Thermal Oxidation Behavior Research Articles

Boron Nitride Nanotubes Versus Carbon Nanotubes: A Thermal Stability and Oxidation Behavior Study.

Nanotubes made of boron nitride (BN) and carbon have attracted considerable attention within the literature due to their unique mechanical, electrical and thermal properties. In this work, BN and carbon nanotubes, exhibiting high purity (>99%) and similar surface areas (~200 m2/g), were systematically investigated for their thermal stability and oxidation behavior by combining thermal gravimetric analysis and differential scanning calorimetry methods at temperatures of up to ~1300 °C under a synthetic air flow environment. The BN nanotubes showed a good resistance to oxidation up to ~900 °C and fully transformed to boron oxide up to ~1100 °C, while the carbon nanotubes were stable up to ~450 °C and almost completely combusted up to ~800 °C. The different oxidation mechanisms are attributed to the different chemical nature of the two types of nanotubes.

Novel CuSiF6-coordinated epoxy–amine composites with reduced combustibility: Elaboration, thermal-oxidative behavior, and ignition susceptibility

In the DGEBA–PEPA–CuSiF6 system (DGEBA is diglycidyl ether of bisphenol A, PEPA is polyethylenepolyamine), a new flame-retardant hardener for epoxy resins in the form of a chelate complex labeled as PEPA–CuSiF6 was synthesized and incorporated into the framework of DGEBA to make a range of CuSiF6-containing epoxy–amine composites (EA–CuSiF6) with reduced combustibility. The resulting EA–CuSiF6 composites were characterized using FTIR spectroscopy, thermogravimetric analysis (TGA), and temperatures of ignition and self-ignition measuring. TGA results showed that the thermal decomposition of PEPA–CuSiF6 ends at 368 °C, and after ignition of its organic component, the maximum temperature of the gaseous products of combustion reached 488 °C. TGA of EA–CuSiF6(22) sample confirms that the incorporation of PEPA–CuSiF6 into DGEBA significantly increases the thermal stability and reduces the flammability of the epoxy–amine composites. The combustibility of the epoxy–amine composite samples was investigated using “Ceramic tube” (CT) method. Results of CT measurement reveal that the maximal temperature of combustion gases for EA–CuSiF6(66) in comparison with unmodified epoxy–amine polymer (EAP) appreciably goes down and relative loss of the mass lessens. The measured ignition and self-ignition temperatures showed that depending on the amount of CuSiF6 added, tignition and tself-ignition for this type of composites increase by 15–34 °C and 25–58 °C, respectively, compared to EAP that does not contain additives.

The Thermal-Oxidation Behavior of Pristine and Doped Magnéli Phase Titanium Oxides

Magnéli phase titanium oxides (Ti n O 2n-1 , 4 < n < 10)1 are promising alternatives to carbon-based materials in aqueous electrochemical technologies,2 –5 but their passivation during operation remains an important challenge to address.6 –8 To elucidate the mechanism for their oxidation and to investigate the influence of doping on their oxidation stability, the thermal-oxidation behavior in air of Ti4O7 doped with V, Cr, Fe, and Ga was investigated by thermogravimetric analysis. Both thermal and electrochemical oxidation of Ti4O7 form the electrically-insulating TiO2 in sufficiently oxidizing conditions. V- and Fe-doping improved the thermal stability of Ti4O7 as evidenced by higher onset temperatures in their thermograms. Three-dimensional diffusion reaction models adequately describe the solid-state kinetics of thermal oxidation of Ti4O7 in air as demonstrated by linear model-fitting. Doping shows a mixed influence on these kinetics reducing both the Arrhenius pre-exponential factor and the activation energy. Cr-doping significantly shortens the lifetime of Ti4O7 in ambient conditions as determined by kinetic predictions. References S. Andersson, B. Collén, B., U. Kuylenstierna and A. Magnéli, A. Acta Chem. Scand., 11, 1641 (1957).J. R. Smith, F. C. Walsh and R. L. J. Clarke, J. Appl. Electrochem., 28, 1021 (1998).F. C. Walsh and R. G. A. Wills, Electrochim. Acta, 55, 6342 (2010).B. Xu, H. Y. Sohn, Y. Mohassab and Y. Lan, RSC Adv., 6, 79706 (2016).B. P. Chaplin, Acc. Chem. Res., 52, 596 (2019).W. Kao, P. Patel, P. and S. L. Haberichter, J. Electrochem. Soc., 144, 1907 (1997).G. Chen, C. C. Waraksa, H. Cho, D. D. Macdonald and T. E. Mallouka, J. Electrochem. Soc., 150, E423 (2003).D. Bejan, J. D. Malcolm, L. Morrison and N J. Bunce, Electrochim. Acta, 54, 5548 (2009). Figure 1

