Effect Of Different Process Parameters Research Articles

Parametric optimization of fatigue behaviour of hybrid aluminium metal matrix composites

Abstract For various aerospace applications aluminium has emerged as most preferred material due to desirable attributes such as superior strength to density ratio, greater specific strength, better corrosion resistance, high toughness and cost effectiveness. The most desirable characteristics for aerospace materials are ability to withstand elevated temperature and sustain higher fatigue loadings. Current experimental investigation was carried out to explore and optimize fatigue characteristics of hybrid composites developed by infusing particulate reinforcements into aluminium alloy. Eggshell particles (wt% 0.5, 1 and 1.5, average particle size ≈ 60 µm), Silicon Carbide particles (wt% 1, 1.5 and 2, average particle size ≈ 65 µm) and Aluminium Oxide particles (wt% 1.5, 2 and 2.5, average particle size ≈ 90 µm) were reinforced into Al 7075-T6 metal matrix through electromagnetic stir casting route as per L9 orthogonal array of Taguchi’s approach in order to synthesize hybrid aluminium metal matrix composites with enhanced fatigue resistance. Analysis of variance (ANOVA) was also conducted to observe the effect of different process parameters on fatigue life of developed composites. Nine hybrid composite specimens and one as-cast Al7075 -T6 specimen (in three replications) were prepared in accordance with ASTM E 468/606 and were evaluated for low cycle fatigue resistance at a constant load of 2 kg and constant speed of 500 rpms on rotating beam fatigue testing machine. It was observed that at 30 °C temperature, hybrid composite specimens exhibited significant enhancement in fatigue resistance in terms of reversible load cycles survived. The as-cast Al 7075-T6 specimen sustained only 94 load cycles while the highest number of load cycles i.e. 4560 were survived by hybrid composite specimen with Al 7075-T6 as base metal reinforced with 1.5 wt% of eggshell particles, 1.5 wt% of SiC particles and 1.5 wt% of Al2O3 particles (total reinforcement content only 4.5%) and mechanically stirred for 360 s.

Molecular dynamic simulation and DFT computational studies on the adsorption performances of methylene blue in aqueous solutions by orange peel-modified phosphoric acid

Adsorptive removal of methylene blue dye (MB) from aqueous medium using orange peels treated with phosphoric acid (OP-H 3 PO 4 ) was examined. The OP-H 3 PO 4 was characterized using Fourier transform Infra-red spectroscopy, X-ray diffraction, scanning electron microscopy, Energy Dispersive X-ray Spectroscopy, and thermogravimetric analysis. The effect of different process parameters, namely contact time, initial dye concentration, initial solutions pH, and temperature effect were examined. Equilibrium experimental data were fitted by Langmuir, Freundlich, Redlich-Peterson (R-P) and Sips isotherm models. For the two-parameter models, the data fitted well with the Langmuir isotherm model suggesting a monolayer adsorption of the dye onto the homogeneous adsorbent surface. However, regarding the three-parameter models, for the whole temperature range, both the sips and the Redlich-Peterson models showed high correlation factors, indicating that calculated data were close to those found experimentally and suggesting that MB adsorption occurs on both homogeneous and heterogeneous surfaces of OP-H 3 PO 4 The present study revealed that OP-H 3 PO 4 is an effective and efficient adsorbent for the removal of basic dyes from aqueous solution. In addition, quantum chemical calculations realized with density functional theory (DFT) method were successfully considered to correlate the experimental results. Moreover, the molecular dynamics simulations (MDS) were used to simulate the interactions between the MB molecule and the OP-H 3 PO 4 (110) surface, indicating that the MB molecule adsorbs onto the OP-H 3 PO 4 (110) surface in a nearby horizontal position. • High adsorption potential of OP-H3PO4, about 307.63 mg/g at 25 °C. • Adsorption kinetics shows that the pseudo-second-order model was the most reliable to describe experimental data. • The equilibrium data indicates that both Sips and Langmuir models could represent the MB uptake onto OP-H 3 PO 4. • The results of the ionic strength effect showed that the competition between the MB dye and the Na + ions led to a decrease in the amount adsorbed.

