Taguchi Matrix Research Articles

Customized boron-doped diamond electrodes for efficient water treatment via HF-CVD parameter optimization

Among the Design of Experiments (DoE) approaches available, the Taguchi method offers a methodical and effective way to optimize designs with fewer experimental trials. The effects of deposition conditions on the final properties of boron-doped diamond (BDD) films for water treatment applications deposited in a Hot Filament Chemical Vapor Deposition (HF-CVD) reactor were evaluated by applying a Taguchi Matrix. Methane to hydrogen (CH4/H2) ratio, argon mass flow, and total gas pressure were the controllable factors, each in three different levels. Diamond quality was affected by a combination of the three considered factors. A 0.02 CH4/H2 ratio was found as the optimal value to yield films with reduced non-diamond carbon inclusions in our CVD system. Resistivity, residual stress, double-layer capacitance, and surface roughness were mainly affected by total pressure and argon content. The methane content and the total pressure significantly influenced growth rate and grain size. The latter was primarily responsible for changes in the electrochemical potential window and the electron transfer process of the BDD films. Within the studied range of deposition conditions, the optimal deposition parameters to obtain BDD films for water treatment applications were: 0.02 CH4/H2 ratio, 25 mbar total gas pressure, and 30 sccm argon mass flow.

New nutrients evaluation in Spirulina maxima growth for phycocyanin, carbohydrate, and biochar production

Purpose The purpose of this study is to investigate the influence of light intensity and sources of carbon and nitrogen on the cultivation of Spirulina maxima. Design/methodology/approach Cultures were carried out in a modified Zarrouk medium using urea, sodium acetate and glycerol. A Taguchi experimental design was used to evaluate the effect on the production of biocompounds: productivities in biomass, carbohydrates, phycocyanin and biochar were analyzed. Findings Statistical data analysis revealed that light intensity and sodium acetate concentration were the most important factors, being significant in three of the four response variables studied. The highest productivities in biomass (46.94 mg.L−1.d−1), carbohydrates (6.11 mg.L−1.d−1), phycocyanin (3.62 mg.L−1.d−1) and biochar (22, 48 mg.L−1.d−1) were achieved in experiment 4 of the Taguchi matrix, highlighting as the ideal condition for the production of biomass, carbohydrates and phycocyanin. Practical implications Sodium acetate and urea can be considered, respectively, as potential sources of carbon and nitrogen to increase Spirulina maxima productivity. From the results, an optimized cultivation condition for the sustainable production of bioproducts was obtained. Originality/value This work focuses on the study of the influence of light intensity and the use of alternative sources of nitrogen and carbon on the growth of Spirulina maxima, as well as on the influence on the productivity of biomass and biocompounds. There are few studies in the literature focused on the phycocyanin production from microalgae, justifying the need to deepen the subject.

Multi-response assessment for carbon emission and hardening effect in laser surface quenching.

Laser surface quenching (LSQ) is gaining popularity in engineering applications, but it generates non-negligible carbon emissions. However, existing research mostly focuses on quenching performance. Little attention has been paid to carbon emissions of LSQ process. In this study, we build an experimental platform including fiber laser system (IPG YLR-4kW) and carbon emission measurement system for a synergistic study of environmental impacts and processing quality in LSQ. Based on the L16 (43) Taguchi matrix, LSQ experiments are conducted on the shield disc cutter. The influences of laser power, scanning speed, and defocusing distance on carbon emissions and hardening effects are studied. The carbon emission efficiency of LSQ is analyzed and compared with the competitive technology. The geometry and the maximum average hardness (MAH) of LSQ high-hardness zone (HHZ) are studied. A comprehensive evaluation considering carbon emissions and hardening effects is conducted. The results show that the maximum value of carbon emission is 1.4 times the minimum value. The maximum depth and width of HHZ are respectively 0.507 and 3.254mm. The maximum MAH is 3.5 times the hardness of base metal. Compared to the average experimental responses, the experiment with the highest comprehensive score respectively increases by 26.4%, 17.1%, and 30.3% in depth, width, and MAH of HHZ, and reduces by 5.8% in carbon emissions.

