Selection Of Process Parameters Research Articles

Closed-Loop Process of Extracting and Separating Zinc Impurities from Industrial Cobalt Products—Pilot Test Study

The cobalt-containing products of an enterprise were selected as the object of this study. The separation effect of Cyanex 272 on Zn and Co was studied through a pilot test. The results showed that Cyanex 272 had a high extraction rate for Zn at pH 3–3.4, up to 99.8%. The extracted Zn2+ was enriched in the organic phase, and the Zn2+ in the organic phase was extracted back into the aqueous phase in the stripping stage by adding strong acid. Addition amounts of strong acid of 50 g·L−1, 80 g·L−1, and 100 g·L−1 were set. The results showed that the addition amounts of 80 g·L−1 and 100 g·L−1 could significantly reduce the pH of the back-extraction solution and effectively enrich Zn2+ in the solution. There was a large amount of Zn2+ in the back-extraction solution, which could be used twice to prepare zinc carbonate products through neutralization and precipitation. By comparing the extraction effect, economic cost, and resource loss under different strong acid addition amounts, it was found that the 80 g·L−1 strong acid addition amount was more suitable for the actual production process. This study provides data support and practical evidence for the selection of industrial extraction process parameters for Zn2+ separation in actual cobalt products.

Crystallization modeling of two semi-crystalline polyamides during material extrusion additive manufacturing

In this work, a heat transfer model is developed for thermally-driven material extrusion additive manufacturing of semicrystalline polymers that considers the heat generated during crystallization by coupling crystallization kinetics with heat transfer. The materials used in this work are Technomelt PA 6910, a semicrystalline hot melt adhesive with sub-ambient glass transition temperature (Tg) and slow crystallization, and PA 6/66, a traditional semicrystalline polyamide with a higher Tg and fast crystallization. The coupled model shows that the released heat during crystallization depends on material selection, with Technomelt PA 6910 and PA 6/66’s temperatures increased by less than 1 °C and up to 6.3 °C, respectively, due to enthalpy of crystallization. Increasing the layer time decreases the layer temperature as well as the initial crystallinity. However, its effect on final crystallinity in Technomelt PA 6910 is negligible due to continued crystallization of the material after printing. Experimental validation shows good agreement for Technomelt PA 6910, but consistently underpredicts PA 6/66 crystallinity. Increasing modeled environmental temperature leads to better agreement with experimental results for PA 6/66, suggesting that higher temperatures may have been experienced. Shear-induced crystallization may also be contributing to crystallinity in this material. The results from this model highlight the importance of and interrelationships between material and processing parameter selection and can aid in achieving quality prints from semicrystalline thermoplastics.

Enhancing EDM Productivity for Plastic Injection Mold Manufacturing: An Experimental Optimization Study.

Electrical erosion molding (EDM) is an unconventional machining technology widely used in the manufacture of injection molds for plastics injection molding for the creation of complex cavities and geometries. However, EDM productivity can be challenging, directly influencing mold manufacturing time and cost. This work aims to improve EDM productivity in the context of mold manufacturing for plastics injection molding. The research focuses on the optimization of processing parameters and strategies to reduce manufacturing time and increase process efficiency. Through a rigorous experimental approach, this work demonstrates that the optimization of EDM parameters and strategies can lead to significant productivity gains in the manufacture of plastic injection molds without compromising part quality and accuracy. This research involved a series of controlled experiments on a Mitsubishi EA28V Advance die-sinking EDM machine. Different combinations of pre-cutting parameters and processing strategies were investigated using copper electrodes on a heat-treated steel plate. Productivity was evaluated by measuring the volume of material removed, and geometrical accuracy was checked on a coordinate measuring machine. The experimental results showed a significant increase in productivity (up to 61%) by using the "processing speed priority" function of the EDM machine, with minimal impact on geometric accuracy. Furthermore, the optimized parameters led to an average reduction of 12% in dimensional deviations, indicating improved geometric accuracy of the machined parts. This paper also provides practical recommendations on the selection of optimal EDM processing parameters and strategies, depending on the specific requirements of plastic injection mold manufacturing.