Sensitivity Analysis of Laser Quenching Parameters of ASTM 1045 of Disk Laser Based on Response Surface Method

Laser hardening is an important branch of laser surface hardening technology, which is widely used in metallurgy, transportation, machinery manufacturing, aerospace and other fields. At present, relying entirely on experience or process trial-and-error method, it can not effectively reveal the transient mechanism of laser quenching of disk laser, which is not conducive to shortening the research and development cycle and saving costs. The numerical simulation provides an effective way to obtain the dynamic evolution law of multi-field coupling in laser quenching process. In this paper, a thermo-mechanical coupling model of ASTM 1045 laser quenching process by disk laser is established. In the model, the temperature-dependent physical parameters were calculated by CALPHAD method. The transient law of temperature and microstructural transformation during quenching was obtained by solving the model. The formation and transformation degree of martensite were characterized by the dynamic changes of the depth and width of quenched transformation layer. The quenching structure and transformation hardening law were observed by Axioskop 2 SEM and Zeiss-IGMA HD FE-SEM to verify the accuracy of the simulation results. On this basis, the process parameters of laser quenching were sampled by Monte-Carlo method based on response surface methodology. The sensitivity effects of different process parameters on the temperature field and phase change field of laser quenching were analyzed, which laid a theoretical foundation for the optimization of process parameters. (1) Establish a thermo-mechanical coupling model for quenching process of ASTM 1045, and the sensitivity of the system is calculated. (2) The model can accurately reproduce the transient process of temperature and phase transformation field during laser quenching. (3) The laser power and laser incident angle are positively correlated with the response value. (4) The spot diameter and scanning speed are negatively correlated with response value. (5) The model can effectively calculate the sensitivity of laser quenching, predict the width and depth of quenching layer, and optimize process parameters.

Advances in Materials Science and Engineering: Prediction of AISI 304 Stainless Steel Pipe Deformation by FEM Simulation

The high quality standards required for metal forming call for compliance tests aimed to guarantee that such standards are met. Such tests often imply a waste of time and of economic resources. In particular, when stainless steel pipe forming is considered, many factors need to be taken into account. This paper analyzes the effect of different process parameters and geometrical constrains on the cold forming of austenitic stainless steel pipes by the finite element method (FEM). The results of such analysis will allow one to map the effect of different parameters.

Microstructure and properties of Mg–Al–Mn magnesium alloy under shear deformation coupled tension rolling

Shear coupling tension rolling is based on equal diameter angle rolling, which meets the requirements of modern industrial development with high production efficiency and short process. It is of great significance to improve the defects of uneven texture distribution and insufficient grain refinement in continuous casting billet rolling process. In this study, the effects of different reduction rate, circular arc radius and tensile angle of shearing roll on the stress and strain of sheet metal were studied by means of high precision constitutive model and rigid plastic finite element analysis software. At the same time, the effects of different process parameters on the microstructure and mechanical properties of rolled magnesium plate were analyzed. The results show that the larger the single pass reduction rate is, the smaller the arc radius of the shear roll is and the smaller the tensile angle is, the greater the equivalent strain and equivalent stress at the corner are. The higher the reduction rate is, the greater the tensile strength and yield strength are and the smaller the extension is. The smaller the arc radius and tensile angle of the shear roll are, the greater the tensile strength and extension are, the smaller the yield strength is, and the easier it is to form dynamic recrystallization.

