Optimal Setting Of Process Parameters Research Articles

Intelligent Optimization of Process Parameters in Limit Gauge Hot Strip Rolling

Aiming at the problems of large rolling deviation and low stability in limit specification of hot strip rolling, the optimal rolling suggestions were obtained based on back propagation (BP) neural network and genetic algorithm. According to equipment state and strip specification to select excellent sample set, in the sample set based on the data of application of neural network to build the mapping relationship between process parameters and the rolling stability, limit specifications of the mapping model is set up, and then using the genetic algorithm for the search of this mapping model, the search model of rolling stability of ideal point, determine a set of process parameters optimal advice accordingly. Taking the rolling of MRTRG00201_1276_3 as an example, a set of optimal process parameters are obtained by simulating rolling of MRTRG00201_1276_3. Then the sample distribution and rolling stability of each process are analyzed in turn. The results show that the process parameters obtained by optimizing the model accord with the distribution law of rolling samples, can obtain high rolling stability, and can play a guiding role in limit specification rolling.

Influence of cooling conditions on tensile lap shear strength and microstructure of friction stir welded aluminum alloy 5052-H32 and polycarbonate light weight hybrid joint

The joining of dissimilar materials, notably polymer and metal, is incredibly demanding due to the differences in the materials' mechanical, chemical, and thermal characteristics. In this present study, the feasibility analysis of dissimilar materials joints of aluminum alloy AA5052-H32 and polycarbonate (PC) was performed utilizing Friction Stir Welding (FSW) in the lap joint taper threaded tool pin profile. Response surface methodology (RSM) was implemented as a statistical design of the experiment tool for working process parameter optimization. Optical and Field emission scanning electron microscopy was employed to characterize the detailed microstructure of friction stir welded hybrid joint of AA5052-H32 alloy and PC. The mechanical and metallurgical findings demonstrate that AA5052-H32 and PC sheets were effectively bonded together utilizing a mix of macro mechanical interlocking and secondary chemical adhesive bonding of the materials, providing a viable relaxation to adhesive bonding or mechanical fastening. The hardness of the polymer in as-received conditions welded normally and in underwater conditions was measured onshore D hardness scale. The joint obtained at a rotational speed 1118 rpm and welding speed 48 mm/min with a 2° tilt angle had the maximum tensile lap shear strength of 14.86 MPa in air-cooled and 12.47 MPa in a water-cooled environment. Additionally, shore D hardness for optimal set of process parameters were 72 and 75 for air-cooled and water-cooled conditions respectively.

Study of Ultimate Tensile Strength and Wear Rate of Squeeze Cast Al-Si-Cu Alloy with DOM and TOPSIS Approaches

Aluminium alloys are widely used to produce aerospace and agricultural sector components. Squeeze casting (SQC) is a liquid forging process to enrich the mechanical characteristics of light metal alloy castings. Al-Si-Cu castings were fabricated through SQC process adopting Response Surface Methodology (RSM) following Box-Behnken experimental design. Fifteen castings were fabricated by varying input factors such as squeeze pressure, pouring temperature and dwell time. Optimal process parameter settings were predicted for the responses Ultimate Tensile Strength (UTS) and Wear rate by Desirability Optimization Methodology (DOM) and Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS). The details of experiments and analysis are presented. The examination of microstructure and worn-out surface of squeeze castings indicated that the refi ned grain structure due to squeeze pressure application improved UTS and Wear resistance. Confi rmatory tests were conducted for settings suggested by DOM and TOPSIS. The setting suggested by DOM resulted in greater improvement. The value of UTS and wear rate predicted with DOM were verifi ed through confi rmatory tests and the measured values are in agreement with predicted values. An optimal improvement of 99.3% and 53.75% were achieved on ultimate tensile strength and wear resistance respectively in comparison with gravity die-cast components.

A Study on the Residual Stress of the Co-Based Alloy Plasma Cladding Layer.

