Addition Of Aluminum Research Articles

Corrosion of austenitic Fe-Ni based alloys with various chromium and aluminum additions in a carburizing-oxidizing atmosphere at 800ᵒC

Corrosion of austenitic Fe-Ni based alloys with various chromium and aluminum additions in a carburizing-oxidizing atmosphere at 800ᵒC

First principles study on heterogeneous interfaces of TiCu alloys through aluminum addition

This paper investigates the heterogeneous nucleation interface resulting from the addition of Al element to TiCu alloy, focusing on the essential phases Ti2Cu and TiCu. Employing first principles calculations, we explore the refinement mechanism of this interface. Initially, the lattice mismatch between Al/Ti2Cu and Al/TiCu interfaces is calculated to assess the potential for heterogeneous nucleation. Four distinct interfacial types are established following a surface convergence test. The adhesive work (Wad) and Interfacial energy (γ) are computed for each interface to ascertain their crystallization potential. Furthermore, the differential charge density (DCD) and projected density of states (PDOS) for the four interfacial types are determined to analyze bonding characteristics. Results indicate a mismatch degree of 4.09 % for Al (110)/Ti2Cu (110) and 5.29 % for Al (110)/TiCu (110). These values suggest a tendency to form a heterogeneous interface with a coherent lattice, primarily characterized by Cu-Al and Ti-Al metallic bonds. The Al-Ti2Cu interface exhibits a larger nucleation work of 2.23 J/m2 and a smaller interface energy of −53.007 J/m2. This study demonstrates that Al effectively serves as a heterogeneous nucleation center within the Ti2Cu/TiCu system, contributing to substrate phase refinement and strengthening the TiCu alloy. The optimization of these findings provides valuable insights into the alloy's microstructural evolution, facilitating the design and enhancement of advanced materials for diverse applications.

Influences of alumina type and sulfate content on hydration and physicochemical changes in Portland–limestone cement

This study explored the influence of alumina type and gypsum content on the hydration, mechanical properties, and chemical changes of Portland–limestone cement (PLC) using isothermal calorimetry, inductively coupled plasma-optical emission spectroscopy (ICP-OES), ionic chromatography (IC), compressive strength testing, X-ray diffraction (XRD), 27Al magic angle spinning nuclear magnetic resonance (27Al MAS NMR) spectroscopy, and mercury intrusion porosimetry (MIP) testing. The addition of alumina shortened the induction period, accelerated the acceleration period, and increased the mechanical strength of the PLC pastes with 3 and 7 wt% gypsum. The acceleration effect and strength enhancement were not distinct in the PLC pastes with less gypsum (0.1 wt%). The addition of γ-alumina led to the greatest accelerating effect and strength improvement in the PLC pastes with 3 and 7 wt% gypsum, and the compressive strength achieved was comparable to those of pure Ordinary Portland cement (OPC) pastes without limestone. The addition of γ-alumina induced the rapid dissolution of gypsum and consumption of sulfate ions. The chemical change affected by the addition of alumina varied greatly depending on the gypsum content, and trends in AFt and AFm formation in the PLC pastes with different gypsum contents were confirmed. Finally, pore size refinement was observed through the addition of alumina to PLC pastes with 3 and 7 wt% gypsum.

Preparation and stability of zinc‐based mesoporous sorbent modified with aluminium for high temperature coal gas desulphurization

AbstractZinc‐based sorbents with ordered mesoporous structure were modified with aluminium and the key factors in the preparation were optimized based on the results of desulphurization tests performed in a fixed‐bed reactor with simulated coal gas. It was shown that the sorbents for hydrogen sulphide removal reached an optimum sulphur capacity of 9.14% when prepared under conditions of 10.0 crystalline pH, 30:1 Si:Al molar ratio, 0.32:1 Zn:Si molar ratio, and 1:3 Zn:TAA molar ratio. The sorbent without aluminium was synthesized synchronously as a comparison sample to investigate the effect of aluminium addition on the desulphurization properties. The surface acidity of the sorbents is enhanced by the addition of aluminium, and the sulphur capacity of the aluminium‐doped sorbent is consequently lower compared to that of aluminium‐free sorbent. Nevertheless, the aluminium‐doped sorbent shows a significant advantage in stability of performance over multiple desulphurization–regeneration cycles and reaches an 81% retention rate of sulphur capacity after five desulphurization, while the aluminium‐free sorbent is only 51% in contrast. The characterization results manifest that aluminium enters the carrier skeleton and increases the wall thickness, which alleviates the collapse of the carrier pore channels and the agglomeration of the active components during the desulphurization process. Stable pore structures and highly dispersed active components facilitate the mass transfer in the reaction process after multiple desulphurization. As a result, the aluminium‐doped sorbent exhibits better performance stability in high temperature coal gas desulphurization.

