Aluminum Nanopowder Research Articles

Experimental study the mechanical properties of nano composite materials by using multi-metallic nano powder/epoxy

The mechanical properties of two commercial epoxides have been investigated in both unfilled and filled with varying the weight fraction of Nano Aluminum powder and Nano Aluminum with Nano Titanium powder. The values of Young’s modulus, modulus of rigidity, yield stress, tensile strength, flexural strength have been studied at room temperature to identify the specific influence of Aluminum powder (the particle size for Aluminum powder is less than or equal to 50 nm (d ≤ 50). The weight fraction has different values (equals to 10%, 20% and 30%), and Nano Aluminum with Nano Titanium powder for Aluminum powder, the particle size (d) is less than or equal to 50 nm (d ≤ 50). The weight fraction has different values (equals to 10%, 20% and 30%). Also for Titanium powder, the particle size is less than or equal to 50 nm (d ≤ 50), and the weight fraction is 1% for each different weight fractions of Aluminum powder to epoxy resin. The experimental results obtained from laboratory have been analyzed in order to achieve the best result. It is concluded that Young’s modulus and modulus of rigidity increase when the weight fraction for Nano Aluminum powder and Nano Aluminum with Nano Titanium powder increase.

Influence of Alumina Nanoparticles on the Mechanical Properties of a Bioresin Composite

A significant part of the research and production activities is represented in the field of bioengineering by the biomaterials used in hard tissue restorations. They are of great interest in dental science, intending to improve technological aspects, monitoring their biological responses to the living organisms, but also to redesign economic aspects, beginning with the choice of raw materials. In the present work, light-curing composite biomaterials were made from a composite polymer matrix consisting of specific concentrations of bisphenol A-glycidyl methacrylate base monomer (Bis-GMA), a mixture of two co-monomers, triethylene glycol dimethacrylate and ethoxylated bisphenol A-dimethacrylate (TEGDMA/BisEMA), and two alumina nanopowder concentrations (5 wt.% and 10 wt.%). These materials were mechanically tested for flexural strength and compressive strength. The structural analysis of these materials consisted of SEM microscopy and EDX elementary mapping. In order to extract 3D projections of sample surfaces, but also to produce indicative values of their roughness, the SEM micrographs were processed with open-source software. In order to observe a clear evolution of the mentioned properties, the composite biomaterials were compared with materials formed only with the Bis-GMA/TEGDMA/BisEMA composite, and with a commercial composite resin, Filtek™ Supreme Ultra Universal Restorative, also. The findings showed an increase in the mechanical properties of the materials manufactured concerning the concentration of nanoparticles of aluminum. EDX analyzes confirmed the good homogeneity of nanoparticles in the polymer matrix. Mechanical properties of the manufactured nanocomposite biomaterials were reported 28.8 % higher than the control biomaterial. The comparison results with the commercial resin composite are encouraging.

Experimental analysis of effect of speed and time on aluminium nanoparticles fabricated by high energy ball milling

Metal Matrix Composites are technologically advance material identified in recent era as a substitute for traditional engineering materials because of their excellent properties. Out of the available material, demand for Aluminium Matrix Composites are increasing in the sector of aerospace, automobile and defense applications. The Aluminium Matrix Composites are majorly accepted because of their excellent physical and mechanical properties. There are various manufacturing techniques developed for the fabrication of AMCs. High energy ball milling is a one of the most effective and versatile routes for fabrication of nano aluminium powder. The Al powder of 99.55% purity was taken for experimentation. The 60gm of Al powder was taken in stainless steel vial with BPR as 5:1. The stainless steel balls of diameter 4mm was used as a grinding media. The ball milling was performed at different speed and time in presence of 60ml toluene as process control agent. The characterization of powder particle was done with XRD and SEM. The analysis of peak were done on origin software. The optimum speed and milling time for fabrication of Al nanoparticles of size 36 nm were found to be at 250rpm and 3 to 6 hours.

