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A comprehensive experimental study on the high-velocity oxygen-fuel (HVOF) sprayed tungsten carbide/cobalt (WC/Co) deposits using laser cladding was conducted. A response surface methodology based on a central composite design was used to analyze, predict and optimize the WC/Co deposits of the laser-based HVOF sprayed coatings. The morphologies and microstructures of the laser clads were characterized using optical microscope, scanning electron microscope and X-ray diffraction techniques. The crack behavior and residual stress-based fractures were explored. In addition, the relationships between the residual stress of the laser clad and three factors: laser power, scanning speed and stand-off distance were examined. Further, optimization of the control factors: laser power, scanning speed and stand-off distance to minimize the residual stress was attained using a response surface methodology. The resulting lower residual stress has decreased the fracture crack activities and did not easily induce delamination in the laser clads. Findings from this study would greatly contribute to optimizing the experiments and achieve an enhanced structural evolution in the protective coating of traditional handicraft products by laser cladding.

Based on genetic algorithm (GA) and fuzzy neural network, a new method for the study of sputtering process is proposed in this paper. Diamond-like carbon (DLC) coatings were deposited on SKD11 steel by magnetron sputtering. An orthogonal array design is implemented and the effects of control factors on surface properties of the coatings were systematically analyzed. The coating properties were investigated by scanning electron microscopy and Raman spectroscopy, and wear volume surface performance of the Zr-doped DLC coatings was evaluated by a wear tests pin-on-disk tribometer. The Raman analyses showed that, at lower ID/IG ratio, a lower wear volume of the Zr-doped DLC coatings can be obtained. Scratch tests as well as Rockwell indentation tests revealed that the graded Zr-doped DLC structures efficiently provide better adhesive strength of DLC coatings. The results show that the wear behaviors of the DLC coatings can be improved by Zr-doping, which the Zr-doped DLC coatings exhibited promising tribological properties. Also, the predictive ability of the GA-ANFIS computations for the tribological behaviors of the Zr-DLC coatings within the experimental domains proved to be reliably obtained, where the forecasted values and experimental results are close.

The purpose of this study was to construct the indicators of professional competencies of the nanotechnology-based sputtering system industry based on industry requirements and analyse the core competencies of the industry for promoting the human resource of physical vapour deposition technology. The document analysis, expert interview, and Delphi technique surveys were considered and the survey items with 32 items divided into 7 domains were selected according to consensus opinions of 10 experts by the Delphi survey technique. Through three questionnaire surveys’ analysis, the professional competence scales for the K–S tests showed a good internal consistency. The findings of this study provide guidelines for professional competence for nanotechnology-based sputtering technology by applying surface heat-treatment industry. These guidelines can also reveal the practical competency requirements of nanotechnology-based sputtering technology to deal with any subsequent challenges, future developments...

This study reports the use of aluminum nitride(AlN) ceramics as a heat dissipated interface material to enhance the thermal performance of light-emitting diode (LED) packages. AlN ceramics are coated on copper/aluminum substrates by electrostatic spraying. The 18 orthogonal arrays of the LEDs with a signal-to-noise ratio are adopted and the impact of the effect of the spraying parameters on the AlN coatings is examined. Using an optimized design, the thermal performance of the LED is improved and good heat resistance characteristics are achieved. A confirmation run is used to compare results with the overall experimental tests. The results show that using AlN ceramic coating on a heat sink yields a good the thermal performance.

An LED cooling system that uses a micro-tube water-cooling device is studied experimentally and a heat transfer model that uses a finite element method is numerically analyzed. In this experiment, the micro-screw tube system achieves better thermal management and the heat created by the LEDs is effectively dissipated. It is experimentally found that the effect of thermal dissipation occurs by recycling water in the LEDs’ light assemblies are in reasonable agreement.

