Taguchi L9 Research Articles

Study of Variability Phenomena in Direct Energy Deposition of Nickel-Based Superalloy on Geometric Accuracy and Residual Stress Formation

This paper studies the effect of the direct energy deposition (DED) process parameters varying within 20% on the geometric accuracy and formation of residual stresses in the products. In the course of the study, an experiment was carried out according to Taguchi's L9 plan to fabricate samples by varying the laser travel speed, effective focusing distance, feed rate of metal powder composition, and process pause, which were then compared with the rates of geometry change and crystal lattice distortion. The obtained results were subjected to statistical analysis using correlation, regression and factor analysis to determine the influence and significance of factors. As a result, correlations between the process parameters and sample characteristics were identified. As correlation and factor analysis showed, a change in process factors within 20% does not significantly affect most of the quality parameters, except for the level of residual stresses. Geometric and strain parameters are weakly correlated with each other, but no statistically significant correlations were found between them. The analysis of variance showed that the fusion rate and powder flow rate have the greatest influence on the geometric accuracy parameters. These factors have the most significant statistical influence on the response, indicating the importance of controlling these parameters to achieve high geometry accuracy. Regression analysis allowed to obtain adequate models of residual stress level. It was found that the model for residual stress level by planes (200) is more reliable than the model for residual stress level by crystallographic plane (111). The obtained data allow to optimize the DED process in order to achieve a given geometric accuracy and reduce residual stresses in the manufactured products.

Effects of waste glass dust incorporation on the tribological performance of flax-epoxy hybrid composites

Waste glass dust, an industrial waste, generated in the glass-cutting industries, is considered carcinogenic and poses health risks as it is high in silica content. This research essentially explores the alternative use of these waste glass dust as functional fillers in fabricating wear-resistant hybrid polymer composites. It includes fabrication of the hybrid epoxy composites in hand lay-up route with varying weight fractions (0–0.2) of the waste glass dust along with the flax fiber (30 wt. %) and their dry sliding wear behavior is observed. Test sample preparation follows ASTM-G99–05 standard and experiments are conducted considering Taguchi's L25 design. Significant improvement in the wear resistance of the hybrid composites is obtained after incorporating the waste glass dust and flax fibers. Filler content is found to be the most effective factor in affecting the wear rate followed by the sliding velocity during the Taguchi analysis with respective contributions of 54.51% and 38.59% as obtained from the ANOVA analysis of the wear results. Normal load and sliding distance are found to affect marginally the wear rates of the composites. A predictive model is proposed to find the specific wear rate (SWR) using the test results through the regression analysis. The minimum wear rate is obtained for 20 wt. % of filler, 1000 m of sliding distance, 50 cm/sec of sliding velocity, and 10 N of load. The mechanisms predominantly responsible for the wear loss have also been studied using a scanning electron microscope.

Process parameter optimization in polymer powder bed fusion of final part properties in polyphenylene sulfide through design of experiments

AbstractThe Additive Manufacturing (AM) modality of Laser-Based Powder Bed Fusion of Polymers (PBF-LB/P) is an established method for manufacturing semi-crystalline polymers. Like other AM processes, the selection of PBF-LB/P process parameters is critical as it has direct effect on final part properties. While prior research has been predominantly focused on polyamides (e.g., nylon 12), there exists a gap in exploring how process parameters affect higher performance polymers, such as polyphenylene sulfide (PPS). This work aims to explore the effects of PBF-LB/P process parameters on PPS parts printed via PBF-LB/P. While prior PBF-LB/P parameter research primarily relies on evaluating energy input to the system through a single numerical value of energy density, this study investigates the interplay of the print parameters within the energy density equation. To achieve these goals, an analysis was performed on the influence of the laser power, hatch spacing, and beam velocity on ultimate tensile strength (UTS), modulus, and crystallinity of printed parts. A Taguchi L8 array was used in balancing the print parameter combinations allowing for isolation of variance to the specific factors and interactions. Through this approach, print parameter combinations that improved UTS and modulus were identified. Additionally, the study revealed that numerically equivalent energy densities did not lead to equivalent performance, underscoring the significance for including the constitutive process parameters within the energy density equation when establishing process property relationships in printing with PBF-LB/P.