Parametric optimization of calcined and Zn-doped waste egg-shell catalyzed biodiesel synthesis from Hevea brasiliensis oil

The utilization of waste sources for energy development is increasingly gaining popularity because of its two-fold benefit to the environment. The present study discusses the synthesis of biodiesel from commercially available rubber seed oil using two catalysts: CaO derived from calcined waste egg-shells and Zn-CaO prepared by doping ZnSO4 onto the calcined egg-shells through wet impregnation. An L9 Taguchi matrix was used to optimize the process, and can accomodate 4 parameters at 3 levels each. Data obtaind was used for a comparative evaluation of their catalytic performance. During catalyst characterization studies, morphological analyses showed the effectiveness of calcination in development of a porous structure that was capable of adsorbing Zn in high quantities, which was further verified through spectral analyses. Using CaO the optimal biodiesel yield noted was 80.2%, while Zn-CaO enabled a biodiesel yield of 94.12%. The optimal conditions were a reaction temperature of 55°C, methanol to oil molar ratio of 12:1, catalyst concentration of 5% w/w for both catalysts within a reaction duration of 1.5 h (for CaO) and 2 h (for Zn-CaO). Fuel characterization tests through ASTM prescribed procedures showed that the obtained product has acceptable physico-chemical properties and is thus suitable for use as biodiesel. Reusability studies (tested up to 4th reuse) indicated that CaO loses its catalytic efficiency much faster compared to Zn-CaO, primarily due to the vacant active sites in CaO being blocked by increased adsorption of organic molecules during the transesterification phase compared to Zn-CaO.

Optimization Multi Response on Electrical Discharge Machining Sinking Process Using Taguchi-Grey-Fuzzy Methods

Electronic Discharge Machining (EDM) sinking applied widely in advance material manufacturing, every process parameter will count on this company. Their performance evaluated by some parameters such as surface roughness and tool wear ratio. Then they will be a dependent variable on this research. Independent variables on this research are electrode polarization, gap voltage, duty factor and pulse current. Every variable has three levels, except electrode polarization has two levels. This research conducting using Taguchi matrix orthogonal L18 (21×33) methods. The aim of this experiment is to evaluate optimization parameter process on EDM sinking, using Taguchi-Grey-Fuzzy methods. Characteristics response optimal applied are ‘smaller better’ for surface response roughness and tool wear ratio. This research using DAC tool steel as work-piece. DAC is most widely used as die for aluminum and zinc die-casting. The aim of this research is finding contribution of variable in EDM sinking parameter. Result of this research show contribution from variable process to reduce variance total observed response simultaneously, in order are electrode polarization on 49,53%, gap voltage on 23,52%, duty factor on 5,45% and pulse current on 9,92%. From validated optimization in confirmation experiment, to conclude combination variable process optimal response value is electrode polarization on positive, gap voltage at 50V, duty factor at 0.5 and pulse current at 12A.

A study on the surface grinding process of the SUJ2 steel using CBN slotted grinding wheel

Using slotted grinding wheel in machining is a new approach in grinding technology. The slotted grinding wheel is used to improve the introduction of cool lubricant into the cutting zone, improve chip release condition and heat release condition during machining, thereby facilitating to improve the efficiency of the grinding process. However, up to now, the studies that are performed using this type of grinding wheel is very limited. To contribute some results to this rather new research direction, in this article we present the grinding process of SUJ2 steel using CBN slotted grinding wheel. The orthogonal Taguchi matrix with nine experiments was used to design the experimental matrix with three input parameters including workpiece velocity, feed rate, and depth of cut. The output parameters that were used to evaluate the quality and effectiveness of the grinding process were surface roughness, system vibrations in X, Y, Z directions, and the material removal rate. In surface grinding process using CBN slotted grinding wheel, all three input parameters (workpiece velocity, feed rate, and depth of cut) have a significant influence on the surface roughness, vibration. In which, the feed rate has the most influence on the output parameters. The second factor that influenced on the output parameter was the depth of cut. The workpiece velocity has the smallest influence on the output parameters. Data Envelopment Analysis Based Ranking (DEAR) method was used to solve the multi-objective optimization problem in surface grinding process. By applying this method, the optimal value of input parameter that were determined to obtain the minimum values of surface roughness and system vibration components, and to obtain the maximum of material removal rate. The optimum values of input parameters were the workpiece velocity of 15 m/min, the feed rate of 4 mm/stroke, and cutting depth of 0.015 mm. DEAR method can be applied to improve the quality and the effectiveness of the grinding process by reducing the surface roughness and system vibration components and increasing the material removal rate.

