Al-Mn Alloys Research Articles

Microstructure and radiation shielding capabilities of Al-Cu and Al-Mn alloys

In this study, the microstructure and elemental analysis of aluminum-copper alloy type-2024, Al-2024, and aluminum-manganese alloy type-3003, Al-3003, have been investigated by using a scanning electron microscope (SEM) equipped with Energy dispersive spectroscopy (EDS) detector. Experimental and theoretical radiation shielding studies were performed to assess the radiation shielding capabilities of the studied alloys. Considering the radiation shielding theoretical assessment, some reliable software tools were used, such as Phy-X/PSD, MCNP5, NXCom, and MRCsC. The microstructural observations and results have shown the presence of second phases rich with the main alloying elements in both alloys. Considering Al-2024 alloy, coarse second-phase particles, having a size range of 8–15 μm, were found aligning in lines parallel to the rolling direction, whereas smaller ones, having a size range of 2–8 μm, were found decorated the grain boundaries. Also, dark holes represent the pull-out large particles separated during preparation indicated poor adhesion with the main matrix that could be a result of losing particle coherency with the matrix where the misorientation in-between the atomic planes increase. However, better adhesion of the second-phase particles with the matrix, which were found possessing smaller particle size, have been observed in the Al-3003 alloy indicating good coherency and better manufacturing process for the non-heat-treatable alloy. The second-phase particles in case of Al-2024 alloy were found containing significant content of high-Z elements like Cu with greater volume fraction equals 7.5%. On the other side, Al-3003 alloy has possessed second-phase particles which lack of high-Z elements with only volume fraction equals 3.5%. All the former besides the higher density and content of high-Z elements like copper in Al-2024 alloy in compare to Al-3003 alloy and pure aluminum, led to relatively better radiation shielding capabilities against energetic photons, the highest in the low energy band and decreases with the increase of the photon energy, and slight superiority in the case of fast neutrons with only 3%inc. over pure aluminum. For instance, the radiation protection efficiency (RPE) values dropped from about; 23.2, 21.6, and 20.8% at 0.100 MeV to only 5.7, 5.9, and 5.6% at Eγ = 2 MeV, for; Al-2024, Al-3003, and Al-Pure, respectively."Please check and confirm that the authors and their respective affiliations have been correctly identified and amend if necessary.""confirmed"

Improving plasticity by Si-addition-induced coherent nanoprecipitates in Cu–Al–Mn alloy fabricated by laser powder bed fusion

In this paper, the Cu-10.8Al-8.3Mn-0.37Si alloy containing Mn5Si3 phase was obtained by adding Si element to the Cu-10.8Al-8.3Mn alloy. The two alloys were printed by laser powder bed fusion. The changes in the organization and tensile properties of the alloys and the mechanism were investigated. After Si addition, the Mn5Si3 nano phase precipitated in the alloy in addition to the β1 austenite phase. The Mn5Si3 phase was co-lattice with the β1 phase with an average size of 10 nm and was diffusely distributed. Standard tensile experiments showed that the yield strength of the Cu-10.8Al-8.3Mn-0.37Si alloy decreased by 57.7% and the elongation increased by 266% compared to the Cu-10.8Al-8.3Mn alloy, while the tensile strength remained essentially unchanged. The presence of Mn5Si3 phase provided nucleation points for martensite and promoted the generation of stress-induced martensite. Hence the yield strength was reduced. TEM results showed that the β1 phase in the Cu-10.8Al-8.3Mn-0.37Si alloy was fully transformed into stress-induced martensite after deformation, which displayed the transformation induced plasticity effect and hindered the slip of dislocations. Meanwhile, the Mn5Si3 phase was sheared by the stacking faults, which promoted the accumulation of hetero-deformation-induced stress. Therefore, the hardening capacity and plasticity of the Cu-10.8Al-8.3Mn-0.37Si alloy were enhanced. This work provides a new idea for the plasticity enhancement of Cu–Al–Mn-based shape memory alloys achieved by co-lattice nano-precipitated phase strengthening.