The distribution law of residual stress in multi-channel scanned plasma cladding of Co-based alloy under different process parameters was studied by means of simulation and tests, and the optimum process parameters were optimized. The simulation model of the plasma cladding stress field was established by ABAQUS software, and the influence law of the working current, scanning speed, and scanning mode on the residual stress of the Co-based alloy multi-channel scanning was studied. A set of optimal cladding process parameters were obtained. The residual stress of the cladding layer was measured by the blind hole method and compared with the stress value in the finite element model. The results show that there is residual tensile stress on the surface of the cladding layer. The residual stress along the direction of the scanning path is greater than that along the direction of the scan sequence. The residual stress increases with the increase of the working current. The scanning speed is greater, and the residual stress is smaller. The residual stress of the short-edge scanning is greater than that of the long-edge scanning. The residual stress of the successive scanning is greater than that of the reciprocating scanning. The long-edge reciprocating scanning is the best scanning mode. The best combination of process parameters is the working current of 90 A, the scanning speed of 100 mm/min, and the long-edge reciprocating scanning mode.

INFLUENCES OF BORON CARBIDE PARTICLES ON THE WEAR RATE AND TENSILE STRENGTH OF AA2014 SURFACE COMPOSITE FABRICATED BY FRICTION-STIR PROCESSING

In this article, a boron carbide particle (B4C) reinforced AA2014 surface composite was first fabricated by friction-stir processing (FSP) to investigate the impact of the volume percentage of B4C, tool rotational speed and table speed on the tensile strength (TS) and wear rate (WR). The AA2014 composite is one of the important candidates for making defense and aerospace components due to its high strength and minimum weight. Taguchi orthogonal array was employed to design and predict the maximum tensile strength and minimum wear rate. The volume percentage of B4C is the most momentous parameter for both the tensile strength and wear rate. The optimum parameter settings for attaining the maximum tensile strength of 605 MPa and a minimum wear rate of 1.2 mm3/Nm are a B4C volume of 15 %, tool rotational speed of 900 min–1 and table speed of 60 mm/min. The optimum process-parameter settings were used to make a specimen for validating the estimated results. The microstructure and chemical composition of the surface composite of the optimum specimen were illustrated using scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS), respectively. The surface profile and microscopic view of the worn-out surface composite were also examined using SEM images.

Effects of selective laser melting process parameters on the accuracy of the intaglio surface of maxillary removable partial denture frameworks

PurposeThis in vitro study aims to explore the effects of selective laser melting (SLM) process parameters on the accuracy of the intaglio surface of cobalt–chromium alloy (Co–Cr), commercially pure titanium (CP Ti) and titanium alloy (Ti–6Al–4V) maxillary removable partial denture (RPD) frameworks and optimize these process parameters.Design/methodology/approachMaxillary RPD framework specimens designed on a benchmark model were built. The process parameters, including contour scan speed and laser power, infill scan speed and laser power, hatch space, build orientation and metallic powder type, were arranged through the Taguchi design. Three-dimensional deviations of the clasps area, connector area and overall area of maxillary RPD frameworks were analyzed by using root mean square (RMS) as a metric. One-way analyses of variance with the above RMSs as the dependent variable were carried out (α = 0.05).FindingsMaxillary RPD frameworks built horizontally had a more accurate intaglio surface than those built at other orientation angles; CP Ti or Ti–6Al–4V maxillary RPD frameworks had a more accurate intaglio surface than Co–Cr ones; the Maxillary RPD framework built with a higher infill scan speed and lower infill laser power had the more accurate intaglio surface than the one built with other levels of these two process parameters.Originality/valueA novel benchmark model for evaluating the accuracy of the intaglio surface of maxillary RPD frameworks manufactured by SLM is proposed. The accuracy of the intaglio surface of maxillary RPD frameworks can be improved by adjusting SLM process parameters. The optimal setting of process parameters concerning the accuracy of the intaglio surface of maxillary RPD frameworks was given.

Parameter optimization in hot precision forging process of synchronizer ring based on grey relational analysis and response surface method

In this work, the hot precision forging process was proposed to manufacture the synchronizer ring made of HMn64–8–5–1.5 alloy, and the forming process parameters were optimized. The true stress-strain data of HMn64–8–5–1.5 alloy were obtained through the isothermal compression test. Then, the finite element model of the hot precision forging process of the synchronizer ring was built, and two schemes of the forming process were analyzed and compared. To solve the problems during the hot precision forging process of synchronizer ring, i.e. forging defects, low material utilization and large forming load, a multi-objective optimization method based on grey relational analysis (GRA) and response surface method (RSM) were introduced to optimize the process parameters. As a result, a set of optimal process parameters was determined through the model calculating. Numerical simulation and experiment were carried out to verify the optimal scheme, which was set up based on the obtained optimal process parameters. The results of experimental and numerical simulation have good consistency. The results show that the optimal scheme can ensure product quality, enhance material utilization and reduce forming load.