Statistical analysis on influence of groove patterns on the mechanical strength of friction-welded SAE1018 steel

This research work focuses on the impact of various groove pattern, groove depth, and their combination on SAE 1018 mild steel rod friction welded mechanical properties. SAE 1018 steel was used, with a modified vertical milling machine with parameters of the Taguchi's L9 Orthogonal array used in the welding process. The groove pattern and groove depth which provides maximum UTS were determined with the help of ‘Minitab 17 software analysis’. The parameters with the best characteristics of measurement system were grooves made on the stationary and rotating specimens, equal to 1.5 mm groove depth, and hash pattern. The initial optimization predicted the UTS to be 542 MPa however the experimental analysis resulted in a value of 564 MPa which is greater than the base material UTS of 436 MPa. It was also observed from ANOVA that the groove on both specimens had the greatest effect on the UTS percent contribution of 58.65% followed by the depth and pattern percent contribution of 20.42% and 13.55% respectively. Hardness analysis pointed to the maximum microhardness value of 300 HV at the weld center and the minimum value of 200 HV at 15 mm from the center. The difference in hardness between the two rotating and the two stationary discs was ascribed to increased frictional and plastic flow on the rotating side. XRD characterization of the samples supported the findings of the presence of both α-Fe and FeO phases for all the samples and MnO was detected primarily in the Z Groove pattern.

Experimental investigation of the friction stir welding process of AA5059 and AA7079 and prediction using fuzzy approach

Aluminum alloys AA 5059 and AA7079 have high strength, excellent weldability, and corrosion resistance, widely used in train and truck bodies, armored vehicles, and defense applications. Recent materials engineering tasks call for minimizing material weight and to achieve this objective, the solid-state joining approach of Friction stir welding (FSW) is utilized for material joining. FSW has produced sound welds with high joint strength and good ductility. This research investigates the weldability of AA5059 and AA7079 dissimilar aluminum alloys. In this FSW process, a threaded tapered cylindrical tool pin profile was selected, and welding trials were conducted at three different speeds of 500, 750, and 1000 rpm, with the 75 mm/min constant feed rate. The Taguchi L9 orthogonal array was selected to design the process parameters, that is, tool traversing speed, rotational speed, axial force, feed rate, and effect on dissimilar aluminum weld joints. The Mamdani-type fuzzy logic model predicted welded specimens’ ultimate tensile strength and yield strength. Microstructural analysis revealed that the grains in the stirring zone had undergone a full transformation into homogenous, evenly distributed, refined grains, which had a positive impact on the remarkable mechanical properties.

Experimental investigation and parametric optimization of FSW of mineral-reinforced AA6061 matrix composite

Abstract In this work, rutile reinforced AA 6061 matrix composites were joined using friction stir welding and the process variables were optimized using Taguchi L27 orthogonal design of experiments. The rotational speed, axia force and tool tilt angle were the parameters taken into consideration. The optimum process variables were determined with reference to tensile strength, impact strength and hardness of the joint. The predicted optimal value of output responses were confirmed by conducting the confirmation run using optimum parameters. The optimal process variables combination values that resulted in improved mechanical properties were observed at a tool rotational speed of 1400 rpm, a tool tilt angle of 2 degree, and an axial force of 3KN. Scanning electron microscopy (SEM) analysis were used to probe the microstructures.