Microstructure, thermal characteristics, and thermal cycling behavior of the ternary rare earth oxides (La2O3, Gd2O3, and Yb2O3) co-doped YSZ coatings

In this paper, La2O3, Gd2O3, and Yb2O3 co-doped yttria stabilized zirconia (LGYYSZ) thermal barrier coatings were prepared on a nickel-based superalloy by atmospheric plasma spraying. The phase stability, coefficient of thermal expansion (CTE), and thermal conductivity of the LGYYSZ and YSZ coatings were measured. Thermal cycling at 1400 °C was implemented to evaluate the feasibility of LGYYSZ as an optimal ceramic material for thermal barrier coatings (TBCs) of next-generation gas turbines. The results show that the LGYYSZ coating exhibits a stable cubic phase, even after annealing at 1500 °C for 100 h. The CTE of LGYYSZ is slightly higher than that of YSZ. The thermal conductivity of the LGYYSZ coating at 1400 °C is 1.08 W∙m−1∙K−1, which is ~26.5% lower than that of YSZ. The thermal cycling lifetime of the LGYYSZ coating at 1400 °C is 468 cycles, which is ~2.7 times that of the YSZ coating. The longer thermal cycling life of the LGYYSZ TBC can be attributed to the excellent phase stability and lower thermal conductivity.

The Thermal-Oxidation Behavior of Pristine and Doped Magnéli Phase Titanium Oxides

Magnéli phase titanium oxides (Ti n O2n–1, 4 ≤ n ≤ 10) are promising alternatives to carbon-based materials in aqueous electrochemical technologies, but their passivation during operation remains an important challenge to address. To elucidate the mechanism for their oxidation and investigate the influence of doping on their oxidation stability, the thermal-oxidation behavior in air of Ti4O7 doped with V, Cr, Fe, and Ga was investigated by thermogravimetric analysis. V-doping and Fe-doping improved the thermal stability of Ti4O7 as evidenced by higher onset temperatures in their thermograms. Three-dimensional diffusion reaction models adequately describe the solid-state kinetics of thermal oxidation of Ti4O7 in air as demonstrated by linear model-fitting. Doping shows a mixed influence on the kinetics for thermal oxidation in air reducing both the Arrhenius pre-exponential factor and the activation energy. Cr-doping significantly shortens the lifetime of Ti4O7 in ambient conditions as determined by kinetic predictions.

Oxidation behavior and thermal stability of Cr2AlB2 powders

Thermal stability and oxidation behavior of Cr2AlB2 powders were investigated at 600−1200 °C. Cr2AlB2 is stable up to 900 °C in argon, partially decomposes into Cr4AlB4 and Al at 950−1070 °C, and partially decomposes into CrB and Al at 1090−1200 °C. Oxidation in air initiates at 680 °C and up to 1200 °C exhibits an initial rapid linear oxidation followed by a slow parabolic oxidation behavior. A protective Cr2O3 (below 750 °C) or Al2O3 (above 800 °C) scale is formed, which makes Cr2AlB2 exhibit good oxidation resistance. Based on the calculated free energies associated with the oxidation reactions, a good correlation with the experimental results was found.

Influence of Ru-addition on thermal decomposition and oxidation resistance of TiAlN coatings

