Addition Of Mn Research Articles

CALPHAD-guided investigation on enhancing NiAl bronze properties and microstructures evolution with Mn addition

The effect of Mn addition on microstructures and properties of as-cast NiAl bronze was systematically investigated in this study. Phase diagram calculations (CALPHAD) were employed to investigate the phase transformation process, composition, and fraction of Cu-10Al-5Fe-5Ni-xMn (x = 0, 1.5, 4.5, 7 wt%) alloys. With the increasing Mn element, the β phase region expands, and the precipitation temperature of κⅢ phase increases while the κⅣ phase decreases. The microstructure characterization and quantitative analysis reveal significant morphology changes. The polygonal α-Cu phase transforms to the acicular α-Cu phase while the fraction of κⅢ phase increases. The atomic-scale interface between the κⅢ/α and the composition of the κⅢ phase are analyzed using transmission electron microscopy. The results indicate that the κⅢ phase exhibits a Nishiyama-Wasserman (NW) orientation relationship with the α-Cu phase in Mn-containing alloys. Additionally, optimal mechanical properties of UTS = 795 MPa, YS = 438 MPa are achieved with the addition of 4.5 wt% Mn, while the best EL = 20.8 % is attained with 1.5 wt% Mn.

Optimizing the Morphology and Solidification Behavior of Fe-Rich Phases in Eutectic Al-Si-Based Alloys with Different Fe Contents by Adding Mn Elements.

A high Fe content easily produces Fe-rich phases with a harmful morphology, resulting in a huge detrimental effect on the properties and recycling ability of Al-Si alloys. Therefore, finding ways to effectively transform Fe-rich phases to form a beneficial phase or shape is of great significance. Accordingly, Al-Si-based alloys with Fe contents ranging from 0.1 wt.% to 2.0 wt.% were modified by different Mn additions. Moreover, experiments combined with simulations were utilized to comprehensively analyze the mechanism of Mn on the morphology and microstructural evolution of Fe-rich phases from different perspectives. The current findings determine that adding different Fe contents changes the phase-transition reactions in alloys. Without Mn, and by increasing the Fe content from 0.1 wt.% to 2.0 wt.%, the Fe-rich phases gradually convert from a skeleton-shaped α-Al8Fe2Si (<0.25 wt.%) to β-Al9Fe2Si2 with a fibrous (0.5 wt.%), needle-like (1.0 wt.%) and plate-like shape without curvatures (2.0 wt.%). The maximum length and mean aspect ratio increase from 12.01 μm to 655.66 μm and from 1.96 to 84.05, while the mean curvature decreases from 8.66 × 10-2 μm-1 to 8.25 × 10-4 μm-1. The addition of 0.35 wt.% Mn promotes a new Chinese-character and petal-shaped α-Al15(FeMn)3Si2, with an atomic ratio of Fe and Mn of 1:1 when the Fe content is lower than 0.5 wt.%, while it transforms to β-Al15(FeMn)3Si2 with an atomic ratio of 5:1, presenting as a refined plate-like shape with a certain curvature, as the Fe content increases to 2.0 wt.%. Mn alters the phase reactions and increases the threshold of the Fe content required for β-Al15(FeMn)3Si2, limiting the formation and growth of them simultaneously in time and space. The enrichment of Mn atoms and solute diffusion at the growth front of β-Al15(FeMn)3Si2, as well as the strong atomic-binding ability, can deflect the growth direction of β-Al15(FeMn)3Si2 for it to have a certain curvature. Additionally, the enriched Mn atoms easily form α-Al15(FeMn)3Si2 and cause the long β-Al15(FeMn)3Si2 to be broken and refined to further reduce the damages caused to the alloy's performance. Ultimately, the maximum length and mean aspect ratio can be effectively reduced to 46.2% and 42.0%, respectively, while the mean curvature can be noticeably increased by 3.27 times with the addition of Mn.