This article presents the distribution of the varying magnetic field and its effect by magnetron sputtering on mechanical properties of CrN films. The magnetic field variations in the sputtering processes were explored, and the strength of magnetic field in the unbalanced magnetic sputtering systems is controlled. In addition, the microstructure, composition and surface properties of CrN films prepared by magnetron sputtering were investigated. At a GDMT of 27mm, the highest wear rate value and hardness values seems to be appeared, while the higher critical force value appears to occur at 49mm GDMT during 18 tests. The experimental results have showed that in the enhancement in overall intensity at the gap distance of 27mm between magnet set and the target surface (GDMT), magnetic field strength varied having a significant influence on the CrN structures was readily noticeable, while the wear scar curve at 49mm GDMT possessed better tribological properties than those of the others. Thus, magnetic field variations play a crucial role in determining the properties of the films

Analysis of mechanical properties of diamond-like carbon (DLC) films based on experimental designs was reported to optimize characterize by a magnetron sputtering. An orthogonal array experiment was introduced and the effects of deposited parameters on the films were systematically explored. The films were analyzed by scanning electron microscopy (SEM). Friction and wear tests were carried out using a pin-on-disk tribometer. In this study, the two stages such as adhesive and abrasive wears for tribological properties are clearly visible among L18 tests, where at the higher wear volume losses exist an abrasive wear while the less wear volume losses appear an adhesive wear. A slightly worn surface with a glassy carbon phase appeared and a lower wear volume loss became visible in the DLC films. Through the optimal design, the experimental results demonstrate the tribological properties on DLC multilayer films are increased by a magnetron sputtering, thereby justifying the reliability and feasibility of the approach.

The surface properties of plasma-sprayed partial Y2O3 stabilized ZrO2 coatings with different travel speed and powder-feeder rate of sprayed gun on aluminum substrates have been reported. Several coatings analytical parameters were studied and these factors affecting coating properties were carried out in the plasma-sprayed experiments. Experimental results have shown that the structure of the sprayed coatings that makes relatively diverse in texture for most of the coatings was examined by a SEM. The hardened strength with a low level of a slant of powder-feeder rate became significantly weaker as the travel speed was decreased. Interestingly, the structure of the specimens for the travel speed of 30mm/s is more homogenous than that of the others, indicating a coating with good homogenous structures, while the interfaced structure of the specimens for the powder-feeder rate of 25 mm/s is more homogenous than that of the others, indicating a coating with good adhesive structures. The tendency of the effect of travel speed of sprayed gun on the hardened surface of coatings at powder feeder rate of sprayed gun varied to 30g/min from 20g/min seems to be apparent.

This study reports on the use of Fuzzy-Grey systems, with a Taguchi designed experiment to enhance the quality characteristics of yttria stabilized zirconia (ZrO2/8%Y2O3) coatings, made by a plasma-sprayed process. Eight control factors were designed in an L18 orthogonal array experiment, and the effects of the control parameters on the surface properties were critically evaluated in the experiments. Multi-response characteristic terms-surface roughness, hardness and wear depth values in the sprayed ZrO2/8%Y2O3 coatings through the optimization were studied comparatively. A Fuzzy-Grey approach, based on the Taguchi orthogonal experiments for optimizing multi-response performance in the coatings, was reported. In addition, the influence of control factors on the Fuzzy-Grey systems for spraying processes was investigated by analysis of variance. In addition, a confirmation experiment was conducted. Experimental results have shown that the hardness increased by 18.67%, while the surface roughness decreased by 32.01%and the wear rate improved by 30.52%. It is clear that the multi-response quality characteristics for plasma sprayed coatings are greatly improved through Taguchi-Fuzzy-Grey analysis, and that these findings achieved the desired values in regard to the mechanical properties.

A new approach with adaptive network-based fuzzy inference systems (ANFIS) based on experimental designs was used to model and characterize the tribological behaviors of diamond-like carbon (DLC) films deposited by a magnetron sputtering system. An orthogonal array experiment was introduced and the effects of deposited parameters on the films were systematically explored. The films were analyzed by X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). In this study, a group of highly developed hillock-like textures appeared and a lower wear volume loss became visible in the DLC films. Furthermore, the predicted values and experimental results, in which the ANFIS effectively predicts the tribological behaviors of the DLC films, are similar. It was experimentally confirmed the ANFIS predictions agreed with the experiments. Therefore, the experimental results demonstrate the tribological properties on DLC multilayer films are accurately predicted by ANFIS, thereby justifying the reliability and feasibility of the approach.