Optimization and kinetics of copper cementation from bio-leachate generated during the waste printed circuit board (E-waste) processing

The leach solutions of waste printed circuit boards contain a variety of base as well as precious metals with different concentrations. So, it is necessary to recover such metals for downstream processing of leach solutions. Cementation process is widely used at the industrial scale due to lower operational cost. In the present study, recovery of copper was performed by scrap iron and aluminium as cementing agents. Use of scrap iron resulted in a 99% copper recovery. Effects of different process parameters were studied to achieve maximum copper recovery. Kinetic study of copper cementation showed that the rate-controlling step was diffusion and the activation energy was 38.83 kJ/mol. Using flask data, the scale-up study was carried out with scrap iron for 8 L of the pregnant bio-leach solution. Complete recovery of copper was achieved within 120 min of reaction time in the scale-up study. The purity of recovered copper was 93% after the recovery process. Scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM- EDX) and X-ray powder diffraction (XRD) analysis of recovered copper was performed to characterize the recovered metal.

Effects of initial cell concentration, growth phase, and process parameters on the viability of Lactobacillus rhamnosus GG after spray drying

During spray drying, probiotics encounter several stresses which can reduce their viability. To obtain powder with a sufficient amount of viable probiotics, we evaluated the effects of different process parameters, such as initial cell concentration and the bacterial growth phase, on the viability of the model probiotic Lactobacillus rhamnosus GG. Increasing the initial biomass did not positively impact bacterial viability after spray drying. For growth, we found that stationary grown bacterial cells were more resistant to the spray-drying process than mid-log grown cells, probably owing to an initiated stress response. Furthermore, a full factorial 3³ design was used to assess the influence of three different conditions of inlet temperature, feed rate, and atomizing air flow on the outlet temperature and bacterial viability after spray drying. As expected, inlet temperature had the largest influence on both outlet temperature and log-reduction in bacterial viability. An interaction effect was also observed between feed rate and inlet temperature. Considering the viability of L. rhamnosus GG, the optimal outlet temperature ranged between 50 and 60 °C for obtaining powders with the lowest log-reductions in viability.

Process Optimization for Compression Molding of Carbon Fiber-Reinforced Thermosetting Polymer.

To enhance the quality and mechanical performance of a carbon fiber–reinforced polymer (CFRP) workpiece, this paper prepares a polyacrylonitrile (PAN)-based carbon fiber–reinforced thermosetting polymer (CFRTP) laminated board through compression molding, and carries out orthogonal tests and single-factor tests to disclose the effects of different process parameters (i.e., compression temperature, compression pressure, pressure-holding time, and cooling rate) on the mechanical performance of the CFRTP workpieces. Moreover, the process parameters of compression molding were optimized based on the test results. The research results show that: The process parameters of compression molding can be ranked as compression temperature, pressure-holding time, compression pressure, cooling rate, and mold-opening temperature, in descending order of the impact on the mechanical property of the CFRTP; the optimal process parameters for compression molding include a compression temperature of 150 °C, a pressure-holding time of 20 min, a compression pressure of 50 T, a cooling rate of 3.5 °C/min, and a mold-opening temperature of 80 °C. Under this parameter combination, the tensile strength, bending strength, and the interlaminar shear strength (ILSS) of the samples were, respectively, 785.28, 680.36, and 66.15 MPa.

Selective separation of antimony from a Sb-Fe mixed solution by hydrolysis and application in the hydrometallurgical process of antimony extraction

In this study, the hydrolysis of Sb to form Sb4Cl2O5 from a Sb-Fe mixed solution was first investigated using NH4OH as a neutralizer. The effects of different process parameters on the hydrolysis ratio of antimony, separation coefficient of Sb-Fe and product features were investigated in detail. The results indicated that the hydrolysis ratio of antimony and Fe was higher than 99.0% and lower than 0.1% under the optimized conditions: hydrolysis temperature of 30 °C, final pH of 0.5, and neutralizer dropping speed of 1.33 mL/min. The residual content of Sb was 0.12 g/L, and the hydrolysis exhibited high selectivity and completeness. Then, the Sb4Cl2O5 generated was further converted to Sb2O3 by using Na2CO3, NaOH and NH4OH as conversion agents. The antimony oxide product had an excellent crystal form and high purity. Lastly, this hydrolysis - transformation method was applied for Sb recovery from a post-electrowinning solution obtained from a wet Sb smelter that showed a continuous increase in Fe iron concentration caused by Fe ore leaching in stibnite, and an open loop for solution purification must be used. High purity (above 99.5%) and fine (below 100 μm) Sb2O3 was obtained that met commercial antimony white standards.