Effects of Sn and Mn additions on microstructural characteristics and tensile properties of Mg-1Gd alloy

Effects of Sn, Mn, and their combined additions on microstructural characteristic and tensile properties of extruded Mg-1Gd (G1) alloy are explored. Compared to the sole Sn or Mn addition, an excellent grain refining is happened with the Sn and Mn combined addition. The average grain size of G1, Mg-1Gd-0.8Sn (GS10), Mg-1Gd-0.7Mn (GM10) and Mg-1Gd-0.8Sn-0.7Mn (GSM100) alloys is ∼21.3, 10.1, ∼12.8 and ∼6.8 μm, respectively. The sole Mn addition enhances the strength and ductility of G1 alloy. The forming the fine α-Mn particles and grain refining are attributed to the improved properties of GM10 alloy. The sole Sn addition increases the yield strength of G1 alloy along extrusion direction (ED), but it decreases along transverse direction (TD), The inhomogeneous distribution of coarse GdMgSn particles and formation of TD-split texture should play an important role. The combined effects of Sn and Mn additions guarantee high strength-ductility synergy of GSM100 alloy. The GSM100 alloy exhibits the ultimate strength, yield strength and ductility of ∼276, ∼158 MPa and 24.7 % along ED, and ∼253, ∼157 MPa and 17.5 % along TD, respectively. The jointly effect of the fine grains, a lot of fine GdMgSn and α-Mn particles, the texture weakening and Sn solute atom contributes to the enhancement of properties of GSM100 alloy.

Effect of Ash and Sulphate on Corrosion of Ni-Based Alloys in a Simulated Oxyfuel Combustion Environment

AbstractAlloys of Ni–25Cr–(2Mn–1Si) under mixed deposits of ash + (0, 10, 50 and 90) wt% sulphate were exposed to an Ar–60CO2–20H2O gas at 650 and 750 °C for up to 300 h, forming both protective chromia and regions of Ni-rich oxide. The presence of ash + sulphate mixtures improved Ni–25Cr alloy protection, increasing surface coverage by thin, protective chromia compared with the deposit-free condition. Increasing sulphate proportions in these mixtures led to an accelerated chromia scale growth and reduced internal oxidation zone (IOZ). These beneficial effects were more significant at 750 °C, where surface coverage by the protective scale was increased, and a chromia band was formed beneath nonprotective regions at the IOZ-substrate interface. Alloy additions of Mn and Si generally slowed the growth of outer NiO and IOZ but did not lead to exclusive chromia scale formation.

Effect of Mn, Ni, and Zr Addition on the Tensile Properties and Precipitation Behavior of Sr-Modified Al–Si–Cu–Mg-Based Alloys

Effect of Mn, Ni, and Zr Addition on the Tensile Properties and Precipitation Behavior of Sr-Modified Al–Si–Cu–Mg-Based Alloys

Narrowing Band Gap of Zno Codoping (Al+Mn) as a Photocatalyst Candidate for Degraded Textile Dye Wastewater

Photocatalyst degradation is one method to reduce industrial textile dye pollution in water. In this study, ZnO material has been synthesized by codoping Al and Mn by chemical coprecipitation method to determine the structural properties and optical properties of the material. From this research, it was found that the structure of ZnO after codoping Al and Mn did not change the hexagonal wurtzite phase but changes in other lattice parameters. The addition of Mn and Al codoping is reported to affect the intensity of XRD peaks, especially on the 101 lattice. The higher the scattering peak, the more angular the shift, indicating the magnitude of oxygen vacancies. The reflectance confirms this result that increasing Mn concentration decreases the energy gap to 3.258 eV. From these structural properties and energy gap values, ZnO codoping Al and Mn materials can be included in candidate materials that can be used as photodegradation agents for textile dyes.

