Increasing Aluminum Content Research Articles

Influence of external fields on the exciton binding energy and interband absorption in a double inverse parabolic quantum well

Ground-state binding energy and optical absorption coefficient of exciton in a symmetric double inverse parabolic quantum well system in the presence of external electric and magnetic fields are investigated theoretically. Numerical calculations have been carried out with the variational technique considering the single-band effective mass approximations. Results reveal that the excitonic binding energy and interband optical absorption depend on significantly on the geometrical and structural parameters defining carriers’ double inverse parabolic confinement potential, the aluminum concentration at the well center, the electric field, and the magnetic field. The exciton binding energy is a decreasing (increasing) function of the electric field (magnetic field). The increase in aluminum concentration creates a blueshift at the resonance peak positions. As a result, the tunability of the excitonic effects is expected to be of importance in developing stable and high-efficiency nanoscale excitonic optoelectronic devices . • Analyses of double inverse parabolic quantum well. • Exciton binding energy. • Interband transitions. • Electric and magnetic field effects.

Optimization of biocorrosion resistance and mechanical properties of PM Ti–XAl–2Fe–3Cu alloys by response surface methodology

In the current study, the biocorrosion resistance and mechanical properties of the Ti–XAl–2Fe–3Cu (wt%) (X = 6, 4, 2 wt%) alloy produced by powder compact extrusion of blended elemental powders were optimized by using the response surface methodology in order to gain the best combination of processing parameters. To run the optimization process, central composite design with three equal levels of oxygen, hydrogen and aluminum was used and, by employing ANOVA, the analysis of variance was implemented. The results showed that the content of aluminum has a significant effect on the microstructure, mechanical properties, biocorrosion resistance and fracture behavior of the extruded rods. The highest aluminum content corresponds to the highest alloy strength and biocorrosion resistance. This was due to the reduction of the lamella thickness and of the material colonies as the aluminum content increases. Also, by running the experimental and optimization tests, the mechanical properties resulted 1245 MPa in yield strength and 1340 MPa in ultimate tensile strength with 0.1 µAcm−2 in corrosion current.

Effect of FeSi Alloy Additions and Calcium Treatment on Non-Metallic Inclusions in 304 Stainless Steel during AOD and LF Refining Process

Non-deformable inclusions are detrimental to the surface quality and mechanical properties of stainless-steel plates. Plant trials were conducted to investigate the effect of different ferrosilicon alloys and calcium treatment during argon oxygen decarburization (AOD) and ladle furnace (LF) refining on inclusions in Si-killed 304 stainless steel. The inclusions were examined by scanning electron microscope with energy dispersive spectrometer. The results show that both the contents of soluble aluminum in molten steel and Al2O3 in slag increase with the increase of aluminum content in FeSi alloy. The content of soluble aluminum in liquid steel could be limited to lower than 0.004% when using ultra-purity FeSi alloy. When the calcium wire addition is 2 m/t, inclusions are located in the low-melting-temperature region, and the inclusion rating of hot rolled plates is mainly C-class. Industrial application shows that, by decreasing the soluble aluminum content in liquid steel, decreasing the MgO and Al2O3 in slag in AOD, and applying low basicity refining slag as well as calcium treatment, the inclusions are low melting point silicates. The inclusion rating of hot rolled plates is mainly fine C-type with a small amount of class-A, and surface polishing qualification rate is increased from 17.8% to more than 88.7%.

Effect of aluminium on microstructure and shape memory effect in Cu-Al-Ag-Mn shape memory alloys

ABSTRACT The objective of the present investigation is to synthesise and characterise the Cu-Al-Ag shape memory alloys with minor Mn addition. Synthesis of Cu-Al-Ag-Mn SMA was done by induction furnace and gravity die casting, with constant Ag/Mn ratio (5% Ag and 2% Mn), the aluminium composition is varied from 8% to 14%. The as-cast sample will be further subjected to thermo-mechanical treatment to produce a sheet which exhibits shape memory effect. This study is to determine the influence of Al content on shape memory characteristics, microstructure, and phase transformation temperatures. The phase fraction of β’1 increased from 56% to 67% along with subsequent reduction of γ1’ phase fraction from 23% to 17%, which is essential for improvement of shape memory properties with increase of aluminium constituent. X-ray diffraction revealed that the crystalline size decreased 79 to 32 nm and lattice strains increased from 0.24% to 0.69% with increase of Aluminium. With an increase in aluminium content, the martensite transformation temperature decreased from 386°C to 246°C, and the shape memory effect increased from 81 to 90% strain recovery. The ability to control shape memory characteristics by changing Al composition will improve the scope for this alloy in various shape memory applications.

