to-noise ratio and orthogonal array tools from the statistical design of experiments. These tools allow instead of full factorial parametric analysis minimize the design parameters; thus, increase the convergence speed and generate more accurate solutions. TM is used to determine an optimal set of amplitudes and positions of CAA for 8, 10, and 12 elements. Comparison of the results of the TM with those of latest meta-heuristic algorithms in the literature reveals that the CAA design with TM provides the best SLL reduction performance in all cases.

Abstract: Nowadays, the demand for achieving cars with higher strength, lower fuel consumption, and better safety considerations propels automakers to produce parts with extremely high strength-to-weight ratios. This criterion is done through the hot-stamping process considered as a novel technology employed for producing high-strength steel parts with low springback, particularly appropriate for the vehicle body. In this paper, firstly, numerical simulation of the hot-stamping process of a blank consisted of boron-alloyed steel 22MnB5 (with commercial name of Usibor 1500) is performed. Secondly, effects of different design parameters including blank holder force, die radius, gap between the punch and die, and forming time on the final temperature distributions as well as springback of the part is investigated. Consequently, optimization has been performed using Taguchi L16 orthogonal array to obtain the parameters which minimize above-mentioned parameters as two objective functions. Obtained results are verified b...

Abstract: This paper presents a study of the Taguchi application to optimize surface quality based on fractal theory in meso-scale end-milling operation. Usually, the surface quality is characterized by roughness, but in the meso-scale area, the size of the workpiece will be difficult to meet the requirements of the sampling length, which will have a huge influence on the characterization results. Although there are many algorithms for adjusting, the operation process is very cumbersome; for this reason, characterization method based on fractal theory is introduced and applied to evaluate the machined surface in the research. Also, the Taguchi method is applied to search the optimal parameters combination, during which spindle speed, depth of cut, and feed rate are considered as the control factors. Specifically, firstly, the machining surface characterization method based on fractal theory is introduced in details; then, an orthogonal array of L25(53) is used for the experimental study; through ANOVA analyses, the significant factors which affect surface quality are established, and the optimal cutting parameter combination is determined; later, confirmation tests are carried out to verify the applicability of the characterization methods for the meso-scale cutting surface. Research shows that fractal characterization method is better to evaluate the surface quality in the meso-scale.