Study on Indium (III) Oxide/Aluminum Thermite Energetic Composites

Thermites or composite energetic materials are mixtures made of fuel and oxidizer particles at micron-scale. Thermite reactions are characterized by high adiabatic flame temperatures (>1000 °C) and high heats of reaction (>kJ/cm3), sometimes combined with gas generation. These properties strongly depend on the chemical nature of the couple of components implemented. The present work focuses on the use of indium (III) oxide nanoparticles as oxidizer in the elaboration of nanothermites. Mixed with an aluminum nanopowder, heat of reaction of the resulting Al/In2O3 energetic nanocomposite was calculated and its reactive performance (sensitivity thresholds regarding different stimuli (impact, friction, and electrostatic discharge) and combustion velocity examined. The Al/In2O3 nanothermite, whose heat of reaction was determined of about 11.75 kJ/cm3, was defined as insensitive and moderately sensitive to impact and friction stimuli and extreme sensitive to spark with values >100 N, 324 N, and 0.31 mJ, respectively. The spark sensitivity was decreased by increasing In2O3 oxidizer (27.71 mJ). The combustion speed in confined geometries experiments was established near 500 m/s. The nature of the oxidizer implemented herein within a thermite formulation is reported for the first time.

Heat Transfer in Laminar Graetz and Taylor Flows Incorporating Nanoparticles

This study investigates the thermal and hydrodynamic effects of incorporating nanomaterials to the continuous and gas-liquid Taylor flows in mini scale tubes. Aluminum Oxide nanopowder was dispersed in distilled water to produce three nanofluid concentrations: 1, 2 and 4 wt% using a two-step method. Heat transfer enhancement in miniscale tubes (1.5 mm) was assessed using Nusselt number and dimensionless mean wall heat flux. The experiments were conducted under laminar developing flow with isothermal boundary condition. In addition, nanofluid experiments covered: thermal conductivity measurements, scanning electronic microscopy, and performance efficiency analysis. The thermal and hydrodynamic effects of incorporating nanoparticles to the base fluid were evaluated using performance efficiency analysis which considers friction factor and Nusselt number. The results demonstrated that heat transfer enhancement is associated with the nanoparticles concentration when compared with Graetz theory. Total enhancement in segmented nanofluid flows was observed to be a combination of the individual contributions of internal circulations within the liquid slugs and the interaction between the nanoparticles. Overall, the present study highlights the potential of heat transfer enhancement within mini/micro tubes using segmented nanofluid flows.

Electrophoretic deposition of coatings and bulk compacts using magnesium-doped aluminum oxide nanopowders

The electrophoretic deposition (EPD) of coatings and bulk compacts in a wide range of thicknesses (from 23 to 1800 μm) from stable suspensions of a magnesium-doped aluminum oxide nanopowder with subsequent sintering of samples into dense ceramics was studied. The initial nanopowder was obtained by the method of electric explosion of an Al-Mg alloy wire with a Mg content of 1.3 wt. %. The study of the dispersion composition, kinetics of deaggregation under the ultrasonic treatment and zeta potential in the nanopowder-based suspensions was carried out. It was shown that a nearly linear increase in the deposited mass and thickness of EPD deposits occurred at a constant voltage of 20 V and an average deposition current of approximately 40 μA when the deposition time was varied from 1 to 180 min. Drying of the coatings with a thickness of less than 35 μm led to the formation of a net of small cracks, while drying of the bulk compacts with a thickness of more than 1 mm occurred without cracking. The ceramic bulk sample with a thickness of 1.2 mm and the density of 98.7% TD was successfully obtained by sintering at 1650 °C for 4 h. It was characterized by a dense grain structure with an average grain size of 5 μm and the presence of a small number of closed pores less than 1 μm in size. Sintering of ceramics was revealed to be accompanied by the formation of a MgAl2O4 crystalline spinel phase, localized mainly at grain boundaries.