ANALYZING THE EFFECTS OF MANUFACTURING PARAMETERS MODIFICATION ON FINAL SURFACE ROUGHNESS IN SELECTIVE LASER MELTING PARTS

Selective Laser Melting (SLM) is an additive manufacturing technique widely used today for producing metal components. This method enables the fabrication of geometrically complex parts while reducing costs and production time compared to traditional manufacturing techniques. However, a notable drawback of SLM is its tendency to produce high surface roughness and superficial defects such as balling, porosity, debris, and waviness. This study evaluates the effects of modifying two manufacturing parameters—scanning speed and laser power—on the final surface roughness. To achieve this, cylindrical specimens were fabricated using various combinations of these parameters, and the resulting surface roughness metrics (Sa, Sq, Ssk, Sku, Sdr, among others) were measured using an optical 3D surface roughness measurement instrument. A Taguchi L8 design was applied to analyse the influence of the manufacturing parameters on the measured roughness characteristics. This study investigates the influence of laser power and scanning speed on surfaces manufactured through Selective Laser Melting (SLM) and their effects on the previously described roughness parameters. The authors observed that the manufacturing parameters have varying impacts on the final surface roughness of components produced via SLM. Due to the inherent characteristics of the process, a specific combination of parameters that reduces roughness within a specimen's layer may increase roughness at the layer boundaries. These findings underscore the complex relationship between manufacturing parameters and surface roughness in SLM-produced parts, emphasizing the need for strategies, such as surface finishing post-treatments, to achieve the desired surface quality.

Machinability investigation on CNC milling of recycled short carbon fiber reinforced magnesium matrix composites

Abstract This study investigates the machinability of magnesium matrix composites reinforced with short carbon fibers, which represent novel materials in the field. AZ91 alloy and its composites containing 2.5 and 5 wt% recycled carbon fiber (rCF) reinforcements were used as workpieces. Face milling was conducted using uncoated carbide cutting tools under dry cutting conditions with varied cutting speeds (480–560–640 m min−1) and feed rates (0.65–0.8–0.95 mm min−1). The experimental design was based on the Taguchi L9 (33) orthogonal array. Analysis included cutting forces, surface roughness, wear on cutting inserts, and chip morphology to assess machinability. Taguchi, analysis of variance, and regression methods were employed to analyze cutting force and surface roughness results. Findings indicated satisfactory machinability for AZ91 alloy and comparatively poorer performance for the 5 wt% rCF reinforced composite, with increased reinforcement content correlating with higher cutting force and surface roughness. SEM and EDX analyses revealed significant built-up layer formation on cutting inserts, with predominantly spiral-shaped continuous chips observed in the experiments. Overall, the study affirmed the machinability of the composites and identified suitable cutting parameters for further investigations.

Effects of Cutting Parameters on Tool Wear in Milling Inconel 625 Superalloys with a SiAlON Ceramic and the Prediction of Tool Life

Inconel 625 superalloys are widely preferred in various industries because of their superior mechanical properties at high temperatures. The superior properties they exhibit make the machinability of Inconel 625 alloys difficult. This situation can cause rapid wear of the cutting tools, making the cutting tool unusable in very short periods of time and causing deterioration of the workpiece surface quality. Therefore, improving the machining performance of Inconel 625 alloys, optimizing the machining parameters and using the optimum cutting tool material and geometry are important. In this study, SiAlON ceramic cutting tools, which have been widely used in recent years, were preferred. SiAlON tools supplied in raw rod form were subjected to various processes and finalized into final products. The effects of three different cutting speeds (vc), feed rates (f) and axial depth of cut (ap) on tool life (T), wear patterns and mechanisms were investigated with 9 tests designed according to the Taguchi L9 orthogonal array. The results revealed that the f values, the effects of which were analysed, had the most significant effect on T. By performing regression analysis with T values, the coefficients used in the extended Taylor T equation were determined, and T predictions were obtained. The regression model was found to be consistent with the experimental results, with an effect of 99.34%, and the model was significant according to analysis of variance. The predominant wear patterns of the cutting tools were flaking at a low vc, nose collapse at a high vc and an adhered workpiece under all conditions. The wear mechanism was found to be predominantly adhesion and fracture. The presence of Ni, Cr, Mo, Nb and Fe on the cutting tool surface was determined, and the effect of the concentrations was observed to increase/decrease significantly depending on the parameter values examined.

