Liquid Aluminum Research Articles

Intelligent Identification of Liquid Aluminum Leakage in Deep Well Casting Production Based on Image Segmentation

This study proposes a method based on image segmentation for accurately identifying liquid aluminum leakage during deep well casting, which is crucial for providing early warnings and preventing potential explosions in aluminum processing. Traditional DeepLabV3+ models in this domain encounter challenges such as prolonged training duration, the requirement for abundant data, and insufficient understanding of the liquid surface characteristics of casting molds. This work presents an enhanced DeepLabV3+ method to address the restrictions and increase the accuracy of calculating liquid surface areas for casting molds. This algorithm substitutes the initial feature extraction network with ResNet-50 and integrates the CBAM attention mechanism and transfer learning techniques. The results of ablation experiments and comparative trials demonstrate that the proposed algorithm can achieve favorable segmentation performance, delivering an MIoU of 91.88%, an MPA of 96.53%, and an inference speed of 55.05 FPS. Furthermore, this study presents a technique utilizing OpenCV to accurately measure variations in the surface areas of casting molds when there are leakages of liquid aluminum. In addition, this work introduces a measurement to quantify these alterations and establish an abnormal threshold by utilizing the Interquartile Range (IQR) method. Empirical tests confirm that the threshold established in this study can accurately detect instances of liquid aluminum leakage.

On estimating the intrinsic surface tension of liquid aluminum and its temperature coefficient

On estimating the intrinsic surface tension of liquid aluminum and its temperature coefficient

Comparative study on the preparation of phosphate-based geopolymers using different activators

Fly ash has the potential to be used as the precursor in the acid-activated geopolymer preparation, fly ash can react with phosphorus-containing activators to form geopolymers, but different types of activators present different activation effects on fly ash. In this study, common liquid phosphoric acid (PA), liquid aluminum dihydrogen phosphate (ADP), solid sodium dihydrogen phosphate (SDP) and solid potassium dihydrogen phosphate (PDP) are used as a single-component or composite activators and fly ash as raw material to prepare phosphate-based geopolymers (PGEOs). The effect of different activators on setting time, pH, electrical conductivity (EC) and compressive strength of PGEOs were assessed. Moreover, the activation mechanism of different activators on fly ash was revealed by using X-ray diffraction, Fourier transform infrared spectroscopy, Mercury Intrusion Porosimetry, X-ray Photoelectron Spectroscopy and Scanning Electron Microscopy-Energy Dispersive Spectroscopy. The results showed that geopolymer prepared using ADP exhibited the highest compressive strength among the different activators, but combining ADP and PA would prolong setting time. However, the unreacted SDP and PDP particles were detected in geopolymers activated by PA+SDP and PA+SDP composite activator due to insufficient geopolymerization. Nonetheless, combining PDP or SDP with PA as composite activator is more effective than the single-component PDP or SDP activator in improving compressive strength. The pH values of the geopolymers increased with the curing time while EC showed a decreasing trend which was independent of the activator type. AlPO4 phase was found in all samples, and Al-containing phases are the main strength-given component of PGEOs.

Perancangan Kursi Kerja yang Ergonomi untuk Pekerja di UKM Wintolo

UKM Wintolo is a small and medium business that produces molds using liquid aluminum as the base material. UKM Wintolo has 3 workers with different age ranges. When initial observations were made, it was seen that the position and posture of workers when working were not neutral and not ergonomic, so community service activities were carried out at UKM Wintolo with the theme of improving processes and work environments in accordance with ergonomics rules at UKM Wintolo. This activity was carried out for 2 days, namely the first day was carried out by providing socialization material according to the theme of the activity, and taking measurements using the anthropometric method in making work facilities. The work facilities that have been refurbished include work chairs that are used for the mold preparation process and the process of taking mold results. On the second day, the products that had been made for these two activities were handed over. Community service activities are carried out to avoid musculoskeletal disorder (MSDs) complaints and this will subsequently have an impact on increasing worker productivity. Through this activity, it can be seen that there is a change in the position and posture of workers while working.