Aging behavior of aluminum nanopowders: accelerated aging experiments and modeling of the influence of temperature and humidity on the aluminum content

A quantitative study on the aging behavior of aluminum nanopowders is presented. While previous studies in literature focused on a few conditions of temperature and/or humidity, towards an understanding of the physical process behind the aging, no study investigated yet sufficient conditions to develop an accelerated aging model specific to aluminum nanopowders. This study investigated aluminum nanopowders obtained by plasma electro-condensation, submitted to a range of 11 conditions of humidity (25 to 75%) and temperature (298 to 348 K) over periods of 1 h to 71 days. Apart from the storage time in the climatic chamber, the powders were stored in a low-oxygen and low-humidity glovebox to prevent the influence of natural aging. The powders were then analyzed through thermo-gravimetric analysis (TGA) combined with differential scanning calorimetry (DSC) to retrieve the aluminum content as well as the humidity content. The decrease in aluminum content over time for each storage condition was then modeled with a power law. Finally, the fitting coefficients determined from the power law were used to build an accelerated aging model taking into account temperature and humidity effects, and that can predict the oxidation due to natural aging. Furthermore, the activation energy of the aging process determined through the model can also be used in the accelerated aging model of Bohn with a similar F coefficient.

Two-brightness-amplifier imaging system for energetic-materials-combustion study.

This paper discusses a laser monitor with two channels for acquiring images synchronized in time and its use for visualizing the surface of metal nanopowders during combustion. Each channel is an independent optical system based on a copper bromide vapor brightness amplifier and a high-speed camera that allows visualizing a specified area of the sample. Thus, the laser monitor allows real-time imaging of the same sample area with different spatial resolutions and simultaneously two areas of the sample. In comparison with the "master oscillator-power amplifier" system and a bistatic laser monitor in the proposed system, the radiation pulses of the brightness amplifiers are synchronized in such a way that the inversion in the active media is formed at different time intervals. Such a system makes it possible to register processes in one area of the sample in the mode of double frames with a time shift of 35ns. As an additional option in the proposed system, it is possible to implement a laser illumination mode in which an additional camera is used with a narrow-band filter installed on it for the emission wavelength of brightness amplifiers, and the same radiation from the brightness amplifier is used as an illuminating light source. The proposed technique was used to visualize the combustion of aluminum nanopowders without additives in real time in the area of laser initiation with different spatial resolutions and nanoAl + microAl + microFe powder mixtures in the laser ignition area and the adjacent area of the sample simultaneously as the combustion wave propagates.

Mathematical Model and Numerical Investigation of Combustion Front Propagation Velocity in an Aerosol of an Aluminum Nanopowder Suspension in Kerosene

Mathematical Model and Numerical Investigation of Combustion Front Propagation Velocity in an Aerosol of an Aluminum Nanopowder Suspension in Kerosene

Improvement of microstructure and mechanical properties of dissimilar friction stir welded aluminum/titanium joints via aluminum oxide nanopowder

Aluminum oxide nanopowder has been fabricated and characterized successfully to improve the properties of friction stir welded aluminum/titanium joints, which pose a great challenge due to the great difference in mechanical properties. Intermetallic compounds (IMCs) of large sizes formed at the welding interface are a significant problem that deteriorates joint strength due to the uncontrollable thermal effect generated in the joint. Therefore, friction stir processing was integrated with friction stir welding, in which a dissimilar lap joint of AA6061-T6 and Ti6Al4V was reinforced with γ-Al2O3 nanoparticles of about 8 nm in diameter. First, several attempts were conducted to determine the most effective parameters in the welding process of the aluminum/titanium reinforced joint and then the effects of γ-Al2O3 nanopowder on microstructure, mechanical properties, and weldability were analyzed and compared to a welded joint without reinforcing powder. Sound joints have been successfully produced using welding speed of 25 mm/min, and tool rotational speed of 600 rpm. Lap shear fracture load and displacement of the Al/Ti joint increased from 3.5 KN and 1.25 mm to 3.7 KN and 2.45 mm, respectively, while the hardness of the reinforced joint increased from 384 HV to 391 HV at the Al/Ti weld interface with a remarkable improvement at the Al and Ti sides.