Finite-element simulation of melt pool geometry and dilution ratio during laser cladding

To analyze the influence of processing conditions on the melt pool geometry and dilution ratio of the Ni-based alloy during laser cladding, a finite element model of heat transfer and fluid flow with multi-physical parameters was established. This model is used to simulate the temperature and velocity fields of melt pool. Thermodynamic processes such as phase transition, Marangoni convection and buoyancy were considered in this model. Adding materials in real time was considered by introducing powder feeding rate. The relative energy–mass ratio (REMR) was introduced to simplify process analysis, and the effects of different processing parameters on the dilution rate and on the melt pool geometry were explored through the established model. The results show that dilution ratio and REMR are linearly related within a certain range. In addition, due to the fluid flow, the boundary at bottom of melt pool changes gradually from shallow arc shape to wave shape, and finally to deep arc shape with increased REMR.

Evaluation of the Effect of different Process Parameters of Air Curtain through CFD Analysis

Evaluation of the Effect of different Process Parameters of Air Curtain through CFD Analysis

Optimizing reactive ion etching to remove sub-surface polishing damage on diamond

Low defect smooth substrates are essential to achieve high quality diamond epitaxial growth and high performance devices. The optimization of the Ar/O2/CF4 reactive ion etching (RIE) plasma treatment for diamond substrate smoothing and its effectiveness to remove subsurface polishing damage are characterized. An O2/CF4 RIE process and the effect of different process parameters (inductively coupled plasma, platen power, and pressure) were initially examined. This process, however, still produced a detrimental effect to surface roughness, with etch pits across the surface of the sample. The addition of argon to the process achieved near-zero surface pit density and reduced roughness by 20%–44% after 6 and 10 μm etching. Iterative high-resolution X-ray diffraction measurements provided a nondestructive tool to examine the effectiveness of polishing damage removal and in this case reduced after removal of 6 μm of material from the surface of the diamond substrate with the smoothing treatment.

Effect of the Process Parameters on Machining of GFRP Composites for Different Conditions of Abrasive Water Suspension Jet Machining

The selection of parameters for abrasive water suspension jet (AWSJ) machining of GFRP composites is a major aspect to be considered for optimizing the process. Generally, machining of plastics, polymer matrix composites are accomplished by the AWSJ machining carried out in the presence of atmospheric air; however, the existence of air around the AWSJ may lead to expansion of jet which results in increase in the kerf width and surface roughness; thus to overcome this drawback, an effort has been made in the current work to compare the effect of different process parameters on kerf width and surface roughness while using AWSJ techniques for machining glass fibre-reinforced plastic composite submerged in water. The exploratory outcomes have herewith validated the fact that the surface roughness and kerf width diminishes in under water machining when contrasted with that of free air machining; this is majorly attributed to the fact that the jet diameter reduces in under water AWSJ machining, thereby reducing the kerf width and surface roughness for optimized values of the parameters of speed, feed and standoff distance. Further, the experimental trials have clearly shown that the AWSJ machining used with an optimized set of parameters yields better machining capabilities as compared to abrasive water jet machining.