Determination of stress triaxiality by experiment-simulation and obtaining of johnson-cook damage criterion for Al-Mn alloy

Abstract Al-Mn alloy is extensively implemented in new energy vehicles. Damage prediction is the key to its safety application. The Johnson-Cook (JC) constitutive relationship parameters of Al-Mn alloy were first determined by standard tensile tests to predict the damage behavior of Al-Mn alloy. Subsequently, different notch specimens were designed to study the influence of stress state on damage behavior. By combining tensile tests and simulations, the stress triaxiality of Al-Mn alloy under different stress states was accurately obtained. On this basis, the JC damage criterion parameters were obtained. Finally, the obtained JC constitutive relationship and damage criterion parameters were imported into the tensile simulation models. The results showed that the force-displacement curves of the tensile experiments and simulations matched well, which can effectively simulate the deformation and fracture behavior of the Al-Mn alloy.

Realizing rechargeable cathode-free aluminum-ion batteries via regulating solvation structure in aqueous-aprotic electrolytes

Aqueous aluminum-ion batteries (AIBs) are promising candidates for large-scale energy storage due to the abundant resource reserve, high theoretical capacity, intrinsic safety, and low cost of Al. However, the development of aqueous AIBs is constrained by the inefficient Al plating, inevitable parasitic side reactions, and the collapse of the cathode materials. Herein, we propose a novel Al3+/Mn2+ hybrid electrolyte in a water-acetonitrile co-solvent system with a regulated solvation structure to realize cathode-free AIBs. The inclusion of acetonitrile as a co-solvent plays a crucial role in reducing the desolvation energy and suppressing side reactions. The introduction of Mn2+ can enable the reversible plating/stripping of Al-Mn alloy with reduced overpotentials on the anode and deposition/stripping of AlxMnO2 on the cathodic current collector to realize cathode-free AIBs. The architected AIB delivers a high discharge capacity of 397.9 mAh g−1, coupled with superior rate capability and stable cycling performance. Moreover, the cathode-free AIB shows superior low-temperature performance and can operate at −20 °C for over 120 cycles. This work provides new ideas for developing high-performance and low-cost aqueous AIBs.

Strain Hardening in Dilute Binary Al–Cu, Al–Zn, and Al–Mn Alloys: Experiment and Modeling

During thermo-mechanical processing, dissolved alloying elements have a huge impact on the microstructure evolution by influencing the overall dislocation storage rate. Especially, for non-heat treatable Al alloys, the effects of strain-hardening and solid solution strengthening are of significant practical interest. In the present work, a detailed study of the room temperature work-hardening behavior of binary Al–Cu, Al–Zn, and Al–Mn alloys with varying solute concentrations is carried out. Stress–strain curves at different strain rates are recorded and computationally analyzed by an advanced 3-Internal-Variables-Model (3IVM) approach for the dislocation density evolution. The initial strengthening rate is examined as a function of the solute concentration.

Investigation of metal non-opaque foreign bodies of firearm origin by radiation methods

Background. The purpose is to investigate metal non-opaque foreign bodies of firearm origin. Materials and methods. Five cases of removing soft tissue foreign bodies of gunshot origin were investigated, when radiography of the limb soft tissues didn’t detect foreign bodies, but they were removed during the primary surgical wound debridement. X-ray of soft tissue gunshot wounds found no foreign bodies. To study radiographic density, foreign bodies were placed in a foam model with subsequent multislice computed tomography. For spectral analysis of metal foreign bodies, we used wavelengths unconventional for X-ray, which allowed to conduct X-ray fluorescence and X-ray structural studies. Results. Radiographic density of metal foreign bodies ranged from 989 to 2123 HU. Given the different thickness of foreign bodies, from 0.4 to 3.2 mm, the average was 1700 ± 189 HU. The foam had radiographic density of –969 HU with model dimensions of 200 × 100 × 50 mm. When examining samples of foreign bodies, it was found that they are deformed, have different thicknesses. One of the samples is light and smooth on one side, and dark and rough on the other. X-ray fluorescence results: composition on the light side (% by mass): Al — base, Mn — 0.8, Fe — 0.3, Zn — 0.1, Cr — 0.05, Ti — 0.2, corresponding to Al-Mn alloy. The dark side is an oxidized Al-Mn alloy. In the spectrum of the dark side of the sample, the Br-Kα line was detected, which indicates the participation of bromine compounds in the oxidation process. From the smooth side of the sample, the spectrum of this line is not determined. Conclusions. Non-opaque metal foreign bodies of gunshot origin are a rare phenomenon. Metal foreign bodies with low radiographic density are non-ferromagnetic, the use of modern magnetic surgical instruments will not be effective. Visualization of metal foreign bodies, which are not determined by radiography, is possible with the help of multislice computed tomography. The use of the wavelength of primary radiation, which is unconventional for X-ray spectral analysis, and original X-ray optical schemes allows for quantitative determination of the composition and structure of any metal foreign bodies.