Decreased Metal Dusting Resistance of Ni-Cu Alloys by Fe and Mn Additions

AbstractNi-Cu alloys are promising for application at temperatures between 400–900 °C and reducing atmospheres with high C-contents. Typically, under such conditions, metallic materials in contact with the C-rich atmosphere are degraded by a mechanism called metal dusting (MD). Ni-Cu-alloys do not form protective oxide scales, but their resistance is attributed to Cu, which catalytically inhibits the C-deposition on the surface. Adding other alloying elements, such as Mn or Fe, was found to enhance the MD attack of Ni-Cu alloys again. In this study, the effect of the Mn and Fe is divided into two affected areas: the surface and the bulk. The MD attack on binary Ni-Cu alloys, model alloys with Fe and Mn additions, and commercial Monel Alloy 400 is experimentally demonstrated. The surface electronic structure causing the adsorption and dissociation of C-containing molecules is investigated for model alloys. Analytical methods such as scanning electron microscopy combined with energy-dispersive X-ray spectroscopy, electron probe microanalysis combined with wavelength-dispersive X-ray spectroscopy, X-ray diffraction analysis, and near-edge X-ray absorption fine structure measurements were used. The results are correlated to CALPHAD calculations and atomistic simulations combining density functional theory calculations and machine learning. It is found that the Cu content plays a significant role in the surface reaction. The effect of Mn and Fe is mainly attributed to oxide formation. A mechanism explaining the enhanced attack by adding both Fe and Mn is proposed.

Pearlite Growth Kinetics in Fe-C-Mn Eutectoid Steels: Quantitative Evaluation of Energy Dissipation at Pearlite Growth Front Via Experimental Approaches

Essential understanding of the pearlite growth kinetics is of great significance to predict the lamellar spacing and the resultant mechanical properties of pearlitic steels. In this study, a series of eutectoid steels with Mn addition up to 2 mass pct were isothermally transformed at various temperatures from 873 K to 973 K to clarify the pearlite growth kinetics and the underlying thermodynamics at its growth front. The microscopic observation indicates the acceleration in pearlite growth rate and refinement in lamellar spacing by decreasing the transformation temperature or the amount of Mn addition. After analyzing the solute distribution at pearlite growth front via three-dimensional atom probe, no macroscopic Mn partitioning across pearlite/austenite interface is detected, whereas Mn segregation is only observed at ferrite/austenite interface. Furthermore, in-situ neutron diffraction measurements performed at elevated temperatures reveal that the magnitude of elastic strain generated during pearlite transformation is very small. Based on the thermodynamic model, these experimental results are used to estimate the contribution of various factors to the total energy dissipation. Compared with the Mn-free alloy, the retardation effect of Mn addition on pearlite growth kinetics, which is partly due to the reduced driving force for pearlite growth, can be well explained by further considering the solute drag effect of Mn.

Effect of Mn, Ti and Sc Addition on Hardness in an Artificially Aged 2024 Al Alloy

Effect of Mn, Ti and Sc Addition on Hardness in an Artificially Aged 2024 Al Alloy

Dilatometric study on phase transformations in non-deformed and plastically deformed medium-Mn multiphase steels with increased Al and Si additions

AbstractIn this work, two novel alloys containing 4 and 5 mass.% Mn were subjected to theoretical calculations using JMatPro software and experimental studies using dilatometry in order to determine their critical temperatures and ranges of phase transformations of supercooled austenite in undeformed and deformed states. The differences in the kinetics of phase transformations and final microstructures were observed using a light microscope and compared for both investigated alloys. The Mn addition had a strong effect on reducing the Ac3 and Ms temperatures. The plastic deformation applied prior cooling affected the Ms temperature of investigated alloys and kinetics of phase transformations. Both investigated alloys showed high hardenability in the deformed and non-deformed states; and therefore, they can be used as good candidates for products obtained via the Quenching and Partitioning process. Investigated alloys can be used both for sheets and plates of increased thickness because the homogeneous martensitic microstructure can be obtained in a wide range of cooling rates during quenching. The obtained results show a wide technological window for the investigated alloys in producing sheets and plates via the Quenching and Partitioning process.