Research on wafer-level SiC microgroove array process via integrated molding-etching process

Silicon carbide (SiC) microgroove arrays (MGAs) play a pivotal role as optical components in modern optical engineering. This paper introduces an innovative approach for the fabrication of MGAs on hard materials. This method integrates hot embossing (HE) and inductively coupled plasma (ICP), utilizing polydimethylsiloxane (PDMS) as the intermediary mold due to its excellent demolding performance and shape replication qualities. The process involves transferring the MGAs from the Ni-P master mold to the PDMS mold, followed by replication onto the photoresist surface by hot embossing. Subsequently, the MGAs on the photoresist mask is etched into the hard substrate material using ICP etching. For efficient customization of MGAs, a reliable geometrical model based on angular dependence theory is developed to assist in selecting process parameters and designing masks. The correlation between etching selectivity and characteristic dimension is elucidated. Experimental results demonstrate that the sidewall angle decreases with higher selectivity and increases with a greater sidewall angle on the patterned mask. Plasma etching reveals unaffected areas in convex corners and the forming errors in concave corners, highlighting a high angular dependence of the etch rate. Moreover, minimizing microdefects can be achieved by optimizing process parameters and reducing etch time.

A comprehensive validation of GRA with ant colony optimization for robust optimal design: A case study on the forming process

Sheet metal forming design involves numerous factors and controlling all these parameters to prevent cracks is a major challenge to maintain the quality. Therefore, the careful selection of process parameters is critical for ensuring product longevity. Several researchers employed different techniques for optimal selection of process parameters but consistency among the techniques and validation of results in real time scenarios will play a pivotal role in determining the suitable parameters. Therefore, the current work presents a validation method of Grey Relational Analysis (GRA) results with Ant Colony Optimization (ACO) for the robust optimum design with an illustrative example of forming process. Al 6061 – T6 alloy was chosen as a material for deep drawing process and L27 Orthogonal Array was planned to conduct experiments with four input parameters such as blank thickness, Die and Blank Temperature, Die Speed, Lubrication at three levels each. Punch force and Thickness variation were considered as the output parameters. GRA Technique was implemented to find the best optimal combination and regression equation was developed to predict the nature of objective function. These results were given as an input to ACO, a nature inspired algorithm to search for the optimal solution with in the design space. Sensitivity analysis has also been performed to highlight the effectiveness of the proposed solution in terms of solution quality and computational efficiency. The ACO method, GRA technique and the experimental results are almost similar with a margin of acceptable deviation. The results indicated the robustness of the projected approach in achieving the quality of solution.

A hybrid of RSM, ANFIS, and machine learning algorithm approach for ultrasound-assisted extraction of bioactive compounds from Semecarpus anacardium Linn

ABSTRACT Ultrasound-assisted solvent extraction (UASE) was appslied to extract phytoconstituents from Semecarpus anacardium L. The effective extraction parameters were optimized using the Response Surface Methodology (RSM) with Central Composite Face Centered design (CCFC), and the optimization parameters were validated through Adaptive Neuro-Fuzzy Inference System (ANFIS) and Machine Learning (ML) algorithm models. The four independent parameters, i.e. ethanol concentration (X 1: 62–72% v/v), temperature (X 2: 38–48°C), ultrasonic-exposure time (X 3: 12–24 min), and particle size (X 4: 2–5 mm) were optimized. The maximum yield of phytocompounds was achieved at X 1 = 67%, X 2 = 43°C, X 3 = 18 min, and X 4 = 3.5 mm. The optimized yield of total phenolic, flavonoid, and antioxidant activity was considered when selecting process parameters. In this scenario, the optimized yields of total polyphenolic content (y1 = 619.25 mg gallic acid equivalent (GAE)/g), total flavonoid content (y2 = 151.24 mg Quercetin equivalents (QE)/g), free radical scavenging abilities (%DPPH*sc (y3 = 66.41%), and %ABTS*sc (y4 = 56.94%). The LC-MS peaks identify the presence of semecarpetin, butein, and amentoflavone, whereas GS-MS peaks represent seventeen gaseous components. Furthermore, the bioactive-rich optimized extract was nontoxic and supported the growth of macrophage- and epithelial cells in vitro. Conclusively, optimizing the UASE parameters enhanced the yield of bioactive compounds of S. anacardium L.