In the previous study, the dye decolorization was investigated byTsukamurellasp. J8025 under the static condition at 30°C. The object of this study was to evaluate the influence of light irradiation with 15W low-pressure mercury lamp on dye decolorization. Three kinds of common culture medium Luria-Bertani (LB), Tryptic Soy Broth (TSB), and Yeast extract-Malt Extract (YEME) were used in this study. Strain J8025 was cultivated in different media added with methyl orange, and the rate of color removal was determined by measuring the absorbance at specific wavelengths. The experiments proved the decolorization efficiency after 48h under light irradiation in LB medium was up to 40%, that in TSB medium was up to 50%, and that in YEME medium was up to 68%, respectively. The decolorization process needed glucose as an energy source to support the bacterial growth and promote the decolorization rate. Due to the salt contained in the dye-wastewater, the effect of salt was investigated. The results showed nearly 98% color was removed after 48 h in the presence of 1% NaCl under light irradiation, but the decolorization was inhibited by high concentrations of salt. The results indicated a strain J8025 coupling with the light irradiation could be potentially used to improve the dye decolorization.

This study reports the statistical optimization of experiments, designed by Taguchi, to improve the wear-resistance of the tungsten carbide/cobalt-based coatings applied using high-velocity oxygen-fuel (HVOF) spraying processes. In this study, a group of needlelike textures appeared in the HVOF WC-Co coatings. The structures were evenly distributed and compacted closely, showing a more dense and homogenous configuration. The coating that formed with a large amount of pores, microcracks and unmolten particles was much looser, and the interface was locally prone to defects. The coatings were obviously not homogenous. Experimental results show that the wear-resistant coatings are highly dense, with an elastic lamellar structure. The tribological properties were significantly improved and the surface textures showed uniformity, in a molten droplet flattened formation. A homogenous, morphological structure, with local small aggregation, was more obvious after HVOF WC-Co coating. Accordingly, it is clear that the surface properties determined proved favorable to the mechanical properties of the WC/Co coatings. In addition, we compared the linear models with the quadric models, using RSM methods, in all the experiments. Statistically, the linear models produced an average error of 8.285％, while the quadric models generated an average error of 1.399％. It is clear that the RSM models successfully fitted the HVOF WC-Co coating process and the quadric models yielded more accurate predictions than the linear models, in most cases. The proposed procedure was applied to HVOF spraying of WC-CO coatings. The results demonstrated its feasibility and its effectiveness in improving the HVOF WC-Co coating.

This paper reports the effects of varying magnetic field strength on CrN films, deposited by a magnetic sputtering process. The strength of magnetic field in unbalanced magnetic sputtering processes is controlled by adjusting the gap distance between the magnet set and the target surface (GDMT). An improvement in overall intensity, at low GDMT, was observed by adjustable magnetic field distributions. In the chamber, it was readily noticeable that varying the magnetic field strength has an influence on the CrN structures. In experiments, at low GDMT, a high hardness value and lower wear rate become visible in the CrN films. In addition, the CrN films formed have a smooth surface with a dense tiny structure and display preferential orientation in the Cr2N(111) and Cr2N(002) planes, whereas CrN films prepared at higher GDMT exhibit more roughness and the CrN (200) plane is evident. Furthermore, the Cr2N (111) (002) plane possessed better tribological properties than that of the CrN(200) plane, where the wear scars show little failures on the coating surface.

This paper introduces a module using the RGB-based LED design to improve the thermal management of a mixied white light LED and describes a system for heat dissipation in illuminated, high-power LED arrays. Mixed light LEDs can be produced by combining appropriate amounts of light from the red, green and blue LEDs in an array. A LED cooling system, using a micro- tube water-cooling device, was fabricated. Recycling water in the system, gave more efficient convection and the heat created by the LEDs was easily removed, in the experiments. It was shown that micro-tube water-cooling systems rendered an improvement in thermal management that effectively decreases the thermal resistance and provides very good thermal dissipation. Furthermore, the results of experiment and simulation demonstrated that a micro-tube water-cooling system is very effective in heat dissipation in LEDs and the fabrication of practical micro-water tube cooling devices for mixing light LEDs was feasible and useful

