Suitable Process Research Articles

Research on the welding process of Q355ND thick plate with narrow gap double wire submerged arc welding

Abstract Aiming at the problems of low welding efficiency and unstable quality of thick plates of marine equipment in offshore deep-water areas represented by offshore wind power, the high-efficiency welding process of narrow-gap double-wire submerged arc welding of 30 mm thick Q355ND low alloy high-strength steel plate was developed by selecting the suitable welding material and welding process parameters. The results show that the welded joint has a beautiful appearance, well-fused sides, and no defects. The structure of the heat-affected zone of the joint is mainly composed of pro eutectoid ferrite, acicular ferrite, bainite, and a small amount of pearlite. The center of the seam is composed of a large amount of massive ferrite and a small amount of bainite. The average tensile strength of the joint reaches 536.5 Mpa, and the average impact energy of the weld center at -20°C reaches 48.4 J. The average impact energy of the heat-affected zone reaches 164 J. All physical and chemical performance tests meet the standard requirements. The development of welding processes has important practical significance for improving production efficiency and product quality. It will be widely used to construct offshore wind power towers, offshore platform jackets, and other offshore deep-water engineering equipment.

Influence of Excitation Parameters on Finishing Characteristics in Magnetorheological Finishing for 6063 Aluminum Alloy.

The present work is aimed at studying the effects of the magnetorheological finishing process, using a low-frequency alternating magnetic field, on the finishing performance of 6063 aluminum alloy. The study investigates the influence of key excitation parameters such as current, frequency, excitation gap, and iron powder diameter on the material removal and surface roughness (Ra) of the finished workpiece by experiments. This study employs a single-factor experimental method, and the finish surface is analyzed by a Zigo non-contact white light interferometer. The magnetic field strength in the processing area increases with the increase in the excitation current and decreases with the increase in the excitation gap. When the current frequency is set to 1 Hz, the circulation and renewal of abrasives in the magnetic cluster is most sufficient, resulting in the optimal surface roughness value for the workpiece. According to the experimental results of the excitation parameters, more suitable process parameters were selected for a two-stage finishing experiment. The surface roughness of 6063 aluminum alloy was improved from 285 nm to 3.54 nm. Experimental results highlighted that the magnetorheological finishing using a low-frequency alternating magnetic field is a potential technique for obtaining nano-scale finishing of the 6063 aluminum alloy.

The Characteristics of Polyester Concrete with Local Sand of East Borneo as Filter

Concrete is a mixture of coarse aggregate and fine aggregate mixed with water and cement as a binder and filler. The disadvantages of traditional concrete are that high water absorption causes low chemical resistance, low modulus of elasticity, low impact strength and a long hardening time to reach its maximum properties, namely 28 days. The solution to these shortcomings that is being developed for construction material applications is by using polymers as polymer concrete. In this research, polyester resin and sand aggregate were used as basic materials. Polyester resin is a type of thermosetting polymer that is widely used in various applications such as automotive parts, composites and construction because of its suitable processing characteristics and affordable price. Meanwhile, the sand used is local Kalimantan sand, where from the XRF and XRD test results, local Kalimantan sand is included in the silica sand type. This research varies the weight fraction of polyester resin used to determine its effect on polymer concrete characteristics such as porosity, water absorption, compressive strength, and macro observations. Variations in the polymer weight fraction used were 20%, 25% and 30%. Compressive strength testing was carried out at the age of 7 days of concrete. The results of the porosity test show that the average porosity of all variations is ± 0.5%. Meanwhile, the average value of water absorption for all fractions is 0.2%. And the highest average value of compressive strength in the 30% polyester resin weight fraction was 66.9 MPa. So it can be concluded that all variations meet SNI standards to become concrete materials.

Exploring FAST Technique for Diffusion Bonding of Tungsten to EUROFERE97 in DEMO First Wall.