A holistic assessment of a stiffened panel production using a novel thermoplastic material and implementing the induction welding process

PurposeThe purpose of this paper is to investigate the feasibility to produce a novel aircraft full stiffened panel using entirely a new hybrid thermoplastic composite material allowing for appreciably lower processing temperatures as compared to conventional structural thermoplastic composites.Design/methodology/approachFor stiffening the fuselage skin panel, the out of autoclave welding of four composite stringers was obtained using a modified induction welding (IW) process. The quality of the welds was investigated using micro-tomography and the mechanical strength of the lap joints was assessed by means of single-lap shear strength (SLSS) tests. Moreover, a holistic design index was implemented as a decision support tool for selecting the optimal set of IW process parameters. Based on the index used, the quality as well as the entire life cycle cost and environmental impact are accounted for.FindingsLow porosity values as well as no deconsolidation were observed at the investigated application, and the average measured SLSS, even found lower, lies within the range of the respective values encountered in other similar high-performance applications. It is exhibited that after the optimization, the IW process offers significant potential to replace the autoclave process in welding applications. Thus, it paves the way for reduced cost and increased sustainability, while still meeting the predefined quality constraints.Originality/valueAlthough several studies on the IW application have been conducted, limited results exist by using novel thermoplastic materials for aircraft structural applications.

A study on bi-objective optimization for end milling of Aluminium based composite

The composites are renowned for better properties than base alloy. In general, 2-8% weight fraction of reinforcement has been researched for various industrial applications. The addition of reinforcement gives improvement in mechanical properties but badly affects ductility. Liquid route method (casting) has been employed for fabrication of SiC reinforced aluminum composites. Machining has been performed by controlling input parameters such as cutting speed, feed rate and depth of cut. Roughness parameter (Ra) and material removal rate (MRR) have been considered for evaluation of surface quality and productivity respectively. Only MRR has been given consideration for rough machining conditions. Whereas, both surface roughness and MRR have been considered for the finish machining conditions. Standard L9 orthogonal array have been employed for the experimentation. The occurrence of hard reinforcement in the base alloy creates the casted composite tough to machine. The confirmation experiments have been performed with the optimal settings of process parameters to confirm the output responses.

Study of Coefficient of Friction and Spring back Analysis of Brass in Bending at Elevated Temperature Conditions

In the present work, finite element analysis is carried out for the minimization of springback in theV-bending process for high-strength brass sheet metal. Firstly, the uniaxial tensile test is conducted to determine the variousmaterial properties required for finite element analysis. The various test parameters considered in the V-Bending process aretemperature (573 K, 673 K and 773K), punch speeds (1 mm/min, 5 mm/min and 10 mm/min), holding time (30 s, 60 s and90 s) and sheet orientation concerning rolling direction RD (00), ND (450) and TD (900) for finite element analysis. Thebending under tension test is used to determine the coefficient of friction at different temperatures and lubricationconditions, and these values are implemented in finite element simulations of the V-bending process. Taguchi analysis iscarried out to determine springback of high-strength brass alloy by selecting four control factors (temperature, punch speed,holding time, and orientation). From the analysis of the signal-to-noise (S/N) ratio, it is reported that the temperature(46.93%) is the most significant parameter which influences the springback followed by holding time (26.29%), sheetorientation (24.07%) and punch speed (2.69%). The optimal set obtained for the minimum springback of brass alloy and theconformation test is performed at the optimum set conditions (773 K temperature, 1 mm/min punch speed, 90 s holdingtime, and 90° to the rolling direction of a sheet). With the optimal set of process parameters, Springback decreasedsignificantly to around 68.68%. Through the investigation of springback analysis, it is directly proportional to thetemperature and holding time and inversely proportional to the punch speed, but sheet orientation doesn’t follow any trends.