Optimisation Studies on Performance Enhancement of Spray Cooling - Machine Learning Approach

The performance optimisation of spray cooling heat transfer systems has been identified as a significant step in improving process efficiency, and the application of machine learning tools is a recent development that has enhanced this. This study aims to maximise the heat transfer coefficient for spray cooling at low heat flux levels. The effects of nozzle inclination angle, water pressure, and spray height on heat transfer coefficient were studied. Taguchi L27 orthogonal array technique was used to perform the experiments. A maximum heat transfer coefficient of 181.4 kW/m2K was obtained at a nozzle inclination angle of 60o, spray height of 4 cm, and water pressure of 15 psi. Analysis of variance was performed to find the significance of each variable and its interactions. The results show that for the maximum heat transfer coefficient (181.4 kW/m2K), the optimum levels of the independent variables were A3H1P3, i.e., the highest level of nozzle inclination angle (60o), the lowest level of spray height (4 cm), and the highest level of water pressure (15 psi). The support vector machine outperformed the Random Forest algorithm and Multiple Regression analysis regarding prediction accuracy with a maximum error of 0.15% and root mean squared error of 0.01.

Development and optimization of parameters for HVOF sprayed Al2O3 and ZrO2 blended aluminum coating on 316L SS

Abstract A significant number of gas turbines, aircraft engines, bearings, and automotive engines operating under a wide temperature range fail frequently due to fatigue and surface oxidation. Thus, a new coating formulation 40Al-35Al2O3-25ZrO2 was deposited on 316L SS substrate through the high velocity oxygen-fuel (HVOF) thermal spray coating method. The number of passes, spray distance and oxygen flow rate were varied by using Taguchi L9 array to achieve an optimized coating with higher hardness, less porosity, and roughness. The coating phase analysis, microstructure, elemental composition, microhardness and nano hardness were examined by x-ray diffraction (XRD), scanning electron microscopy (SEM), field emission scanning electron microscopy (FESEM), energy dispersive x-ray spectroscopy (EDX), Vickers microhardness and nano indentation testing. The sample 5 prepared at spray distance of 20 cm and oxygen/acetylene ratio of 2 exhibited optimal hardness (1972 HV1), tensile strength (6.463 GPa), porosity (0.75%) and roughness (6.2 μm) due to α-Al2O3 and t-ZrO2 phases. Oxygen flowrate was the influential parameter contributing 48.71% to microhardness and 42.41% to roughness, while spray distance with contribution 51.62% was influential parameter for porosity.

Optimization of low-velocity impact behavior of FML structures at different environmental temperatures using taguchi method and grey relational analysis

Carbon fiber-reinforced Aluminum Laminate (CARALL) is a new generation of Fibre Metal Laminate (FML) material. This study investigates the low-velocity impact behavior of CARALL structures at different environmental temperatures (−40°C, 23°C, and 80°C). Two different groups of CARALL composite structures with varying fiber orientations were produced by hot pressing in a 3/2 arrangement: C1 (Al/0°90°/Al/90°0°/Al) and C2 (Al/0°0°/Al/0°0°/Al). Low-velocity impact tests were conducted at 23 J, 33 J, and 48 J energy levels using a Ø20 mm spherical impactor tip. The area of damage was detected by ultrasonic C-Scan. In addition, analysis of variance (ANOVA) was applied to reveal the influential parameters and their effect levels. After conducting experiments using the Taguchi L18 test set, it was observed that the C2-coded specimen yielded better results in terms of maximum peak load, maximum displacement, and damage area. While the decrease in temperature increased the damage and maximum peak load, the increase in temperature did not cause a significant change in the maximum peak load. The primary damage mechanisms observed in damage investigations were matrix cracks and delamination between composite layers. Although delamination is present between the Al/CFRP layer, it is not significant. According to ANOVA results, impact energy was the most effective parameter for maximum impact force, maximum displacement, and damage area, with contribution rates of 81%, 74%, and 76%, respectively. The optimal experimental conditions (23°C temperature and 23 J impact energy with the C1-coded sample) were determined using grey relational analysis based on principal component analysis.

