Effect Of Manganese Addition Research Articles

Study of the Effect of Manganese on The Structural and Optical Properties of Sno2 Membranes

The effect of manganese addition on precipitated tin dioxide on quartz was studied using the pulsed laser method if the X-ray diffraction results showed that the pure tin oxide membrane has a polycrystalline structure and a quaternary phase, with growth in the crystalline directions (110), (101), (200), and (211) and the predominant ones were (101). Using a high-benefit electron scanning microscope (FE-SEM), the results showed that the addition of manganese smearing in small proportions significantly affected the surface nature and grain size, as the surface uniformity and grain size increased with increasing the percentage of distortion. Through optical examinations through the permeability spectrum of thin films of pure and tinged tin oxide, a gradual increase in permeability with an increase in the concentration of impurities, reaching high values ranging between 80-90%. As for the energy gap, the energy gap for manganese-inlaid membranes has been increased from 3.33 eV for the pure membrane to 3.57 eV. The sensing properties of these membranes were studied as a function of time at temperatures between 50-200 °C .

Effect of manganese addition on sintering behavior and mechanical properties of alumina toughened zirconia

The effect of MnO2 additives on the sintering behavior and mechanical properties of alumina-toughened zirconia (ATZ, with 10 vol% alumina) composites was investigated by incorporating different amounts of MnO2 (0, 0.5, 1.0, and 1.5 wt%) and sintering at various temperatures ranging from 1300 to 1450 °C. The addition of MnO2 up to 1.0 wt% improved the sintered density, hardness, flexural strength, and fracture toughness of the composite. However, the addition of 1.5 wt% MnO2 degraded the relative density, hardness, and flexural strength of the composite due to the transformation of the ZrO2 phase from tetragonal to monoclinic and grain coarsening. Optimal results were obtained with 1.0 wt% MnO2 and sintering at 1450 °C, which improved the mechanical properties (hardness: 13.5 GPa, flexural strength: 1.2 GPa, fracture toughness: 8.5 MPa m1/2) and lowered the sintering temperature compared to the conventional sintering temperature of ATZ composites (1550 °C). Thus, the ATZ composite doped with MnO2 is a promising material for structural engineering ceramics owing to its improved mechanical properties and lower sintering temperature.

The effect of the electrolyte concentration on the charge transfer at the electrolyte/silicon-carbon interface: Electrochemical impedance spectrometry study

Silicon-carbon films were synthesized by electrochemical deposition from methanol/ethanol and hexamethyldisilazane solution. SEM studies have shown that samples with manganese and those obtained from the methanol-based electrolyte are distinguished by the presence of three-dimensional agglomerates on the surface, while the morphology of films obtained from ethanol-based solution is more uniform. Raman studies confirm the formation of silicon-carbon bonds and the effect of manganese addition on the film structure. Electrochemical behavior was studied using the Mott-Schottky analysis. The plots of all samples contain linear sections with both positive and negative slopes, which indicates n-type and p-type semiconductor behavior The highest charge carrier density was found in the “pure” silicon-carbon films obtained from the methanol-based solution. The Bode plots showed a mix of resistive and capacitive behavior and they do not change much with the type of the sample and electrolyte concentration.

An Analysis of the Amount of Retained Austenite in Manganese Alloyed Austempered Ductile Iron

Abstract Austempered ductile iron (ADI) is a revolutionary material which has excellent mechanical properties with ease of manufacturing. Manganese addition to the ductile iron is a complex job as it may segregate at the grain boundary causing brittleness to the material. Hence, it is important to select the optimum level of manganese which may be added to the ADI without causing any adverse effect on the mechanical properties. In this study, the effect of manganese addition and heat treatment parameters on the amount of retained austenite is studied. Manganese is added in three different proportion. Microstructure and XRD analysis have shown that increasing the austempeirng temperature has resulted in the increase in volume fraction of retained austenite. Manganese addition up to 1 wt% did not cause any adverse effect on the amount of retained austenite. Higher volume fraction of retained austenite obtained at 420°C is found be 36%.

The Effects of a Trace Amount of Manganese and the Homogenization on the Recrystallization of Al-7Mg-0.15Ti Alloys.