Optimizing Main Process Parameters When Conducting Powder-Mixed Electrical Discharge Machining of Hardened 90CrSi

In the current study, an optimization process of powder-mixed electrical discharge machining (PMEDM) process when machining cylindrically shaped parts made of hardened 90CrSi steel is reported. In this study, SiC powder was mixed into the Diel MS 7000 dielectric solution. Additionally, graphite was chosen as the electrode material. The multi-objective functions were minimizing the surface roughness (SR) and electrode wear rate (EWR) and maximizing the material removal rate (MRR). The used input parameters of the optimization process included the powder concentration, the pulse-on time, the pulse-off time, the pulse current, and the servo voltage. A combination between the Taguchi method and the grey relation analysis (GRA) method with the support of Minitab R19 software was used to design the experiment and analyze the results. It was found that the optimal set of process parameters that can satisfy the above responses are Cp of 0.5 g/L, Ton of 8 µs, Toff of 8 µs, IP of 5 A, and SV of 4 V.

Optimization of Injection-Molding Process for Thin-Walled Polypropylene Part Using Artificial Neural Network and Taguchi Techniques.

Plastics are commonly used engineering materials, and the injection-molding process is well known as an efficient and economic manufacturing technique for producing plastic parts with various shapes and complex geometries. However, there are certain manufacturing defects related to the injection-molding process, such as short shot, shrinkage, and warpage. This research aims to find optimum process parameters for high-quality end products with minimum defect possibility. The Artificial Neural Network and Taguchi Techniques are used to find a set of optimal process parameters. The Analytic Hierarchy Process is used to calculate the weight of each defect in the proposed thin-walled part. The Finite Element Analysis (FEA) using SolidWorks plastics is used to simulate the injection-molding process for polypropylene parts and validate the proposed optimal set of process parameters. Results showed the best end-product quality was achieved at a filling time of 1 s, cooling time of 3 s, pressure-holding time of 3 s, and melt temperature of 230 °C. The end-product quality was mostly influenced by filling time, followed by the pressure-holding time. It was found that the margin of error for the proposed optimization methods was 1.5%, resulting from any uncontrollable parameters affecting the injection-molding process.

Process parameter optimization for thin-walled tube push-bending using response surface methodology

In this paper, the response surface methodology (RSM) and finite element (FE) simulation were applied to optimize the push-bending process parameters of the thin-walled tube with polyurethane mandrel. The objective of the present work is to predict the optimal set of process parameters including the length to diameter ratio of the mandrel (L/D), the friction coefficient between die and tube ( $${\mu }_{1}$$ ), the friction coefficient between polyurethane and tube ( $${\mu }_{2}$$ ), and Poisson’s ratio of polyurethane ( $$\upsilon$$ ) to obtain qualified bent tubes. Three empirical models were developed to describe the relationship between process parameters and quality parameters of the bent tubes. In addition, the significant factors affecting the forming quality were analyzed using analysis of variance (ANOVA) of each model. Response surfaces were constructed to study the effect of each process parameter on the quality of the bent tubes. Finally, the process optimization window with the maximum thinning rate ( $$\varphi$$ ) less than 20%, the maximum thickening rate ( $$\psi$$ ) less than 17%, and the maximum cross-section ovality ( $$\xi$$ ) less than 5% of the bent tube was established. Qualified bent tubes with diameter of 144 mm, wall thickness of 2 mm, and bending radius of 280 mm were formed experimentally by following the established process window.

Hemp fibers modified with graphite oxide as green and efficient solution for water remediation: Application to methylene blue

In this paper, the use of hemp fibers modified with graphite oxide for the removal of methylene blue (MB) from aqueous solutions was investigated. Parameters such as contact time, pH, temperature, initial concentration of dye and ionic strength were varied and their effects on the adsorption recovery were evaluated. The adsorption process attained the equilibrium within 30 min while the adsorption capacity was found to increase with increasing contact time. The experimental data were fitted through a pseudo-second order model. Maximum adsorption capacity slightly increases with temperature changing from 54 mg/g to 58 mg/g at pH = 7.5, from 37 mg/g to 45 mg/g at pH = 3 and from 44 mg/g to 49 mg/g at pH = 12, by increasing the temperature from 20 °C to 80 °C indicating that the process is slightly endothermic (ΔH = 3.43 kJ/mol). The thermodynamic parameters were even calculated demonstrating that the process is spontaneous (ΔG ≈ −4.4 J/mol K and ΔS = 3.16 J/mol K)). Finally, a mathematical algorithm was applied to forecast the response surface model. A second order model was chosen to fit the experimental data and the statistical effect of the process parameters were estimated. A numerical optimization was even performed to individuate the optimal set of process parameters (pH = 9.25, T = 53.8 °C and C0 = 13.2 mg/L) which maximizes the removal capacity. A possible adsorption mechanism was even presented. So, it was proved the efficiency of the adsorption of a novel, inexpensive and sustainable composite material obtained from agro-waste resources by performing reusability cycles.