The European Fusion Reactor (DEMO, Demonstration Power Plant) relies significantly on joining technologies in its design. Current research within the EUROfusion framework focuses on developing materials for the first wall and divertor applications, emphasizing the need for suitable joining processes, particularly for tungsten. The electric field-assisted sintering technique (FAST) emerges as a promising alternative due to its high current density, enabling rapid heating and cooling rates for fast sintering or joining. In this study, FAST was employed to join tungsten and EUROFERE97 steel, the chosen materials for the first wall, using 50-µm-thick Cu foils as interlayers. Three distinct joining conditions were tested at 980 °C for 2, 5, and 9 min at 41.97 MPa to optimize joint properties and assess FAST parameters influence. Hardness measurements revealed values around 450 HV0.1 for tungsten, 100 HV0.1 for copper, and 390 HV0.1 for EUROFER97 under all joining conditions. Increasing bonding time improved joint continuity along the EUROFER97/Cu and W/Cu interfaces. Notably, the 5 min bonding time resulted in the highest shear strength, while the 9 min sample exhibited reduced strength, possibly due to Kirkendall porosity accumulation at the EUROFER97/Cu interface. This porosity facilitated crack initiation and propagation, diminishing interfacial adhesion properties.

Design and Effect Evaluation of a Hydrogen–Natural Gas Mixing Device at Jingbian Compressor Station

Abstract Hydrogen gas is an environmentally friendly alternative energy source with zero emissions, making it highly valuable for replacing fossil fuels and reducing carbon emissions. One effective method of transporting hydrogen gas is by injecting it into existing natural gas pipelines. In this research, we focus on the Jingbian compressor station. This station is used for hydrogenation, blending hydrogen with the natural gas flowing through the pipelines. We propose a suitable process for hydrogen blending and design a mixing device to facilitate this process. To evaluate the mixing effect of the blended gas, we conducted numerical simulations to analyze the velocity and concentration distribution along the continuous section of the hydrogen blending pipeline. The results indicated that achieving a hydrogen branch length of 1/2 the diameter of the natural gas main pipe and a hydrogen flowrate of 10% resulted in a nonuniformity of hydrogen concentration at L = 30D of less than 0.05. Furthermore, when the hydrogen concentration was set at 3%, 10%, and 30%, the hydrogen concentration in the cross section of the pipe gradually approached the expected concentration as the mixed gas flowed. It is worth noting that during transportation of hydrogen-containing natural gas to the outlet, the velocity distribution on the cross section remained asymmetric, potentially leading to measurement errors. However, the use of a flow conditioner resulted in a further reduction in hydrogen nonuniformity and minimized velocity fluctuations, resulting in a small and uniformly distributed flow, which is advantageous for accurate measurement and transportation purposes.

Selecting serum-free hepatocyte cryopreservation stage and storage temperature for the application of an “off-the-shelf” bioartificial liver system

The bioartificial liver (BAL) system can potentially rescue acute liver failure (ALF) patients by providing partial liver function until a suitable donor liver can be found or the native liver has self-regenerated. In this study, we established a suitable cryopreservation process for the development of an off-the-shelf BAL system. The viability of hepatocyte spheroids cryopreserved in liquid nitrogen was comparable to that of fresh primary hepatocyte spheroids. When hepatocyte spheroids were subjected to cryopreservation in a deep freezer, no statistically significant differences were observed in ammonia removal rate or urea secretion rate based on the cryopreservation period. However, the functional activity of the liver post-cryopreservation in a deep freezer was significantly lower than that observed following liquid nitrogen cryopreservation. Moreover, cryopreserving spheroid hydrogel beads in a deep freezer resulted in a significant decrease (approximately 30%) in both ammonia removal and urea secretion rates compared to the group cryopreserved in liquid nitrogen. The viabilities of spheroid hydrogel beads filled into the bioreactor of a BAL system were similar across all four groups. However, upon operating the BAL system for 24 h, the liver function activity was significantly higher in the group comprising hydrogel beads generated after thawing hepatocyte spheroids cryopreserved in liquid nitrogen. Consequently, the manufacturing of beads after the cryopreservation of hepatocyte spheroids is deemed the most suitable method, considering efficiency, economic feasibility, and liver function activity, for producing a BAL system.