A FeCrB-based composite containing multi-scale corrosion-resistant phases: Application in high-temperature liquid aluminum corrosion

In this work, FeCrB-based composites modified by in-situ ceramic particles (TiB2 and TiC) were synthesized, and the effects of ceramic particles on their microstructure evolution and the corrosion-resistant behavior in liquid aluminum were systematically investigated. Results indicate that the introduction of in-situ ceramic particles can significantly improve the size, morphology and distribution of borides, thus leading to a remarkable enhancement of the corrosion resistance. Based on the growth-dissolution kinetic relationship of intermetallic compounds (IMCs) at the corrosion interface, a theoretical numerical model was established to quantitatively describe the corrosion behavior of ferrous alloys in liquid aluminum, and the multi-scale corrosion-resistance mechanism is proposed to elucidate the excellent performance of FeCrB-based composites in liquid aluminum.

Whisker Bond: From Findings to Concept in Refractories

Ceramic bonds are conventionally formed during the<sup> </sup>burning of<sup> </sup>refractory bricks and by using pre-fabricated blocks or monolithic lining, which is characterized as the coalescence of the particles by liquid sintering. However, the whisker bond was discovered with the outstanding performance of unburnt periclase–spinel–Al bricks while substituting magnesia–chrome bricks in the chromium-free campaign of refractory lining of RH degassers. Thanks to the prominent effect of the whisker bond, such a refractory material demonstrates ultrahigh hot strength, high resistance to slag penetration, and thermomechanical stress. Investigations reveal the initial melting of metal Al at the melting point of 660°C, aluminum liquid rims around the cavities formed before ~800°C, gaseous AlN yielded and distributed throughout<sup> </sup>the matrix with increasing temperature, gaseous Mg reduced from ~1000°C, and MgAlON whiskers eventually formed in the matrix. Microstructure observations show a dense interwoven whiskers bonded matrix in most residual parts of the used periclase–spinel–Al bricks. The whisker network in the matrix is made up of<sup> </sup>straight columns<sup> </sup>of 1–5 µm in diameter and 20–40 µm in length, which is different from birdnesting, nano-size curly whiskers observed in the past. The findings suggest a whisker-bond concept in terms of the bond mode of the whisker network and the process of the vapor-solid forming mechanism.

Structure and dynamical properties during solidification of liquid aluminum induced by cooling and compression

Abstract The structural transformation from a liquid to a crystalline solid is an important subject in condensed matter physics and materials science. In the present study, firstprinciples molecular dynamics calculations were performed to investigate the structure and properties of aluminum during the solidification which was induced by cooling and compression. During both the cooling and compression processes, it was found that the icosahedral short-range order was initially enhanced and then began to decay, the face-centered cubic short-range order eventually became dominant before it transformed to a crystalline solid.

Quality Control of Liquid Aluminium Alloy Using Thermal Imaging Camera

This paper presents the results of a study on the use of infrared thermography to assess the quality of liquid metal, a basic semi-finished product used in foundry production. EN AC-46000 alloy with the designation AlSi9Cu3(Fe) was used for the study. The crystallization process of the alloy was investigated using the TDA method with a Crystaldigraph device and Optris PI thermal imaging camera. The research describes how to use a thermal imaging camera to assess the quality of aluminium alloys. These alloys, due to their propensity in the liquid state to oxidise and absorb hydrogen, a refining procedure in the melting process. The effects of alloy refining are evaluated during technological tests of hydrogen solubility, density and casting shrinkage. The results presented in this paper showed that there is a statistical correlation between the density of the metal and the temperature values from the thermogram of the sample, obtained during its solidification. The existing correlation makes it possible to develop a thermographic inspection algorithm that allows a fast and non-contact assessment of aluminium alloy quality.

Corrosion Behavior of 10 ppi TAD3D/5A05Al Composite in a Chloride Environment.

This study utilizes desalted and denitrated treated aluminum dross (TAD) as a raw material, along with kaolin and 10 ppi (pores per inch) polyurethane foam as a template. The slurry is converted into an aluminum dross green body with a three-dimensional network structure using the impregnation method. A three-dimensional network aluminum dross ceramic framework (TAD3D) is created at a sintering temperature of 1350 °C. The liquid 5A05 aluminum alloy at a temperature of 950 °C infiltrates into the voids of TAD3D through pressureless infiltration, resulting in TAD3D/5A05Al composite material with an interpenetrating phase composite (IPC) structure. The corrosion behavior of TAD3D/5A05 composite material in sodium chloride solution was examined using the salt spray test (NSS) method. The study shows that the pores of the TAD3D framework, produced by sintering aluminum dross as raw material, are approximately 10 ppi. The bonding between TAD3D and 5A05Al interfaces is dense, with strong interfacial adhesion. The NSS corrosion time ranged from 24 h to 360 h, during which the composite material underwent pitting corrosion, crevice corrosion and self-healing processes. Results from Potentiodynamic Polarization (PDP) and Electrochemical Impedance Spectroscopy (EIS) indicate that, as corrosion progresses, the Ecorr of TAD3D/5A05Al decreases from -0.718 V to -0.786 V, and Icorr decreases from 0.398 μA·cm-2 to 0.141 μA·cm-2. A dense oxide film forms on the surface of the composite material, increasing the anodic Tafel slope and decreasing the cathodic Tafel slope, thus slowing down the rates of cathodic and anodic reactions. Factors such as lower interface corrosion resistance or a relatively weak passivation film at the interface do not significantly diminish the corrosion resistance of TAD3D and 5A05Al. The corrosion resistance of the composite material initially decreases and then increases.