Promoting effects of aluminum addition on chlorophyll biosynthesis and growth of two cultured iron‐limited marine diatoms

AbstractAluminum (Al) may play a role in the ocean's capacity for absorbing atmospheric CO2 via influencing carbon fixation, export, and sequestration. Aluminum fertilization, especially in iron (Fe)‐limited high‐nutrient, low‐chlorophyll ocean regions, has been proposed as a potential CO2 removal strategy to mitigate global warming. However, how Al addition would influence the solubility and bioavailability of Fe as well as the physiology of Fe‐limited phytoplankton has not yet been examined. Here, we show that Al addition (20 and 100 nM) had little influence on the Fe solubility in surface seawater and decreased the Fe bio‐uptake by 11–22% in Fe‐limited diatom Thalassiosira weissflogii in Fe‐buffered media. On the other hand, the Al addition significantly increased the rate of chlorophyll biosynthesis by 45–60% for Fe‐limited T. weissflogii and 81–102% for Fe‐limited Thalassiosira pseudonana, as well as their cell size, cellular chlorophyll content, photosynthetic quantum efficiency (Fv/Fm) and growth rate. Under Fe‐sufficient conditions, the Al addition still led to an increased growth rate, though the beneficial effects of Al addition on chlorophyll biosynthesis were no longer apparent. These results suggest that Al may facilitate chlorophyll biosynthesis and benefit the photosynthetic efficiency and growth of Fe‐limited diatoms. We speculate that Al addition may enhance intracellular Fe use efficiency for chlorophyll biosynthesis by facilitating the superoxide‐mediated intracellular reduction of Fe(III) to Fe(II). Our study provides new evidence and support for the iron–aluminum hypothesis.

Development of Self-Passivating, High Strength Ferritic Alloys for CSP and TES Application

The addition of aluminum to ferritic stainless steels can result in self-passivation by the formation of a compact Al2O3 top layer, which exhibits significantly higher corrosion resistance to solar salt compared to a Cr2O3 surface layer. The development and qualification of realistic experimental methods for fatigue testing under superimposed salt corrosion attack will enable safe component design. Salt corrosion experiments were carried out at 600 °C with and without mechanical fatigue loading at a novel, self-passivating trial steel, using “solar salt” (60 wt.% NaNO3 and 40 wt.% KNO3). Cyclic salt corrosion tests at 600 °C under flowing synthetic air (without mechanical loading) showed that self-passivation to molten salt attack and mechanical strengthening by precipitation of fine Laves phase particles is possible in novel ferritic HiperFerSCR (Salt Corrosion Resistant) steel. A compact, continuous Al2O3 layer was formed on the surface of the model alloys with Al contents of 5 wt.% and higher. A distribution of fine, strengthening Laves phase precipitates was achieved in the metal matrix.

Characterization and Modelling of Particulate Composite with Flaky Aluminium Additives

The utilisation of flaky aluminium as an additive in the composite matrix has shown the ability to overcome the brittle nature encountered in epoxy resins. The additive increases the overall composite toughness without compromising its strength. The novelty of the present work is the demonstration of modelling the constitutive response of the particulate composite from the uniaxial tension tests conducted at three different displacement rates. Utilising two different mean-field homogenisation schemes (Dilute inclusion and Mori-Tanaka), the macro-scale properties were estimated and compared with the material constants obtained from experiments for this new particulate composite, which is proposed in the current study. The rate-independent response, at lower loading rates, is modelled by the elasto-plastic (EP) model, and the rate-dependent response, at higher loading rates, is modelled by elastic-viscoplastic (VP) model while capturing an inelastic deformation as seen in the fractographs. The EP and VP model material constants are then successfully obtained by optimisation employing the Levenberg–Marquardt algorithm and are eventually used in validating the experimental stress response.