Preparation and characterization of zirconium carbide nano powder by hydrothermal and carbothermal reduction methods

A hydrothermal method was employed to synthesize the precursor of nano-zirconium carbide, which was subsequently heat treated at high temperatures under vacuum to obtain finely dispersed nanometer-sized zirconium carbide powder through a carbothermic reduction reaction. Scanning Electron Microscopy (SEM) was utilized to examine the microstructure of the precursors obtained under different hydrothermal conditions and carbon contents. The effects of different heat treatment temperatures on the microstructure of the products were analyzed. Transmission Electron Microscopy (TEM) confirmed the boundary coating structure of the hydrothermal precursor and provided insights into the phase structure of the nanometer-sized zirconium carbide. The reaction mechanism and temperature involved in the carbothermic reaction process were determined through calculations. Furthermore, the energy, phase and microstructure of the reaction were investigated using Thermogravimetric Analysis (TG-DSC) and X-ray Diffraction (XRD) at different temperatures. The obtained results revealed that the zirconium carbide precursor was synthesized via the hydrothermal method exhibited a core-shell structure with a boundary coating, which not only ensured uniform contact between C and ZrO2 particles but also facilitated the formation of zirconium carbide. The results show that the most suitable process parameters are Zr/C 1: 7, 240 °C and 24 h. The thermodynamic calculation results show that ZrO2 combines with carbon to form CO and ZrC when the temperature reaches 1656.56 °C. As the temperature rises, CO reacts with ZrO2 to form ZrC and CO2. TG-DSC shows that the carbothermal reduction reaction starts at 1100 °C and reaches its peak at 1418 °C. XRD analysis confirms that when the temperature reached 1450 °C ZrC appeared. At 1600 °C, the phase transition of ZrC is basically completed. TEM images showed that the synthesized zirconium carbide particles were about 30 nm.

Application of Nonlinear Analysis in Evaluating Additive Manufacturing Process for Engineering Design Features: A Study and Recommendations

In today’s world, Additive Manufacturing (AM) is quickly becoming the dominant manufacturing technology. Massive development has occurred in recent decades, and it is occurring at a much faster rate. It has also progressed from simple prototype to actual end-use items and manufacturing tools. Various manufacturing processes, such as SLS, LENS, FDM, PolyJet, SLA, LTP, DMLS FDM, and binder jet printing, are produced using additive manufacturing techniques. Layer by layer material deposition/addition is a critical component in all these operations, which is why this technology is known as additive manufacturing. Rapid prototyping, 3D printing, digital manufacturing, and other such names are used. Automotive, Aerospace components, medical equipment parts, consumer goods and gadgets, fashion sector, jewelry, and other industries employ additive manufacturing.Currently all designed parts can manufacture using either subtractive or additive manufacturing processes. However, distinct design elements established for production provide additional manufacturing obstacles in metal substation and metal addition manufacturing procedures. As the number of parts made directly utilizing additive manufacturing techniques grows, it is critical to compile a list of the best design for manufacturing principles applicable for various additive manufacturing procedures. This will assist the design community in ensuring that items are developed for additive manufacturing rather than generic strategy and produced.The primary goal of this effort is to evaluate and comprehend the various additive processes and choose the optimal design for manufacturing procedures to be used. As a result, one should be prepared to select a suitable additive manufacturing process for printing based on the design aspects of the component to be produced.

Development of a method to investigate the influence of engine oil and its additives on combustion anomalies in hydrogen engines

To counteract the anticipated consequences of climate change, significant efforts are required across all industries. The use of hydrogen in internal combustion engines can make a valuable contribution as a carbon-neutral bridging technology. One challenge in developing a suitable combustion process is the high ignition propensity of hydrogen, impacting combustion stability due to combustion anomalies. Avoiding such combustion phenomena is of utmost relevance to ensure a long-term stable engine operation. Oil entry into the combustion chamber can impact the occurrence of combustion anomalies. Therefore, a specific method for controlled oil entry into the combustion chamber has been developed, and this method is detailed in the following article.

