Desirability Function Analysis (DFA) in Multiple Responses Optimization of Abrasive Water Jet Cutting Process

This paper introduces optimization of machining parameters for high-pressure abrasive water jet cutting of Hardox 500 steel utilizing desirability function analysis (DFA). The tests were carried out according to the orthogonal matrix (Taguchi) L9. The control parameters of the process such as pressure, abrasive flow rate, and traverse speed was optimized under multi-response conditions namely cutting depth and surface roughness. The optimal set of control parameters was established on the basis of the composite desirability value obtained from desirability function analysis and the significance of these parameters was determined by analysis of variance (ANOVA). The effects show that optimal sets for high cutting depth and small surface roughness is high pressure, middle abrasive flow rate, and small traverse speed. A confirmation test was also leaded to validate the test results. Results of the research have shown that machining efficiency at keeping good level quality of cut surface can be improved this approach.

Effect of chamfer width and chamfer angle on tool wear in slot milling

The tool geometry is generally of great significance in metal cutting performance. The response surface method was used to optimize chamfer geometry to achieve reliable and minimum tool wear in slot milling. Models were developed for edge chipping, rake wear, and flank wear. The adequacy of the models was verified using analysis of variance at a 95% confidence level. Each response was optimized individually, and the multiple responses were optimized simultaneously using the desirability function approach. The Monte Carlo simulation method was applied to tolerance analysis. All milling tests were conducted at dry conditions; the chamfer width and the chamfer angle varied between 0.1 and 0.3 mm, and 10 and 30°, respectively. Optimal chamfer geometry for minimizing chipping and rake wear was small chamfer width and chamfer angle. The flank wear reached the minimum value for the tool with 0.18 mm chamfer width and 10° chamfer angle. The obtained composite model predicted good edge strength and minimum overall wear when the chamfer was 0.1 mm wide at a 10° angle. Thermal cracks were observed on the tools. They were small on the edges with the finest and least negative chamfer but were more significant on the more negative and greater chamfer. A great chamfer width and chamfer angle also resulted in insufficient chip evacuation. The results show how the edge geometry affects the tool’s reliability and wear and may help manufacturers minimize tool cost and downtime.

Maximization of Tensile Strength of Aluminum 6061 Alloy T6 Grade Friction Welded Joints by Using the Desirability Function

Various joining techniques are consistently used in fabrications and maintenance applications of numerous parts in manufacturing industries. Typically, the friction welding technique acquired attention in joining of aluminum and its different alloys for very general structural usages in small to medium to large-scale manufacturing sectors. This is an experimental attempt to weld aluminum 6061 alloy T6 grade of 3mm thickness metal sheets. The hexagonal-shaped steel pin of grade H13 is used. The experiment is performed by using the Taguchi L9 approach, and nine welded specimens are prepared. The chosen factors are rotating speed of the tool, tilting angle, and feed. After the welding, the tensile testing is followed for the measurement of strength of the welded samples. The analysis suggested that the chosen working limits of feed and rotational speed is significant and having impacts on weld strength. The maximum strength is obtained as 212MPa when the ranges of above said factors are 560RPM, 0degree, and 20mm/min.

Application of Box–Behnken Design and Desirability function in the Optimization of Aceclofenac-Loaded Micropsonges for Topical Application

Background: The aim of the present investigation was to develop optimized Aceclofenac-loaded microsponges using Box-Behnken design (BBD) and desirability function. Material and Method: Aceclofenac-loaded microsponges were developed using ethyl cellulose, ethanol and polyvinyl alcohol (PVA). Initially, a trial batch was developed using quasi-emulsion solvent diffusion method, and by optimizing the drug-polymer ratio. A 3-level, 3-factor BBD was used to investigate the effect of PVA, ethanol and stirring speed on particle size and entrapment efficiency (EE). The models used for the optimization were analyzed through ANOVA and diagnostic plots. Finally, the desirability function was used for the selection of optimized formulation composition. Results: A drug-polymer ratio of 1.5:1 was taken as optimized ratio for all the formulations. The developed microsponges were of the spherical shape having size and %EE in the range of 22.54±2.85 µm to 49.08±5.01 µm and 70.57±4.19% to 86.43±2.58 %, respectively. The amounts of PVA, ethanol and stirring speed were noted to have a significant impact on particle size and %EE. Finally, an optimized formulation (size-22.69 and %EE-86.42) was developed with a desirability value of 0.9967. Conclusion: The BBD is a valuable tool for the development of optimized microsponges with desired properties.

Optimization and Sensitivity Analysis of the Cutting Conditions in Rough, Semi-Finish and Finish Honing

Honing processes are currently employed to obtain a cross-hatched pattern on the internal surfaces of cylinders that favors oil flow in combustion engines or hydraulic cylinders. The main aim of the present paper is to optimize the machining conditions in honing processes with respect to surface roughness, material removal rate and tool wear by means of the desirability function. Five process variables are considered: grain size, density, pressure, linear speed and tangential speed. Later, a sensitivity analysis is performed to determine the effect of the variation of the importance given to each response on the results of the optimization process. In the rough and semi-finish honing steps, variations of less than 5% of the importance value do not cause substantial changes in the optimization process. On the contrary, in the finish honing step, small changes in the importance values lead to modifications in the optimization process, mainly regarding pressure. Thus, the finish honing phase is more sensitive to changes in the optimization process than the rough and the semi-finish honing phases. The present paper will help users of honing machines to select proper values for the process variables.