This study presented the application of Taguchi designed experiments to optimize the tungsten carbide/cobalt (WC-Co) deposited quality properties of the high-velocity oxygen-fuel (HVOF) process. The eight control factors were designed in a L18 factorial orthogonal array experiment, and the effects of control parameters on the surface properties were critically evaluated in the experiments. The surface anti-wear properties by optimal design have been studied comparatively. By optimization from Taguchi S/N ratios and analysis of variance, the surface wear volume values are decreased by 37%. It was clear that anti-wear performance estimations of HVOF sprayed WC-Co coatings are greatly improved by way of the optimal experiment, and these findings achieved the desired values in the WC-CO coatings. The experimental results indicated that the proposal method offers an effective and efficient approach for developing a robust and highly quality HVOF sprayed WC-Co coating.

This study presented the desirability function based on Taguchi designed experiments to solve multiple responses statistical optimal problems for the tungsten carbide/cobalt (WC-Co) coatings of high-velocity-oxygen-fuel (HVOF) processes. The eight control factors based on L18 arrays were conducted and the multi-responses of wear-resistant coatings such as hardness, deposited thickness and wear rate were evaluated simultaneously in the desirability-based experiments. Based on desirability analysis, the optimal settings have been identified, and the impacts of control factors are determined by analysis of variance on the multi-responses. Further, a confirmation run was conducted to validate the tests. Experimental results have shown that the hardness increased by 16.61% and the deposited thickness improved by 10.50%, while the wear rate decreased by 34.03%. It was clear that confirmation tests are greatly improved by way of the desirability-based multi-responses on HVOF WC-Co experiments, and these findings achieved the desired values on wear-resistant coatings. The proposed procedure was applied at HVOF sprayed WC-Co experiments, and the implementation results demonstrated its feasibility and effectiveness to maximize hardness, make a target of deposited thickness value and minimize wear rate by a HVOF.

This study reported on Taguchi-Fuzzy logic model with statistical experiments to characterize the tungsten carbide/cobalt (WC-Co) deposited quality properties of the high-velocity oxygen-fuel (HVOF) process. The eight control factors were designed in a factorial orthogonal array experiment, and the effects of control parameters on the integrated surface properties were critically evaluated in the Taguchi designed experiments. A fuzzy logic system with knowledge bases in the inference engine was used to explore the relationships between variables and responses in the modified structures. In addition, the structure and properties of HVOF sprayed WC-Co coating were reported. Furthermore, a confirmation experiment of the optimal process was conducted. It was clear that HVOF sprayed WC-Co coating estimations are greatly improved through the Taguchi-Fuzzy logic operation, and these findings achieved the desired values in the modified properties.

Amorphous carbon (a:C-H) coatings with high hardness and low friction coefficient are widely applied in die and mold industries. Zirconium-containing a:C-H (a-C:Zr) coatings with double interlayered Zr/ZrC were deposited by unbalanced magnetron sputtering system. A L18 orthogonal array experiment was designed to investigate the effect of process parameter on the friction coefficient of deposited films. Control factors, such as methane flow rate, bias voltage, sputtering frequency, zirconium target current and work distance were schematized for experiments. The experimental results show that zirconium target current exhibits about 45% percent contribution in analysis of variance, and the friction coefficient of a-C:Zr coatings range from 0.13 to 0.31. From effect plots, the optimum parameters are bias voltage at -70V, zirconium target current at 0.6 A, pulse frequency at 90 kHz, methane flow rate at 6 sccm and work distance at 15 cm. The friction coefficient performs as 0.106 in verification experiments. Meanwhile, one-by-one factorial experiments were also carried out and discussed in this study.