Particle Size and Crystal habit Modification of Ammonium Perchlorate Using Cooling Sonocrystallization Process

AbstractAmmonium perchlorate (AP) is a widely used solid oxidizer in solid propellant formulations, with its particle size and crystal habit significantly affecting performance. Since controlling these properties remains challenging, this study employs an intensified crystallization strategy, specifically a cooling sonocrystallization process, to recrystallize AP to control and modify its particle size and crystal habit. The effects of solution concentration, sonication intensity, sonication pulse on/off recipe, and cooling rate on the recrystallization of AP are first investigated using a Taguchi L9 orthogonal array design. By understanding the main effect of these operating parameters, further sonocrystallization experiments are designed for process improvement. Compared with the unprocessed AP, the crystal habit and mean particle size of AP are considerably modified after cooling sonocrystallization, achieving a mean size of approximately 50 µm with a regular habit. Consistency in crystal structure and spectrometric properties between sonocrystallized and unprocessed AP was confirmed. Furthermore, the thermal properties and decomposition behavior of the sonocrystallized AP are analyzed, revealing improved exothermic characteristics. These results prove that cooling sonocrystallization is an efficient tool for producing AP particles and also holds the potential for preparing fine particles of other energetic materials.

Multi-objective Optimization of Turning Titanium Alloy by Grey Rational Analysis

In order to optimize the turning operation on titanium alloy, one needs to understand how different parameter combinations serve under varied conditions and needs. It is critical to compare single and multiple objectives in optimization. This study focused on single and multi-objective optimization evaluations for the primary performance responses of surface roughness (SR) and tool flank wear (TW), aiming for optimal turning process parameters. To examine the effects of feed rate (f), cutting speed (R), depth of cut (d), cutting angle (X), and mist inlet pressure (P) on the responses of both SR and TW, Taguchi L27 orthogonal arrays were used in this study. Moreover, analysis of variances (ANOVA) and grey relational analysis (GRA) have been incorporated in this study, where the former was used to study the influence of each parameter on SR and TW while the latter was used to determine the best combinations for the multi-objective optimization process. The results revealed that for single-objective optimization of SR, the optimal values for f, R, d, X, and P were found to be 0.3 mm/rev, 250 rpm, 1.5 mm, 100 degrees, and 1 bar mist inlet pressure, respectively. For single-objective optimization of TW, the optimal values for f, R, d, X, and P were found to be 0.20 mm/rev, 250 rpm, 0.5 mm, 50 degrees, and 3 bar mist inlet pressure, respectively. Meanwhile, for multi-objective optimization, the optimal values for f, R, d, X, and P were found to be 0.30 mm/rev, 500 rpm, 2.0 mm, 75 degrees, and 1 bar mist inlet pressure, respectively. These optimal combinations of turning parameters resulted in the lowest SR and TW simultaneously.

Microstructural analysis of AA8079 alloy sheets formed by friction stir incremental forming

Friction Stir Incremental Forming (FSIF) is an innovative solid-state metal-forming technique that uses frictional heat and mechanical deformation to create complex shapes without dyes. It has found applications in industries like aerospace, automotive, and consumer goods. In this study, FSIF was applied to AA8079 alloy sheets to form cone and pyramid geometries. A detailed investigation of process parameters such as spindle speed, table feed, step size, and coatings was conducted to assess their effects on surface roughness and forming forces. Optimal parameters were identified using the Taguchi L27 orthogonal array and the TOPSIS method, which determined the best settings as a wall angle of 20°, a step size of 1 mm, a spindle speed of 1500 rpm, and a table feed of 2400 mm/min. Scanning electron microscopy was employed to study surface roughness, texture, and defects, revealing the influence of these parameters on surface quality. Additionally, Finite Element Method (FEM) analysis, performed using ABAQUS software, was used to predict formability and stress distribution during the forming process. Key results showed successful formation of cone and triangular pyramid shapes on AA8079 sheets, with FEM accurately predicting stress levels. This comprehensive study provides valuable insights into optimizing FSIF for improved material performance and structural integrity. The findings emphasize the importance of fine-tuning FSIF parameters to enhance surface finish and reduce defects, offering potential improvements for various industrial applications.