Role of Al content on tensile properties and stretch formability of Mg–Al–Mn alloy sheet produced by continuous hot-rolling

Continuous rolling is a novel cost-effective process to fabricate high-performance Mg alloy sheets with good room-temperature formability, and we investigated the effect of Al content on tensile properties and room-temperature formability of a recently designed Mg–Al–Mn alloy sheet. An excellent combination of tensile 0.2 % proof stress (TPS) and limiting dome height (LDH) was achieved by adding the moderate content of Al (2 % or 4 %). The sheets annealed at a low temperature of 250 °C showed the TPSs of ∼170–180 MPa and LDHs of ∼8 mm. The LDHs further increased to ∼9 mm by the annealing at 350 °C, while moderate TPSs of ∼150–160 MPa were maintained. Further, the sheets had an in-plane isotropy in which the tensile properties along the rolling direction were very similar to those along the transverse direction. The good properties were achieved by fine grain structure with the reduced intensity of the (0001) poles. Indeed, the Elasto-ViscoPlastic Self-Consistent modeling revealed the increase of the activity of the prismatic slip by adding 4 % of Al, while it had a limited effect in improving the stretch formability. Further, we found that the deformation microstructure of the as-rolled sheets became uniform by the 2 % and 4 % Al addition, which would contribute to the reduced intensity of the (0001) poles after the annealing.

Gaining understanding of the effect of alloy composition on the properties of Ti–Cu–Mn–Al alloys

High performance cheaper Ti alloys can be developed based on the addition of several alloying elements, amongst which are Cu, Mn and Al. Studies are available in literature about binary and some ternary alloys based on the addition of these elements; however, no quaternary Ti–Cu–Mn–Al alloys were developed. Therefore, in this study quaternary Ti–Cu–Mn–Al alloys were manufactured via powder metallurgy to gain a better understanding of the effect of the alloy composition and the achievable mechanical performance. It is found that the selected quaternary Ti–Cu–Mn–Al alloys are characterised by a lamellar structure, which is progressively refined as the amount of alloying elements increases, and precipitation of the Ti2Cu intermetallic occurs if the Cu content is high enough. The amount of residual porosity increases and changes morphology as more thermal energy is invested in the diffusion of the alloying elements. In terms of mechanical behaviour, the quaternary Ti–Cu–Mn–Al alloys undergo both elastic and plastic deformation upon tensile loading. Strength and hardness linearly increase and the ductility monotonically decreases, which is the result of the compromise between the amount of residual porosity and the several strengthening mechanisms brought about by the actual total amount of alloying elements added.

Introducing the chemical potential of Cu–Mn–Al alloys for structural, electrical and thermal properties

Introducing the chemical potential of Cu–Mn–Al alloys for structural, electrical and thermal properties

The microstructure evolution and strengthening mechanism of fine-grained Al–Mn alloy with nanoscale precipitates during cryorolling

In this work, the fine-grained Al–Mn alloys with nanoscale precipitates was designed, and the texture evolution and strengthening mechanism for fine-grained Al–Mn alloy with nanoscale precipitates during cryorolling were investigated by EBSD and TEM analysis. The results show that the dislocation tangles gradually evolved into dislocation cells, and then into subgrains/ultrafine grains with boosting rolling reduction. The initial grains and precipitates can be significantly refined by cryorolling. Furthermore, the dominating P and M textures in the solution-treated Al–Mn alloy gradually converted to α-fiber and β-fiber textures during cryorolling. The formation of α-fiber and β-fiber textures is beneficial for improving the strength of the Al–Mn alloy. An excellent strength-ductility synchronization can be achieved in the Al–Mn alloy cryorolled at a rolling reduction of 50 %. The strengthening mechanism of Al–Mn alloy subjected to cryorolling is associated with texture strengthening, dislocation strengthening, grain refinement strengthening and precipitation strengthening.