COMPARATIVE ANALYSIS ON NUMERICAL MODELLING AND EXPERIMENTS OF THE CUTTING TEMPERATURE IN MAGNETIC ABRASIVE FINISHING PROCESS

In Magnetic Abrasive Finishing (MAF) process the cutting temperature is generated from two sources, from the electromagnetic flux (electrical heat), and from magnetic abrasive brush due to the friction force (mechanical heat). The cutting temperature has significant effects upon the condition of the surface, whereas it is less studied than the other parameters. In this study, an attempt has been made to simulate and investigate the influence of cutting parameters on the cutting temperature, to improve the thermal effect by MAF process. The aims of this study was to determine the distribution of the cutting temperature in the working gap, numerically and experimentally, then compared the results. In addition, to determine the most influence parameters affecting on the cutting temperature for Brass alloy CuZn28. Two dimensional Finite Element Models (FEM) with two software’s were developed to predict the temperature by dynamic electric and magnetic field, the first was DEFORM 10.2 used to calculate the mechanical heat and the second was COMSOL5.2 used to calculate the electrical heat. Sixteen tests designed according to Taguchi matrix through the orthogonal array (OA) L16 (). There are four various parameters that, have a large impact on cutting temperature, with four levels (rotational speed (A), working time (B), current (C), and working gap (D)). The analysis of the variance (ANOVA) technique was utilized to analysis the results, by using the statistical software (MINITAB-17). From the results, it is concluded that the Numerical modeling gives a very good comparison with the values of experimental tests. The maximum difference between the numerical and experimental temperature for brass CuZn28 is less than (9%).

Parameter study and optimization of a half-vehicle suspension system model integrated with an arm-teeth regenerative shock absorber using Taguchi method

Abstract This paper presents a novel regenerative shock absorber that utilizes an arm-teeth mechanism to convert linear to rotational motion and to amplify the generator input speed. The flywheel of the arm-teeth mechanism also acts as an energy-storing element, allowing for smooth operation especially on a rough and uneven road surface. The critical parameters are identified through experiments and the simulation model is established based on a half-vehicle suspension system model. The novelty of this work is the proposed arm-teeth mechanism and the optimization of the half-vehicle suspension system through the Taguchi method. In this method, the ratio of the peak output power over the squared excitation displacement amplitude and the frequency bandwidth of the front and rear shock absorbers are set as targets and evaluated respectively. The effects of each parameter on the targets and the optimal parameter combinations are identified through the Taguchi matrix calculations. The optimized system is evaluated under the excitation of the road surface profiles of Class A, C and E of ISO 8606. It is found that the optimized system is able to harvest more energy with a broader frequency bandwidth than the original system at a certain speed for all three random road profile classifications.

Multi response optimization of process parameters using grey relational analysis for milling of hardened Custom 465 steel

Abstract This study focused on optimizing the process parameters during end milling operation of hardened Custom 465 steel with multi-response criteria based on orthogonal Taguchi matrix with grey relational analysis. Nine experimental tests based on L9 orthogonal network of the Taguchi method have been carried out using Titanium aluminium nitride (TiAlN) coated carbide inserts under a dry environment. Cutting speed, feed rate and depth of cut are optimized by taking various multiple performance characteristics such as cutting force, temperature, surface roughness and material removal rate. Grey relational analysis is a method for analyzing the relationship between sequences using less data with multiple factors and is considered helpful to statistical regression analysis. Based on the grey system theory, the grey relational analysis can be used to solve complicated interdependence of parameters among multiple performance characteristics effectively. A grey relational grade (GRG) is determined from the grey analysis. Optimum levels of parameters have been identified based on the values of grey relational grade to solve the end milling process with multiple performance characteristics. In addition, analysis of variance (ANOVA) is also applied to identify the most significant factor influencing the machinability. Finally, comparisons were made between the experimental results and the predicted model developed. Experimental results have shown that the machining performance in the milling process can be improved effectively with this approach.