Simulation of process forces and topographical characteristics of single grains in microfinishing processes

Honing operations, e.g. microfinishing, are resulting in high quality surfaces with a roughness values, e.g., average roughness Ra, of only a few micro- to nanometer [1]. The simulation of honing processes can be beneficial to reduce experimental effort in terms of determining suitable process parameters for such processes. Various aspects of the finishing process can be investigated with the aid of process models, such as tool wear, tool life, the resulting surface quality or shape deviation. In addition, process simulations can be used to assist in the design of components with regard to desired functional properties. In order to model processes with such high accuracy, it is necessary to be aware of process influences on a microscropic scale. Such influences can be analyzed separately, for instance, by means of analogy experiments to reduce the complexity and dependencies of the occurring effects. In this work, a process force model was developed based on single-grain scratch tests, which takes into account the process-inherent kinematic variations. The occurring single grain forces in dependence of the orientation of the grains and in relation to the cutting direction were analyzed and modeled. This is important for a further analysis of the influences on tool wear to increase the accuracy of corresponding models.

Preparation, Microstructure, and Mechanical Properties of Al Matrix Composites Reinforced with High‐Entropy Alloys: A Review

Al matrix composites (AMCs) are innovative materials prepared by introducing various reinforcements into Al alloys using suitable processes. Traditional particle‐reinforced AMCs usually have high strength but poor interfacial bonding, resulting in low plasticity. Researchers are attempting to solve this problem by identifying more proper reinforcing particles. High‐entropy alloys (HEAs) with excellent mechanical properties including high strength, ductility, and wear resistance are becoming attractive candidates for the reinforcement of Al alloys. The HEAs‐reinforced AMCs (HEAs@AMCs) combine the lightweight property of Al alloys and superior mechanical properties of HEAs. In this article, a comprehensive overview is provided on the HEAs@AMCs, starting with an introduction to the properties of HEAs, followed by the design principle of HEAs for the metal matrix composites. After that, the preparation, microstructure, and mechanical properties of the HEAs@AMCs are examined. In addition, the effects of HEAs on the microstructure and mechanical properties of the HEAs@AMCs are explored.

Process parameters settings of friction stir welding using multi-response optimization for aluminum alloys

The defense and aerospace industries utilize the AA2050, an aluminum-lithium alloy of the third generation. Principal component analysis (PCA) and Taguchi-grey relational analysis (GRA) are utilized in this study to enhance the process constraints for friction stir welding (FSW). The quality of the weld can be influenced by various process factors such as the speed at which the weld is traversed, the speed at which the tool is rotated, the angle at which the tool is tilted, the diameter of the shoulder, and the shape of the tool pin. The combination of PCA and the well-known Taguchi-GRA approach enables the objective estimation of response weights. Here, a Taguchi L16 orthogonal array was designed, and sixteen tests were carried out using it. These experiments were conducted with various assessments including tensile strength, yield strength, elongation percentage, hardness of the weld zone, bending load, etc Through the utilization of Taguchi-GRA-PCA analysis, the most suitable process parameters were identified as a traverse speed (TS) of 160 mm min−1, a rotating speed (RS) of 900 rpm, a tilt angle (TA) of 2 degrees, a shoulder diameter (SD) of 16 mm, and with a straight square tool pin profile (TPP). ANOVA revealed the relevance of all five characteristics, with rotational speed being the most influential, accounting for 43.56% of the entire result. A confirmation experiment done under ideal conditions revealed a significant improvement in total weld quality of 19.06%.

Model for designing process strategies in ultrafast laser micromachining at high average powers

The great potential to scale the productivity of laser micromachining processes offered by the development of ultrafast lasers with average powers exceeding 1 kW comes at the cost of new physical and technical challenges. The large number of adjustable parameters, the different physical process limits, and the various possible optimization strategies complicate the design of suitable laser micromachining processes that enable high quality and high throughput.In this contribution, a comprehensive model is proposed that helps to identify the optimization strategies and process parameters required for the scaling of laser micromachining to high throughput at high average laser power without exceeding the process limits to ensure high surface quality.The model was experimentally verified on the example of laser micromachining of pockets in metals and silicon using an ultrafast laser with an average power of 1.01 kW, a pulse duration of 600 fs, different pulse energies, pulse bursts, and beam diameters. As a result, high material removal rates exceeding 120 mm3/min were achieved for silicon, stainless steel, copper, and aluminum, which exceed previously achieved removal rates by one to two orders of magnitude. The machined surfaces exhibit high quality as confirmed by the low measured roughness of about 1 µm.