The Influence of Precipitated Particles on the Grain Size in Cold-Rolled Al-Mn Alloy Foils upon Annealing at 100-550 °C.

The Al-Mn alloy heat exchanger fin production process includes a brazing treatment at s high temperature of 600 °C, in which coarse grains are preferred for their high resistance to deformation at elevated temperatures by decreasing the grain boundary sliding. In this study, Al-1.57Mn-1.57Zn-0.58Si-0.17Fe alloy foils cold rolled by 81.7% (1.1 mm in thickness) and 96.5% (0.21 mm in thickness) were annealed at 100-550 °C for 1 h to investigate their recrystallization behavior, grain sizes, and precipitates by increasing the annealing temperature, using micro-hardness measurement, electron back-scattered diffraction (EBSD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) techniques. The micro-hardness results showed that the recrystallization finishing temperatures for the two samples were almost the same, 323 ± 2 °C. The EBSD results showed that when the annealing temperature decreased from 550 to 400 °C, the recrystallized grain sizes of the two samples were nearly identical-both increased slightly. Further decreasing the annealing temperature from 400 to 330 °C caused the grain sizes to increase more, with the thinner foil sample having a more significant increase. The SEM and TEM observations showed that the micron-sized primary-phase remained unchanged during the annealing process. The nano-sized secondary phase precipitates formed during the hot-rolling process experienced a coarsening and dissolving process upon annealing. The particle size of the secondary phase increased from 32 nm to 44 nm and the area fraction decreased from 4.2% to 3.8%. The nucleation analysis confirmed that the large primary-phase could act as a nucleation site through particle stimulated nucleation (PSN) mode. The relatively dense secondary phase precipitates with small sizes at lower temperatures could provide higher Zener drag to the grain boundaries, leading to fewer nuclei and thereafter coarser grains. The coarsening of the recrystallized grains in the foils could be implemented through thickness reduction and/or precipitation processes to form densely distributed nano-sized precipitates.

Effect of Al and Mn substitutions on hydrogen activation performances of La–Ni–Al–Mn alloy

To interpret the effect of Al and Mn substitutions on activation performances of La–Ni–Al–Mn alloy, the initial activation curve has been measured, which shows that the incubation time of activation is prolonged with the increase of Al content in alloy, while shortened duo to Mn substitution. Further, the first-principles calculations are employed. We find that (1) (100)/(010) surface of LaNi5 is the most stable and its stability can be improved by Al substitution for Ni while decreased by Mn substitution; (2) the preferential hydrogen adsorption sites are the hole and Ni (or Mn)-top sites; (3) Al and Mn substitutions can increase the hydrogen adsorption stability, but Al doping decreases the number of available sites, therefore retarding activation, while Mn doping guarantees the number of available sites, making activation easier; (4) H bonds covalently with neighbor Ni (or Mn) and ionically with La, together determining the stability of hydrogen adsorption.

High-throughput synthesis of binary Al–Mn alloys by directed energy deposition with improved accuracy of composition adjustment

High-throughput synthesis of binary Al–Mn alloys by directed energy deposition with improved accuracy of composition adjustment

High spin polarization in quaternary Heusler Fe–Rh–Mn–Al alloys

In this theoretical study, we investigate novel quaternary Heusler Fe–Rh–Mn–Al alloys in the X-type structure with different types of atomic ordering in the unit cell within the spin-polarized density functional calculations. The calculations showed that the 24 possible configurations converge to the 6 nonequivalent solutions. Two types of atomic ordering with the lowest total energy Fe(4c)Rh(4d)Al(4b)Mn(4a) and Mn(4c)Al(4d)Fe(4b)Rh(4a) are half-metallic ferrimagnets in which the spin polarization at the Fermi level is close to 100 %. However, no gap is open in the majority spin projection. The following values of the total magnetic moments for these alloys were obtained: 3.01 and 3.19 μB/f.u., respectively. In the other types of atomic ordering, the half-metallic state is not formed. In FeAlRhMn, the magnetic moment on the manganese ion compensates for the moments on the other ions, and the total moment is close to zero. In the types (MnFeRhAl, AlRhFeMn) of atomic ordering with high energies, the metallic state is also realized, and the magnetic moments on the ions are ordered ferrimagnetically. In this work, we analyzed novel quaternary alloys with different types of atomic ordering motivated by the demand for alloys with a high spin polarization, among which the FeRhAlMn and MnAlFeRh alloys were found. Both with a half-metallic ferrimagnetic state and the lowest total energy among these alloys with the same chemical composition, which indicates the stability of the half-metallic state. The other types of atomic ordering are less energetically favorable, those alloys are ferrimagnetic metals with the low spin polarization. Taking into account the half-metallic state and high spin polarization, the quaternary FeRhAlMn and MnAlFeRh alloys have prospects for use in spintronic devices.