Doping element into transition metal nitride coatings to optimize their performance against machining has attracted wide research interests. Here, we report the influence of Ru-addition concerning the thermal decomposition and oxidation behavior of TiAlN coatings. Incorporation of Ru results in a structural transformation of cubic Ti0.46Al0.54N and Ti0.43Al0.50Ru0.07N into mixed cubic and wurtzite Ti0.34Al0.51Ru0.15N. With 5 at.% Ru-addition, a comprehensive improvement both in hardness (from ~29.94 to 33.15 GPa) and in fracture resistance (raising the H3/E2 ratio by ~39.8%) is obtained. However, further addition of Ru leads to a drop in hardness (to ~26.09 GPa) for Ti0.34Al0.51Ru0.15N due to the precipitation of wurtzite-structure AlN. Moreover, Ru-containing coatings exhibit a later occurrence of spinodal decomposition, indicating their better thermal stability in comparison with Ti0.46Al0.54N. Nevertheless, the Ru-addition accelerates the transformation from anatase to rutile and hence causes the degeneration in oxidation resistance. Additionally, a mixed oxide scale including Al2O3, RuO2, and TiO2 is formed on the surface of Ti0.34Al0.51Ru0.15N coating at the early stages of oxidation. Both this porous oxide scale and high density of grain boundaries allow the rapid inward diffusion of oxygen, which is also responsible for the inferior oxidation resistance of our Ru-containing coatings. Based on the comprehensive improvement in hardness and thermal stability, the tool life can be improved by ~32% through 5 at.% Ru addition under certain machining condition.

Exploration on the influence mechanism of heteroatom doped graphene on thermal oxidative stability and decomposition of polypropylene

The inferior thermal oxidative stability of polypropylene (PP) is a limitation for its practical applications. In this study, PP composites filled with heteroatom doped graphene are prepared. Heteroatoms with different electronegativity values, including nitrogen, phosphorus and boron, are successfully doped into the structure of reduced graphene oxide (RGO) through high temperature annealing. Doped RGO is characterized by Fourier transform infrared spectroscopy, X-ray diffraction, Raman spectroscopy, X-ray photoelectron spectroscopy and transmission electron microscopy. PP/doped graphene composites are acquired by solution blending. The effects of heteroatom doped RGO on thermal oxidative stability and decomposition behavior of PP are investigated by thermogravimetric analysis and thermogravimetric-infrared spectrometry, respectively. The results indicate that doped RGO can significantly improve thermal oxidative stability of PP. Compared with neat PP, the temperature at maximum weight loss rate of PP/N-RGO-2.0, PP/B-RGO-2.0 and PP/P-RGO-2.0 are increased by 112 °C, 141 °C and 122 °C, respectively. Thermal oxidative decomposition mechanism of PP/doped RGO composites is discussed based on the analyses of pyrolysis gaseous products and chemical structures of doped RGO. This work provides a novel exploration for enhancing thermal stability of polymer. This work provides an investigation strategy for in-depth study of enhancement mechanisms of graphene on thermal stability of polymers.

Microstructural evaluation and thermal oxidation behaviors of YSZ/NiCoCrAlYTa coatings deposited by different thermal techniques

In this paper, two coating techniques, the high velocity oxy-fuel (HVOF) and air plasma spray (APS) techniques, were used to deposit a bond coat of NiCoCrAlYTa on the Inconel 625 substrate, followed by applying a topcoat of yttria-stabilized zirconia (YSZ). The samples were preoxidized in an argon-controlled furnace at a temperature of 1000 °C for 12 and 24 h to characterize the microstructure of a thermally grown oxide (TGO) using the two coating techniques. The most suitable preoxidized samples were further tested for isothermal oxidation at 1000 °C for up to 120 h, and a hot corrosion test was performed at 1000 °C for up to 52 h or until spalling occurred. As-sprayed and oxidized samples prepared with different coating techniques were evaluated in terms of their microstructure using different characterization methods, such as field emission scanning electron microscopy (FESEM), variable pressure scanning electron microscopy (VPSEM), energy dispersive X-ray spectroscopy (EDS) equipped with energy dispersive X-ray and X-ray diffraction (XRD) analyses. In addition, the mechanical properties of these samples were evaluated using adhesion tests. The results show that the YSZ/NiCoCrAlYTa coating applied with the HVOF technique forms a more thin and continuous layer of TGO than that obtained when applying a YSZ/NiCoCrAlYTa coating using the APS technique, indicating that a severe brittle oxidation interface exists between the two layers. The results also indicate that the mechanical strength obtained from the adhesion test of the coated samples is observably affected by the oxidation behaviors obtained with the different deposition techniques chosen.