TiB reinforced Ti-6Al-4V matrix composites with improved short-term creep performance fabricated by laser powder bed fusion

This study investigates the short-term creep performance of laser powder bed fusion (L-PBF) fabricated Ti-6Al-4V (Ti64) and TiB-reinforced Ti64 matrix composite (TMC) parts. The TMCs were fabricated by L-PBF processing of 0.2wt.%B4C/Ti64 composite powder. The optimum set of process parameters was used to manufacture creep test specimens. In addition to the as-built scenario, supertransus heat treatment was conducted to eliminate the microstructural anisotropy. Creep testing of the as-built and heat-treated samples was performed at 600 °C under a constant tensile stress of 200 MPa. Microstructural evolutions were scrutinized before and after the creep test. Results revealed a slightly longer rupture time for Ti64 than the TMC part in the as-built state. Although the boundaries of prior β grains were detected as the preferential void nucleation sites in both as-built samples, the TMC part featured a significantly higher frequency of smaller voids near the fracture location. The heat-treated Ti64 sample showed the most inferior creep performance with a premature failure due to continuous networks of grain boundary α (GB-α). However, the heat-treated TMC counterpart showed a noticeably improved creep performance with a rupture time of 5.8 h owing to the absence of GB-α, presence of hard and stiff TiB reinforcements, and the increased fraction of interfaces (α-α, α-β, and α-TiB).

Utilisation of Non-Edible Source (Pongamia pinnata Seeds Shells) for Producing Methyl Esters as Cleaner Fuel in the Presence of a Novel Heterogeneous Catalyst Synthesized from Waste Eggshells.

Waste eggshells were considered for synthesising a precursor (CaO) for a heterogeneous catalyst, further impregnated by alkali caesium oxide (Cs2O). The following techniques were used to characterise the synthesised catalysts: X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Energy-dispersive X-ray spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS) and Temperature Programmed Desorption (CO2-TPD). The synthesised catalyst revealed its suitability for transesterification to produce biodiesel. The biodiesel production process was optimised, and it showed that the optimal biodiesel yield is 93.59%. The optimal set of process parameters is process temperature 80 °C, process time 90 min, methanol-to-oil molar ratio 8 and catalyst loading 3 wt.%. It has been found that the high basicity of the catalyst tends to give a high biodiesel yield at low methanol-to-oil ratio 8 when the reaction time is also less (90 min). The fuel properties of biodiesel also satisfied the standard limits defined by ASTM and the EN standards. Thus, the synthesised catalyst from waste eggshells is highly active, improved the biodiesel production conditions and PPSS oil is a potential nonedible source.

Modelling using dimensional analysis and optimization with grey-taguchi based fuzzy approach in s-eddg of skd-11 steel

The SKD-11 steel was machined by the hybrid surface-electro discharge diamond grinding (S-EDDG) machining process with an aim to determine the optimum setting of process parameters for multi-output optimization and thereafter developed the mathematical-models of material-removal-rate (MRR), and surface-roughness (Ra) through the Dimensional Analysis method. In this research work, Grey-Taguchi based Fuzzy method is utilized for multi-output optimization of process parameters. The various process-variables selected in this research work are current, voltage, wheel speed, pulse-on-time, duty-cycle, and nozzle flushing aid. Total 18 experiments have been conducted on S-EDDG set-up according to Taguchi’s L18 orthogonal array. The response table and Analysis of Variance investigation are used to determine the optimum setting of process control-parameters and further help to determine the impact of these control-factors on the multi-output performance index (MPI). In this research work, the Dimensional Analysis method is utilized for the development of mathematical models of MRR, and Ra. The experimental results and predicted estimation of values from the developed models were compared and showed satisfactory matching between them. The optimum combination of process variables suggested by the hybrid optimization method was validated through confirmation experiment whose result depicts that aimed MPI is significantly improved by 0.435. The suggested optimum setting of process variables helps the production engineer to set-up the economical-cum-efficient process.

