Addition Of Aluminum Research Articles

Compositional effects in potassium metakaolin geopolymers containing alumina and glass frit

Geopolymers represent a distinct class of materials characterised by their X-ray amorphous nature and nanoporous, nanoparticulate structure. Geopolymers can be conveniently mixed, poured, and cured under ambient conditions. This makes this class of materials an interesting alternative to ordinary Portland cement for structural processes. Additionally, the addition of alumina can improve mechanical properties, while the addition of glass can form an impermeable glaze which could be useful for molten salt containment. Therefore, in this investigation, potassium metakaolin-based geopolymer composites with varying proportions of glass particles and alumina platelets were fabricated, cured, heat-treated, and analyzed to study the effects of composition on material properties. Various attributes including rheological properties, densities, mass loss, shrinkage, and porosities were compared. It was observed that certain compositions exhibited high viscosities, making high shear mixing challenging, while also displaying significant permeability that would hinder their ability to contain liquids without leakage. Additionally, certain samples showed reduced densities, suggesting potentially weaker mechanical properties; however, the investigation did not include a direct assessment of mechanical properties. The most promising candidates for containing liquids at high temperature contained 50 wt% KGP, 25 or 35 wt% glass powder, and 25 or 15 wt% alumina platelets, respectively. ASH-G slurries required a minimum of 65 vol% KGP to produce a homogenous material compatible with additive manufacturing. The minimum amount of glass phase to form surface glazes was 16 vol%. Only samples containing more glass phase than alumina phase produced glazed composites.

Effects of aluminum particle size on metal acceleration for CL-20-based aluminized explosives

The addition of aluminum (Al) powder to CL-20 significantly enhances the overall energy of mixed explosives. Nonetheless, the metal acceleration ability of explosion after Al addition shows unpredictable behavior due to the unclear reaction characteristics of Al in CL-20 detonation products. This study utilizes a plate push test employing CL-20-based aluminized explosives to acquire the reaction degree formulation for Al powder with varying particle sizes in a CL-20 detonation environment. Moreover, it elucidates the reaction mechanism of microsized Al particles during the initial phase of afterburning. Additionally, this reaction formulation enhances the equation of state (EOS) for CL-20-based aluminized explosives. Subsequently, the new EOS is implemented in LS-DYNA to simulate the metal flyer acceleration process. Consequently, the impact of Al particle size on the metal acceleration capability of aluminized CL-20 is examined. The results indicate that for CL-20-based aluminized explosives with 15 % Al content, an optimal Al particle size of 34.12 μm exists when the particle size exceeds 10 μm. This optimum increases the speed of the driving metal plate by 7.4 % compared to CL-20/LiF explosives.

Electrolytes for solid state lithium batteries in the [N13pip]ClO4-LiClO4-Al2O3 system for solid state lithium batteries

The transport, electrochemical, structural, and thermal properties of electrolytes in the ternary system [N13pip]ClO4-LiClO4-γ-Al2O3 (N13pip is N-methyl-N-ethyl-piperidinium cation) were investigated at the molar ratio [N13pip]ClO4:LiClO4 = 0.82:0.18. The addition of alumina leads to a change in the thermodynamic properties of the [N13pip]ClO4-LiClO4 system that can be explained by a partial transfer of lithium perchlorate from the organic phase to the surface of γ-Al2O3. The highest ionic conductivity of 6.2∙10–4 S/cm at 110 °C was observed for the composition containing the volume fraction (f) of γ-Al2O3 equal to 0.5. The increase in conductivity compared to the binary system 0.82[N13pip]ClO4-0.18LiClO4 is achieved due to the amorphization of the organic salt near the salt/LiClO4/oxide interfaces. Galvanostatic cycling with Li electrodes shows that composites with f = 0.5 are stable at 110 °C for at least 68 charge/discharge cycles, and the electrolyte is shown to be electrochemically stable up to 5 V. This system can be used as a solid-state electrolyte in lithium-ion current sources.