Mechanistic insights into the thermal deposition of highly thermal-stable jet fuel

Highly thermal-stable jet fuel plays an important role in the advanced supersonic aircrafts, but its oxidation to the insoluble deposits is a serious problem when serving as a coolant. However, there are few reports as to the deep insights of insoluble deposits formation. Here we apply the PetroOxy device to investigate the thermal oxidation and deposition behaviors of highly thermal-stable jet fuel, using decalin as the model jet fuel, in order to explore the formation mechanism of insoluble deposits. All oxidation products (gas, liquid and solid) of fuel at different oxidation stages were separated and carefully characterized. The initial oxidation of fuel produces hydroperoxides, which then decompose rapidly to produce gas products (H2, CO or CO2) as well as large amounts of polar species (soluble oxidized products, e.g., alcohols, ketones, and molecular growth products). Meanwhile, these polar monomer species condense to produce soluble macromolecular oxidatively reactive species (SMORS) and insoluble deposits. The SMORS amount increases during the overall oxidation process, but the amount of insoluble deposits increases only in the presence of oxygen. The characterizations of liquid chromatography/electrospray ionization mass spectrometry and solution-state 2D heteronuclear single quantum coherence NMR confirm that the concentration of highly polar macromolecular species in insoluble deposits is much higher than that in SMORS, which causes the precipitation of the insoluble deposits from the bulk fuel. We further propose the detailed formation process and chemical structures of the insoluble deposits during the autoxidation of highly thermal-stable jet fuel, which would be helpful for a better understanding of the deposition mechanism of jet fuel and the improvement of its thermal stability.

The Examination of Microstructure and Thermal Oxidation Behavior of Laser-Remelted High-Velocity Oxygen Liquid Fuel Fe/Al Coating

Aluminide intermetallics with superior mechanical and thermal properties can be produced using various techniques. Laser-remelted coating surfaces provide lower porosity and superior adhesion to the substrate. In the present study, Fe and Al powders were sprayed on the 316L stainless steel substrate using high-velocity oxygen liquid fuel (HVOLF) technique. The produced composite coating was subjected to laser heat treatment for the remelting of the coating layer. HVOLF Fe/Al coating, the remelted coating and the substrate were exposed to isothermal oxidation tests at 950 °C for 5, 25, 50 and 100 h. Before and after the oxidation tests, the samples were characterized using x-ray diffraction, scanning electron microscopy (SEM) and SEM elemental mapping analysis. Fe and Al were alloyed with the substrate via laser melting, and thus, an alumina-forming surface layer was obtained. Besides, the surface hardness of the substrate was increased by the remelting process. After the oxidation tests, the obtained results showed that the laser-remelted coating exhibits better oxidation performance compared to the substrate material and HVOLF Fe/Al coating with the effect of the formation of the protective alumina oxide layer.

Facile Fabrication of Highly Efficient Hollow Ni/Al Bimetal Fuel with Enhanced Thermal Oxidation Behavior

Al powder has been used as a common fuel in various energetic materials because of the high enthalpy of its oxidation. The thermal oxidation behavior of Al fuel is a key issue that can determine th...

Thermal oxidation characteristics of Fex(CoCrMnNi)100-x medium and high-entropy alloys

The thermal oxidation behavior of Fex(CoCrMnNi)100-x high-entropy alloys (x = 20 and 40 at.%) and medium-entropy alloy (x = 60 at.%) at temperatures ranging from 900 °C to 1100 °C under air atmosphere was investigated. The oxidation kinetics of the alloys followed the parabolic law, indicated by the increase of oxidation rate constants with increasing Fe content and temperature. The addition of Fe content lowered the configurational entropy and activation energy of the alloys, supporting the acceleration of metal atoms diffusion. Furthermore, the oxide scales formed on the surface were strongly dependent on the alloy composition. In general, a Cr2O3 inner layer, spinels (NiCr2O4 and CoMn2O4) as intermediate layers, and the outer layers of Fe3O4 and Mn3O4 were formed after oxidation at 900 °C in all alloys. On the other hand, severe internal oxidation and pores were observed in the alloy containing 60 at.% of Fe after oxidation at 1100 °C. In addition, the pores were formed due to the Kirkendall effect, acting as diffusion path and reaction place which may facilitate the oxidation process.