The influence of ultrasonic vibrations on material removal in the silicon wafer polishing using DDCAMRF: Experimental investigations and process optimization

The present experimental investigation attempts to understand and address the effect of ultrasonic vibrations on material removal in the polishing of silicon wafers (1 0 0). The requisite finishing experimentations were performed on an indigenously developed experimental arrangement of double-disc chemical assisted magnetorheological finishing (DDCAMRF) process with longitudinal vibrations. The MR fluid used in the experiments consists of a water-based suspension prepared by mixing suitable amounts of carbonyl iron particles (CIPs), abrasive particles, and additives or stabilizers. The prepared MR fluid uses both mechanics and chemistry to finish the silicon surface. Mechanics is mainly responsible for micro-scratching of silicon surface, which gets “softened” by hydration utilizing DI water in the MR fluid. In this study, the ‘response surface methodology (RSM)’ was chosen for designing the experiments to evaluate the significance of different process factors, namely polishing speed, abrasive concentration, and ultrasonic power on the material removal rate (MRR) in DDCAMRF process. The material removed from the wafer surface was measured using the precision digital weighing balance. It was observed that the MRR was found to increase with the increase in various process factors used. Further, analysis of variance (i.e., ANOVA) technique with a 95% confidence interval was performed to analyze the significant contribution of different process factors on MRR. The validation of developed model was done by performing experiments on random and optimized set of process factors. From, the statistical investigation it was discovered that ultrasonic power has highest contribution of 57.9% on MRR, followed by the polishing speed (13.3%), and abrasive concentration (12.5%). Furthermore, a genetic algorithm optimization tool was utilized to obtain optimum set of process parameters to maximize MRR.

Effects of Injection Molding Process Parameters on the Chemical Foaming Behavior of Polypropylene and Polystyrene.

In the present study, semi-crystalline polypropylene (PP) and amorphous polystyrene (PS) were adopted as matrix materials. After the exothermic foaming agent azodicarbonamide was added, injection molding was implemented to create samples. The mold flow analysis program Moldex3D was then applied to verify the short-shot results. Three process parameters were adopted, namely injection speed, melt temperature, and mold temperature; three levels were set for each factor in the one-factor-at-a-time experimental design. The macroscopic effects of the factors on the weight, specific weight, and expansion ratios of the samples were investigated to determine foaming efficiency, and their microscopic effects on cell density and diameter were examined using a scanning electron microscope. The process parameters for the exothermic foaming agent were optimized accordingly. Finally, the expansion ratios of the two matrix materials in the optimal process parameter settings were compared. After the experimental database was created, the foaming module of the chemical blowing agents was established by Moldex3D Company. The results indicated that semi-crystalline materials foamed less due to their crystallinity. PP exhibits the highest expansion ratio at low injection speed, a high melt temperature, and a low mold temperature, whereas PS exhibits the highest expansion ratio at high injection speed, a moderate melt temperature, and a low mold temperature.

Optimization of Laser Engraving of Acrylic Plastics from the Perspective of Energy Consumption, CO2 Emission and Removal Rate

This paper focuses on optimizing the laser engraving of acrylic plastics to reduce energy consumption and CO2 gas emissions, without hindering the production and material removal rates. In this context, the role of laser engraving parameters on energy consumption, CO2 gas emissions, production rate, and material removal rate was first experimentally investigated. Grey–Taguchi approach was then used to identify an optimal set of process parameters meeting the goal. The scan gap was the most significant factor affecting energy consumption, CO2 gas emissions, and production rate, whereas, compared to other factors, its impact on material removal rate (MRR) was relatively lower. Moreover, the defocal length had a negligible impact on the response variables taken into consideration. With this laser-process-material combination, to achieve the desired goal, the laser must be focused on the surface, and laser power, scanning speed, and scan gap must be set at 44 W, 300 mm/s, and 0.065 mm, respectively.