Fabrication, characterization and evaluating properties of 3D printed PLA-Mn scaffolds

Polylactic acid (PLA) based scaffolds have attained considerable attention in recent years for being used as biodegradable implants in bone tissue engineering (BTE), owing to their suitable biocompatibility and processability. Nevertheless, the mechanical properties, bioactivity and biodegradation rate of PLA need to be improved for practical application. In this investigation, PLA-xMn composite filaments (x = 0, 1, 3, 5 and 7 wt%) were fabricated, characterized, and used for 3D printing of scaffolds by the fused deposition modeling process. The effect of Mn addition on the thermal, physical, mechanical, and structural properties, as well as the degradability and cell viability of 3D printed scaffolds were investigated in details. The obtained results indicate that the PLA-Mn composite filaments exhibit higher chain mobility and melt flow index values, with lower cold crystallization temperature and a higher degree of crystallinity. This higher flowability led to lower dimensional accuracy of 3D printed scaffolds, but resulted in higher interlayer adhesion. It was found that the mechanical properties of composite scaffolds were remarkably enhanced with the addition of Mn particles. The incorporation of Mn particles also caused higher surface roughness and hydrophilicity, a superior biodegradation rate of the scaffolds as well as better biocompatibility, indicating a promising candidate for (BTE) applications.

Effect of manganese amino acid complexes on growth performance, meat quality, breast muscle and bone development in broilers

ABSTRACT 1. This study was conducted to investigate the effects of dietary supplementation of manganese (Mn) amino acid complexes on growth performance, Mn deposition, meat quality, breast muscle and bone development of broilers. 2. A total of 504, one-day-old male Arbor Acres broilers were randomly divided into seven treatments; control diet (CON; basal diet, no extra Mn addition), manganese diet (MnN as Numine®-Mn; CON + 40, 80, 120 or 160 mg Mn/kg), manganese-S group (MnS; CON + 120 mg Mn/kg as MnSO4·H2O), manganese-A diet (MnA as Mn from hydrolysed feather meal; CON + 40 mg Mn/kg as MnA). 3. There were no significant differences for average daily gain (ADG) or feed intake (ADFI) among diets during the feed phases (p > 0.05). The FCR in the starter and over the whole period were quadratically affected by dietary MnN dosage and gave the lowest FCR at 80 mg/kg (p < 0.05). The Mn content of thigh muscle, jejunum, heart, pancreas, liver and tibia increased linearly with MnN addition (p < 0.05). 4. For meat quality, MnN significantly increased colour (a*), pH45 min and pH24 h, reduced shear force, drip loss and pressure loss of breast muscle (p < 0.05). 5. Moreover, MnN significantly upregulated MYOD expression at d 21 and SOD expression at d 42, decreased MuRF1 and Atrogin-1 mRNA level at d 42 in breast muscle. Transcriptome analysis revealed that the regulating effect of MnN on muscle development significantly enriched signalling pathways such as adhesion, ECM-receptor, MAPK, mTOR and AMPK. Furthermore, dietary MnN significantly affected tibia length and growth plate development (p < 0.05) and promoted growth plate chondrocytes by increasing SOX-9, Runx-2, Mef2c, TGF-β, Ihh, Bcl-2 and Beclin1 and decreasing Bax and Caspase-3 (p < 0.05) expression which affect longitudinal tibial development. 6. In conclusion, Mn amino acid complexes could improve growth performance, tissue Mn deposition, breast muscle development, meat quality and bone development.

Optimization, kinetic analysis, and photocatalytic degradation of rhodamine B using manganese doped nanoscale nickel oxide nanoparticles

This work focuses on the synthesis and characterization of nanoscale nickel oxide (NiO) nanoparticles doped with manganese (Mn) utilizing the cost-effective co-precipitation technique. For extensive characterization, a range of analytical methods are used, such as photoluminescence (PL) spectroscopy, X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), Raman spectroscopy, ultraviolet–visible (UV) spectroscopy, and Brunauer–Emmett–Teller (BET) surface area analysis. The findings demonstrate that the addition of Mn causes the synthesized nanoparticles' crystalline size to decrease, which narrows the band gap to 3.13 eV. Furthermore, compared to pure NiO (44.11 m2/g), the surface area of Mn-doped NiO increases to 178.87 m2/g. Also as compared to pure NiO the electron-hole recombination rate of % Mn-doped NiO has decreased and an increase in the defect is observed. The study of Mn-doped NiO nanoparticles' photocatalytic activity against Rhodamine B (Rh. B) demonstrates their improved efficiency under solar light irradiation, as evidenced by their degradation up to 97.57 %, which is higher than that of pure NiO (90.94 %) in 70 min. Numerous aspects are investigated, including pH, catalyst dosage, original dye concentration, and scavenger studies. Studies on regeneration show that 5 % Mn-doped NiO nanoparticles may be recycled effectively and steadily for up to five cycles. These results demonstrate how effective photocatalysts for environmental remediation applications may be made from Mn-doped NiO nanoparticles.