How aluminium additions improve the performance of zinc‐rich organic coatings

How aluminium additions improve the performance of zinc‐rich organic coatings

Influence of aluminum addition on structure, hardness, and oxidation resistance of Ta1−xAlxN thin films

Ta1−xAlxN thin films with 5, 15, and 40 at.% Al addition were co‐deposited by reactive magnetron sputtering and characterized by Rutherford backscattering spectroscopy (RBS), grazing angle X‐ray diffraction (GAXRD), X‐ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), nanohardness, and oxidation tests. GAXRD and XPS analyses showed, regardless of the % Al added, the non‐existence of ternary nitride Ta1−xAlxN, but always as individual binary nitrides, TaN and AlN. Sample TaAlN_15 obtained the highest hardness and H3/E2 values, possibly due to the AlN grains presence, which were efficient in distorting the TaN lattice. All samples failed oxidation tests at 873 K, showing that the Al addition was not efficient in improving this property for tantalum aluminum nitride thin films.

The investigation of the performance and exhaust emissions of the compression-ignition engine with a mixture of diesel and aluminum particles

In this study, aluminum particles were added to diesel fuel in amounts of 75 and 150 ppm, with a particle size of 15 micrometers and a purity of 98.95 %. A magnetic stirrer was used to achieve homogeneous mixing of aluminum particles in diesel. In order to prevent aluminum particles from settling, fuel mixtures were stirred for 45 minutes for every 2 kg of fuel mixture. Fuel mixtures prepared to prevent settling were used immediately to avoid affecting the experimental results. The experiments were conducted at torque values of 100, 150, and 200 Nm, with a constant 660 rpm. The experiments initially started with pure diesel. Then, they continued with diesel fuels containing 75 and 150 ppm of aluminum additives, respectively. Positive effects of aluminum addition on engine performance were observed. The highest efficiency was obtained with the fuel containing 75 ppm of aluminum additive. The fuel with 75 ppm of aluminum additive provided efficiency increases of 4.57 %, 2.90 %, and 2.23 % compared to pure diesel at torque values of 100, 150, and 200 Nm, respectively. Although the fuel with 150 ppm of aluminum additive showed less efficiency improvement compared to 75 ppm, it still provided efficiency improvement compared to pure diesel. Improvements in NOx, CO, and HC emissions were observed in experiments conducted with aluminum particle-added fuels. The aim of this study is to increase the efficiency of diesel engines and reduce exhaust emissions by using aluminum particle additives.

Effect of reinforcement particles (Sic / Alumina) addition on Al6061 alloy and optimization of dry sliding wear properties using GRA

Effect of reinforcement particles (Sic / Alumina) addition on Al6061 alloy and optimization of dry sliding wear properties using GRA

Investigation of effects of aluminum additions on microstructural evolution and mechanical properties of ultra-high strength and vanadium bearing dual-phase steels

The effects of aluminum (Al) additions (0.04, 0.4, and 0.8 wt%) on the microstructural evolution, tensile properties, and sheared-edge ductility of dual phase (DP) steels were investigated. The DP steels were processed with distinct coiling temperatures after finish rolling, cold rolled, and subjected to two continuous galvanizing line (CGL) simulations: standard galvanizing (GI) and supercooling process (SC). Al expanded both the ɑ-ferrite and (ɑ+γ) phase fields at the expense of the γ-austenite region. Continuous cooling transformation (CCT) diagrams showed that Al increased ferrite start temperatures, broadened the ferrite transformation zone, and reduced austenite stability. Austenite growth kinetics during intercritical annealing, quantified using a modified Johnson-Mehl-Avrami-Kolmogorov (JMAK) model, revealed Avrami exponents ranging from 0.72 to 0.81 and apparent activation energies increasing from 422.9 to 496.7 kJ mol−1 with Al additions. Microstructural characterization revealed larger ferrite grain sizes and higher ferrite volume fractions with higher Al levels. Ultimate tensile strength (UTS) was influenced by Al contents, coiling temperatures, and CGL simulation methods. Global ductility (total elongation, TE) was highest for the 0.8Al Steel with a high coiling temperature and GI annealing, while local ductility (hole expansion ratio, HER) was maximized for the 0.04 Al Steel with a low coiling temperature and SC annealing. The majority of the CGL simulated DP steels exhibited good strength-ductility combinations, with the 0.8Al Steels demonstrating superior properties compared to current automotive advanced high-strength steel (AHSS) grades.