The paper describes response surface methodology (RSM) based on design of experiments and analysis of variance (ANOVA) as a statistical design while developing a robust plasma transfer arc (PTA)coating process. Based on ANOVA, The relative important parameters with respect to surface at hardness values were identified in the Taguchi design, where they were further used in predictors. In addition, we applied three-dimensional graphs in RSM to develop a robust PTA response surface yielding the desired-better area of a treated layer. In this study, a quadratic polynomial with a Box-Behnken design is utilized. The results reveal that RSM provides the effective methods as compared to the traditional trial-and-error method for exploring the effects of controlled factors on response. A very good agreement was observed, as evidenced by R-squared value, 90%, between the predicted and the experimental data, and its error percent is found to be approximately 3.801% in the PTA-coating process. It is clear that RSM model demonstrated better accuracy in predicting surface hardness for PTA-coating process. Accordingly, RSM based on design of experiments was used as statistical PTA-coating design tools combined with the hardness model. Device zone optimization and yield enhancement have been demonstrated.

The effect of composition on the Curie temperature of κ phase Fe3AlCx was investigated by thermomagnetometry analysis (TMA). Results reveal that increasing carbon content decreases the Curie temperature. Serrations in the magnetization vs. temperature curve in the Fe3AlCx found at about 100°C, may arise from the fluctuation of carbon atoms between Site I and II of κ phase unit cell.

This study reports on the Grey relational system, with a statistical experiment to enhance the quality characteristics of yttria stabilized zirconia (ZrO2/8%Y2O3)coatings made by a plasma-sprayed process. The eight control factors were designed in an L18 factorial orthogonal array experiment, and the effects of the control parameters on the surface properties were critically evaluated in the experiments. The characteristic terms- surface roughness, porosity, hardness, and wear volume in the sprayed ZrO2/8%Y2O3 coatings through the optimization- were studied comparatively. A grey relational system, based on the Taguchi orthogonal experiment for optimizing multi-responses in the modified properties, was reported. In addition, the influence of control factors on the grey relational system for spraying processes was investigated by analysis of variance. In addition, a confirmation experiment was conducted. Experimental results have shown that the hardness increased by 31.19%, while the surface roughness decreased by 40.67%, the porosity was reduced by 53.53%, and the wear rate improved by 24.21%. It is clear that the quality characteristics for plasma sprayed coatings are greatly improved through grey relational analysis, and that these findings achieved the desired values in regard to the modified properties.

This study optimizes the thermal dissipation ability of aluminum nitride (AlN) ceramics to increase the thermal performance of light-emitting diode (LED) modulus. AlN powders are deposited on heat sink as a heat interface material, using an electrostatic spraying process. The junction temperature of the heat sink is developed by response surface methodology based on Taguchi methods. In addition, the structure and properties of the AlN coating are examined using X-ray photoelectron spectroscopy (XPS). In the XPS analysis, the AlN sub-peaks are observed at 72.79 eV for Al2p and 398.88 eV for N1s, and an N1s sub-peak is assigned to N-O at 398.60eV and Al–N bonding at 395.95eV, which allows good thermal properties. The results have shown that the use of AlN ceramic material on a heat sink can enhance the thermal performance of LED modules. In addition, the percentage error between the predicted and experimental results compared the quadric model with between the linear and he interaction models was found to be within 7.89%, indicating that it was a good predictor. Accordingly, RSM can effectively enhance the thermal performance of an LED, and the beneficial heat dissipation effects for AlN are improved by electrostatic spraying.

This paper presents the application of artificial neural networks (ANNs) with statistical experiments to model and characterise WC/Co deposits of the plasma sprayings. In this study, the eight control factors were designed in a L18 factorial orthogonal array, and the effects of process conditions on the surface morphology were critically reviewed in the experiments. The surface topography properties and microstructure were studied.A gradient steepest descent algorithm in the trained ANN was used to explore the relationships between variables and responses. Artificial neural network modelling for WC/Co coatings estimation is compared by response surface methodology. The best values obtained were 2·164 and 2·871% of error percentage for the surface roughness by the best ANN and the response surface methodology model respectively. The experimental results indicate that using a statistical experiment coupled to an ANN strategy offers an effective, efficient and adaptive approach for developing a robus...