Organic pollutant degradation over highly efficient Mn–Mo(O,S)2 oxysulfide photocatalyst under visible light illumination

Metal oxide semiconductor photocatalysts have received remarkable consideration as a promising technology for environmental remediation and energy conversion. Oxysulfide semiconductors have narrow band gaps which are appropriate for photocatalytic removal of toxic organic pollutants under visible light illumination. For the elimination purpose of these pollutants, Mo(O,S)2, Mn(O,S)2, and Mn–Mo(O,S)2 oxysulfide catalysts containing various Mn contents were synthesized at low temperatures via a simple method. The structural, morphological, electrochemical, compositional, and optical properties of the as-synthesized catalysts were exhaustively characterized. The photocatalytic degradation activity of the bares Mo(O,S)2, Mn(O,S)2, and other Mn–Mo(O,S)2 compositions were evaluated over different types of organic pollutants under visible light illumination. The addition of Mn in Mo(O,S)2 structure improved the photodegradation activity, and Mn–Mo(O,S)2-30 was found to be the best composition with superior photodegradation performance towards the four cationic, anionic, and neutral dyes. The degradation efficiency of 10 ppm of MB, and MO dyes reach 99.7 % and 98.6 %, within 30 and 120 min, respectively. Mn–Mo(O,S)2-30 catalyst also shows a good photodegradation performance on Rh B and NR organic pollutants. According to the recycling test, the catalyst exhibited excellent performance. The photodegradation follows pseudo-first order kinetics with a rate constant of 0.097 and 0.036 min−1 for MB and MO dyes, respectively. The trapping experiment showed that superoxide anion radicals (O2•-) and holes (h+) are the responsible active species for the degradation on MO and MB, respectively. The novelty of using Mn–Mo(O,S)2-30 for various dyes degradation lies in its remarkable catalytic properties.

Influence of Mn on dry yield and nutrient uptake by new jute variety BJRI Tossa-7

A field experiment was conducted during the year 2018-2019 at the vital place of Bangladesh Jute Research Institute (BJRI), Dhaka. The aim of the study was to evaluate the influence of Mn fertilizer on the dry matter yield and potential nutrient uptake of the newly developed jute variety BJRI Tossa jute-7. The treatments used in the experiments were T1: Control, T2: RDF sole (N90P10 K30 S20kg/ha), T3: RDF + 1 kg Mn/ha, T4: RDF + 2 kg Mn/ha, T5: RDF + 3 kg Mn/ha and T6: RDF + 4 kg Mn/ha. Mn application had a favorable effect on the dry matter yield of jute. Among the fertilizers of Mn with RDF, interaction promoted the dry yield biomass compared to sole RDF and control. Maximum dry matter yield (leaves + shoots + roots) achieved (20000 kg/ha) with T5 (RDF + 3 kg Mn/ha) and minimum (6421 kg/ha) in T1 (control). Study indicated that it needs to apply Mn to obtain optimum yield production. The interaction effect of Mn, NPK and S fertilizer significantly influenced nutrient uptake by the jute plant. The uptake of nutrient found highest N (218.9 kg/ha) in T5, P (92.75 kg/ha) in T3, K (239.73 kg/ha) with T6, S (19.59 kg/ha) in T4, Fe (0.64 kg/ha) in T5, Zn (0.38 kg/ha) in T5 and Mn (0.63 kg/ha) recorded in T6. The amount of micro nutrient uptake may be arranged in the order of Mn &gt;Zn&gt; Fe. Considering the highest uptake of major element, it can be kept as in the order of K &gt; N&gt;P&gt;S. Study indicated that a higher rate of nutrient uptake was promoted dry matter accumulation in jute. Research revealed that the rate of nutrient uptake maximized with the addition of Mn in the RDF treatment. Hence, it could be concluded that applying RDF + 3 kg Mn/ha may be a suitable dose for optimum yield production of jute. Yet, in order to draw a sound conclusion, repeating the experiment is needed. In the future, the study will be a guideline for further investigation. Int. J. Agril. Res. Innov. Tech. 14(1): 87-95, June 2024