Synthesis and Characterization of Tertiary Nanothermite CNMs/Al/KClO4 with Enhanced Combustion Characteristics

AbstractMuch attention has been directed toward the development of new energetic materials to achieve the increasingly demanding performance of high‐speed propulsion systems. Nanothermite is one of the main approaches for the development of new energetic materials by the close integration of oxidizer and metal fuel. This study is devoted to evaluating the impact of different carbon nanomaterials (graphene oxide, reduced graphene oxide, carbon nanotubes, and carbon nanofibers) on the thermal behavior of nanothermites based on potassium perchlorate and nano aluminium powder. Nanothermite compositions were prepared using a conventional sonication method. The morphology of nanothermites was characterized by a scanning electron microscope (SEM) coupled with energy dispersive spectroscopy (EDS), which confirmed that the nanoparticles are homogeneously dispersed without agglomeration. The structure of nanothermite was also characterized by Fourier Transform Infrared Spectroscopy (FTIR), X‐ray diffraction (XRD), and Raman spectroscopy. The impact of carbon nanomaterials on the combustion behavior of nanothermite was evaluated by thermal gravimetric analysis (TGA), differential scanning calorimetry (DSC), and bomb calorimetry. There was good agreement between results from DSC and bomb calorimetry. In general, the total heat released improved with the addition of carbon nanomaterials and particularly graphene oxide, which generated the highest increase in the heat of combustion. In addition, the maximum decomposition temperature shifted to a lower temperature, which indicates enhanced ignition characteristics. This is the first time reporting on the synthesis and characterization of tertiary nanothermites based on nano‐aluminum, potassium perchlorate, and carbon nanosize materials. It can be concluded that these novel nanothermite compositions exhibit dramatically improved properties as demonstrated by a 200 % increase in the heat of combustion with only a 5 % addition of graphene oxide. Moreover, the ignition temperature decreased from 545.1 °C to 508.7 °C enhancing the overall combustion characteristics.

Influence of waste alumina powder on self-compacting concrete resistance under elevated temperature

Influence of Nano-Alumina (NA) powder prepared from damaged alumina rollers that are waste objects from the production line in a tile and ceramic factory on Self-Compacting Concrete (SCC) under elevated temperature are investigated in this study. Three mix designs including without NA, with 1%NA, and 2%NA, that were replaced for cement, were investigated under temperatures of 27 ̊C, 100 ̊C, 200 ̊C, 300 ̊C, 450 ̊C, and 600 ̊C. To evaluate compressive strength and modulus of elasticity (E-value) of each mix design, 7-day and 28-day samples were tested before or after heating for ten or 60 min. For each mix design, cured samples experiencing only the ambient temperature of about 27 ̊C were also tested as reference samples. Results show that using NA decreases compressive strength of 7-day samples in the ambient temperature, but improves their compressive strength after 10 min heating under the target temperature of up to 200 ̊C. Nano-alumina improves compressive strength of 28-day SCC samples by its pozzolanic activity for the ambient temperature and under 100 ̊C. For the higher target temperatures at both ages, NA particles are effective to reduce strength degradation due to heating. Compared to the samples without NA, compressive strength of the 28-day samples with 1%NA and 2%NA, after experience of 10 min heating, were 11.7% and 16.2% higher, respectively. These values for the samples experiencing 60 min heating were 22.4% and 26.5%. Results of E-value tests on 28-day samples exhibit positive influence of NA under ambient temperature and these nanoparticles are able to slow down degradation of E-value after an experience of ten or 60 min under the target temperatures. However, almost different from previous literature, the 2%NA has a higher influence to reduce SCC strength degradation than 1%NA. This may be attributed to the NA resource that is from waste materials containing some impurities.

Experimental research on the mechanism of chemical energy conversion to light energy under thermal induction