This article presents the application of the artificial neural network (ANN) of a statistically designed experiment for developing a robust wear-resistant zirconia coating. In this research, experimental design with orthogonal arrays efficiently provides enough information with the least number of experiments, reducing the cost and time. A radial basis function (RBF) network for the wear behavior is adopted. The friction and tribological properties of zirconia coatings were investigated. The microstructural feature of the coatings is also addressed in this study. It is found that the worn volumes of plasma-sprayed zirconia coatings after wear tests are greatly improved by the optimal parameters. The relationships between the microstructure of the worn surface and their properties are examined, and the results reveal a higher wear resistance and a lower worn surface roughness with a large amount of plastic deformations. These wear resistant structures formed as a result of a dense lamellar formation during sprayed zirconia coatings. The RBF network can be established efficiently. A comparison of the predicted results with that of the RBF network and the Taguchi method predictor shows average errors of 2.735% and 9.191% for the RBF network and the Taguchi method, respectively. It is experimentally confirmed that the RBF network predictions are in agreement with the experiments, and it can be reliably used for the prediction of wear for plasma sprayings. The experimental results demonstrate that the RBF network used for a statistically designed experiment is an effective, efficient, and intelligent approach for developing a robust, high efficiency, and high-quality zirconia coating process.

This paper proposes a design for an adaptive system by modeling the relationship between coating surface roughnesses and the controling factors in plasma spray coating processes. A statistical design was used to obtain sufficient experimental information with the least number of experiments. Analysis of variance was then used to select significant control factors for reinforced coatings, and these identified factors used to construct an adaptive fuzzy logic control model. In order to model the process, a fuzzy logic controller (FLC) was utilized. A genetic algorithm (GA) was applied as a tool to optimize rule bases from traditional FLCs. Therefore, with the use of a GA-optimized FLC, robust reinforced deposition for coatings in the plasma spraying process can be obtained. The experimental results show that the obtained optimal rule base for FLC is capable of achieving the desired results. That is to say, the proposed design, which combines a statistical method and a GA-optimized FLC, is efficient and robust for the investigation of reinforced coatings in a plasma spraying process.

This paper presents the application of a fuzzy logic controller and Taguchi's design in developing partially stabilized zirconia (PSZ) plasma spraying coatings. In this study, a fuzzy logic controller was used to explore functional relationships between variables, to determine the effect of operating parameter, and to achieve optimal process conditions. In addition, the most relevant input variables are identified through analysis of variance, and implemented in the construction of an appropriate fuzzy logic controller model. The experimental results indicate that the combination of Taguchi's design and a fuzzy logic controller makes a robust, effective, and efficient approach. A confirmation run of the optimal conditions was successfully carried out and shown to achieve desirable results.

The purpose of this article is to address the applications of an operating window with a Taguchi-fuzzy logic design in conducting a reduced number of experiments to yield the optimal conditions and to develop robust melted bead properties of the electron beam (EB) process. The effects of parameters produced on a window on EB bead surface are studied, and dimensions of operating window using travel speed while adding different noise factors are identified. Using ANOVA, significant factors are identified and accounted for nearly 75% of the total variance. The defects can be reduced by widening an operating window. The experimental results show that, an extensive analysis of the quality of the results can be obtained with the successful optimization of functional characteristics. This new strategy allows one to design, simulate, and optimize a system, and accurately performs in a group of characteristics.

The paper aims at proposing a method to develop a robust partially stabilized zirconia (PSZ) performance for the plasma spraying process with applications of surface response methodology and fractional factorial experiment. First, with the application of analysis of variance, significant factors are screened. Appropriately choosing control factors while constructing response functions helps to develop a robust process. Second, a nonlinear response surface function is designed to explore the space of the process. This smooths the progress of developing not only a proper relation between yielded and process variables, but also an optimal parameter setting that produces desirable response values. Experimental results show that a quadratic model with the proposed two-step design make it a simple, effective, and efficient way to a robust process. Model prediction is improved by additional data transformation. Optimization of PSZ performance in the plasma spraying process has been achieved.

In this paper, we present the application of the fuzzy logic analysis to a Taguchi orthogonal experiment for developing a robust model with high efficiency in multiple performance characteristics (MPCs) of the plasma transfer arc welding (PTAW) hardfacing process. It eliminates uncertain information and is a simple, effective, and efficient approach. A fuzzy logic system is used to simultaneously investigate relationships between various MPCs and to determine the efficiency of each trial of the Taguchi experiments. From the fuzzy inference process, we are able to determine the optimal setting of factor-levels for the MPCs. In addition, we also use the analysis of variance (ANOVA) to identify the significant factors, which coincide with findings from the fuzzy logic analysis and are found to account for about 79% of the total variance. Furthermore, a confirmation experiment of the optimal process is conducted, and it verifies that both individual performance characteristics and MPCs are successfully optimized and satisfy our desired levels of MPCs.