Thermomechanical properties of poly(vinyl alcohol) prepared at room temperature as a function of degree of hydrolysis and aluminium addition

Poly(vinyl alcohol) (PVOH) is widely used in various industrial applications. However, its water solubility reduces film performance, which is important in PVAc-based wood adhesives. In this sector, AlCl3 is often used as a complexing agent for PVOH. In this work, the effect of heating and aluminium addition on the structure and viscoelastic properties of PVOH with different degrees of hydrolysis (DH), 88%, 92% and 99%, was studied. Products treated with either HCl or acetic acid were also considered. The polymer properties were evaluated by infrared spectroscopy and dynamic mechanical analysis, and the mass loss of the polymers on heating was also evaluated to explain the observed differences. The measurements showed that the peaks of the tanδ curves occurred at slightly lower temperatures as the DH increased, although higher crystallinity was observed at the end of the DMA tests for higher DHs. This is due to the increasing affinity of highly hydrolysed PVOH for water molecules. However, as the temperature increased, the storage modulus was higher for higher DHs due to the better mutual interaction of OH groups that develops during the tests in highly hydrolysed polymers. The addition of aluminium caused a slight increase in Tg, the magnitude of which was inversely proportional to the DH. However, as the temperature increased, the storage modulus decreased more at lower DHs than at higher DHs. This effect was related to a combination of factors: the lower presence of crystallites in products with lower DH and the formation of conjugated polyenes, which was also more pronounced in products with lower DH. Both mechanisms were due to the action of aluminium. Thus, both heat and the addition of aluminium had a determining effect on the properties of PVOH films, although the degree of importance depended on the degree of hydrolysis of the polymer.

Effect of TPMS reinforcement on the mechanical properties of aluminium–alumina interpenetrating phase composites

AbstractTriply Periodic Minimal Surface (TPMS)-based aluminium–alumina Interpenetrating Phase Composites (IPCs) manufactured through the combination of Additive Manufacturing (AM) and investment casting are explored in this study. Multiple alumina TPMS structures (Gyroid, Diamond, and Primitive) with different geometries and volume fractions were designed and fabricated using Digital Light Processing (DLP) AM technology. Afterwards, these ceramic structures were filled with an aluminium alloy via investment casting, uncovering an aluminium–alumina IPCs. A global characterization was performed, including ceramics shrinkage and mass loss; specimens’ morphology; chemical and crystalline characterization; density analysis and mechanical testing. Overall, DLP technology was found effective for producing these highly complex ceramic structures, with high surface quality. The sintered alumina structures presented a relative density of ca. 76.3% and a pseudo-ductile layer-by-layer failure behaviour, with Diamond-based TPMS exhibiting the highest compressive strength. Regarding the IPCs, the addition of aluminium significantly changed the compressive behaviour of the samples, presenting an energy absorption behaviour. The integration of the alumina phase into the aluminium alloy led to an improvement on the compressive offset stress of approximately 6% when compared to the aluminium alloy used. Diamond and Gyroid IPCs demonstrated similar mechanical behaviour and the highest mechanical performance. Graphical Abstract

Overview of corrosion behaviour of ceramic materials in molten salt environments

This study reviewed previous studies between the years 2015 and 2021 on how ceramic materials degraded in the presence of molten salt environments. The processes of corrosion resistance of various ceramic compositions subjected to various molten salt compositions and temperatures were also scrutinized. The results offer important new insights into the variables affecting ceramics' corrosion behaviour and the production of corrosion products. The reported result reveals that the ceramic material with the composition (Sm0.5Sc0.5)2Zr2O7 performed better than that of Sm2Zr2O7 in terms of hot corrosion resistance in molten salt (V2O5 + Na2SO4). It has also been reported that corrosion behaviour is influenced by particle size. Notably, zirconia (n-YSZ) with nanoscale grain sizes was more susceptible to hot corrosion, which was explained by increased specific surface areas. On the other hand, sintering and additives have been found to enhance corrosion resistance. The Y-Y2Si2O7 ceramic's resistance to corrosion in (V2O5 + Na2SO4) molten salt was enhanced by the addition of alumina. The results of these investigations help us understand how corrosion works and what influences ceramic materials' susceptibility to deterioration in molten salt media. This information can direct the creation of more corrosive-resistant ceramic materials for use in high-temperature environments or molten salt-based energy systems, among other corrosive uses.