Tunable Redox Temperature of a Co3–xMnxO4 (0 ≤ x ≤ 3) Continuous Solid Solution for Thermochemical Energy Storage

Heat storage technologies are well suited to improve energy efficiency of power plants and recovery of process heat. A good option for high storage capacities, especially at high temperatures, is storing thermal energy by reversible thermo-chemical reactions. In particular, the Co3O4/CoO and Mn2O3/Mn3O4 redox-active couples are known to be very promising systems. However, cost and toxicity issues for Co oxides and sluggish oxidation rate (leading to poor reversibility) for Mn oxide, hinder the applicability of these singles oxides. Considering instead binary Co-Mn oxide mixtures could mitigate the above-mentioned shortcomings. To examine this in detail, here we combine first-principles atomistic calculations and experiments to provide a structural characterization and thermal behavior of novel mixed metal oxides based on cobalt/manganese metals with spinel structure Co3-xMnxO4. We show that novel Co3-xMnxO4 phases enhance indeed the enthalpy of the redox reactions, facilitate reversibility, and mitigate energy losses when compared to pure metal oxide systems. Our results enlarge therefore the limited list of today's available thermochemical heat storage materials and pave the way towards the implementation of tunable redox temperature materials for practical applications.

Thermal oxidation behavior of trimethylolpropane trioleate base oil when exposed to iron surfaces

PurposeThis paper aims to investigate the thermal oxidation behavior of trimethylolpropane trioleate (TMPTO) base oil when exposed to Fe surfaces.Design/methodology/approachSamples of TMPTO bulk oil were placed in Fe vessels and heated in an oven to accelerate the oxidation at different time intervals, while others were placed in glass vessels and used as experimental controls. Subsequently, the physicochemical properties of the oxidized TMPTOs, including the kinematic viscosity and acid value, were measured and a structural analysis was conducted using the Raman and Fourier transform infrared (FTIR) techniques.FindingsThe results demonstrate that the TMPTO bulk oil exhibited an exponential increase in the kinematic viscosity along with the increasing acid value over the oxidation time. The Fe surface significantly increased the kinematic viscosity of TMPTO, while only mildly impacting its acid value compared with the experimental controls. The structural analysis results of the TMPTO suggest that the C = C and = C-H bonds were the vulnerable sites. Furthermore, the results suggest that the Fe surface evidently accelerates the chemical reactions of the C = C and the = C-H bonds, and less alcohols and more carbonyl products were identified in the oil samples that were heated in the Fe vessels.Originality/valueThe results demonstrate that the Fe surfaces affected the oxidation behavior of the TMPTO base oil, and an interaction mechanism between the Fe and the TMPTO is developed.

Microstructural and electrochemical corrosion properties of electroless Ni-P-TaC composite coating

Ceramic particles are frequently used as reinforcements in electroless Ni-P coating to enhance the mechanical and electrochemical properties. Tantalum carbide (TaC) is a well-known refractory ceramic material, with excellent mechanical properties such as high hardness and fracture toughness. However, its performance as a composite additive has not yet been investigated in the electroless Ni-P coating system. A detailed surface and microstructural analysis have been carried out to explain the mechanical hardness, as well as corrosion-resistant behavior of as-plated and heat treated Ni-P and Ni-P-TaC coating systems. Nanocrystallites of Ni and Ni3P phases along with incorporated TaC particles are distributed in heat treated composite coating as revealed by XRD and TEM analysis. A unique amorphous interface between TaC particle and coating matrix is observed in the Ni-P-TaC composite coating that has provided a protective layer to the corrosion attack at the grain boundaries and defects presented in the coatings. The phase and thermal oxidation behavior of Ni-P and Ni-P-TaC system studied via temperature-dependent Raman measurement show that the coating systems are stable in ambient environment up to 500 °C. The electrochemical corrosion test suggests good corrosion resistance properties of the heat treated Ni-P-TaC composite coating over as-plated Ni-P coating.

Screening of Spontaneous Ignition Feasibility During Air Injection EOR Process Based on Thermal Experiments

The feasibility of spontaneous ignition is extremely important to the success of AIP (air injection process) projects. However, no laboratory experiments were reported on the detection of crude oil spontaneous ignition during AIP. The initial intention of the thermal experiments is to screen candidate oil reservoirs for the application of AIP in a faster and less expensive way than combustion tube tests. However, instead of performing a feasibility study, most of the research only employed thermal experiments as a tool to obtain kinetic data and to characterize the thermal-oxidative behavior for different crude oil samples. The question of how to use the thermal experiments to determine the feasibility of spontaneous ignition has not been answered yet. This study proposes a practical method to investigate the spontaneous ignition feasibility during AIP, which directly relates the oil reactivity and reservoir properties. An example of the application of this method was presented in this paper, where a mixture of a light oil and sand was tested by the TGA and DSC to obtain the kinetic data and net heat. The obtained parameters were then used to evaluate the feasibility of spontaneous ignition. The results showed that the tested oil and sand mixture cannot lead to spontaneous ignition due to crude oil’s insufficient reactivity. Furthermore, the typical crude oil kinetic data and reservoir conditions were used to investigate the screening criteria for spontaneous ignition. The results indicated that the crude oil’s activation energy and frequency factor need to be less than 60 kJ/mole and higher than 2 s−1, respectively, in order to satisfy the need of spontaneous ignition.