Degradation of Reactive Dye in Aqueous Solution by Fenton, Photo-Fenton Process and Combination Process with Activated Charcoal and TiO2

In the present work, a comparative efficiency of photo-Fenton (PF) treatment process and its combined process with activated carbon (AC) and titanium dioxide (TiO2) have been investigated using reactive yellow 145 as a model compound. These processes are based on in situ production of hydroxyl radical, a highly strong oxidant, which allows the degradation of organic dye until their mineralization into CO2 and H2O. The effect of different process parameters, such as initial dye concentration, pH of the solution, Fe2+ concentration, catalyst and adsorbent loadings, and effect of various systems and irradiation times have been studied. The degradation of the dye was monitored by decolorization and COD analysis and then analyzed by high-performance liquid chromatography and IR analysis. Obtained results showed that PF combined with titanium dioxide (PF-TiO2) for removal of TOC was more efficient than PF or combination with AC. About 73.7% of TOC removal was obtained after 240 min of UV–F–TiO2 process, whereas the PF and UV–F–AC process yielded TOC reduction of 61.5% and 54.8% after 240 min. Mineralization studied reveals that effectiveness of treatment processes for RY145 is UV–F–TiO2 > PF > UV–F–AC > F–AC > F–TiO2.

The effect of the number of passes in friction stir processing of aluminum alloy (AA6082) and its failure analysis

Abstract Friction stir processing (FSP) is a technique based on micro-structural modification. Though this concept attracts the attention of the researchers, there arise a necessity of deep investigation in many areas to understand the changes and failure caused by the process. To achieve the required micro grain size, few process attributes like tool geometry, rotational speed, transverse speeds, etc., are to be regulated. The defects, especially tunnel voids can be greatly reduced by identifying the adequate process parameters. The reason for such defect is due to inadequate heat supply during processing and dynamic recrystallization. In this study, FSP of aluminum AA6082 alloy is performed to investigate the effect of different process parameters, such as number of passes and tool rotational speed. Mechanical and microstructure analysis of the specimens were conducted to determine the changes in the properties of the aluminum alloy. Temperature distribution was also monitored using infrared (IR) camera to determine the temperature intensity in degrees at limited points. The results show that the heat generation increases when rotational speed increases. Hardness and tensile strength were tested across the FSP processed zone. After FSP, the microstructure of the alloy is found to be exceedingly refined. However, FSP causes minuscule improves the hardness of the material, whereas the tensile and impact strength improves significantly.

Enhancing natural gas dehydration performance using electrospun nanofibrous sol-gel coated mixed matrix membranes

The dehydration process of natural gas was investigated by mixed matrix membranes (MMM), which were fabricated by electrospinning and sol-gel coating methods. Silica and titania nanoparticles (NPs) were incorporated into the polymer matrix via sol-gel method. The fabricated MMMs were characterized by field emission electron microscopy (FESEM), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). Dehydration tests were carried out for wet pure methane and natural gas streams individually. The effects of different process parameters, including feed and sweep gas flow rates, moisture content in the feed, feed pressure and other hydrocarbons in the feed were investigated. The prepared electrospun nanofibrous supports (ESNS) have smaller fiber diameters in comparison to previously reported works, and with regard to the commercially available materials, contribute to higher water vapor permeation. The results showed that by increasing the feed pressure from 2.5 to 15 bar for the membranes without NPs, the permeance of methane and water vapor was decreased by 8.2 and 29%, respectively. It was also observed that the permeance of heavier hydrocarbons in Pebax 1657 membrane is higher than methane, leading to the increase of H2O/CH4 selectivity and the loss of heavier hydrocarbons. Finally, determining the resistances of the support and selective layers based on the existing empirical relations demonstrated that the total resistance to water vapor transmission had decreased by 75.2% using ESNS instead of microporous supports (MPS). In addition, the contribution of support layer resistances was decreased from 67% in MPS membranes to less than 30% in ESNS ones.