Experimental study of liquid aluminum droplet breakup characteristics based on a Drop-on-demand (DOD) magnetohydrodynamic actuation

In magnetohydrodynamic (MHD) drop-on-demand (DOD) actuation, Lorentz force generated in different excitation stages are exerted on the liquid metal jet to form a "push-pull" mechanism, which is crucial for generating accurate and repeatable metal droplets. In this study, the important parameters of the excitation current waveform in the magnetohydrodynamic (MHD) process, including the influence of the excitation voltage pulse width ratio and current amplitude on the velocity, energy, volume, and breakup length of aluminum droplets are studied. The conversion process of surface energy and kinetic energy during the formation and fall stage of liquid droplets is analyzed. The results show that the negative and positive excitation voltage pulse width ratio of the MHD pump has a significant effect on the droplet velocity, breakup time, size, and sphericity. The amplitude of the excitation current and Hartmann number has a significant impact on the generation of stable droplets. The results show that the single droplet ejection state can be achieved within the Ha number between 319.5 and 391.1. As the Ha number increases, the volume, length, kinetic energy and surface energy of the droplets at breakup time also increase. The size of droplets can be adjusted by changing the amplitude of excitation waveform.

Study on Al2O3/Fe-Al gradient coating assisted prepared by ionic liquid for Lead-Bismuth eutectic corrosion resistance

Alumina coating which has excellent corrosion resistance to lead–bismuth eutectic (LBE) is very promising to be used in future LBE cooling system. In this paper, the Al2O3/Fe-Al gradient coating is prepared on the surface of SIMP steel assisted by ionic liquid aluminum electroplating and subsequent heat treatments and selective oxidation. The protective Al2O3 layer is composed of much γ-phase and a small amount α-phase. The Fe-Al transition layer is mainly composed of FeAl alloy phase. After being exposed for 600 h to LBE at 600 °C, the coating still maintains intact and dense structure and good compatibility to the substrate, effectively preventing the substrate steel from the corrosion attack of LBE. While obvious LBE attack can be observed in the compared bare steel. Finally, to verify the possibility of this approach preparing Al2O3/Fe-Al coating on complex geometries, we have also successfully prepared this sort of coating on the inner surface of a steel tube, indicating that this coating has a great application potential in the future.

Castor oil‐based polyurethane ternary composites with enhanced thermal conductivity and mechanical properties by using liquid metal as second filler

AbstractWith the miniaturization, high frequency of electronic devices, and low‐carbon and sustainable development, higher requirements are put forward for thermal conductive polyurethane composites in terms of comprehensive performance and renewable raw materials. Herein, choosing bio‐based polyurethane (PU) derived from castor oil as matrix, and liquid metal (LM) and aluminum hydroxide (ATH) as hybrid thermal conductive filler, castor oil‐based PU composites were developed via high‐speed rotation and in‐situ polymerization method. The LM‐ATH hybrid filler displayed a synergistic enhancement effect on the thermal conductivity of composites due to the presence of LM‐bridging significantly improved the effective contact probability between ATH fillers. The thermal conductivity of 50LM‐ATH/PU reached 1.69 Wm−1 K−1, which was 9.9 times and 1.4 times higher than that of pure PU and 50ATH/PU, respectively. Notably, the 50LM‐ATH/PU exhibited outstanding mechanical properties including tensile strength up to 4.0 MPa and adhesion strength up to 7.9 MPa, especially elongation at break up to 120% which was improved by 200% compared with 50ATH/PU (40%). Additionally, the composite possessed excellent electric insulation, thermal stability, and inflaming retarding properties, showing great application potential in the electronic devices field.Highlights Castor oil‐based PU composites with ATH‐LM hybrid filer were developed. LM‐ATH hybrid filler of 2:8 promoted the thermal conductivity of composites. Hybrid filler than ATH‐endowed composites with better mechanical properties. The ATH‐LM/PU exhibited excellent electric insulation.