Taguchi L8 Orthogonal Array and ANOVA-Based Optimization of Injection Molding Parameters for Reducing Warpage in Set-Top Box Components

Taguchi L8 Orthogonal Array and ANOVA-Based Optimization of Injection Molding Parameters for Reducing Warpage in Set-Top Box Components

Effect of Wetting and Drying Cycles on Resilient Modulus and Microstructure Characteristics of Heterogeneous Quicklime-Stabilized Subgrade

The resilient modulus changes due to post-compaction seasonal variations in weather such as wetting and drying, thus affecting pavement performance. Existing research highlights significant differences in back-calculated resilient modulus test outcomes for compacted quicklime-stabilized subgrades after construction. Nonetheless, limited studies exist on the effect of the wetting and drying cycles considering the variability in the compacted quicklime stabilized composites. Using a Taguchi L9 orthogonal array, four groups of nine samples varying in dry density, water, and quicklime contents were created and subjected to multiple wetting and drying cycles (0th, 4th, 8th, and 12th). Resilient modulus testing revealed an initial increase up to the 8th cycle, followed by a decrease, with a more pronounced negative effect on samples with lower quicklime and water contents. SEM-EDX, XRD, and FTIR analyses indicated distinct microstructural responses after each cycle, with SEM micrographs showing complex pore structures of low circularity and the formation of average form factors ranging from 0.301 to 0.3564. Canonical correlation analysis between the pore geometrical properties and resilient modulus is approximately 0.689, the associated Wilks' Lambda value is 0.526, and the eigenvalue of 0.901, thus offering direct relationships between macroscopic and microscopic properties of the materials. The highest calcium content was found in the 0th cycle samples. This study contributes to a better understanding of the resilient modulus characteristics and microstructural evolution of stabilized quick-lime subgrades, offering valuable insights for engineers and researchers in pavement design and maintenance.

Synthesis of strontium and manganese co-doped hydroxyapatite nanoparticles by ultrasound-supported hydrothermal technique and Taguchi design of experiments for biomedical applications

The present study aims to develop Strontium (Sr) and Manganese (Mn) co-doped Hydroxyapatite (HA) nanoparticles using the Taguchi design of experiments to understand the effect of process parameters on cell viability of human osteosarcoma MG-63 cells and antibacterial properties. An ultrasound-supported Hydrothermal technique was implemented for the synthesis, considering hydrothermal temperature; time for ultrasonic pretreatment; concentration of Sr; and concentration of Mn as important variable process parameters. They were varied at 145°C, 160°C, and 175°C; 10 min, 20 min, and 30 min; 0 wt%, 5 wt%, and 10 wt%; and 0 wt%, 5 wt%, and 10 wt%, respectively using Taguchi L9 orthogonal array. The particles displayed doping-induced colour variation. Powder X-ray diffraction (PXRD) analysis confirmed the samples' phase purity. Field effect-scanning electron microscopy (FE-SEM) and Transmission electron microscopy (TEM) were used to confirm the morphological similarity. Energy dispersive X-ray (EDX) analysis and Fourier transform–infrared (FT-IR) spectroscopy were used to ensure the chemical purity of the samples. To confirm the non-toxicity of samples, the MTT assay was utilized for MG-63 human osteosarcoma cells. All nine samples displayed cell viability greater than 80%. Additionally, the antibacterial properties were checked against S. aureus, S. pyogenes, E. coli and P. aeruginosa using the broth dilution method. The particles displayed comparable antibacterial properties against only E. coli bacterial strain. The obtained data of cell viability (%) and Optical density of broth against blank at 600 nm (OD600) for the antibacterial properties were analyzed using the Taguchi S/N ratio considering the larger-the-better case and smaller-the-better case, respectively. Based on the response table and ANOVA, it is inferred that the dopants’ concentration played the most significant role in controlling the cell viability and antibacterial properties. Since the Taguchi method can not simultaneously optimize two responses, multi-response optimisation will be considered in future studies.