The effect of Al addition on solid solution strengthening in CoCrFeMnNi: Experiment and modelling

The effect of aluminum addition to the Cantor alloy in the composition range of 0.25–5 atomic percent towards solid solution strengthening of supposedly single-phase HEA was investigated using experiments and first principle simulation-guided constitutive modeling. The continuous increase in yield and tensile strength without significant change in ductility is observed for the alloys with increasing aluminum content. The constitutive modeling of the strengthening has been performed using traditional as well as recently developed models for solid solution strengthening. It indicated a significant contribution (50% increases from Cantor alloy to Cantor alloy containing 5 atom % Al) of solid solution strengthening due to the addition of Al having a relatively larger size (̴12 %) than the size of elements in the Cantor alloy, causing severe local lattice distortion. The experimental yield strength could be best explained based on the large apparent distortion volume of the Al atom acting as a stronger barrier to dislocation motion based on the Varvenne model by incorporating the lattice distortion. First-principles simulations indicate that local and global lattice distortion contributes to an increase in the strength by strong pinning of dislocations by aluminum atom leading to high strength.

3D printing of silica-based ceramic cores reinforced by alumina with controlled anisotropy

Ceramic core (CC) is a key component in the casting of aero-engine turbine blades, and CC through 3D printing is crucial to the growing aviation technology. However, these silica CCs are highly limited by their high temperature softening and inevitable anisotropy. In this work, silica-based CCs reinforced by alumina powders are manufactured by 3D printing via digital light processing (DLP) stereolithography, and the anisotropy in microstructure and property was investigated. In the CC without alumina powders, multilayer structures with significant interlayer gaps are exhibited in horizontal printing direction suggesting significant anisotropy in microstructure, which is related to the particle deposition in printing. As the alumina content is 6 wt%, microstructures become uniform, due to the enhanced particle rearrangement between different layers. To assess the mechanical anisotropy, the ratio of vertical strength to horizontal strength (σV/σH) is raised, and the σV/σH ratios rise from 0.45 to 0.86 at room temperature and 0.52–0.89 at 1540 °C with increasing alumina content from 0 to 6 wt%. As the alumina content is 6 wt%, the CC exhibits high temperature flexure strengths as high as 17.9 MPa and 19.5 MPa in different directions, well satisfying the demands for turbine blades casting. This article inspires a profound understanding on the anisotropy control in 3D printing of CC with excellent high-temperature mechanical properties.

Experimental Study on the Modification Mechanisms of Dispersive Soil Treated with Hydroxyl Aluminum

Dispersive soil is a special clay that is easy to disintegrate and disperse into particles and suspend in water, which can easily cause erosion and piping damage of dams, grooves, and road slopes. In this study, a new dispersive clay modifier hydroxyl aluminum (a positively charged aluminum hydroxide electrolyte) was proposed. Previous studies have shown that it can well coat montmorillonite in clay and combine with it to stabilize the properties of clay. The modification effect and interaction mechanism of hydroxyl aluminum on dispersive soil were studied through indoor dispersion discrimination, physical and mechanical, and micro mechanism tests (SEM and XRD). The experimental results indicate the following: With the increase of hydroxyl aluminum content, the dispersion of dispersed soil decreases and becomes nondispersive soil. Hydroxyl aluminum has an excellent inhibiting dispersion effect on dispersive soil, and it has the “agglomeration” and “cementation” effect on the dispersive soil particles. The addition of hydroxyl aluminum makes the dispersive soil agglomerated crystals arranged closely, and the number of pores between the particles reduces clearly, making the dispersed particles agglomerated. It can also reduce the alkalinity of the clay and make the clay structure more stable to restrain the dispersion of clay.