The aim of this study is to explore the effects of Manganese addition and homogenization treatment on the microstructures and mechanical properties of the Al–7Mg–0.15Ti (B535.0) alloy. The optical microscopy, electrical conductivity measurements, transmission electron microscopy, scanning electron microscopy (SEM + EBSD), as well as Rockwell hardness and tensile tests, were exploited for this purpose. The main objectives are to refine the grain size, inhibit grain growth in the annealed state, and enhance the mechanical strength of the alloy. The results show that the addition of manganese to the Al–7Mg–0.15Ti alloys refined the as-cast and recrystallized grains of the alloys. During the homogenization process, Al4Mn high-temperature stable dispersoids were precipitated in the aluminum matrix. After annealing, the Al4Mn particles blocked the movement of grain boundaries during the growth of the recrystallized grains and inhibited grain growth. Consequently, the annealed alloys showed grain refinement and dispersion strengthening. The Al4Mn dispersoids of the alloys with manganese added were smaller and denser after a two-stage homogenization process compared to those that underwent a one-stage homogenization process. By contrast, for the alloys without the addition of manganese, the recrystallized grains showed normal growth after annealing, and different homogenization processes had no significantly different effects.

Effect of Manganese Addition on 94NBT-6BT Lead Free Multilayer Ceramics

In this study, lead-free 94Bi0,5Na0,5TiO3-6BaTiO3 (94NBT-6BT) ceramics were fabricated by solid-state synthesis method at ambient atmosphere. Glassy phase and rounded particles in 94NBT-6BT was observed with increasing Mn content. The effects of doping manganese on the ferroelectric properties of 94NBT-6BT bulk ceramics were evaluated. From the XRD results of the calcined powders, peaks were slightly changed to higher 2 theta value while increasing manganese ratio. Multivalence additive Mn ions act as acceptor dopant in 94NBT-6BT structure at ambient atmosphere. Samples were sintered from 1075 ℃ to 1175 ℃ for 2 hours to obtain highest piezoelectric values. SEM results show that glassy phase and rounded particles in 94NBT-6BT was observed with increasing Mn content so, bulk density was enhanced up to 1125C. From the results, 0.3 wt% manganese doped 94NBT-6BT samples have highest electromechanical coupling factor about 0.23, mechanical coupling factor (Qm) 150 and d33 110 pC/N respectively. Further work, 94NBT-6BT and Mn-doped 94NBT-6BT multilayer actuators were manufactured by water-based tape casting technique. The active area was 49 mm2 MLA and was fabricated by using Ag-Pd internal electrode without Pd-Bi reaction at the electrode-ceramic interface. Hysterisis loop measurements of manufactured lead free actuators were done by using Aixacct CMA module. Remnant polarization values of Mn-doped 94NBT-6BT MLA for a layer were higher than 6 µC/cm2.

Effect of Mn addition on serrated plastic flow behaviour in high-strength multiphase steels with retained austenite

The effect of manganese addition (from 3 to 5%) on the serrated plastic flow behavior in medium manganese TRIP steels was investigated in static tensile tests performed in a temperature range of 20-200°C. The Portevin-Le Chatelier (PLC) effect was observed in a steel containing the higher Mn content. The effect of deformation temperature on the critical strain for the serrated flow was noted. The relationships between the manganese content, deformation temperature, mechanical properties and the appearance of serrated flow were characterized.

Effect of Manganese Addition on the Microstructure and Mechanical Properties of Ti-Nb Biomedical Alloys

A series of Ti-24Nb-xMn alloys were fabricated by no consumable electrode vacuum arc furnace, with the focus on the effect of Mn addition on the structure and mechanical properties of the alloys. Experimental results indicated that α” phase-dominated binary Ti-24Nb alloy exhibits a fine, acicular martensitic structure. When 1wt% Mn was added, equated β phase structure was retained. The M1 alloy with instability β phase exhibits the two-stage yielding from stress-strain curves due to the stress-induced martensite transformation from β to α” phase during tensile deformation. Addition of a small amount of Mn (1 and 3 wt %) improved the plasticity of alloys and the elongation increases from 33% to 41%. The strength of the alloy with Mn content of 3% is the highest, and the tensile strength is 893MPa. All the alloys with Mn exhibit the high micro hardness, the highest is 345HV, which is 1.13 times than binary Ti-24Nb alloy. The elastic modulus of M1 is the highest of all alloys-172GPa. The elastic modulus of the other alloys with Mn are about 82-87GPa, close to those of human skeletons. These alloys seem to have a great potential for use as an implant material.

The effect of manganese additions on the high temperature oxidation behaviour of the high-vanadium cast iron

Manganese (Mn) addition was found to remarkably relieve the weight gain of the wear-resistant high vanadium cast iron during oxidation at 950 °C. The mechanism of such oxidation behaviour in the associated cast iron was investigated through adding different Mn contents. During oxidation process, the decrease in weight gain was sensitive to Mn addition, where the smallest weight gain corresponded to an optimal content of 3.0 wt.% Mn. Meanwhile, the degree of macrocracks was closely dependent on Mn contents. Using FIB-TEM site-specific sample preparation technique, an initial Cr2O3 layer with a thickness of 50–200 nm was identified between the matrix cast iron and the post layer of other oxidation products. In addition, Mn additions promoted to refine the precipitating V4C3 particles that uniformly distributed in the matrix cast iron. The relationship between Mn and cracking was then analysed subsequently. Based on oxidation tests and microstructural characterization, the kinetic mechanism of oxidation behaviour of the high-vanadium cast iron at high temperature was then proposed.