Characterization and classification of ductal carcinoma tissue using four channel based stokes-mueller polarimetry and machine learning

Interaction of polarized light with healthy and abnormal regions of tissue reveals structural information associated with its pathological condition. Even a slight variation in structural alignment can induce a change in polarization property, which can play a crucial role in the early detection of abnormal tissue morphology. We propose a transmission-based Stokes-Mueller microscope for quantitative analysis of the microstructural properties of the tissue specimen. The Stokes-Mueller based polarization microscopy provides significant structural information of tissue through various polarization parameters such as degree of polarization (DOP), degree of linear polarization (DOLP), and degree of circular polarization (DOCP), anisotropy (r) and Mueller decomposition parameters such as diattenuation, retardance and depolarization. Further, by applying a suitable image processing technique such as Machine learning (ML) output images were analysed effectively. The support vector machine image classification model achieved 95.78% validation accuracy and 94.81% testing accuracy with polarization parameter dataset. The study's findings demonstrate the potential of Stokes-Mueller polarimetry in tissue characterization and diagnosis, providing a valuable tool for biomedical applications.

Tailoring supramolecular solvents with phosphoryl groups for highly efficient extraction of chlorophenols in natural waters

BackgroundChlorophenols are routinely determined in aquatic systems to check compliance with the restrictive international legislations set for protection of human and aquatic life. Their control requires affordable analytical methods, particularly in labs at low- and medium-income countries. Liquid chromatography-UV detection is a convenient technique for this purpose, but the availability of suitable sample processing remains pending. Organic solvents are inefficient for extracting the whole range of chlorophenols whereas solid-phase extractions are expensive and labour-intensive. So, an efficient, fast and cheap extraction of chlorophenols, amenable to any lab, would help to cope with their worldwide analytical control in natural waters. ResultsA supramolecular solvent (SUPRAS) was tailored for providing mixed interaction mechanisms aimed at the efficient extraction of chlorophenols prior to LC-UV. The SUPRAS was synthesized from the self-assembly of hexylphosphonic acid under acidic conditions and consisted of sponge-like nanostructures made up of amphiphile and water. The phosphoryl (PO) group was selected as the major driver of the extraction because of its ability to act as halogen and hydrogen bond acceptor for chlorophenols. Additional interactions were hydrogen bonds from O–H amphiphilic groups and the surrounding water, and dispersion and CH-π interactions in the hydrocarbon chains. The number of binding sites in the SUPRAS could be modulated by addition of salt. The SUPRAS formed in situ in the sample, the extraction took 5 min, the concentration factor was around 220, quantification limits (0.1–0.3 μg L−1) were below the EU standards, and the method worked for natural waters. SignificanceA fast, low-cost, and organic solvent-free sample processing only requiring conventional lab equipment (stirrers and centrifuges) provided SUPRAS extracts that could be directly analyzed by LC-UV. SUPRAS synthesis occurred spontaneously in the water sample under addition of hexylphosphonic acid and the whole process required low skills. The method meets the analytical and operational performances for the analytical control of chlorophenols in natural waters and it is within the reach of any lab.

Evaluation of a multi-user requirements axiomatic design decision support tool for manufacturing process selection

AbstractManufacturing process selection presents numerous challenges to designers, including product complexity, consideration of production volumes and part tolerances. This paper introduces a design support tool based on the axiomatic design model to systematically transform requirements into functions and technological capabilities. The results from an evaluation of the implemented prototype tool in the field of medical device design demonstrates its usefulness in selecting the most suitable candidate manufacturing process for a given artifact, while taking into account multiple user requirements.

Influence of deep rolling at different temperatures on near-surface and mechanical properties of a Maraging C250 steel

Due to an outstanding combination of high strength and fracture toughness Maraging steels are used in numerous industries, e.g., in the aerospace sector. The high strength can be attributed to precipitation strengthening by conventional age-hardening heat treatments. However, as many of the envisaged applications will suffer from cyclic loadings, the fatigue properties are of significant interest in terms of a reliable use. Generally, Maraging steels are characterized by a relatively low fatigue strength limiting the use in certain applications. In this context, mechanical surface treatment processes are promising candidates to overcome these challenges. In particular, deep rolling represents a suitable process, as it is known for increased depth effects as well as smoother surface profiles compared to other mechanical surface treatment processes. Moreover, aging heat treatments can easily be implemented into the process. Accordingly, the present study focuses on near-surface and mechanical properties of a Maraging C250 steel after deep rolling. Characterization of the near-surface area was conducted by X-ray diffraction and hardness measurements. Mechanical properties were assessed by tensile and fatigue tests. The results presented reveal a great potential of the integration of an aging heat treatment into the deep rolling process eventually leading to significant process time reduction.