On the feasibility of a predictive model of mechanical properties of AM Inconel 718 thin wallets produced by DED-LB process monitored with thermal methods

AbstractNickel-based superalloys are widely used in applications requiring resistance to high temperatures and high strain rates. Various additive manufacturing (AM) processes, such as Laser Metal Deposition (LMD), a Directed Energy Deposition (DED) process, can be used to produce these components. The quality of the components depends on the process parameters, so it is crucial to investigate the influence of each parameter and their combinations through extensive experimental campaigns. In this scenario, it would be very important to predict the mechanical properties of the produced components through the online monitoring of the process parameters using non-destructive techniques, such as thermography. The aim of this work was to explore the feasibility to predict the mechanical properties of Inconel 718 thin wallets around 10 mm produced by DED-LB, based on the extraction of suitable thermal features directly during the production. An experimental campaign analysed the effect of different process parameters (laser power, scan speed, powder flow rate, and energy density) on the mechanical properties achieved. All sample production was monitored with an infrared uncooled camera integrated with the laser head moving at the same scan speed. After the process, hardness measurements and tensile tests in both growth directions were carried out for each sample to evaluate the mechanical behaviour of the "as-built" coupons and the influence of selected process parameters. Macrographic analyses of the material structure were performed to determine the morphology of the passes and the degree of overlap between different passes and layers. Various thermal features and statistical models were considered to demonstrate the possibility of establishing a predictive model. The obtained results demonstrated the correlation between the hardness and the apparent temperature assuming a confidence level of 95%, and the possibility of predicting in this sense the final macrostructure and the mechanical behaviour of the printed material considering an empirical model with the R2 coefficient around 0.8.

A HYBRID MEREC-TOPSIS APPROACH FOR THE IMPROVEMENT OF PHYSICAL VAPOUR DEPOSITED TITANIUM CARBO-NITRIDE COATING

Titanium carbo-nitride (TiCN) comes under the metal nitride group which can provide a combined property of titanium carbide (TiC) and titanium nitride (TiN) coating. TiCN Coating possess an excellent mechanical and tribological, properties which leads its application in many industries particularly in the Automotive and aerospace industries. TiCN films can be very hard and strong based on the composition and synthesis process. Physical Vapor Deposition (PVD) technique is widely used for the preparation of thin film coating because of its ability to precisely control the composition and thickness of the coatings. The properties of the developed coating significantly affect by the PVD process parameters and their levels. Multi-Criteria Decision Making (MCDM) methods are widely used in many sectors for the selection of process parameters based upon some specific criteria. In the present work TiCN coatings were synthesized by using one of the most widely used PVD method called magnetron sputtering. L16 orthogonal array was used as a design of experiment for the experimental work by varying the sputtering process parameters like bias voltage, N2 flow rate and substrate to target distance. After the synthesis, the developed films were tested using atomic force microscopy (AFM), Scanning electron microscopy (SEM), and Nanoindentation. From the characterization three response parameters such as hardness (H), Modulus of elasticity (E) and surface roughness (Ra) of the coating has been considered. A hybrid method based on improved removal effects of criteria- technique for order performance by similarity to ideal solution (MEREC-TOPSIS) approach has been considered for the for the process parameters selection. The results have also been compared with other weight calculation techniques. In all the cases it is observed that experiment no 16 and 15 have got the 1st and second rank respectively. However, experiment no 1 is the last rank in all the cases. From the correlation analysis it is found a strong positive correlation between MEREC-TOPSIS and other methods. The method provides a significant advancement in the selection of optimal parameters, ensuring enhanced coating properties crucial for industrial applications.