Improving the technology of rolling rail steels by a comprehensive optimization parameter

The authors have developed a technique for improving the rolling modes of rail steels based on a complex optimization parameter. The technology of rolling rail profiles in the roughing stands of rail-and-structural steel mills and the technology of rolling ball blanks and grinding balls from the rejection of continuously cast blanks of rail steels are selected as the methodology objects. The generalized optimization parameter is the generalized Harrington desirability function, which depends on the partial desirability indicators according to the criteria of energy efficiency, quality of rolled products, material conservation and mill productivity. The share of influence of the listed partial optimization criteria on the generalized desirability function is taken into account by using weighting coefficients. Justification of the coefficient values is based on the results of a comparative analysis of reserves for reducing costs or losses in value terms. An algorithm for applying the technique has been developed. The analysis and generalization of the available initial data and additional research were carried out as a part of the first block. These studies are aimed at obtaining justified analytical dependencies of particular optimization criteria and measured rolling parameters. The second block is justification of the specific direction of rolling modes, the choice of which is carried out on the basis of checking the compliance of boundary conditions. The third block includes development of the parameters of the new rolling mode and assessment of its applicability and effectiveness. The fourth block involves pilot testing of a new rolling mode in the conditions of an existing rolling mill and if it is necessary, adjusting the methodology for determining the forecast values of the measured indicators. With the use of the developed methodology, the modes of rolling of railway and sharp rails in the roughing stands of universal rail-and-structural steel mill of JSC “EVRAZ ZSMK” were improved, and the mode of rolling grinding balls from the rejection of rail blanks at the cross-screw rolling mill of JSC “GMZ” was changed. There is a significant improvement in the quality, technical and economic indicators, which indicates the effectiveness of the developed methodology.

КОМПЛЕКСНЫЙ АНАЛИЗ СОСТОЯНИЯ РЕГИОНАЛЬНОЙ СОЦИО-ЭКОЛОГО-ЭКОНОМИЧЕСКОЙ СИСТЕМЫ (НА ПРИМЕРЕ НИЖЕГОРОДСКОЙ ОБЛАСТИ)

In order to assess the state of affairs in a region with account for the economic, socio-demographic and environmental aspects, to find out the causes of backwardness, and to work out ameliorating measures, it is reasonable to regard each administrative-territorial unit (ATU) as an integral socio-environmentally-economic system (SEES). ATUs in the Nizhegorodskaya Oblast were chosen to evaluate the suggested approach to integral analysis of SEES conditions and developmental degree. The approach implies calculating the values of the generalized desirability function (GDF) and their assessment using principal components and SWOT analyses. The calculated GDF values for the years 2016–2018 made it possible to distinguish leaders and outsiders among ATUs. Among all ATUs, 78% fall into the two lower classes of GDF gradation, which means that conditions are poor there. The results were confirmed by statistical analysis and were interpreted analytically using SWOT analysis. The suggested methodology makes it possible to distinguish “pain spots” and “points of increase” and correct decision making aimed to promote sustainable development at a regional level.

Prediction and Compensation of Color Deviation by Response Surface Methodology for PolyJet 3D Printing

PolyJet 3D printing can produce any color by mixing multiple materials. However, there are often large deviations between the measured color of printed samples and the target color (when the target color is used as the specified color in the printer software). Therefore, to achieve a target color on a printed sample, the specified color in the printer software should not be the same as the target color. This study applies response surface methodology (RSM) to determine the optimal color specification to compensate for color deviations of the measured color of printed samples from the target color in PolyJet 3D printing. The RSM has three steps. First, a set of experiments are designed for a target color according to central composite design. Second, the experimental data are used to develop a second-order multivariate multiple regression model to predict the deviation between the measured color and the target color. Third, the optimal color specification (often different from the target color) is determined by using the developed predictive model and the desirability function. When the optimal color specification is used as the specified color in the printer software, the deviation between the predicted color of the printed sample and the target color is minimized. The proposed method is applied to four target colors to demonstrate its effectiveness. The results show that the proposed method performs better than the conventional color specification method without compensation in achieving the four target colors by 33% on average.

Modelling and Optimizing the Removal of Methylene Blue by a Mixture of Titaniferous Sand and Attapulgite Using Complete Factorial Design

This paper focuses on the removal of methylene blue by adsorption using a mixture of titaniferous sand and attapulgite. The different adsorbents were characterized by X-ray fluorescence spectroscopy and their different parameters such as pH, zero charge potential, and specific surface area were determined. The experiments performed were optimized and modeled by a full 2-level and 4-factor design. The four factors are the ratio of titaniferous sand and attapulgite, the concentration of methylene blue, pH, and time. These vary from 4 to 19, 20 to 100 mg/L, 2 to 9, and 30 to 150 min respectively. The study of the effects of the different factors showed that the effect of methylene blue concentration and pH significantly influence the adsorption capacity and removal efficiency of the dye. The optimum parameters (adsorbent ratio, adsorbate concentration, pH and time) obtained for the adsorption capacity through the desirability function are: 19, 100mg/L, 9 and 150min. Those obtained for the yield are: 4, 100mg/L, 9, 150min. The pseudo second order adsorption kinetics gave an equilibrium adsorption capacity qe (calculated) = 7.6863 mg/g which is almost equal to that obtained experimentally qe (exp) = 7.3562 mg/g. This shows that the pseudo second order kinetic model is the adequate mathematical model to describe the methylene blue adsorption phenomenon on the mixture of titaniferous sand and attapulgite. The thermodynamic study showed that the methylene blue adsorption reaction is exothermic, non-spontaneous, and the degree of disorder of the particles at the adsorbing surface decreases.