New insights into the mechanism of ultrasonic atomization for the production of metal powders in additive manufacturing

Ultrasonic atomization is one of the promising technologies for producing metal powders for additive manufacturing, where precise control of particle size and morphology is essential. In this study, we coupled an ultrasonic transducer with a carbon fiber plate and atomized liquid droplets and films under different vibration amplitudes. Water, glycerol, and pure aluminum melt were used to study the atomization mechanism and the resulting droplet/powder characteristics, respectively. High-speed optical and ultrafast synchrotron X-ray imaging were used to study in situ the ultrasonic atomization dynamics, including pulsation and clustering of cavities inside the liquid layer/films, development of capillary waves, and formation of liquid droplets. For the first time, we observed and captured the occurrence of cavitation during the atomization of resting drops, films and impact droplets. The inertial cavitation events interfered with the capillary waves across the interphase boundary, puncturing and breaking the boundary to produce atomized mist. The in situ observation revealed the intricate dynamics of ultrasonic atomization and underscored the pivotal role of cavitation events throughout the entire atomization process. We also conducted experiments on ultrasonic atomization of liquid aluminum, producing particles of perfectly spherical shape. The particle size tended to decrease with reduced vibration amplitude Our work has demonstrated the important processing strategies on how to tailor the particle size while ensuring consistent particle shape and morphology, which is the key processing capability for producing high quality powders for additive manufacturing applications.

Calculations of Non-Metallic Particles Removal from Liquid Aluminium to Top Slag

In the paper, the results of a numerical analysis of KCl and KF particles present in liquid aluminium assimilation to the slag are presented. The authors analysed particle movement in the slag model, which is based on buoyant, capillary, viscosity, Newton and repulsion forces, interfacial tensions at the interface of phases and surface energy during the particle movement through phases boundary. On the basis of the mathematical model, a computer programme was written to make simulations under different conditions. The results of particle position in the slag are presented for different particle radiuses: 1, 5, 10, 20 μm, and constant viscosity of the slag including velocity evolution of the velocity. Another approach was used to indicate the influence of slag viscosity on particle and slag penetration depth. During computations, selected viscosities of slag of 0.0012, 0.0015, 0.0018 [kg/m·s] were taken into account. Different comparisons were made for the chosen particle sizes. Each examination takes into account the impact of the particle type. The results clearly show that for larger particles the penetration depth is greater and viscosity of the slag has an impact on the velocity evolution during assimilation process.

Effect of tools rotational speed on the mechanical properties of one-step double-acting friction stir welded aluminum alloy AA 6061 hollow panel

The utilization of Aluminum hollow panels enhances structural strength while simultaneously ensuring a lightweight and efficient use of materials. During their application, these panels necessitate a welding process that is susceptible to porosity due to the disparity in hydrogen gas solubility between liquid and solid aluminum. Solid-state welding techniques, such as Friction Stir Welding (FSW), have proven to be effective and appropriate solutions for overcoming this issue. However, due to the thickness of the hollow panels, FSW process is unfeasible as it requires welding on both sides, resulting in prolonged production times. Consequently, the development of a one-step double-acting FSW technique becomes necessary, involving the simultaneous utilization of two tools. The usage of two tools introduces two sources of friction-stir forces, heat, and axial forces, demanding an assessment of the novel response from the specimens. This research aims to analyze the effect of a specific parameter, namely the tool rotation speed, within the one-step double-acting FSW process on the physical and mechanical properties of the AA6061 hollow panels. The One-Step Double-Acting FSW process involved conducting variations in the tool rotation speed on both sides of the welds. Specifically, for the 4G weld position (underside of the workpiece with an overhead weld position), speeds of 1200, 1500, and 1800 rpm were employed. Meanwhile, a consistent rotation speed of 1500 rpm was maintained for the 1G weld position (overside of the material with a flat weld position). The transverse speed and tilt angle are set at 30 mm/min and 2°, respectively. Elevating the tool rotation speed results in increased hardness, load capacity, and bending strength of the weld joints. The specimen subjected to the highest rotational speed (1800 rpm) exhibits the most exceptional mechanical properties, including a hardness of 73.46 HVN, load capacity of 18.47 kN, and bending strength of 60.56 MPa.