Non-planar 5-axis directional additive manufacturing of plastics: Machine, process, and tool path

Additive manufacturing (AM) of plastics is a rising research and application area for light weighting. The conventional way of AM is conducted layer-by-layer, whereas recently non-planar AM is proposed with several advantages such as better use of the material through decreased weight-to-strength ratio, reuse of support material and increased conformity for AM of complex shapes. As for all the tool path-based manufacturing processes, generation of the tool path, selection of process parameters and the machine tool configuration significantly affects the product quality. In this study, non-planar AM of plastics is handled in a holistic manner covering tool path, process, and machine perspectives. Tool path generation for non-planar and directional AM is discussed in accordance with the CAD-CAM software, where the tool path is generated using a novel approach which works with the bead directions obtained from FEM based mechanical analysis. The effects of critical process parameters on the geometrical conformity for non-planar AM are discussed through visual inspection. The proposed cluster-based tool path planning is successfully shown demonstrated from the geometrical perspective.

Assessment of recycling and repair methods for discontinuous glass fiber reinforced vitrimer composites with reclaimed parts

In the context of fiber-reinforced polymer composites, the pursuit of sustainability is of paramount importance to promote environmentally responsible practices. Vitrimer materials have recently gained significant attention for their potential to enable repair and recycling, rendering them an attractive choice for manufacturing eco-friendly composites while maintaining mechanical strength akin to a thermoset resin like epoxy. This study specifically focuses on glass fibers, and delves into the examination of mechanical properties using both chemical and mechanical recycling methods for quasi-isotropic, randomly dispersed discontinuous glass fiber-reinforced vitrimer composites. It places specific emphasis on the optimization of factors to promote sustainable production. The findings indicate that chemical recycling methods are remarkably effective, resulting in the almost complete restoration of mechanical properties when appropriately selected process parameters are applied. Additionally, this study investigates diverse repair techniques, with the overlap repair method exhibiting the highest degree of recovery. These findings underscore the remarkable potential of glass fiber reinforced vitrimer composites, characterized by their high mechanical properties, for applications in various industries, particularly in structural contexts. Overall, this study highlights the significant reduction in composite waste achievable through recycling and repair strategies, aligning with the broader goal of advancing sustainability within the domain of engineering and manufacturing.

Enhancement of material properties of SS 316 L base metal by TIG cladding process

The Tungsten Inert Gas (TIG) welding process was utilized to apply stainless steel (SS) 304 filler cladding onto the stainless steel (SS) 316 L base metal. This cladding resulted in an enhancement of the base metal's properties. An optical study and scanning electron microscope (SEM) analysis conducted to investigate the metallurgical properties revealed refined grain structures, indicating improved deposition of the SS 304 filler. The optical survey classified the different zones as base metal, weld metal, and transition line, with the transition line distinguishing the deposition of the filler metal through the cladding process. The refined grain structures, optimal process parameter selection (current, gas flow rate, and travel speed at a minimal level), and double-pass cladding have significantly influenced microhardness and tensile test values. The cladding of SS 304 fillers on SS 316 L alloys demonstrated improvement in the microhardness and tensile properties by 42.5 % and 13.2 %, respectively. Further investigation into the nozzle gun's heat input, current, and travel speed showed that maintaining a consistent travel speed with a steady heat source had a substantial impact on the material properties of the base metal.

Comparative study of the strain and strain rate hardening mechanisms and its workability during hot deformation of TC4 titanium alloys

Localized thinning is one of the main defects in hot forming processes, which is determined by the hardening behaviour during deformation. This study focused on building a hot-workability map to prevent localized thinning in wide ranges (650–950 °C & 0.001–1 s−1) for industrial significance. Insights into the associated strain and strain rate hardening mechanisms were provided by visualizing the microstructure evolutions using both in-situ High-Temperature Laser Scanning Confocal Microscope (HTLSCM) and Electron Backscattered Diffraction (EBSD). Results show that the highest uniform strain, up to 0.250, is achieved in the viscoplastic region due to the cooperative strain and strain rate hardening, where dislocation slip, α/β transformation and grain sliding concurrently occur. Significant grain refinement is also achieved. The optimum forming condition was identified in the viscoplastic region and is further verified by forming an ultra-thin large bend component, reducing thickness unevenness from 18.6 % to 13.1 %. This research finding could aid in understanding the effects of strain and strain rate hardening on forming uniformity and further provide scientific guidance for industrial processing parameters selection, reducing localized thinning and hence scrap rates.