Influence of the elemental composition on the structural and mechanical characteristics of entropy-stabilized HfZrCeYMgAlO thin films prepared by reactive magnetron sputtering

Entropic stabilization of the crystal structure of solids was demonstrated for various systems, starting with metals and continuing with oxides, nitrides, borides, and more complex structures. The influence of additional thermodynamic driving forces sometimes allow to stabilize the material in a crystalline configuration that is unusual for it. In this paper, we focused on the HfZrCeYMgO system, which has shown excellent mechanical properties and a stable crystal structure. We added different concentrations of aluminum oxide, but found that even in significant quantities, it was embedded in the lattice without separating into separate phases. At the same time, we found that the addition of aluminum significantly increases the crystallinity of the coating as well as its mechanical characteristics. We associate the increase in coating crystallinity with a consistent increase in the entropy of mixing in the HfZrCeYMgAlO system.

Comparison of Mechanical Properties of Bulk NiAl-Re-Al2O3 Intermetallic Material Manufactured by Laser Powder Bed Fusion and Hot Pressing

AbstractThe low fracture toughness of NiAl at room temperature is one of the critical issues limiting its application in aircraft engines. It has been previously shown that a small addition of rhenium and alumina significantly improves the fracture toughness of hot-pressed NiAl. In this work, NiAl with an admixture of rhenium and alumina was produced by laser powder bed fusion additive technology (LPBF). The purpose was to compare the fracture toughness, bending strength, and microhardness of the NiAl-Re-Al2O3 material produced by LPBF and hot pressing (HP). Our results show that the LPBF material has lower fracture toughness and bending strength compared to its hot-pressed equivalent. Microcracks generated by thermal stresses during the LPBF process were the primary cause of this behavior. To improve the LPBF material, a post-processing by HP was applied. However, the fracture toughness of the (LPBF + HP) material remained at 50% of the KIC of the HP material. This study supports hot pressing as a suitable processing method for NiAl with rhenium and alumina additions. However, a hybrid approach combining LPBF and HP proved to be highly effective on the raw NiAl powder, resulting in superior fracture toughness of the final material compared to that consolidated by singular HP.

Carbonation of photocatalytic aluminosilicate cement composites: Evolution of self-cleaning and radiative cooling properties

This study aims to understand the impact of carbonation on the photocatalytic self-cleaning and radiative cooling properties of autoclaved cement composites. The composites are prepared with varying silica contents and sources, with and without alumina addition under autoclave conditions. The phase composition, microstructure, optical properties, and photocatalytic self-cleaning performance are systematically characterized and analyzed. Outdoor measurements are conducted to validate the cooling performance of the material under ambient conditions. Cracking behaviors during autoclave/carbonation treatments and the performance degradation in functionalities upon carbonation are observed. The cement/nanosilica/alumina ternary system demonstrates the best overall performance, considering productibility during autoclave curing, effectiveness, and carbonation durability of functionalities. C-A-S-H minerals, mainly Al-Foshagite, in this system, serve as precursors for the generation of γ-Al2O3 upon carbonation, mitigating the deterioration of photocatalytic properties. The findings are expected to provide new insights for the development and engineering practice of functional cementitious materials for durable cooling applications.

Engineering Compounds for the Recovery of Critical Elements from Slags: Melt Characteristics of Li5AlO4, LiAlO2, and LiAl5O8.

Engineered artificial minerals (EnAMs) are the core of a new concept of designing scavenger compounds for the recovery of critical elements from slags. It requires a fundamental understanding of solidification from complex oxide melts. Ion diffusivity and viscosity play vital roles in this process. In the melt, phase separations and ion transport give rise to gradients/increments in composition and, with it, to ion diffusivity, temperature, and viscosity. Due to this complexity, solidification phenomena are yet not well understood. If the melt is understood as increments of simple composition on a microscopic level, then the properties of these are more easily accessible from models and experiments. Here, we obtain these data for three stoichiometric lithium aluminum oxides. LiAlO2 is a promising EnAM for the recovery of lithium from lithium-ion battery pyrometallurgical processing. It is obtained through the addition of aluminum to the recycling slag melt. The high temperature properties spanning from below to above the liquidus temperature of three stoichiometric Li-Al-Oxides: Li5AlO4, LiAlO2, and LiAl5O8 are determined using molecular dynamic simulations. The compounds are also synthesized via the sol-gel route. The Li+ ion exhibits the largest diffusivity. They are quite mobile already below the liquidus temperature, i.e., for LiAlO2 at T = 1700 K, the diffusion coefficient of the lithium ion equals D = 3.0 × 10-9 m2 s-1. The other ions Al3+ and O2- do not move considerably at that temperature. The diffusivity of Li+ is largest in the lithium-rich compound Li5AlO4 with D = 32 × 10-9 m2 s-1 at 2500 K. The lower the viscosity, the higher the lithium content. The Li5AlO4 exhibits a viscosity of η = 2.2 mPa s at 1328 K which matches well with the experimentally determined 2.5 mPa s at this temperature. The viscosity of LiAlO2 at 1800 K is more than two times higher. These data sets can help to describe the melts on a microscopic level and understand how the melt properties will change due to gradients in the Li/Al concentration.