Since the discovery of glare illuminators, considerable efforts have been devoted to achieving a breakthrough of high light intensity on the order of magnitude. In this paper, we prepared strong flash blinding agents for the first time by using aluminum powder, oxidant, and adhesive as the main materials, and tris-(8-hydroxyquinolinato) aluminum (Al2q3), triazoindolizine, or nano zinc oxide, etc. as electronic output brightener after mixing and granulation according to the developed formulation. It was discovered that the luminescence intensity was related to the thermal effect of the substance while the brightener only served as an auxiliary brightening effect to achieve energy non-destructive conversion. With the same formula, the luminescence intensities of glaze agents with ADN and potassium perchlorate as oxidants were slightly higher than that of ammonium perchlorate oxidant; the brightening effect of nano-zinc oxide was slightly higher than those of tris-(8-hydroxyquinolinato) aluminum (Al2q3) and triazoindolizine. The luminescence intensity of the substance with a high thermal effect value was high, but the luminescence time was slightly short. Under identical conditions, the luminescence effect of nano-aluminum powder was obviously better than that of micro-aluminum powder with the highest luminescence intensity of 3.9 × 1010 ~ 1.9 × 1011 cd and the luminescence time of 39 - 48 ms. The effects of shell material and structure and the effect of heat-induced mode on the luminescence intensity were also investigated. The luminescence intensity of the glare agent with a high shell strength was high, but the luminescence time was slightly short. Moreover, the energy level of the brightener is excited under the induction of high temperatures, which leads to a blue shift to promote the chemical reaction of the material in a favorable direction. Finally, the optical radiation of the thermally induced high-temperature combustion system was analyzed from the aspects of thermal effect, combustion temperature, and chemiluminescence effect. A way to improve the optical radiation intensity of a high-temperature combustion system was proposed.

Oxidation Behaviors of Aluminum Nanopowders with Different Particle Sizes: A Real-Time Synchrotron X-ray Scattering Study.

We have studied the oxidation behaviors of aluminum (Al) nanopowders with different particle sizes using a real-time synchrotron X-ray scattering during annealing in air. The Al nanopowders with small particle size of 78 nm at room temperature (RT) were a single crystal. The surface of the nanopowders was first oxidized to amorphous Al oxide near 450 °C, and then crystallized to γ-Al₂O₃ phase at 550 °C. The inside of the nanopowders existed as crystal Al phase at 680 °C, high compared to the melting temperature of Al bulk, 660 °C. In contrast, the Al nanopowders with large particle size of 816 nm at RT have multi grains inside a particle. The surface and grain boundary of the powders were first oxidized to amorphous Al oxide near 470 °C, and then crystallized to γ-Al₂O₃ phase at 550 °C. The inside of the powders existed as amorphous Al phase at 620 °C, melted at 656 °C, and then oxidized gradually above 656 °C.

WITHDRAWN: Influence of aluminium in firecracker chemical composition on workplace hazards

Abstract In the firecracker industry, the employees are exposed to various health and safety issues in their workplace due to the handling of different chemical powders. Normally prepare the firecracker it needs potassium nitrate (60%), sulfur (20%), and aluminium (20%). Among this firecracker chemical mixture, aluminium is a highly hazardous material because of its sensitivity and reactivity. The fire and explosion easily occur in the workplace during the handling of chemical mixtures and during the bursting of firecrackers, the environment also will be getting affected. In this work, with consideration of the aforementioned issues, a new firecracker is prepared by reducing nano aluminum powder at different compositions like 2%, 4%, 6%, 8%, and 10%, it is even handed by Tamarind Seed Powder (TSP). The performance characteristic like noise level, sensitivity tests like impact and friction sensitiveness are measured for both existing and modified crackers chemical mixture. The modified chemical mixture does not have frictional sensitivity. The performance like the sound level of the modified cracker is increased slightly and the value is 116 dB (AI). The sound level of the normal firecracker is 107.9 dB (AI). So, this new cracker chemical composition promotes workplace safety and creates a safe working environment in the workplace.

Formation of Oxidized Aluminum Nanopowders by Exposing Aluminum to a Series of Double Laser Pulses in Air

The effects of the interval between pulses and the number of double laser pulses on the component and charge composition of the laser plasma formed by these pulses acting on an AD1 aluminum alloy target (LSS-1 spectrometer) are studied. It is shown that the concentration of Al ions and the products of their interaction with atmospheric O2 and N2 increase by several orders of magnitude if an interval between pulses of 7–16 μs rather than a zero interval is used. Formation of Al ions is studied as a function of pulse energy with an interval between pulses of 10 μs. The strongest lines for Al III ions are observed for a small number (~15) consecutive double pulses in series and a pulse energy of 53 mJ. The intensity of the lines for Al III ions decreases by about five times if the number of pulses in the series increases above a certain level (10–20) because of their active interaction with atmospheric molecules and atoms at the exit of the micronozzle when the channel shape is changed. Al nanopowders coated with a layer of aluminum oxide produced by irradiating an Al target with a series of 15 double laser pulses per point have sizes of mainly 50–60 μm.