Investigating the friction stir additively manufactured AA2024 build and the influence of material flow in enhancing the inter-surface bonding

Friction Stir Additive Manufacturing (FSAM) is a solid-state joining process that operates below the material’s melting point, avoiding the drawbacks of fusion-based methods. In FSAM, inter-surface bonding is crucial for the build strength and is influenced by material flow at the interface. This study examines the influence of flat-faced (square) and smooth (threaded conical) pins, along with rotational speed, on the material flow, using Al-clad as a tracer. It also analyses the microstructure, micro-texture, mechanical properties of the builds, and the role of the forging force in FSAM. Defect-free builds were achieved with a forging force above 7000 N. The threaded conical pin caused upward migration of Al-clad, while the square pin led to fragmentation and distribution, offering excellent inter-surface bonding. Refined grain structures (∼5 µm) were observed in the top layers. The highest tensile strengths were 392 MPa in the weld direction (80 % build efficiency) with the threaded conical pin, and 358 MPa in the build direction (75 % build efficiency) with the square pin. Strong γ-fiber in ODFs indicates better ductility, with up to 60 % improvement in elongation. The current research shall guide the selection of appropriate process parameters and, in turn, reduce trial-and-error during manufacturing aluminum alloys through friction stir additive manufacturing.

Numerical simulation and analysis on melting characteristics of a solid-liquid phase change process based on hot air riveting

To improve welding efficiency, a hot air riveting technology applicable to simultaneous welding at multiple stations is proposed, with the challenge lying in clarifying the melting state of the weldment. A numerical simulation method is proposed to investigate the melting state of the tag, using the Audi airbag tag as an example. The effects of various process parameters, including the exhaust duct distance, hot air temperature, hot air velocity, and the diameter ratio β, on the melting state of the tag are discussed. The melting mass, internal contour plots of the weldment and the melting rates are compared among the different parameter settings. The results indicate that under a heating temperature of 240 °C, the increase in hot air velocity has the most significant promotional effect on the melting of the weldment. Moreover, regardless of the velocity level, an increase in hot air temperature consistently enhances the melting of the weldment. Concurrently, an increase in the exhaust duct distance has an adverse impact on melting, yet this effect diminishes as the heating temperature rises. Finally, it is observed that at lower temperatures (200 ℃), diameter ratio β = 2.0 is more conducive to melting, whereas at higher heating temperatures (240, 280 ℃), β = 2.5 is more favorable for the melting of the weldment. This method effectively grasps the melting behavior of the weldment, enabling the selection of appropriate process parameters for hot air welding in actual production based on specific requirements.

Wettability Behaviour of Metal Surfaces after Sequential Nanosecond and Picosecond Laser Texturing.