Development of Process for Fast Plasma-Chemical Through Etching of Single-Crystal Quartz in SF6/O2 Gas Mixture

Process for deep plasma-chemical etching of single-crystal quartz plates in a SF6/O2 gas mixture was developed. The method of scientific experiment design based on the Taguchi matrix technique was used to rank basic technological parameters (bias voltage applied to the substrate holder, output power of the high-frequency generator, oxygen flow rate, and position of the substrate holder relative to the lower edge of the discharge chamber) as regards their influence on the etching rate. The ranking results were used to optimize the plasma-chemical etching process and perform a control experiment on through etching of windows with large linear dimensions (3 × 10 mm) in a single-crystal quartz plate (z-cut) with thickness of 369 μm.

55. Using experimental designs for validating a unique beam model for four accelerators

Introduction While commissioning a linear accelerator, depth dose, radial and diagonal profiles as well as output factors have to be measured in multiple setups before being entered into the treatment planning system (TPS). The beam model then needs to be validated by comparing computed and measured doses. The objective of this study is to use the same measured dataset for the beam model of four different accelerators and to validate the beam models using experimental designs. Coming from the industry, this method optimizes the number of tests to be performed by methodologically varying several parameters at the same time. Methods Raw data were measured on a Novalis TrueBeam STx and were entered in the TPS for the Novalis as well as for a TrueBeam Tx, a Trilogy and a C-linac 2300 iX. All accelerators were matched by Varian for the 6 and 16 MV. A Taguchi matrix L36 was selected to validate the AAA algorithm. The use of experimental designs enables testing the following factors in 72 tests: energy, MLC, depth, X, Y1 and Y2 field size and wedge. Results The mean deviation between calculated and measured doses was 0.1 ± 0.5%. The maximum deviation was 2.4%, below the 3% tolerance recommended in the IAEA TecDoc 1580. Considering the accelerators separately, the mean deviation was −0.1% for the Novalis, 0.3% for the TrueBeam, 0.2% for the Trilogy and 0.1% for the C-linac. None of the investigated parameter was found clinically significant. Results could be correlated to the accelerator type by statistical tests (Novalis and TrueBeam on one side, Trilogy and C-linac on the other). Conclusions Only one dataset of measurements can be used for several accelerators matched by the vendor. The study conducted could conclude that the four accelerators were dosimetrically equivalent for conformational treatments excluding modulated beams. The use of experimental designs led to a validation of the beam models in 72 comparison points which is time efficient during commissioning.

Применение метода Тагучи для изучения структуры пептидного лиганда в составе сложного комплекса

Taguchi method was used to optimize peptide ligand structure using the H-2/TCR complex (PDB ID 2Z31). This approach greatly reduces the number of experiments that are required to analyze the contribution of various amino acid residues for each position into ligand molecule. Taguchi matrix was used to design a set of peptide ligands for molecular docking and molecular mechanics energy minimization. This approach allowed creating a new peptide structure with lower molecular mechanics energy than native peptide and demonstrates the applicability of the Taguchi method for peptide ligand optimization.

Optimization of technological parameters in plasma chemical etching of quartz single crystals

Main technological parameters of the process of local plasmochemical etching of single-crystal quartz were optimized. The etching was performed in a gas mixture of CF4 and H2 under radio frequency (RF, 13.56 MHz) discharge excitation. The scientific experiment design by the Taguchi matrix method was used to examine the effect of chamber pressure, RF generator power, negative bias applied to the substrate holder, and hydrogen flow rate on the rate of the etching process. The experimental results made it possible to evaluate for the first time the influence exerted by the technological parameters on the etching rate. It was shown that the influence exerted by the technological parameters in the conditions under study decreases in the following order: pressure in the reaction chamber, bias potential, RF power, hydrogen flow rate.