Effect of rolling method on the recrystallization behavior and recrystallization texture of Al-Mn alloy

CC AA 3003 aluminum alloy hot strip was cold-rolled to various thinning degrees along the original rolling and crosswise, followed by annealing at 399 °C and 427 °C for various periods of times. Investigations were conducted on the impact of rolling method on recrystallization and recrystallization texture. The findings demonstrate that the straight-rolled (i.e., in the original rolling direction) sheets annealed at 399 °C have recrystallization textures that are characterized by the M {1 1 3}< 1 1 0 > and P {0 1 1}< 4 5 5 > components, with the M component significantly strengthening with increasing rolling reduction and the P component only slightly strengthening. The M texture diminishes noticeably when the annealing temperature increases from 399 °C to 427 °C, but the P texture weakens very marginally. When the rolling reduction approaches 60% to 70%, the r-cube recrystallization texture is formed in the annealed cross-rolled (i.e., along the original transverse direction) sheets, and the strength of the r-cube texture declines with increasing rolling reduction. The 90% cross-rolled sheet that has been annealed at 399 °C forms the comparatively strong M and extremely weak P textures in comparison to the 90% straight-rolled sheet. With increasing rolling reduction, an increase in the size of recrystallized grains is observed in plates annealed at 399 °C, but it shrinks in sheets that are annealed at 427 °C.

Alloy Quasicrystals: Perspectives and Some Open Questions at Forty Years

Four decades have elapsed since the first quasiperiodic crystal was discovered in the Al–Mn alloy system, and much progress has been made during this time on the science of quasicrystals (QCs). Notwithstanding this, a significant number of open questions still remain regarding both fundamental and technological aspects. For instance: What are QCs good for? How can we improve the current provisional QC definition? What is the role of the underlying quasiperiodic order and the characteristic inflation symmetry of these compounds in the emergence of their unusual physicochemical properties? What is the nature of chemical bonding in QCs formed in different sorts of materials such as alloys, oxides, or organic polymers? Herein these and other closely related issues are discussed from an interdisciplinary perspective as well as prospective future work in the field in the years to come.

Morphology of Al-2.5%Mg/xSiCp Composite developed by Stir Casting Process

. The research was conducted to enhance and solve the issues associated with low wettability and insufficient bonding between aluminum and silicon carbide that usually associated with stir casting process. The study used magnesium, heat treatment of SiCp and metallic (SiO2) coating on SiCp for improved Al-SiCp wettability in the manufacture of composite. The wt.% of SiCp was varied from 5 wt.% to 20 wt.% (uncoated and coated) at 5 wt.% intervals. The characterization conducted are XRD, XRF and SEM on the samples developed. XRD plots confirmed existence of Al with major peaks at 38.5, 45.11, 65.35, and 78.31; while Mg and SiCp were seen at 34.82 and 60.78 respectively. The XRF analysis revealed that major elements are within the range proposed for research with Alumina contains the highest amount of 70.05 – 86.69 wt.%, followed by Magnesium with 2.46 - 2.57 wt.%, and silicon having varying values of 0.91 wt.% for Sample A, 5.91 – 21.01 wt.% for uncoated samples B – E, and higher values of 8.43 – 24.43 wt.% for Samples F – I compared to the control sample, while all other minerals present are in such negligible proportion. The SEM/EDS results showed a fair dispersion of the SiCp particles in the samples with weight percentages of Al between 54.3 – 72.7 wt.%, Mg with 2.33 wt.% for control sample and a higher of values of 3.90 – 8.22 wt.% for composite samples, and Si with 0.10 – 1.32wt.%. Owning to this best performance test results, the coated Al-2.5%Mg/10wt%SiCp (Sample G) may be adopted as an alternate monolithic alloy to the existing AlMn, AlMg and AlMgSi alloys for structural, heavy machineries and marine applications where light weight is required.