On the structure and dynamics of strong and weak eigenvalue detonation in condensed explosives

An eigenvalue detonation, also known as a pathological detonation, is a detonation with incomplete reaction at a point in the detonation reaction zone, that is sonic relative to the leading shock. Aluminized explosives are made by combining a molecular explosive with aluminum and other additives. During detonation, the molecular explosive’s first exothermic decomposition generates products that react exothermically with aluminum, but generate endothermic condensed oxide products, characteristic of eigenvalue detonation.We use a three-component model, for unreacted explosive, intermediate and final products, each with a simple ideal equation of state, and a simple depletion model for the reaction kinetics, with parameters representative of a typical aluminized explosive. We analyze the steady detonation structure in a state-variable, phase plane that allows clear identification of strong and weak eigenvalue detonation. We describe the striking contrast of the strong eigenvalue detonation with significantly higher pressure, density, and temperature in the reaction zone structure, than that of the weak eigenvalue detonation.The accessibility of the strong eigenvalue detonation branch is demonstrated by means of dynamic impact simulations. We present examples of initiation of detonation for reverse impact of unreacted explosive with a stationary wall, and finite thickness, inert flyer impact of unreacted explosive. A control volume analysis is used to describe the energy flow in the region between the incipient sonic point and the flyer explosive interface. This is followed by discussion and conclusions.

Evaluation of Microstructure and Abrasive Wear-Resistance of Medium Alloy SiMo Ductile Cast Iron.

Medium-alloy ductile iron with a SiMo ferritic matrix has very good heat resistance. The addition of chromium and aluminum also increases this resistance. This article presents the impact of chromium and aluminum on the structure of SiMo cast iron, especially their impact on the deformation of the spherical graphite precipitates and the formation of M6C and M3C2 carbide phases. These carbides are formed in a ferritic matrix or at the grain boundaries, resulting in increased hardness and a drastic reduction in impact strength. The article presents the influence of heat treatment on the material's microstructure and resistance to abrasive wear. Chromium and aluminum additions can also indirectly reduce the abrasive wear resistance of SiMo cast iron. The presented research shows the possibility of doubling the abrasive wear resistance of SiMo cast iron.

A new index to estimate the corrosion resistance of aluminium‐containing steel

AbstractA new index that estimates the corrosion resistance of aluminium‐containing steel is established and verified. It is based on the well‐known pitting resistance equivalent number (PREN) but accounts for aluminium additions. It is shown that aluminium enhances the corrosion resistance of chromium‐containing steel, with a coefficient of 5.2. The new corrosion resistance index (CRI) is as follows CRI = Cr + 3.3Mo + 16N + 5.2Al. A minimum of 4 wt% of chromium addition is needed. In addition, the atomic ratio of chromium to aluminium addition needs to be higher than 1, for this new index to be valid. This new index allows for simple alloy design guidelines for steel applications that require improved corrosion resistance. Analysis of the data from the literature shows that this index becomes inaccurate when the corrosion environment is in the presence of NaCl, and aluminium becomes less effective in enhancing corrosion resistance.

Combustion Characteristics and Application Performance of JP-10/Nano-Sized Aluminum Gel-Fueled Scramjet

Using nano-sized energetic materials as fuel additives to hydrocarbon gel fuel has gained in popularity due to the advantages of higher energy density and shorter ignition delay times. Combustion characteristics and application performance of gel fuel containing 16% wt aluminum nanoparticles were investigated on a direct-connect scramjet platform with an inflow Mach number of 2, an inflow total temperature of 1700 K, and a fuel equivalence ratio ranging from 0.6 to 1.0. The gel fuel could be stably injected and atomized efficiently by a nitrogen-assisted injector. The combustion efficiency of JP-10+Al gel fuel was 4.27% higher than that of JP-10 gel fuel, while the addition of aluminum increased the density specific impulse by 6.34%, indicating that the addition of aluminum nanoparticles indeed presented a positive effect on combustion and engine performance. The wall deposition phenomenon of gel fuel was particularly slight as compared to that of slurry fuel cases. Unlike nanoaluminum-blended slurry fuel, nanoaluminum-blended gel fuel controlled the potential risk of increasing thermal load to the least degree within the scope of existing research, with wall heat flux increasing by 7.43% solely as a result of elevated airflow temperature, indicating its advantageous application prospect.