Multi-variable measurements and optimization of GMAW parameters for API-X42 steel alloy using a hybrid BPNN–PSO approach

This research addresses multi criteria modeling and optimization procedure for Gas Metal Arc Welding (GMAW) process of API-X42 alloy. Experimental data needed for modeling are gathered as per L36 Taguchi matrix. Model inputs include work piece groove angle as well as the five main GMAW process parameters. The proposed back propagation neural network (BPNN) simultaneously predicts weld bead geometry (WBG) and heat affected zone (HAZ). Image processing technique along with Bridge Cam and AWS gauges are used to take accurate measurements of WBGs and HAZs. The adequacy of the developed BPNN is established through comparisons against measured process outputs. Measurements indicate that the BPNN model simulates GMAW process with average errors of 0.33 to 0.82%. Next, the BPNN model is implanted into a particle swarm optimization (PSO) algorithm to simultaneously optimize HAZ and WBG characteristics. The hybrid BPNN–PSO determines process parameters values and groove angle so as a desired WBG is achieved while HAZ is minimized. Verification tests demonstrate that the proposed BPNN–PSO is quite efficient for in multi-criteria modeling and optimization of GMAW.

Optimization of process parameters for machining of AISI-1045 steel using Taguchi design and ANOVA

Previous published works on the optimization of parameters in orthogonal cutting process have used a single tool. The parameters considered in these works are: surface roughness, power consumption, deformed chip shape, and temperature in the workpiece. This paper is on the optimization of machining parameters with multiple cutting tools. This is required to reduce the cutting forces and temperature while machining AISI 1045 steel. In this study, this has been achieved by using a combination of statistical tools including Taguchi matrix, signal to noise ratio, and analysis of variance (ANOVA). The effects of varying cutting speed, feed rate, depth of cut, and rake angle in orthogonal cutting process have been considered. The Finite Element (FE) simulations have been carried out with a general purpose commercial FE code, ABAQUS, and statistical calculations have been performed with Minitab. Results show that for optimum cutting forces, feed rate and depth of cut are the most important factors while for lower temperatures, cutting speed and rake angle play a significant role. It is concluded that carbide cutting tools is a better option as compared to uncoated cemented carbide cutting tool for machining AISI 1045 steel as it results in lower cutting forces and temperatures.

Parametric design optimization of hard turning of AISI 4340 steel (69 HRC)

Continuous research endeavors on hard turning (HT), both on machine tools and cutting tools, have made the previously reported daunting limits easily attainable in the modern scenario. This presents an opportunity for a sys- tematic investigationonfinding the current attainablelimitsof hard turning using a CNC turret lathe. Accordingly, this study aims to contribute to the existing literature by providing the latest experimental results of hard turning of AISI 4340 steel (69 HRC) using a CBN cutting tool. An orthogonal array was implemented using a set of judiciously chosen cutting param- eters. Subsequently, the longitudinal turning trials were car- ried out in accordance with a well-designed full factorial- based Taguchi matrix. The speculation indeed proved correct as a mirror finished optical quality machined surface (an av- erage surface roughness value of 45 nm) was achieved by the conventional cutting method using a CBN cutting tool. Fur- thermore, signal to noise (S/N) ratio analysis, analysis of var- iance (ANOVA), and multiple regression analysis were car- ried out on the experimental datasets to assert the dominance of each machining variable in dictating the machined surface roughness and to optimize the machining parameters. One of the key findings was that when feed rate during hard turning approaches very low (about 0.02 mm/rev), it could alone be most significant (99.16 %) parameter in influencing the ma- chined surface roughness (Ra). This has, however, also been shown that low feed rate results in high tool wear; so, the selection of machining parameters for carrying out hard turn- ing must be governed by a trade-off between the cost and quality considerations.