Effect of Manganese Addition on the Structure, Magnetic Properties and Microwave Absorption of La0.8Ba0.2MnxFe½(1-x)Ti½(1-x)O3

We have carried out modification of La0.8Ba0.2MnxFe½(1-x)Ti½(1-x)O3 (x = 0.1 – 0.8) magnetic materials by wet milling method. Raw materials of La2O3, BaCO3, Fe2O3, TiO2 and MnCO3 were mixed according to stoichiometry calculation for each composition. The mixture was milled for 5 hours and then sintered at 1000 °C for 5 hours. The refinement results by X-ray diffraction pattern shows that the increasing Mn composition enhances the mass fraction of La0.8Ba0.2MnxFe½(1-x)Ti½(1-x)O3 phase which has the same structure as LaMnO3. For x = 0.8 a single phase of LaMnO3 was formed. The single phase has a crystal monoclinic crystal structure with space group of I 1 2 / a 1, with lattice parameters given by a = 5.519(5) Å, b = 5.5537(5) Å and c = 7.8176(9) Å, α = γ = 90o and β = 90.345(6)o, V = 239.64(3) Å3, ρ = 6.463 gr.cm-3, wRp = 5.96, and χ2 (chi-squared) = 1.17. The hysteresis curve shows that the sample with composition x = 0.8 produces ferromagnetic behaviour at room temperature. The ferromagnetic properties arise due to the mixed valence of Mn3+ and Mn4+ ions through a double exchange mechanism. The results of the microwave absorption indicated that there was a broadening of absorption peak frequency at 9.9 GHz. The reflection loss (RL) increases with the increasing of LaMnO3 phase. For x = 0.8 we have the best of RL where the microwave absorption was calculated reaching 95% at the highest peak frequency with a thickness of 1.5 mm. Thus we have been successful in creating a single phase of La0.8Ba0.2MnxFe½(1-x)Ti½(1-x)O3 with application as a microwave absorber.

Effect of Mn addition on Fe-rich intermetallics morphology and dry sliding wear investigation of hypereutectic Al-17.5%Si alloys

The effect of Manganese addition on the iron-rich intermetallics and wear behavior of Al-17.5%Si hypereutectic alloys has been studied. Dry sliding wear tests have been conducted using a pin-on-disk machine under different normal loads of 18, 51, 74 and 100N and at a constant sliding speed of 0.3m/s. The addition of 1.2wt.% Fe to the base alloy increased the wear rate due to the formation of needle beta intermetallics. Introducing 0.6wt.% Mn to the iron-rich alloy changed the beta intermetallics into the modified alpha phases, and therefore reduced the detrimental effect of iron. Mn addition up to 0.9wt.% to the 1.8Fe alloy did not impede formation of needle-like intermetallic compounds and had no positive effect on the modification of microstructure.

Investigation on Microstructure of Heat Treated High Manganese Austenitic Cast Iron

The effect of manganese addition and annealing heat treatment on microstructure of austenitic cast irons with high manganese content (Mn-Ni-resist) were investigated. The complex relationship between the development of the solidification microstructures and buildup of microsegregation in Mn-Ni-resist was obtained by using microstructure analysis and EDS analysis. The annealing heat treatment was applied at 700°C up to 1000°C to investigate the effect of the annealing temperature on the microstructure. This experiment describes the characterization of microsegregation in Mn-Ni-reist was made by means of point counting microanalysis along the microstructure. With this method, the differences of silicon, manganese and nickel distribution in alloys solidified in the microstructure were clearly evidenced. The results show microstructure consists of flake graphite embedded in austenitic matrix and carbides. There is segregation of elements in the Late To Freeze (LTF) region after solidification from melting. Manganese positively with high concentration detected in the LTF region. As for heat treatment, higher annealing temperature on the Mn-Ni-resist was reduced carbide formation. The higher annealing temperature shows carbide transformed into a smaller size and disperses through the austenitic matrix structure. The size of carbide decreased with increasing annealing temperature as observed in the microstructure.