Effects of Titanium, Cerium or Aluminum Addition on Microstructure and Mechanical Properties of Ductile Iron Castings

Effects of Titanium, Cerium or Aluminum Addition on Microstructure and Mechanical Properties of Ductile Iron Castings

Evaluation of a Novel High-Efficiency SHS-EAH Multi-Stage DG-ADP Process for Cleaner Production of High-Quality Ferrovanadium Alloy

A novel high-efficiency industrialized clean production technology based on multi-stage gradient batching and smelting was proposed for the production of high-quality ferrovanadium. The thermodynamic mechanism of aluminothermic reduction equilibrium, alloy settlement and raw material impurity distribution were confirmed, and a multi-stage double-gradient aluminum addition pattern (DG-ADP), the highly efficient separation of molten slag and alloy, and typical impurity control standards of raw materials were achieved on the basis of a self-propagating high-temperature synthesis with an electric auxiliary heating (SHS-EAH) process. The reduction efficiency, separation efficiency and the comprehensive utilization rate of the secondary resources were significantly improved, as the whole total vanadium (T.V) content in the industrially produced residue slag reduced from 2.34 wt.% to 0.60 wt.%, while the corresponding smelting yield increased from 93.7 wt.% to 98.7 wt.% and the aluminum consumption decreased from 510 kg·t−1 to 400 kg·t−1. The multi-stage DG-ADP process enabled the internal circulation of vanadium-bearing materials in the ferrovanadium smelting system, as well as the external circulation of iron and residue slag in the same system, and finally achieved the zero discharge of solid and liquid waste from the ferrovanadium production line, which provides a brand-new perspective for the cleaner production of ferrovanadium alloy.

Impacts to FeRAM Design Arising From Interfacial Dielectric Layers and Wake-Up Modulation in Ferroelectric Hafnium Zirconium Oxide.

As ferroelectric hafnium zirconium oxide (HZO) becomes more widely utilized in ferroelectric microelectronics, integration impacts of intentional and nonintentional dielectric interfaces and their effects upon the ferroelectric film wake-up (WU) and circuit parameters become important to understand. In this work, the effect of the addition of a linear dielectric aluminum oxide, Al2O3, below a ferroelectric Hf0.58Zr0.42O2 film in a capacitor structure for FeRAM applications with niobium nitride (NbN) electrodes was measured. Depolarization fields resulting from the linear dielectric is observed to induce a reduction of the remanent polarization of the ferroelectric. Addition of the aluminum oxide also impacts the WU of the HZO with respect to the cycling voltage applied. Intricately linked to the design of a FeRAM 1C/1T cell, the metal-ferroelectric-insulator-metal (MFIM) devices are observed to significantly shift charge related to the read states based on aluminum oxide thickness and WU cycling voltage. A 33% reduction in the separation of read states are measured, which complicates how a memory cell is designed and illustrates the importance of clean interfaces in devices.

Pengaruh Penambahan Serat Kulit Jagung Terhadap Sifat Mekanik Komposit Polipropilena (PP) dengan Penambahan Aluminium Oksida (Al2O3) dan Maleat Anhidrida (MAH) sebagai Coupling Agent

The utilization of polymer composites in the automotive field is expanding due to their characteristics such as strength, stiffness, and light weight. Polypropylene (PP) is one of the thermoplastic polymers widely used in composite manufacturing due to its lightweight, corrosion-resistant, and recyclable properties. However, to improve its mechanical properties, modifications using natural reinforcements and coupling agents continue to be made. Corn husk fiber is a natural resource that has potential as a natural reinforcement in polymer composites, it has the advantages of good tensile strength, light weight, and is biodegradable. The addition of Aluminium Oxide (Al2O3) and Maleic Anhydride (MAH) as coupling agent can improve the adhesion between fiber and polymer matrix, support more even load distribution, and optimize the mechanical properties of the composite Al2O3 and MAH on the mechanical properties of PP composites. The composition used was polypropylene: corn husk fiber rasio :Al2O3: MAH, namely 90:5:5:0, 89:5:5:1, 87:5:5:3, and 85:5:5:5% by weight. Tensile strength test using Universal Testing Machine (UTM) and crystallinity test using Differential Scanning Calorimetry (DSC) were conducted to evaluate the material performance. The highest value of tensile strength and crystallinity in the composition with 0 %weight MAH. The results of these tests, showing that the greater the composition of corn husk fiber has an influence on the decrease in tensile strength and crystallinity of the composite.