Thermodynamic substantiation of compositions of silicon aluminium alloys with increased aluminium content in Fe-Si-Al system

A priority direction of ferrous metallurgy development is to increase in output of the high quality metal and metal products of new assortment. One of the methods to improve a quality of steels is to involve of complex alloys based on aluminum, silicon, manganese, etc. for their output. They are necessary as deoxidizing agents and alloying additives. This paper considers the possibility of the thermodynamic substantiation of the aluminum solubility in the ferrosilicon-aluminum complex alloy (FeSiAl) on the basis of their phase diagrams using the osmotic coefficient of the Bjerrum-Guggenheim. Methodology used is based on the theoretical studies of the phase equilibria using the Bjerrum-Guggenheim concept. It includes a set of computer programs in C# language (C sharp) designed to evaluate a deviation scope of properties of a real system from the ideal one. Criterion for evaluation is an osmotic coefficient of the Bjerrum-Guggenheim. The pattern of change in an osmotic coefficient of the Bjerrum-Guggenheim on the ratio of activity of components in the ideal liquid and solid phases (positive Фi <1 or negative Фi >1) under the boundary forming conditions of crystallization regions of phases related to the melting ferrosilicon-aluminum processes is a direct proof of the possibility to use it as a metal reducing agent. The calculated mathematical dependences of the osmotic coefficient of the Bjerrum-Guggenheim permit us to determine the crystallization temperature of the ferrosilicon-aluminum alloy. The alloying process with rich aluminum content is observed at this temperature. The dependence diagrams of an osmotic coefficient of the Bjerrum-Guggenheim of a crystallizing component on the ratio of its activity in the liquid and solid phases demonstrated that a temperature rise leads to strong negative deviations in silicon properties, and thus to its good mixability in the melt with iron and aluminum. Compositions of silicon-aluminum alloys with high aluminum content in the ferrosilicon-aluminum complex alloy (FeSiAl) were determined on the basis of their phase diagrams using the osmotic coefficient of the Bjerrum-Guggenheim with iron content of 12-37%, aluminum 20-25% and silicon 68-38%. The received theoretical results permit to determine conditions which give the maximum possible aluminum assimilation with the ferrosilicon-aluminum melts supplied from the high-ash coal in the melting process of this metal in the ore-thermal furnaces. Thus it is a direct method to develop the output technology of the complex alloys.

PROSPECTS FOR CREATING SURFACE LAYERS OF DETA-LEU WITH INCREASED TRIBOLOGICAL CHARACTERISTICS USING GAS-DYNAMIC FILLING

The article presents the results of the analysis of antifriction materials based on tin and lead, copper, aluminum, plastics. The advantages and disadvantages of one or another antifriction material, as well as the possibility of their application on the surface of parts by the method of cold gas-dynamic spraying, are shown. The use of liquid and solid anti-friction materials as lubricating oils is considered. Considerable attention has been paid to materials with the same crystal structure as graphite, now known as two-dimensional (2D) materials. Among these 2D materials, the most studied materials are MoS2 and a carbon-based compound, including graphite and graphene. The scheme of interaction of sliding surfaces is considered, including wear, molecular deformation, adhesion, thermal effect and the environment. Analysis of anti-friction materials showed that their application to the surface of parts can be carried out using the process of cold gas-dynamic spraying. The article shows a diagram and type of installation for cold gas-dynamic spraying of antifriction surface layers. For the research, copper-graphite powder with a particle size of 10,7 – 80,8 microns was used. Using the application "Maso central characteristics" of the software "Compass-3D", the mass of the deposited figure as a continuous material for copper-graphite coatings, with a density of ρ1 = 0,0086454 g / mm3, and the porosity of the deposited figure were determined. In the course of the study, it was found that, in comparison with the substrate material AA7075, the sliding friction coefficient was reduced by 47% - 62% for the copper-graphite surface layer. To obtain composite coatings, a mechanical mixture of A30-01 aluminum powder and C01-00 copper was used. The dependences of the coefficients of sputtering of copper and aluminum on the mass content of aluminum in the sprayed mixture at an initial concentration of aluminum of less than 66% are found. The copper deposition rate is higher than the aluminum deposition rate. Both monotonically increase with increasing aluminum concentration until it reaches 61%. At high concentrations of aluminum (more than 66%), the coefficients of deposition of copper, aluminum and their mixtures coincide.

Interfacial Microstructure and Mechanical Properties of Explosively Welded Mg/Al Alloy Plates

The interfacial microstructure and hardness of cladding plates produced by explosive welding between magnesium alloys having different aluminum concentrations and A6005C aluminum alloy were investigated. Further, measurements of residual stress at the interface of cladding plates were performed. In all cladding plates, the bonding interface had a wavy shape. Adiabatic shear bands were formed at the interface on the magnesium alloy side and deformation twins appeared at the interface due to the impact of explosive welding. Microstructure observation using scanning transmission electron microscope revealed that a thin interlayer was formed at the interface in all cladding plates. The thickness of the interlayer increased with an increase in aluminum concentration in the magnesium alloy, while the thickness was 1 μm or less. In the cross-section of the cladding plate, aluminum alloy showed a relatively higher Vickers hardness value compared with the magnesium alloy, and the hardness value increased when approaching the interface. However, nanoindentation tests revealed no increase in hardness was observed at the interface. Measurements of the residual stress using synchrotron radiation x-rays at the interface of cladding plates revealed a tendency for the occurrence of tensile residual stress on the magnesium alloy side and compressive residual stress on the aluminum alloy side. This might be due to a difference in the coefficient of thermal expansion between the magnesium and aluminum alloys.