This study examines the wettability behaviour of 304 stainless steel (304SS) and Ti-6Al-4V (Ti64) surfaces after sequential nanosecond (ns) and picosecond (ps) laser texturing; in particular, how the multi-scale surface structures created influence the lifecycle of surface hydrophobicity. The effect of different post-process treatments is also examined. Surfaces were analysed using Scanning Electron Microscopy (SEM), a white light interferometer optical profiler, and Energy Dispersive X-ray (EDX) spectroscopy. Wettability was assessed through sessile drop contact angle (CA) measurements, conducted at regular intervals over periods of up to 12 months, while EDX scans monitored elemental chemical changes. The results show that sequential (ns + ps) laser processing produced multi-scale surface texture with laser-induced periodic surface structures (LIPSS). Compared to the ns laser case, the (ns + ps) laser processed surfaces transitioned more rapidly to a hydrophobic state and maintained this property for much longer, especially when the single post-process treatment was ultrasonic cleaning. Some interesting features in CA development over these extended timescales are revealed. For 304SS, hydrophobicity was reached in 1-2 days, with the CA then remaining in the range of 120 to 140° for up to 180 days; whereas the ns laser-processed surfaces took longer to reach hydrophobicity and only maintained the condition for up to 30 days. Similar results were found for the case of Ti64. The findings show that such multi-scale structured metal surfaces can offer relatively stable hydrophobic properties, the lifetime of which can be extended significantly through the appropriate selection of laser process parameters and post-process treatment. The addition of LIPSS appears to help extend the longevity of the hydrophobic property. In seeking to identify other factors influencing wettability, from our EDX results, we observed a significant and steady rate of increase in the carbon content at the surface over the study period.

Progress in the Study of Quality and Mechanical Properties of Selective Laser Melting Molded Parts

Abstract: Selective laser melting (SLM) is considered to be a widely promising additive manufacturing technology with the advantages of high machining precision, high manufacturing freedom, and short cycle time, which is widely used in aerospace, the integration of medicine, and industry, chemical, and other fields. The research progress on the temperature field, stress field, forming quality, and mechanical properties during the SLM manufacturing process is reviewed. The study aims to systematically analyze how SLM process parameters affect the temperature field, stress field, forming quality, and mechanical properties, and to discuss the importance of the selection of process parameters and performance regulation to achieve high-quality, highperformance metal parts. The effects of SLM process parameters on temperature field, stress field, surface roughness, densification, hardness, strength, and fatigue properties are analyzed and summarized. The importance of process parameters in the SLM forming procedure in the quality of formed components is emphasized, and conducting an in-depth study on the optimization and performance regulation of the process parameters is of great significance in achieving the high quality and performance of metal parts. With the rapid advancement of technology, the potential of SLM technology in terms of molding quality and mechanical performance has become increasingly significant, heralding significant breakthroughs. These potential breakthroughs will greatly promote the widespread application of SLM technology in various industries, thus more efficiently meeting the growing needs and expectations of industries such as petrochemicals, transportation, aerospace, nuclear energy, as well as food and medical sectors.

Heat-dependent properties of methane diffusion in coal: an experimental study and mechanistic analysis.

Coalbed methane thermodynamic extraction, as an emerging ECBM recovery method, can effectively improve gas recovery rates. And clarifying methane diffusion and migration law in coal under thermal stimulation is crucial for the selection of its process parameters. Based on laboratory methane adsorption-release experiments, the evolution law of methane diffusion characteristics with temperature and pressure was studied, and the control mechanism of heat-dependent methane diffusion behavior was explored. The results show that both thermal stimulation and high adsorption pressure accelerated the methane diffusion rate in coal. Adsorption pressure had little effect on methane diffusion percentage, but thermal stimulation promoted a significant increase in diffusion percentage and improved the net methane yield. The influence mechanisms of adsorption pressure and thermal stimulation on methane diffusion characteristics are elucidated in relation to the amount and proportion of methane-activated molecules in the diffusion process. The constant diffusion coefficient of methane is heat-dependent, based on which a diffusion model is derived to accurately predict the methane release process in coal. Additionally, temperature has a more important effect on transient diffusion coefficient than pressure. Thermal stimulation leads to a net increase rather than a decrease in diffusion coefficient in the early diffusion stages and can also accelerate the attenuation of diffusion coefficient, with this intensifying effect becoming more pronounced at higher temperatures. The research results can provide some reference for the determination of coal seam gas content and the selection of heat injection process parameters.