The Influence of Calcined Alumina Additives on the Mechanical Properties and Chloride-Induced Corrosion of Blended Concrete

The Influence of Calcined Alumina Additives on the Mechanical Properties and Chloride-Induced Corrosion of Blended Concrete

Microstructure, high temperature mechanical properties and sliding wear behavior of (NiCrW)1-x(Al2O3)x

(NiCrW)1-x(Al2O3)x composites with different nano-Al2O3 ratios (x = 0, 1, 2.5, 5 wt %) were prepared using powder metallurgy techniques. The influence of the Al2O3 content on the microstructure, phase composition, high-temperature mechanical properties, and wide-temperature-range friction and wear performance of the composites was investigated. The corresponding high-temperature strengthening and wear-resistance mechanisms were also investigated. The results indicated that as the alumina content increased, the tensile and compressive strengths of the composites decreased at room temperature (RT). However, at high temperatures (800 °C), the opposite trend was observed. Notably, the composite with 5 wt % Al2O3 exhibits the highest tensile strength (189.20 MPa) and compressive strength (446.61 MPa) at 800 °C. The addition of alumina had a relatively minor impact on the friction coefficient of the composites but significantly affected the wear rate. Specifically, the composite with 5 wt % Al2O3 demonstrates optimal friction and wear performance at high temperatures. This enhancement was primarily attributed to the reinforcement of the mechanical properties of the matrix material owing to the addition of alumina. Additionally, the formation of a friction glaze layer rich in Cr2O3 and NiO oxides on the worn surface contributed to improved wear resistance. This study is important for understanding the performance and applications of metallic materials.

Exploring the influence of additives on the ignition, combustion and quenching of electrically controlled solid propellants

AbstractThe influence of additives on the decomposition and combustion characteristics of electrically controlled solid propellants was investigated through small scale experiments. Carbon black and aluminum additives were explored in a polyethylene oxide, lithium perchlorate propellant. Additives were used to improve the voltage response and their impact on ignition and combustion was characterized. The data showed that conductive additives can mitigate the loss of solid phase conductivity through solvent evaporation and that ignition delay decreases with higher voltage and solid phase conductivity. Steady‐state combustion experiments showed that electrical decomposition of the propellants proceeded more rapidly than a purely thermal stimulus illustrating the importance of electrochemistry in ECSP combustion. The combined effects of pressure and voltage on combustion rates were summarized in Saint‐Robert's burn relations. The regression rates increased with both applied voltage and pressure. The pressure deflagration limit of propellants with the carbon black additive was significantly reduced compared to a neat PEO/LP propellant, whereas the addition of 10 % aluminum did not affect the pressure deflagration limit.

Preparation of ferrotitanium alloy by aluminothermic reduction of perovskite

Titanium-bearing blast-furnace slag is an important secondary resource. Artificial perovskite, with CaTiO3 as the main crystal phase, can be obtained after settling of the slag. Preparation of ferrotitanium alloy using perovskite as the titanium-containing material and aluminum as the reducing agent was studied. X-ray diffraction, scanning electron microscopy with energy-dispersive spectroscopy, and elemental chemical analysis were used to determine the composition and microstructure of the products. The results show that FeTi50 alloy can be prepared by aluminothermic reduction of perovskite. Reduction temperature has a strong influence on the separation of alloy and slag: when the reduction temperature increased from 1500 ℃ to 1600 ℃, the ferrotitanium alloy and slag effectively separated and Ti recovery exceeded 80%. The Al and O contents in the alloy decreased with decreasing aluminum addition, but also reduced Ti recovery. An alloy conforming to the industrial standard for FeTi50-A was obtained when the aluminum addition was 90 mass% of the stoichiometric value regarding reduction of perovskite.

Investigation of the Effect of Aluminium Addition on the Additively Manufactured SS309L Alloy

Investigation of the Effect of Aluminium Addition on the Additively Manufactured SS309L Alloy