Effect of Al content on microstructure and wear properties of FeCrNiMnAlx high-entropy alloys

A series of FeCrNiMnAlx (x = 0, 0.3, 0.5, 0.8, 1.0 in molar ratio) high entropy alloys (HEAs) were prepared by the vacuum arc melting method. The effects of Al content on the microstructure, mechanical and wear properties were investigated. For FeCrNiMn alloy, the microstructure was main homogeneous structure with face-centered cubic (FCC) phase, whilst FeCrNiMnAl0.3 produced a dendritic microstructure consisting of a mixture of FCC + BCC + B2 phases, and the mixture BCC + B2 dendritic interdendritic microstructure appeared when the molar ratio of Al is beyond 0.5. The hardness and yield stress of the HEAs are effectively improved with the increased Al amount but the ductility is lowered. In this case, FeCrNiMnAl alloy showed decreased yield stress due to the deteriorated ductility. Moreover, the friction coefficient decreases, and the wear resistance improved with the increased aluminum content. FeCrNiMnAl0.8 HEAs have the best wear resistance due to the advantages of achieving a balance of strength and ductility.

Cesium extraction from the Taron deposit

Cascadero Copper Corp. has developed a hydrometallurgical process to recover cesium from mineral samples of the Taron deposit in Argentina. Cesium was extracted by sulfuric acid leaching both without and with SO2 addition, and then precipitated from the leachate as cesium alum for potential refining to cesium hydroxide. Due to a relatively low cesium content in the deposit (< 1 wt%), the cost of sulfuric acid dominates the economics of cesium recovery. The objective of this investigation was to optimize cesium extraction at an acceptable acid consumption within the constraints of hydrometallurgical processing. In sulfuric acid leaching of mineral samples under the condition of 93 °C, a solids concentration of 265 g/L and 4 h of leaching time, the cesium extraction increased with increasing initial acid concentration, reaching 96% at 200 g/L H2SO4. Higher acid concentration gave only marginal increases in cesium extraction. In two-stage countercurrent leaching with 150 g/L H2SO4, the cesium extraction was improved from 83% (in a single stage leaching) to 95%. Reductive leaching with SO2 addition was used to reduce the acid consumption. More cesium was extracted at a higher SO2 addition and a higher temperature. The SO2 leaching process was also improved with increasing sulfuric acid concentration, indicating that a high acid concentration is needed to release some portion of cesium into the solution. At a solids fraction of 30 to 50 vol%, the cesium extraction decreased with increasing solids content as the slurry became too viscous and difficult to agitate, resulting in a lower leaching rate and lower final extraction. Cesium was precipitated from the leachates as cesium alum at 4 °C and the precipitation was enhanced by increased aluminum concentration.

Preparation of mullite ceramics with equiaxial grains from powders synthesized by the sol-gel method

Four different alumina content of mullite ceramics were fabricated by powders synthesized using the sol-gel method. The synthesis process of powders, microstructure evolution, mechanical and optical properties of the mullite ceramics were studied. The XRD results showed that the precursors transformed into aluminosilicate spinel phase at 1000 °C and mullite phase at 1200 °C. Equiaxial grains were easy to form in the alumina-rich mullite ceramics while elongated grains were easy to form in the alumina-poor mullite ceramics. With the increase of alumina content, the grain size of the samples firstly increased and then decreased, the number of elongated grains decreased while equiaxed grains increased. The flexural strength, compression strength, fracture toughness, and Vickers hardness all decreased firstly and then increased. While the infrared transmittance increased firstly and then decreased. The transmittance at 4 μm (thickness of 0.75 mm) of the ceramics containing 66mol% Al2O3 reached the highest (72%) when sintered at 1780 °C because of the equiaxial grains.