Tuning the Size of TiO2-Supported Co Nanoparticle Fischer-Tropsch Catalysts Using Mn Additions.

Modifying traditional Co/TiO2-based Fischer-Tropsch (FT) catalysts with Mn promoters induces a selectivity shift from long-chain paraffins toward commercially desirable alcohols and olefins. In this work, we use in situ gas cell scanning transmission electron microscopy (STEM) with energy-dispersive X-ray spectroscopy (EDS) elemental mapping, and near-ambient pressure X-ray photoelectron spectroscopy (NAP-XPS) to demonstrate how the elemental dispersion and chemical structure of the as-calcined materials evolve during the H2 activation heat treatment required for industrial CoMn/TiO2 FT catalysts. We find that Mn additions reduce both the mean Co particle diameter and the size distribution but that the Mn remains dispersed on the support after the activation step. Density functional theory calculations show that the slower surface diffusion of Mn is likely due to the lower number of energetically accessible sites for the Mn on the titania support and that favorable Co-Mn interactions likely cause greater dispersion and slower sintering of Co in the Mn-promoted catalyst. These mechanistic insights into how the introduction of Mn tunes the Co nanoparticle size can be applied to inform the design of future-supported nanoparticle catalysts for FT and other heterogeneous catalytic processes.

MOF derived tri-metallic CoNiMn hydroxide assembled on carbon cloth for hybrid supercapacitor and hydrogen evolution

Polymetallic hydroxides are promising electrode materials for supercapacitors and electrocatalysis due to their unique physical and chemical properties. Herein, carbon cloth self-supported cobalt‑nickel‑manganese hydroxide (CoNiMn-OH/CC) composites were synthesized by a facile hydrothermal method with zeolite imidazolate framework-67 (ZIF-67) as a template. The results indicate that the hydroxides maintain the morphology of ZIF-67 template, while the addition of Mn can affect the redox behavior and enhance the electrochemical activity of metal hydroxides. Therefore, the prepared CoNiMn-OH with ultrathin edge-surface stacked nanosheets structure can promote electron/ion transfer, which induces to better charge storage kinetics and activity for supercapacitors and hydrogen evolution reaction (HER). In-situ Raman spectra combined density functional theory calculations co-revealed the reaction mechanism. The optimized CoNi3Mn1-OH nanosheets has a high specific capacity of 955.7C g−1 at 1 A g−1 and excellent rate performance with 91.1 % capacitance retention (870.7C g−1 at 10 A g−1). The hybrid supercapacitor device with CoNi3Mn1-OH as the positive electrode and activated carbon (AC) as the negative electrode has an energy density of up to 30 Wh kg−1, a power density of 0.8 kW kg−1, and excellent cycling stability (78.5 % capacity retention after 10000 cycles at 5 A g−1). In addition, the CoNi3Mn1-OH composite with tuned Ni and Mn metal ratios has a low HER overpotential of 202 mV at 10 mA cm−2.