The comparison and processing of Electromyography (EMG) signals under different actions

The experiment first investigates the working principle and the applications of Electromyography (EMG). Then, the effect of electrode location and electrode size on the EMG signal is explored by the raw data and theory. The reasons for choosing generic surface Ag/AgCl adhesive electrodes are also described. After obtaining the raw EMG signals, suitable data processing methods, such as Root Mean Square (RMS) and digital filtering are applied to generate signals that can drive the motor of a prosthetic arm. The results obtained by the two methods are also compared, where RMS can provide larger peak and mean values, and the digital filtering method can minimise the phase shift. Finally, the limitations of the EMG for prostheses are also analysed by three aspects: different flexion forces, individual finger motion and different reference locations.

Effect of Refractance Window™ and oven drying on physicochemical and sensory properties of peach (Prunus persica L.) surplus.

Currently, approximately 34% of fruit is lost and wasted in emerging economies due to inefficient post-harvest processes, technological shortcomings, lesser valorization of surpluses, and byproducts. Peach (Prunus persica L.) is a fruit with a good yearly growth rate but higher postharvest losses in Colombia. One way to take advantage of this type of product is through the application of drying processes that increase its shelf life and its inclusion in the food chain. Refractance Window Drying (RWD) is a fourth generation drying technique implemented by the food industry in the last few decades and has been applied to several dehydrated food products. This study compared the effects of different drying methods on the physical and sensory properties of peaches surplus. Treatments consisted of (i) peaches were sliced (1, 2, and 3 mm thickness) and dried using RWD at 86°C, (ii) peach pulp mixed with maltodextrin (MD) (0.12-0.33 kg of MD/kg of sample) and RWD (RWD-MD), and (iii) conventional oven drying (OD) at 60°C (3 mm thick) dried for 24 h. The study found that the drying method significantly (p < 0.05) affected the texture, color, and general taste of peaches. The results showed that processing treatments combined with different drying conditions affected the physical properties of the peach. RWD in slices reduced water content to 0.05 kg H2O/kg in 40 min, showing fewer effects on color attributes. A surface response analysis on RWD showed good correlations for water activity (R2 = 0.8652-0.9894) and moisture content (R2 = 0.7048-0.9826). A higher diffusion coefficient (1.63 × 10-6 m2 s-1) was observed for RWD in slices with 3 × 10-3 m of thickness; however, for RWD-MD, differences in diffusion coefficients were present for the lowest MD addition (0.12 kg/kg), vitamin C was not detected on the dried slices, and higher concentration of β-carotene (175.88 μg/100 g) was found on the thinner slices. Principal component analysis showed that RWD in the slices was the most suitable drying process, followed by OD. Sensory analysis showed good acceptability for RWD slices after 30 days of storage.

Machine Learning Applied to Electron Beam Lithography to Accelerate Process Optimization of a Contact Hole Layer.

Determining the lithographic process conditions with high-resolution patterning plays a crucial role in accelerating chip manufacturing. However, lithography imaging is an extremely complex nonlinear system, and obtaining suitable process conditions requires extensive experimental attempts. This severely creates a bottleneck in optimizing and controlling the lithographic process conditions. Herein, we report a process optimization solution for a contact layer of metal oxide nanoparticle photoresists by combining electron beam lithography (EBL) experiments with machine learning. In this solution, a long short-term memory (LSTM) network and a support vector machine (SVM) model are used to establish the contact hole imaging and process condition classification models, respectively. By combining SVM with the LSTM network, the process conditions that simultaneously satisfy the requirements of the contact hole width and local critical dimension uniformity tolerance can be screened. The verification results demonstrate that the horizontal and vertical contact widths predicted by the LSTM network are highly consistent with the EBL experimental results, and the classification model shows good accuracy, providing a reference for process optimization of a contact layer.