Belite Clinkers with Increasing Aluminium Content: Effect of Calcium Aluminates on Calcium Silicate Hydration

Belite Clinkers with Increasing Aluminium Content: Effect of Calcium Aluminates on Calcium Silicate Hydration

Effect of clariflocculator and pulsator based sedimentation technology and poly-aluminium chloride coagulant type on the efficiency of the water treatment plant

Abstract Polyaluminium chloride (PAC) with different basicity is used as a coagulant in most drinking water treatment plants (WTP). The aluminium concentration in PAC and its hydrolysis mechanism varied with the basicity of PAC. Incremental addition of PAC changes various physico-chemical properties and turbidity removal mechanisms in water. Water treatment plants use the PAC concentration beyond its optimum dose without considering other aspects, including residual aluminium concentration. In the present work, the effect of high and medium basicity of PAC on different physico-chemical properties like pH, zeta potential, and residual aluminium concentration of water was investigated. The pH of treated water decreases with the incremental addition of PAC, and an increase in zeta potential and residual aluminium concentration in treated water was evidenced. The change in pH after PAC addition is responsible for deciding the coagulation mechanism and efficiency of the coagulation process. pH reduction is comparatively more in high basicity PAC than medium basicity. PAC hydrolysis mechanism is controlled by the zeta potential of water and can be used as an alternative method to decide the optimum coagulant dose. The performance of clariflocculator and pulsator-based WTP was also evaluated for raw water from the same source. To reduce down the turbidity below the acceptable level, the coagulant requirement for clariflocculator based WTP is comparatively less than pulsator based WTP. The floc blanket in the pulsator gets disturbed with a slight change in the coagulant chemistry and quantity.

The differential tolerance of C3 and C4 cereals to aluminum toxicity is faded under future CO2 climate

Industrial activities have led to a gradual and global increase in soil aluminum (Al) and atmospheric CO2 concentrations. Al bioavailability strongly depends on the soil pH, which in turn is affected by atmospheric CO2 levels. In spite of the concurrent impact which Al and elevated CO2 (eCO2) could have on plants, their interaction and how it might affect the growth of economically important crop species has not been investigated. Here, we have investigated the combined impact of soil Al and eCO2 exposure on key C3 (wheat, oat) and C4 (maize, sorghum) crops, at the physiological and biochemical level. Compared to C3 plants, C4 plants accumulated less Al by stimulating soil Al retention through exudation of root organic acids. Consequently, Al-exposed C4 plants maintained photosynthetic performance and anti-oxidative capacity. Exposure to eCO2 reduced the stress responses of C3 and C4 crops to Al exposure. Elevated CO2 decreased Al accumulation and oxidative damage in all cereals, and ameliorated C3 plant growth. This was reflected on the biochemical level, where eCO2 inhibited ROS production and restored RuBisCo activity in C3 crops only. Overall, our data suggest that, compared to C3 crops, C4 cereals are more tolerant to soil Al exposure under current ambient CO2 (aCO2) levels whereas future eCO2 levels might stimulate Al tolerance in C3 crops.

Microstructure and mechanical properties of melt-grown alumina-mullite/glass composites fabricated by directed laser deposition

Melt-grown alumina-based composites are receiving increasing attention due to their potential for aerospace applications; however, the rapid preparation of high-performance components remains a challenge. Herein, a novel route for 3D printing dense (< 99.4%) high-performance melt-grown alumina-mullite/glass composites using directed laser deposition (DLD) is proposed. Key issues on the composites, including phase composition, microstructure formation/evolution, densification, and mechanical properties, are systematically investigated. The toughening and strengthening mechanisms are analyzed using classical fracture mechanics, Griffith strength theory, and solid/glass interface infiltration theory. It is demonstrated that the composites are composed of corundum, mullite, and glass, or corundum and glass. With the increase of alumina content in the initial powder, corundum grains gradually evolve from near-equiaxed dendrite to columnar dendrite and cellular structures due to the weakening of constitutional undercooling and small nucleation undercooling. The microhardness and fracture toughness are the highest at 92.5 mol% alumina, with 18.39±0.38 GPa and 3.07±0.13 MPa·m1/2, respectively. The maximum strength is 310.1±36.5 MPa at 95 mol% alumina. Strength enhancement is attributed to the improved densification due to the trace silica doping and the relief of residual stresses. The method unravels the potential of preparing dense high-performance melt-grown alumina-based composites by the DLD technology.