Evaluation of Maghemite-Rich Iron Oxide Composite Prepared from Magnetite as Adsorbent for Gold from Chloride Solution

The capacity and effectiveness of a composite magnetic iron oxide, consisting mainly of maghemite $$ (\gamma {\text{Fe}}_{2} {\text{O}}_{3} ) $$, prepared by oxidation of synthetic magnetite at 350°C have been evaluated. X-ray diffraction analysis of the synthesized product indicated an iron oxide with 44%, 33%, and 23% of maghemite, hematite (Fe2O3), and magnetite (Fe3O4), respectively. The produced composite material was used in this study as adsorbent to recover gold from chloride solution. The effects of different process parameters, such as solution pH, contact time, chloride ion concentration, and initial Au concentration, on the recovery of Au were studied. Almost all Au in solution (99.78%) was recovered at pH of about 6.5 after 24 h of contact time. The maximum Au uptake of about 11.5 µmol/g was obtained at initial Au concentration of 3.5 × 10−4 mol/L. No significant difference in Au uptake was observed upon increasing the contact time to 48 h. High chloride concentration was found to be detrimental to Au recovery. These results indicate that the prepared maghemite-rich iron oxide composite is more effective than synthetic magnetite reported in previous studies for recovery of Au from chloride solution.

Effect of different process parameters on non-metallic inclusions during electro-slag remelting of a tempering steel

The remelting behavior of the tempering steel 50CrMo4, was investigated with several experimental melts on a lab-scale ESR-plant. The investigated parameters included a variation of the slag compositions and the use of a protective nitrogen atmosphere. Variations of the slag composition comprised slags with different contents of CaF2, CaO and Al2O3 as well as a variation of the SiO2-content. The remelted ingots were forged and analyzed regarding their chemical composition as well as their distribution and composition of the non-metallic inclusions (NMI) by automated SEM-EDX method. The chemical composition of the slag after remelting was analyzed as well. The results clearly show a relationship mainly of Si and Al in the steel with the process parameters. NMI changed in their total amount, type and size distribution. The protective atmosphere reduced the Si-losses during remelting. The majority of the NMI were of the Al2O3- & MnS-type. In general, remelting lead to an almost complete removal of sulfides, a reduction of oxisulfides and a shift towards more oxides. The total amount of NMI was most strongly reduced by the high CaF2-containing remelting slag.

Surface roughening of Al2O3/Al2O3-ceramic matrix composites by nanosecond laser ablation prior to thermal spraying

Al2O3/Al2O3 ceramic matrix composites are candidate materials for high-temperature applications such as gas turbines. As water vapor corrosion of Al2O3/Al2O3-CMC (ceramic matrix composite) is a major issue, the application of suitable environmental barrier coatings is inevitable. An important factor for coating adhesion, especially in thermal spraying, is mechanical interlocking. Therefore, a rough substrate surface is needed. Although it has been proven that laser ablation is a suitable method for surface preparation of metallic substrates, no studies on Al2O3/Al2O3-CMCs are available. Therefore, the suitability of surface preparation of an Al2O3/Al2O3-CMC by laser ablation for use prior to atmospheric plasma spraying was examined. The laser ablation threshold fluence for Al2O3/Al2O3-CMC was determined. The effects of different processing parameters on the surface were studied. Various surface morphologies were obtained, such as cauliflower and honeycomb structures. The samples were characterized by white light interferometry, laser microscopy, and scanning electron microscopy. The obtained surface structures were coated with Gd2Zr2O7. It was found that the adhesion strength of coatings on laser treated samples was drastically increased.

Parameters of cold pilgering of seamless steel tube

As the process parameters of pilger cold-rolled seamless steel tubes are basically based on experience leading to the generation of defects, 304 stainless steel was chosen and the important process parameters including the feed, rotation angle and Q value (the ratio of the length of the deformation section to that of the finishing section) were selected to analyze the effect of different process parameters on the tube forming process and rules. The results show that during the cold rolling process, the rolling force, the equivalent stress of the tube, the residual stress and the springback of the external diameter increased with the increase in the feed rate and the rotation angle and the decrease in Q value. Increasing the feed quantity and decreasing Q value will lead to the decrement in the roundness of the pipe. After comprehensive evaluation of the advantages and disadvantages, a set of optimal parameters are selected to carry out the experiment. The residual stress and the outer diameter of the finished products were measured. The results of the measurement and the numerical simulation results are within reasonable range, and the accuracy of the numerical simulations and the influence of the process parameters on the pilger cold rolling are further verified.