Effects of Laser Hardening Process Parameters on Case Depth of 4340 Steel Cylindrical Specimen—A Statistical Analysis

Laser heat treatment is considered to be one of best-performing manufacturing processes used currently due to its flexibility and its ability to develop parts with complex geometries. In fact, this process is able to produce reliable parts with hard, thin martensite and compressive residual stresses. This paper explores the heat treatment applied to 4340 cylindrical parts heated using a Nd: Yag 3 kW laser source. In this case, the hardness profile is correlated to process parameters such as the laser source power, the beam scanning speed and the revolution speed of the part during heating. Based on preliminary tests stipulating that each parameter is varied alone within a specific range, a systematic design of final tests is performed using Taguchi matrix. The obtained results are analyzed using ANOVA method to extract the effects, the contributions and the interaction between the factors. The results are then exploited to study the sensitivity of the case depth according the variation of the process parameters. The developed model exhibits good potential for converging towards a robust model able to predict the hardness curve and to generalize it for other dimensions of cylindrical parts.

Influence of steam dilution on the ignition of hydrogen, syngas and natural gas blends at elevated pressures

This paper presents the influence of steam dilution on the autoignition behaviour of hydrogen, carbon monoxide, syngas, methane, and natural gas mixtures under gas turbine-relevant conditions. Rapid compression machine experiments were performed for fuel/air mixtures at equivalence ratios of 0.5, 1.0, and 2.0, in the temperature range 895–1140K for the H2 and CO mixtures and 730–1060K for the natural gas mixtures and at pressures of 10 and 30bar. Shock-tube experiments were performed for CH4–O2–Argon mixtures with and without H2O addition, highly diluted in argon (98% by vol.). The parameters were varied using an L9 Taguchi matrix for equivalence ratios of 0.5, 1.0, and 2.0; pressures of 1.6, 11, and 30atm; and water contents of 0%, 10%, and 30% of the fuel by volume. It was found that significant changes in the thermal properties of the mixtures affect the reactivity, whereas no chemical effect of the steam addition was observed for the majority of the mixtures investigated. Only mixtures of pure carbon monoxide were strongly influenced by water addition. In this case, the presence of water in the mixture allows the formation of relatively reactive ȮH radicals which enhances the possible oxidation chemistry of carbon monoxide leading to a greater observed reactivity of CO in the presence of water.

Evaluation Grain Homogeneity of Aluminium after ECAP Process by ECAP Geometry Analysis Using Taguchi Method

Grain size and homogeneity are influence to aluminium properties, Equal channel angular pressing (ECAP) can produce aluminium with ultra fine grain Size (UFG). The grain size is depends on ECAP Dies geometry (Channel angle Φ, Fillet radius ψ) and friction, taguchi method used to find the optimum dies geometry its can produce smaller grain size and homogeny. Modeling done with channel angels 90, 105 and 120°, fillet radius (inside) 1.5, 5,0 and 10 mm ; fillet radius (outside) 1.5, 5,0 and 10 mm and friction 0, 0,025 and 0,05. Modeling used L9 taguchi matrix, the most homogeny dies is ECAP dies with channel angel 105°, fillet radius (inside) 10 mm ; fillet radius (outside) 0 mm and friction 0,025

Ferritic Cathodes Degradation by Potassium/Chromium Poisoning and Air Humidification

AbstractDegradation mechanisms inherent to ferritic LSF‐SDC and LSCF‐GDC cathodes are studied by post‐mortem analysis of cells which suffered the most significant performance deterioration in a set of 18 500 h tests carried out under a specific experimental design. Three cathode processing parameters (composition, thickness, and sintering temperature) were combined with five operation conditions (chromium presence, current density, operating temperature, air flow, and humidification) through this design of experiments based in a L18 Taguchi matrix. In the case of cells exposed to chromium vapors from Crofer 22 APU pieces, those cells which exhibited K2Cr2O7 deposition in the cathode/GDC barrier interface underwent the most aggressive ASR degradation. Similar deposits were also observed on the surface of LSC current collectors. Two cells exposed to highly humidified air (20%) exhibited cathode delamination and GDC barrier deterioration by crack propagation though no foreign elements diffusion to the interface could be detected.