Effects of SiC and SiC-GNP additions on the mechanical properties and oxidation behavior of NbB2

ABSTRACTMonolithic NbB2, NbB2-SiC, and NbB2-SiC-GNP samples were produced by spark plasma sintering (SPS), and the effects of additives on the mechanical and thermal properties, microstructures, and oxidation behavior of the samples were investigated. The addition of SiC up to 30 vol% decreased the Vickers hardness of the binary composites due to microcrack formation. The fracture toughness and oxidation resistance of NbB2 were improved with the incorporation of SiC. Fracture toughness was higher for all the composites in comparison to monolithic NbB2, moreover the highest value of ~5.2 MPa·m1/2 exhibited by 3 vol% GNP-containing composite. A strong interface and homogeneous distribution of GNPs enhanced the thermal transfer properties and improved the oxidation resistance of selected NbB2-SiC ceramics in oxidation studies at 1200°C. A combination of high mechanical properties, high thermal conductivity, and low mass gain was achieved for the NbB2-SiC-GNP samples with 1 and 3 vol% GNPs.

Determination of the Thermal Oxidation Stability and the Kinetic Parameters of Commercial Extra Virgin Olive Oils from Different Varieties

The use of olive oil with cooking purposes, as final seasoning or within cooked foods is increasing worldwide due to its numerous nutritional and health benefits. These attributes are mainly determined by olive oil chemical composition, which can be altered after thermal processing, oxidation processes, or incorrect practices. For this reason, and due to the numerous factors which have influence in olive oil quality, the correct chemical characterization is highly relevant. In this study, fatty acid composition of four extra virgin olive oil (EVOO) varieties was studied. The major fatty acid (FA) determined was oleic acid (77.1% on average), followed by palmitic (11.5% on average). In addition, thermal oxidation behaviour of the four EVOO samples was studied as an indicator of their quality and stability during thermal processing. This was performed through differential scanning calorimetry (DSC) from a temperature of 40°C at six different heating rates in the range of 0.5–10°C min−1. DSC records showed the same pattern and a small shoulder in the thermo-oxidation peak was present for all samples and all heating rates. The presence of initial and final oxidation products (by monitoring K232 and K270 values, respectively) was discarded according to the International Olive Council method.

The Oxidation and Combustion Properties of Gas Atomized Aluminum−Boron−Europium Alloy Powders

AbstractIn this paper, the Aluminum−boron−europium ternary alloy fuels with boron content of 1.5∼4.85 wt. % and europium content of 3 wt. % were prepared by the close‐coupled gas atomization. XRD, SEM, TG‐DTA and oxygen bomb test were used to analyze the phase constituents, morphology, thermal oxidation behavior and combustion exothermic property of powders, respectively. The functions of boron and europium on the combustion of metal fuels were studied, and a reasonable oxidation model of the alloy particles was proposed. The results show that there are Al, AlB2, Al4Eu and B6Eu in the alloy. When the europium content is constant, the combustion enthalpy of the Al−B−Eu alloy powder firstly increases and then decreases as the boron content increases. Additionally, at oxygen pressure of 3.0 MPa, the Al−3.5B−3Eu ternary alloy powder burned completely with the maximum combustion enthalpy of 33324.5 J g−1. This increases by 11 % compared with theoretical combustion enthalpy of aluminum powder (31.1 kJ g−1). Al−3.5B−3Eu undergoes a dramatic oxidation exothermal phenomenon at 1110 °C with the weight increase efficiency of 53.66 %, which is 1.7 times that of aluminum. Due to the synergistic effects between the phase of B6Eu and AlB2 inside the alloy particles, the Al−3.5B−3Eu alloy powder shows excellent exothermic performance.