Microstructural Evolution as a Function of Increasing Aluminum Content in Novel Lightweight Cast Irons

In the context of the development of new lightweight materials, Al-alloyed cast irons have a great potential for reducing the weight of the different part of the vehicles in the transport industry. The correlation of the amount of Al and its effect in the microstructure of cast irons is not completely well established as it is affected by many factors such as chemical composition, cooling rate, etc. In this work, four novel lightweight cast irons were developed with different amounts of Al (from 0 wt. % to 15 wt. %). The alloys were manufactured by an easily scalable and affordable gravity casting process in an induction furnace, and casted in a resin-bonded sand mold. The microstructural evolution as a function of increasing Al content by different microstructural characterization techniques was studied. The hardness of the cast irons was measured by the Vickers indentation test and correlated with the previously characterized microstructures. In general, the microstructural evolution shows that the perlite content decrease with the increment of wt. % of Al. The opposite occurs with the ferrite content. In the case of graphite, a slight increment occurs with 2 wt. % of Al, but a great decrease occurs until 15 wt. % of Al. The addition of Al promotes the stabilization of ferrite in the studied alloys. The hardness obtained varied from 235 HV and 363 HV in function of the Al content. The addition of Al increases the hardness of the studied cast irons, but not gradually. The alloy with the highest hardness is the alloy containing 7 wt. % Al, which is correlated with the formation of kappa-carbides and finer perlite.

Charge trapping in 0.1 μm AlGaN/GaN RF HEMTs: Dependence on barrier properties, voltage and temperature

The goal of this paper is to describe and understand the de-trapping dynamics in AlGaN/GaN transistors for radiofrequency (RF) applications, as a function of three parameters: the aluminium content in the barrier (22.6%, 24.6%, and 26.6%), the stress voltage applied to the drain and temperature. The analysis is based on threshold voltage transient measurements, carried out under at different stress conditions.The original results of this analysis show that: (i) the analysed devices show the presence of a dominant charge-trapping process E1 that, at room temperature, has de-trapping time constants in the range of 10 ms, and activation energy around 0.6 eV. (ii) trap E1 (that is responsible for ~0.5 V threshold voltage shift) is located in the semiconductor material, and its effect increases with increasing aluminium content in the barrier. (iii) leakage measurements indicate that devices with higher Al content in the barrier have a higher gate leakage. Our hypothesis is that under off-state stress, traps in the semiconductor material are charged by electrons injected from the gate metal through defects located in the AlGaN barrier. (iv) a second trap E2, whose signal is independent on the properties of the barrier, was also detected. This trap is supposed to originate from surface defects, is responsible for a minor (~0.1 V) threshold voltage shift and is weakly thermally activated (0.25–0.4 eV). (v) finally, a detailed analysis of the de-trapping kinetics indicated that the signal associated to trap E1 increases linearly with the drain stress voltage, and the related kinetics are ideal exponentials (consistent with semiconductor traps), while the amplitude of trap E2 does not significantly depend on drain voltage, and its kinetics are described by a stretched exponential behaviour (consistent with surface traps).

Role of Glutathione-S-Transferase M1 (GSTM1) and T1 (GSTT1) Genes on Aluminum Concentration and Oxidative Markers among Autistic Children

Autism Spectrum Disorder (ASD) is considered a multifaceted neurodevelopmental disorder. The last two decades showed an increase in its prevalence until reached about 1 in 54 children. Autistic symptoms may be exacerbated when the interaction of the genetic and the environmental risk factors occur, suggesting that gene-environment interaction could be a mechanism underlying the etiology of ASD. Aluminum is a known neurotoxic metal that has known health effects in humans. Glutathione-S-transferase (GST) genes and their enzymes play a major role in the detoxification of many toxic metals.Data were collected from 76 children aged 2-8 years diagnosed with ASD and 30 sex and age matched healthy children. The aim of this study was to investigate the association of polymorphisms in the two GST genes (GSTM1 and GSTT1) with mean aluminum concentrations (as, gene-environment interaction) and oxidative status markers (GST enzyme, malondialdehyde and nitric oxide) among the studied groups. The study started at December 2019 and last for one year at the clinics of National Research Centre, Egypt.The results of this study showed that the null GSTM1 and GSTT1 genotype is the most common type in ASD and that genotype may predispose ASD children to decreased antioxidant status (GST enzyme activity) which in term lead to mal detoxification of aluminum. There is marked increase in aluminum concentrations in hair of ASD children and oxidative markers (increase in MDA and NO) leading to oxidative damage that may play an important role in children autistic status. The study recommends adding antioxidant supplements to daily diet of ASD children to improve their antioxidant status and in term improving management of patients with autism spectrum disorders. Further studies are needed to describe other GST gene polymorphisms.