Artificial neural network (ANN) modeling and multiple linear regression (MLR) analysis have been used to develop a powder hard-facing process using high-energy plasma-transferred (HEPT) heating. HEPT heating can produce coatings with minimal surface roughness. An optimal procedure was developed involving the least number of process parameters but producing the most desirable performance characteristic. The quality characteristic of interest is the surface roughness after HEPT processing, utilizing the “the-smaller-the-better” criterion. Process performance was evaluated with respect to the signal-to-noise ratios, which were obtainable through experiments. The experimental results conclude that ANN models demonstrate a greater accuracy of predicting the surface appearance than the MLR models in terms of prediction error and the coefficient of determination. The results also reveal the most significant process control parameters. The predicted value of powder hard-facing roughness, through the implementation of optimal settings, produces a satisfactory result. The confirmation experiment showed that the ANN method achieved the expected optimal design goals for the HEPT powder hard-facing, thereby justifying the reliability and feasibility of the approach.

We propose the application of an artificial neural network to a Taguchi orthogonal experiment to develop a robust and efficient method of depositing alloys with a favorable surface morphology by a specific microwelding hardfacing process. An artificial neural network model performs self-learning by updating weightings and repeated learning epochs. The artificial neural network construct can be developed based on data obtained from experiments. The root of mean squares (RMS) error can be minimized by applying results obtained from training and testing samples, such that the predicted and experimental values exhibit a good linear relationship. An analysis of variance indicates that the significant factors explain approximately 70% of the total variance. Consequently, the Taguchi-based neural network model is experimentally confirmed to estimate accurately the hardfacing roughness performance. The experimental results reveal the hardfacing roughness performance of the product of PTA coating is greatly improved by optimizing the coating conditions and is accurately predicted by the artificial neural network model. The combination of the neural network model with Taguchi-based experiments is demonstrated as an effective and intelligent method for developing a robust, efficient, high-quality coating process.

This study applies the Taguchi method to elucidate the quality characteristic of the melt depth in electron beam surface treatment (EBST) of cast iron. The-nominal and the-better was a measured quality characteristic to evaluate the experimental results by computing the signal-to-noise ratios (SNRs) of the EBST melt depth after surface-hardening tests. It includes two steps to determine the optimum parameters or conditions. The first step is to maximize SNR to minimize the variance, and the second step is to adjust the EBST melt depth to a target value using the sensitivity. Results from the experiment indicate that the optimal process parameters are a substrate matrix of gray cast iron, a travel speed of 39 mm/s, an accelerating voltage of 10 kV, an electrical current of 15 mA, a melt width of 20 mm, an elliptical beam oscillation, and a post-process heat treatment at 150 °C. The best EBST melt depth obtained in the study was 0.747 mm, corresponding to the maximum SNR. The microstructure is composed of fine dendrites and martensite phases. The obtained EBST depth is confirmed by its falling into the predicted 95% confidence interval. The prediction of the optimal setting is close to the actual target value. The reproducibility of the optimal EBST parameters was experimentally established with data from the confirmation run. EBST wear-resistant surface hardening can be performed using Taguchi experiments.

The Ti-doped ZnO films compared to un-doped ZnO films were deposited onto Corning XG glass substrates by using a cathodic vacuum arc deposition process in a mixture of oxygen and argon gases. The structural, electrical and optical properties of un-doped and Ti-doped ZnO films have been investigated. When the Ti target power is about 750 W, the incorporation of titanium atoms into zinc oxide films is obviously effective. Additionally, the resistivity of un-doped ZnO films is high and reduces to a value of 3.48 × 10−3 Ω-cm when Ti is incorporated. The Ti doped in the ZnO films gave rise to the improvement of the conductivity of the films obviously. The Ti-doped ZnO films have > 85% transmittance in a range of 400–700 nm.