A Kinetic Study on the Preparation of Al-Mn Alloys by Aluminothermic Reduction of Mn3O4 and MnO Powders

The study of aluminothermic reduction in manganese compounds is a complex challenge in preparing Al-Mn alloys. The primary objective of this study was to ascertain the activation energy values for the aluminothermic reduction of MnO and Mn3O4 oxides derived from alkaline batteries. The study melted aluminum found in beverage cans and utilized the technique of powder addition with mechanical agitation. The kinetics of the reaction were studied under the effects of temperature (750, 800, and 850 °C), degree of agitation (200, 250, and 300 rpm), and the initial concentration of magnesium in molten aluminum (1, 2, 3, and 4% by weight). Kinetic measurements for Mn3O4 particles suggest a reaction mechanism that occurs in stages, where manganese undergoes oxidation states [Mn+3] to [Mn+2] until it reaches the oxidation state Mn0, which allows it to dissolve in the molten aluminum, forming alloys with up to 1.5 wt.% of Mn. Therefore, the kinetic of the aluminothermic reduction of MnO is described by the geometric contraction model, while the mechanism of Mn3O4 reduction occurs in two stages: geometric contraction, followed by an additional stage involving the diffusion of chemical species to the boundary layer. In addition, this stage can be considered a competition between the formation of MnO and the chemical reaction itself.

Microstructure and Corrosion Behavior of Laser-Welded Al-Mn-Zr Alloy for Heat Exchanger.

In this study, an Al-Mn-Zr alloy was designed and its microstructure and corrosion behavior compared after laser welding to that of AA3003. As the results of immersion and electrochemical tests showed, both alloys had a faster corrosion rate in the fusion zone than in the base metal. Laser welding caused interdendritic segregation, and spread the intermetallic compounds (IMCs) evenly throughout in the fusion zone. This increased the micro-galvanic corrosion sites and destabilized the passive film, thus increasing the corrosion rate of the fusion zone. However, Zr in the Al-Mn alloy reduced the size and number of IMCs, and minimized the micro-galvanic corrosion effect. Consequently, Al-Mn-Zr alloy has higher corrosion resistance than AA3003 even after laser welding.

Comparison of shape memory properties between Cu-12.5Al–3Mn and Cu-12.5Al–3Mn–1Ni produced by additive manufacturing technology

In this work, two Cu–Al–Mn shape memory alloys (SMAs), Cu-12.5Al–3Mn and Cu-12.5Al–3Mn–1Ni, were prepared by wire arc melting deposition, and their shape recovery rates, ultimate recoverable strains, additive manufacturing microstructures, memory recovery behaviors, and phase transition properties were comparatively investigated. Meanwhile, the mechanism of Ni in these two alloys was discussed by combining the differences in phase composition of the two alloys. Results showed that the shape recovery rate of Cu-12.5Al–3Mn alloy decreased linearly with increasing pre-strain, from 91.23% at 4% pre-strain to 62.41% at 10% pre-strain, and its ultimate recoverable strain was approximately 7%; while the shape recovery rate of Cu-12.5Al–3Mn–1Ni SMA was 100% at 4%–8% pre-strain, and remained at 96.57% until the pre-strain was increased to 10%, i.e., the recoverable strain was more than 9%. In addition, the phase change temperature of the alloy with Ni addition decreased compared to that of the alloy without Ni addition, especially the temperature hysteresis was narrower. The results indicate the formation of a new κ phase after adding Ni to the alloy. The pinning effect of this new phase significantly improves the order of martensite within the alloy. Moreover, Ni also induces the transformation of the alloy, inhibiting the precipitation of the brittle phase γ2 and leading to a marked increase in the shape memory recovery rate and the recoverable strain of the additively fabricated Cu–Al–Mn alloy. Note that Ni transforms the alloy from hyper-eutectoid components to eutectoid components. Moreover, after adding Ni, the thermoelastic martensite phase transition temperature and temperature hysteresis decreased together with its eutectoid temperature, which made the additive manufacturing Cu–Al–Mn SMA exhibit an explosive response behavior.