Optimization Analysis of Response Surface for Ultrasonic Welding of Battery Tabs

Abstract The response surface methodology was used to optimize the ultrasonic welding process parameters of battery tabs. The three process parameters of welding pressure, welding energy and welding amplitude were selected as the influencing factors, the peel strength and welding time were selected as the response variables, a three-factor and three-level experimental matrix was designed. The experimental results were analyzed by multiple regression fitting and the regression model was established. The optimal parameters derived from the model were verified. The optimum combination of process parameters is pressure (0.25Mpa), energy (649J) and amplitude (75%) with the goal of maximum peel strength and minimum welding time. The test results show that the relative error is within a reasonable range, and the established response surface model has a higher precision, which provides a certain reference for reasonable selection of ultrasonic welding process parameters for battery tabs.

Process Parameters Optimization and Numerical Simulation of AlCoCrFeNi High-Entropy Alloy Coating via Laser Cladding.

The use of laser cladding technology to prepare coatings of AlCoCrFeNi high-entropy alloy holds enormous potential for application. However, the cladding quality will have a considerable effect on the properties of the coatings. In this study, considering the complex coupling relationship between cladding quality and the process parameters, an orthogonal experimental design was employed, with laser power, scanning speed, and powder feed rate as correlation factor variables, and microhardness, dilution rate, and aspect ratio as characteristic variables. The experimental data underwent gray correlation analysis to determine the effect of various process parameters on the quality of cladding. Then, the NSGA-II algorithm was used to establish a multi-objective optimization model of process parameters. Finally, the ANSYS Workbench simulation model was employed to conduct numerical simulations on a group of optimized process parameters and analyze the change rule of the temperature field. The results demonstrate that the laser cladding coating of AlCoCrFeNi high-entropy alloy with the single pass is of high quality within the determined orthogonal experimental parameters. The powder feed rate exerts the most significant influence on microhardness, while laser power has the greatest impact on dilution rate, and scanning speed predominantly affects aspect ratio. The designed third-order polynomial nonlinear regression model exhibits a high fitting accuracy, and the NSGA-II algorithm can be used for multi-objective optimization to obtain the Pareto front solution set. The numerical simulation results demonstrate that the temperature field of AlCoCrFeNi high-entropy alloy laser cladding exhibits a "comet tail" phenomenon, where the highest temperature of the molten pool is close to 3000 °C. The temperature variations in the molten pool align with the features of laser cladding technology. This study lays the groundwork for the widespread application of laser cladding AlCoCrFeNi high-entropy alloy in surface engineering, additive manufacturing, and remanufacturing. Researchers and engineering practitioners can utilize the findings from this research to judiciously manage processing parameters based on the results of gray correlation analysis. Furthermore, the outcomes of multi-objective optimization can assist in the selection of appropriate process parameters aligned with specific application requirements. Additionally, the methodological approach adopted in this study offers valuable insights applicable to the exploration of various materials and diverse additive manufacturing techniques.

Proposal of trapezoidal vibration-assisted diamond cutting for ductile-regime machining of brittle crystals: A case study on KDP crystal

Despite various vibration-assisted cutting techniques have been utilized to increase the machining performances of brittle materials, the highly dynamic variations of cutting process quantities lead to the complicated brittle-ductile transition (BDT) mechanism and the formation of undesired vibration marks on the machined surfaces. In this paper, a novel ultra-precision vibration-assisted cutting process, named trapezoidal modulation diamond cutting (TMDC), is firstly proposed for ductile-regime machining of brittle materials with significantly increased BDT cutting depth. By imposing a dedicate trapezoidal locus to the diamond tool, the unique invariable uncut chip thickness and cutting states were achieved for realizing stable vibration-assisted cutting without the formations of vibration marks. Systematic cutting experiments of KDP crystals were carried out to comprehensively investigate the influences of different process parameters on the machining performances of TMDC process. In addition, the underlying mechanisms of machining performance improvements have been discussed under the different combinations of process parameters, based on which the guidelines for optimal process parameter selection are given for increasing the BDT cutting depths. The outcomes of this study contribute to not only improving the ductile machining efficiency and machining quality of KDP crystals, but also help to deepen the understandings of BDT mechanism during vibration-assisted diamond cutting of common brittle materials.