On the properties of cast and powder metallurgical Cu–6Ni-1.5Si-0.15Al (wt.%) alloy

In this study, Cu–6Ni-1.5Si-xAl (x = 0 and 0.15 wt%) alloys are manufactured as billet materials by casting and their metallurgical and physical properties are characterized. Aluminum modified alloy is obtained also by a powder metallurgical (PM) route and its structural properties are determined to be compared with the cast materials. The findings indicate that (i) solidified alloys have distributed nickel silicides (27.01 %) embedded in α-Cu(Ni,Si) solid solution, (ii) the addition of aluminum increases the amount of silicides (29.09 %) in the solidified matrix and reduces both the grain size and the secondary dendrite arm spacing, (iii) although PM alloy has similar microstructural features as cast alloys, it exhibits the highest hardness (159 HV1) due to both finer grain structure and better distribution of silicides, (iv) both impurity and porosity have a determining effect on the electrical conductivity (27–32 % IACS, International Annealed Copper Standard) values of the alloys.

Melting, Solidification, and Viscosity Properties of Multicomponent Fe-Cu-Nb-Mo-Si-B Alloys with Low Aluminum Addition.

Melting, solidification, and viscosity properties of multicomponent Fe-Cu-Nb-Mo-Si-B alloys with low aluminum addition (up to 0.42 at.% Al) were studied using an oscillating cup viscometer. It is shown that melting and solidification are divided into two stages with a knee point at 1461 K. The temperature dependences of the liquid fraction between the liquidus and solidus temperatures during melting and solidification are calculated. It has been proven that aluminum accelerates the processes of melting and solidification and leads to an increase in liquidus and solidus temperatures. In the liquid state at temperatures above 1700 K in an alloy with a low aluminum content, the activation energy of viscous flow increases. This growth was associated with the liquid-liquid structure transition, caused by the formation of large clusters based on the metastable Fe23B6 phase. Aluminum atoms attract iron and boron atoms and contribute to the formation of clusters based on the Fe2AlB2 phase and metastable phases of a higher order.

Impact of composite and aluminium face sheets on the properties of the 3D-printed cores under quasi-static three-point bending

3D printers have been the focus of many researchers in recent years. Many thin-walled structures can be produced using 3D printers. One of the thin wall structures that can be made with 3D printers is the core of sandwich panels. In this research, cores with rectangular cross section have been made using Acrylonitrile Butadiene Styrene (ABS) and Polylactic Acid (PLA) filaments. These cores were reinforced using aluminum and composite face sheets and subjected to a three-point bending test. Glass fibers with a density of 200 g/m2 were used to make composite shells. The results showed that the addition of aluminum and composite face sheets, although increasing the flexural strength, greatly reduces the flexibility of the core.

Impact of Quenching and Aluminium on Si-Segregation and B2 Superstructure Formation in Solid Solution Strengthened Ferritic Ductile Cast Iron

Solid solution strengthened ferritic ductile iron proves to have a better ratio of tensile strength to elongation than conventional ductile iron grades. This applies up to a maximum silicon content of 4.3 wt%, beyond which it leads to an abrupt decrease in ultimate tensile strength and elongation at fracture. During solidification of high silicon ductile iron, negative segregation of silicon occurs, and the highest silicon concentration is observed near the graphite nodules. This high silicon concentration leads to long-range ordering of iron and silicon, and this ordering results in formation of superstructures like BCC_B2 and D03. The presence of super structures restricts the mobility of dislocations and leads to abrupt fracture of the material. This research focuses on the investigation of silicon homogenization by the addition of aluminium and heat treatments to avoid the formation of brittle iron–silicon superstructure. Thermodynamic–kinetic simulations as well as experimental investigations, including variation in alloy composition and quenching, are performed. The results provide a promising understanding to control the micro-segregation of silicon in ductile cast iron based on heat treatments and alloy composition.

Aluminum, a colorful gamechanger: Uptake of an aluminum-containing food color in human cells and its implications for human health

Aluminum is added to many food colors to change their solubility. This study compares the aluminum-containing food color carmine with its aluminum-free version carminic acid (both E 120), hypothesizing that the addition of aluminum does not only change the color's solubility, but also its effects on human cells. We could show that carmine, but not carminic acid, is taken up by gastrointestinal Caco-2 and umbilical vein endothelial cells (HUVEC). Clear differences between gene expression profiles of Caco-2 cells exposed to carmine, carminic acid or control were shown. KEGG analysis revealed that carmine-specific genes suppress oxidative phosphorylation, and showed that this suppression is associated with neurodegenerative diseases such as Alzheimer and Parkinson disease. Furthermore, carmine, but not carminic acid, increased proliferation of Caco-2 cells. Our findings show that a food color containing aluminum induces different cellular effects compared to its aluminum-free form, which is currently not considered in EU legislation.