Regulate the adsorption of oxygen-containing intermediates to promote the reduction of CO2 to CH4 on Ni-based catalysts

The introduction of oxophilic metals can enhance the selectivity of CO2 reduction reactions (CO2RR) by modulating the adsorption of oxygen-associated active substances on the catalyst surface. Alloying lanthanide atoms into metals has been shown to improve CH4 selectivity by breaking the linear relationship between the adsorption energies of CO* and HxCO*. In this work, a series of oxophilic transition metals (Fe, Mo, Co, Mn) are introduced to explore the influence on the CO2RR. DFT results demonstrate that the doping of oxophilic metals regulates the adsorption strength between the catalyst surface and intermediates, thereby affecting the CH4 and H3COH pathways. Notably, COOH* formation is enhanced on Ni surfaces, leading to increased H3COH production. Ni-Fe and Ni-Mo exhibit significant H3CO* and CO2* binding energies, which reduces the barrier for H3CO*. Meanwhile, the bond energy of M−O is higher than that of C-O in H3CO*, promoting the generation of CH4. The addition of Co and Mn makes the desorbed of HCOOH smaller than the hydrogenation energy barrier, which accelerates the synthesis of formic acid. This research provides a new pathway for the development of inexpensive and resource-rich catalysts.

Tailoring structural and optical properties of ZnO system through elemental Mn Doping through First-principles calculations

In this study, band structure and optical properties of Manganese (Mn) doped ZnO are investigated adopting first-principles study calculations. It is observed that, by addition of Mn in ZnO crystal, the electrical properties like conductivity and dielectric function of material have been improved. The elastic constants for the elements are also calculated which shows that the element is stable after addition of dopant. The computational study is done on CASTEP and Material Studio. The ZnO system is simulated and atoms of Mn has been added replacing Zn atoms. The properties that studied are band structure and optics including conductivity, reflectivity, dielectric function, absorption and refractive index. Furthermore, this study also includes calculation of Elastic constants, XRD Spectra, Phonon dispersion and Temperature profile of doped ZnO systems. The computational study produced promising results and experimental approach can be adopted to reinforce the outcomes of this study.

Effect of Fe and Mn on structure, mechanical properties, and oxidation resistance of lightweight intermetallic Al55Cr23Ti22 complex concentrated alloy

In this study, we analysed the effect of Fe, Mn, or Fe and Mn additions (5 or 10 at%) on the structure, mechanical properties, deformation behaviour, including microstructure evolution, and oxidation resistance of a lightweight (density of 3.92 g/cm3) intermetallic Al55Cr23Ti22 complex concentrated alloy (CCA) with a L12 + C11b structure. The additions of Fe, Mn, or Fe and Mn (at the expense of Cr) retained the density below 4 g/cm3 and resulted in forming a D8a phase (Th6Mn23-prototype; cF120; Fm-3m) in all the alloys, except for the Al55Cr18Ti22Mn5 alloy. The D8a phase nucleated with a different morphology within or adjacent to the C11b phase, and adopted an orientation relationship of (110)C11b || (4‾4‾ 0)D8a, [3 3‾ 1]C11b || [1‾ 11‾]D8a, which provided coherent C11b/D8a interfaces. Alloying with Mn or Fe and Mn had either neutral or negative effect on the mechanical properties, while the Fe additions boosted the strength along with some decrease in the compressive plasticity at room temperature. Specifically, the Al55Cr13Ti22Fe10 alloy showed a yield strength of 250 MPa at 1000°С, which was 60 % higher compared to the Al55Cr23Ti22 alloy. During plastic deformation, all the alloys demonstrated pronounced strain hardening at T ≤ 800 °C and steady state flow at 1000 °C. Post-deformation observation of the microstructure of the Al55Cr13Ti22Fe10 alloy showed the inhomogeneous distribution of the strain-induced defects between the L12 matrix and (C11b + D8a) regions at 800 °C and partial recrystallisation of these phases at 1000 °C. All the alloys exhibited complex oxidation behaviour with multistage oxidation kinetics. The addition of 5 at% of Fe or Mn was beneficial for the oxidation resistance, while the further increase in their contents intensified the mass gain after a certain time. The latter effect was more pronounced in the Al55Cr13Ti22Mn10 alloy than in the Al55Cr13Ti22Fe10 alloy, because of forming a loose Al2O3 oxide layer. All the alloys investigated exhibited a superior synergy of 1000°C-specific yield strength and compressive plasticity at room temperature, as well as a lower mass gain after 100 h at 1000 °C, compared to both lightweight and the most oxidation-resistant refractory CCAs.