Preparation of defect-free alumina insulation film using layer-by-layer electrohydrodynamic jet deposition for high temperature applications

Ultra-high temperature thin-film sensors（UTTSs）have drawn enormous attention due to their wide application prospect in multiple physical parameters monitoring in harsh environment. As an important part of UTTSs, the insulation film between workpiece and sensors plays a crucial role to ensure the accuracy of UTTSs. High insulation resistance (IR) is essential for the reliability improvement of the UTTSs and the reduction of their testing error. However, the defects in the insulation film will form the conductive path between the sensors and their mounting surface at high temperature, leading to a rapid IR drop and stability deterioration of the insulation film. In this work, 10 μm thick alumina film was prepared with suspension made out of alumina gel and alumina nano-powder using layer-by-layer electrohydrodynamic jet (E-jet) deposition (LLED). By adopting this technique, the process defects in one layer can be remedied in situ by the next deposition layer. The prepared film shows satisfactory insulation performance at elevated temperature, and IR of the film can reach 80 MΩ, 3 MΩ and 38 kΩ at 500 °C, 800 °C and 1200 °C, respectively. The thickness-normalized IR of the alumina film at 800 °C in this work is at least 7.8 times that obtained by other methods reported in the literatures. Moreover, after subjected to three thermal cycles from room temperature to 1200 °C, the IR of the film can still remain at 14 kΩ. The high performance of the alumina insulation film in this work can be attributed to the effective reduction of the minor defects in the LLED deposition process.

Investigation of powder mixed electrical discharge machining and process parameters optimization using Taguchi based overall evaluation criteria

Electrical Discharge Machining is a type of nontraditional process can be used for machining of hard materials and making of complicated shape.In EDM, the important parameters are tool, workpiece and dielectric liquid. Dielectric liquid is used to enhance ionization during the process. Powder Mixed EDM (PMEDM) is preferred for enhance the process efficiency. In this work, nano alumina (Al2O3) powder is added to the dielectric liquid and the process parameters effects are investigated. Input parameters considered are pulse on time, pulse off time and current. Output parameters considered are rate of material removal, surface quality and wear in electrode. Nano powders are mixed in the ratio of 2% to the EDM oil during the operation with dielectric fluid weight ratio. Process parameters are optimized using Taguchi based Overall Evaluation Criteria (OEC). The result revealed thatPMEDM is enhanced the process efficiency.

Influence of Additive Alumina Nanopowder on Surface Roughness During WEDM Process

The present paper focuses on the wire electrical discharge machining (WEDM) of titanium alloys. It can be considered as an attempt to develop two dielectrics in the WEDM significantly affects the efficiency of machining. This paper explores surface ruggedness during the processing of titanium of various dielectric fluids, including demineralized water and dielectric alumina. The findings show that dielectric alumina as a dielectric produces decreased ruggedness on the surface. Also, surface rudeness is better for demineralized water as the dielectric powder is mixed with non-conductive alumina powder. Many dielectric liquids show that surface ruggedness decreases. Alumina powder and ethylene glycol to dielectric water. A comparative surface roughness analysis for different dielectric fluids was also performed. Using surface roughness to analyze surface roughness is further studied. Conducting a further investigation to use the response surface method (RSM) on surface integrity in each type of the dielectric with the help of better. Hence, WEDM is performed on Ti-6242 to use the designer expert 10 to analysis ANOVA RSM titanium and varying dielectric fluids. From the findings, it is noted that combining non-conductive alumina powder and demineralized water has a significant impact, which decreased of WEDM machined surface of Ti-6242.

Study of aluminium nanopowder combustion by method of laser-speckle correlation

In this paper, we discuss an application of the method of laser-speckle correlation for studying the combustion process of aluminium nanopowder in air and its mixture of iron nanopowder. It is suggested to characterize the combustion process using the statistic parameter – correlation coefficient. The principle of observation is explained and the experimental schema for investigating is provided. The differences between aluminium nanopowder and its mixture with iron nanopowder are also considered.