This study optimizes aluminum nitride (AlN) ceramics, in order to enhance the thermal performance of light-emitting diode (LED) packages. AlN coatings are grown on copper/ aluminum substrates as a heat interface material, using an electrostatic spraying process. The effect of the deposition parameters on the coatings is determined. The thermal performance of AlN coated Cu/Al substrates is evaluated in terms of the heat dissipated and compared by measuring the LED case temperature. The structure and properties of the coating are also examined a scanning electron microscopy (SEM). In sum, the thermal performance of the LED is increased and good heat resistance characteristics are obtained. The results show that using AlN ceramic coating on a copper/aluminum substrate increases the thermal performance.

An evolutionary algorithm was used to model and characterize the tribological behaviors of diamond-like carbon (DLC) films deposited by an-unbalanced magnetron. An orthogonal array experiment with carbon nitride multi layer films, with and without Zr additives is introduced and the effects of deposited parameters were systematically explored. The surface properties, such wear properties were measured and modeled comparatively. In this study, the HTGA computations for DLC multi layer films are performed to show significant improvements can be obtained and a satisfactory performance has been achieved. The predicted values and experimental results are close within the experimental domains, thereby justifying the reliability and feasibility of the approach.

The applicability of friction stir welding to 6061 aluminum alloy with a cylinder-screw-shaped S45C steel spin has been investigated. Three different tilted angles of spin were designed in the friction stir welding experiments. Experimental results have shown that surface defects at spin tilted angle were not observed at the weld zone such as face, toe and root of the weld, and a concentric onion ring pattern with increasing tilted angle of spin appears to be faintly visible. The tensile strength of the butt joints of tilted angles of spin are found to be higher that that of the normal. Also, butt joints through tilted angles of spin are higher than that of substrate matrix, while the tensile strength of the normal was less that that of the substrate matrix. The proposed procedure was applied at butt joints of friction stir welding, and the implementation results demonstrated its feasibility and effectiveness to improve tensile tested experiments for developing robust friction stir welding

In this work, we report the study of the efficient hydrogen\oxygen generation on different stainless steel electrodes in the electrolytes (NaOH and HNO3). The eight control factors based on L18 arrays were conducted and the flow rate properties of the hydrogen\oxygen generation were evaluated in the experiments. Based on analysis of Taguchi method, the signal\noise ratio is utilized and the optimal settings have been identified. In addition, the flow rate behavior of hydrogen\oxygen generation by water electrolysis was studied by Ritter volumetric meters. The experimental results obtained show that Taguchi design is used not only for predicted optimal process parameters for achieving the desired quality but for process optimization.

This paper reports a micro-tube tank device and FEM simulation using the RGB-based LED design to improve the thermal management of a high power LED arrays. An LED cooling system, using a micro-tube water-cooling device, was successfully designed and simulated. A water-cooling container in the high power LED array gave more efficient convection and the heat created by the LEDs was easily removed in the experiments. It was shown that micro-tube water-cooling systems rendered an improvement in thermal management that effectively decreases the thermal resistance and provides very good thermal dissipation. In addition, both simulation and experimental results show that the LED module with a water-cooling tube exhibits better thermal performances than the others. Accordingly, the results of experiment and simulation demonstrated that a micro-tube water-cooling system is very effective in heat dissipation in LEDs and the fabrication of practical micro-water tube cooling devices for mixing light LEDs was feasible and useful.

In this paper, a Taguchi-sliding-level differential evolution algorithm (TSLDEA) is proposed to use for finding the actual parameters of Chen and Lu chaotic systems. The TSLDEA, a powerful global numerical optimization method, combines the differential evolution algorithm (DEA) with the Taguchi-sliding-level (TSL) method. The TSL method is fused in the crossover operation of a DEA. Then, the systematic reasoning ability of the TSL method is incorporated in the crossover operation of a DEA to select the better offspring to achieve the crossover, and consequently enhance the DEA. Therefore, the TSLDEA can be more robust, statistically sound, and quickly convergent. Two illustrative examples of parameter identification of Chen and Lu chaotic systems are given to demonstrate the applicability of the proposed TSLDEA.