Modeling of Impurities Evaporation Reaction Order in Aluminum Alloys by the Parametric Fitting of the Logistic Function.

Advancements in computer capabilities enable predicting process outcomes that earlier could only be assessed after post-process analyses. In aerospace and automotive industries it is important to predict parts properties before their formation from liquid alloys. In this work, the logistic function was used to predict the evaporation rates of the most detrimental impurities, if the temperature of the liquid aluminum alloy was known. Then, parameters of the logistic function were used to determine the transition points where the reaction order was changing. Samples were heated to 610 °C, 660 °C, 710 °C, and 760 °C for one hour, after which the chemical analyses were performed and evaporation rates were calculated for Cd, Hg, Pb and Zn elements. The pressure inside the encapsulated area was maintained at 0.97 kPa. Whereas parameters that define the evaporation rate increase with the temperature increase, the maximum evaporation rates were deduced from the experimental data and fitted into the logistic function. The elemental evaporation in liquid-aluminum alloys is the best defined by the logistic function, since transitions from the first to zero-order-governed evaporation reactions have nonsymmetrical evaporation rate slopes between the lowest and the highest evaporation rate point.

Corrosion inhibition analysis on cerium induced hydrophobic surface of Al-6061/SiC/Al2O3 hybrid composites

A new kind Al-6061/SiC/Al2O3 hybrid composite was prepared with traces amount of cerium oxide and its corrosion performance was evaluated by potentio-dynamic polarization electrochemical method. A new kind of intermetallic (γ-phase) has been observed in the microstructure with higher content of cerium oxide and Al elements. The corrosion resistance of Al-6061 alloy improved with addition of cerium oxide and this improvement could attribute to depression of the micro-galvanic couples. The corrosion rates were observed as 0.16 and 0.034 mpy corresponding to 3.5 and 2.5 wt% of NaCl corresponding to 2.5 wt% of cerium oxide. Moreover, the formation of cerium oxide and Al enrichment film over the surface of hybrid composites was also found to be main key factor for the inhibition of corrosion resistance. Another key factor that inhibits the further corrosion was observed as hydrophobicity between the aluminium liquid matrix and Al2O3/SiC reinforcement after incorporation of cerium oxide. Improvement in hydrophobicity of composites with Al2O3/SiC is due to increase in contact angle up to 100.78° after addition of 2.5 wt% cerium oxide. Micro-hardness and impact strength of the hybrid composites improved significantly after addition of traces amount of REOs from 0.5 to 2.5 wt%.

Aluminothermic reduction of CeO2: mechanism of an economical route to aluminum-cerium alloys.

Cerium oxide is a low-value byproduct of rare-earth mining yet constitutes the largest fraction of the rare earth elements. The reduction of cerium oxide by liquid aluminum is proposed as an energy- and cost-efficient route to produce high-strength Al-Ce alloys. This work investigated the mechanism of a multi-step reduction reaction to facilitate the industrial adaptation of the process. Differential scanning calorimetry in combination with time-resolved synchrotron diffraction data uncovered the rate-limiting reaction step as the origin of the reported temperature dependence of reduction efficiency. This is the first in situ study of a metallothermic reaction mechanism and will serve as guidance for cost- and energy efficient industrial process control.

The Role of Microfibers and Liquid Aluminum in the Reaction between Boron Nitride and Tantalum Nitride

The Role of Microfibers and Liquid Aluminum in the Reaction between Boron Nitride and Tantalum Nitride

A Novel Strategy for Realizing Reliable Welding of Aluminum-Steel

This study proposed a novel welding strategy called active-expulsion-assisted resistance spot welding (RSW), which was used to address the limitations of RSW of aluminum to steel. The method primarily comprised an intentionally set expulsion stage and a locking stage. In the expulsion stage, a short-duration expulsion pulse with a relatively large welding current was applied to melt the aluminum and induce liquid aluminum expulsion. Then, in the locking stage, a welding current pulse was used to join the locking sheet and the steel workpiece. A combination of quenched and partitioned 1180 steel and AA6016 aluminum alloy with and without adhesive was used for welding. Experimental results showed that the expulsion pulse efficiently removed the aluminum alloy in the weld, creating the conditions for fundamentally avoiding the formation of brittle intermetallic compounds in the nugget during the subsequent welding stage. After the welding pulse, a strong joint was generated between the locking sheet and the steel, thus realizing a firm connection for the combination of welding and riveting between an aluminum alloy and steel substrate.