Investigation of the effects of contour process parameters on mechanical properties and part quality in SLM

AlSi10Mg is an aluminium alloy preferred in the automotive, medical, and aerospace industries due to its engineering properties such as lightness, high corrosion resistance, and excellent castability. In metal-based additive manufacturing, offset value, laser power, and scanning speed are important manufacturing parameters. These parameters significantly impact the formation of defects that adversely affect the microstructure, mechanical properties, surface quality, and dimensional accuracy of the final product. Therefore, it is imperative to select these parameters correctly during the manufacturing process. In this context, the study focuses on improving product quality in the additive manufacturing of AlSi10Mg alloy, and samples were produced using different contour process parameters. The production of samples was carried out according to the Taguchi L27 orthogonal experimental design. Three different offset values (0.140–0.175–0.210 mm), three different laser powers (160–200-240 W), and three different scanning speeds (280–350-420 mm/s) were utilized as contour process parameters. At the conclusion of the study, it was determined that there are ideal process parameters for achieving high mechanical properties, low surface roughness, and dimensional accuracy according to nominal values. It was observed that the product quality decreased in samples produced with non-ideal parameters. Yield strength decreased by 4.12 % with an increase in the offset value from 0.140 mm to 0.175 mm, and by 3.83 % with an increase from 0.175 to 0.210 mm. Increasing the offset value from 0.140 mm to 0.175 mm resulted in a decrease in tensile strength by 1.94 % and increasing it from 0.175 mm to 0.210 mm resulted in a decrease of 2.83 %. The decrease in mechanical properties was attributed to the occurring defects. The lowest Ra value (2.011 µm) was measured at a 0.140 mm offset value, with a laser power of 200 W, and a scanning speed of 280 mm/s. For all offset values, the deviation in thickness measurement varies between approximately −5.13 % and + 4.96 %, and the deviation in width measurement varies between −1.89 and + 1.33. Multi-response optimization was conducted for mechanical properties, surface roughness, and dimensional accuracy using the Taguchi-based gray relational analysis method. According to the experimental results, the optimal contour process parameters for additive manufacturing of AlSi10Mg alloy were obtained as 0.140 mm offset value, 200 W laser power, and 280 mm/s scanning speed.

Optimal Suppression of Photocatalytic Activity of Hybrid TiO2 Particles in Epoxy Thin Film by Using Taguchi Method

In this study, two different Al2O3-TiO2 and SiO2-TiO2 hybrid TiO2 particles were synthesised by using silica (SiO2) and alumina (Al2O3) to suppress the photocatalysis of TiO2. Key variables such as the concentration of the hybridization material (C), heating temperature (Th), and calcinating temperature (Tc) were selected with performance measured by photodegradation rate. The Taguchi L9 orthogonal array, a systematic approach used in the design of experiments (DOE), confirmed A333 (Al2O3-TiO2) achieved 99% photodegradation suppression with photodegradation rate reduced significantly from 0.01305 min−1 to 0.00009 min−1 and improved yellowing resistance by 63%, while S323 (SiO2-TiO2) achieved 75% suppression with photocatalysis activity decreased from 0.01305 min−1 to 0.0033 min−1 and 42% improved resistance. X-ray Diffraction (XRD) analysis showed A333 had a higher rutile phase (40.1% vs. 10.2% for S323), and Fourier Transform Infra Red (FTIR) and Field Emission Scanning Electron Microscopy (FESEM) analyses revealed A333's rougher surface and lower surface area compared to S323 and pure TiO2. Overall, A333 effectively suppressed photocatalysis and improved yellowing resistance of epoxy thin film. Copyright © 2024 by Authors, Published by BCREC Publishing Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).