Effect on Mechanical Properties of Heat Treated High Manganese Austenitic Cast Iron

This work presents an attempt to study the effect of manganese addition and heat treatment on higher carbon austenitic cast iron to form high manganese austenitic cast iron with reduced nickel content (Mn-Ni-resist) on mechanical properties. The combination on microstructure (microsegregation), mechanical properties and the relationship of heat treatment on the alloy were analyzed. For this purpose Mn-Ni-resist (4.50C, 2.64Si, 6.0 Mn, 10 Ni) was melted and cast in the form of Y-block test pieces. Four different heat treatment procedures were applied to the as-cast to investigate the effect of alloy modifications on Mn-Ni-resist. Optical and scanning electron microscopies were used for microstructure investigation. To determine the mechanical properties tensile test and hardness test were carried out. The result indicates both composition and heat treatment affect the performance of Mn-Ni-resist intensively. Microprobe analysis shows some silicon segregation near the graphite and practically little segregation of manganese. The increase in manganese contents developed some fractions of segregated carbide structures in LTF region located at austenite eutectic cell frame, which caused the tensile properties to drop in a small range. Application of annealing heat treatment gradually changed the carbide formation, so is the material’s strength.

Effects of manganese addition on microstructures and corrosion behavior of hot-dip zinc coatings of hot-rolled steels

In the present work, the Zn coatings of hot-rolled steel sheets with different Mn additions were prepared by hot dipping process. The effects of Mn addition on the microstructures and corrosion resistances of the hot-dip Zn coatings were investigated by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and X-ray diffractometry (XRD). The Mn distribution in δ-layer is lower than that of ζ-layer. Mn addition could promote the growth of δ-layer of the coating and inhibit the growth of the columnar ζ phase which morphology was changed to discontinuous phase. It is also found that the surface color of Zn–Mn coating varies with the dipping temperatures. Such phenomenon is supposed to be attributed to the optical interference effect of the Mn oxide film formed on the coating surface. For the corrosion behavior, the as-dipped and ζ layer-exposed Zn coatings were subjected to both Tafel polarization measurements and electrochemical impedance spectroscopy (EIS) tests in 3.5% NaCl solution. The results indicate that Mn addition enhances the corrosion resistance of the as-dipped coatings. The dense corrosion products formed on the top η layer of the Zn–Mn coatings after Tafel polarization corrosion are assumed to inhibit the further corrosion of the coating. However, minor effects of Mn addition to the anti-corrosion performance of ζ layer were noticed.

Piezoelectric and pyroelectric properties of Sr-doped PZT (PSZT) with minor manganese additions

A systematic study was performed to see the effect of Manganese addition and temperature gradient on the electrical properties of PSZT. Pb0.96 Sr0.04 (Zr0.52Ti0.48) O3 (PSZT) containing 0.3%, 0.5%, and 1% Mn was prepared by the sol gel method in order to ensure good stoichiometry and enhanced purity. The powders were calcined at 550 °C and sintered at 1200 °C to achieve 98% of the theoretical density. High field ac study was performed by (P-E) hysteresis measurements at different temperatures (RT, 60, 90, 120 and 150 °C) using an electric field up to 3 kV/mm. It was observed that for a lower Mn concentration P-E loops are pinched at the center while this constriction is found to decrease for greater concentrations. The optimized results were obtained for the 1 mol% of Mn content with 4 mol% of Sr. The values of Qm, k, d33 and tanδ were measured as 756, 0.38, 257 and 0.002 respectively. Higher temperatures coupled with a gradual increase of the electric field resulted in a shift of the hysteresis loops along electric field axis, indicating the presence of an internal bias field. Dependence of pyroelectric properties on applied electric field was also investigated. The value of pyroelectric coefficient was found maximum 6.25 × 10−4 (C/m2K) at 3 kV/mm.

Effect of Mn on cooling behaviour and microstructure of chill cast Zn–Al (ZA8) alloy

In the present work, the effect of manganese addition to ZA8 alloy on thermal analysis parameters, heat transfer and microstructure was investigated. The thermal analysis parameters were found to be significantly affected by chemical modification of ZA8 alloy. Cooling curve and differential scanning calorimetry analyses of modified alloy showed nucleation of new phase other than β dendrites. Chilling of modified alloy resulted in decreased liquidus temperature and enhanced eutectoid transformation. Further, chilling avoids the formation of intermetallic compounds in modified alloy. The heat flux transients were estimated using inverse modelling during solidification of unmodified and modified alloys against different chills. The peak heat flux decreased on addition of Mn to ZA8 alloy. Differential scanning calorimetry analysis indicated that the addition of Mn to ZA8 alloy decreases the heat of solidification. The addition of Mn to ZA8 alloy increased the contact angle, indicating decreased wettability of the modified alloy on the chill surface. The microstructure of ZA8 with Mn showed an increased amount of β phase and a decreased amount of eutectic. X-ray diffraction analysis confirmed the formation of MnAl6 intermetallics in Mn added ZA8 alloy. Chilling with chemical modification resulted in enhanced decomposition of β phase.

Effects of Manganese Addition on Tensile Strength of AA6063 Alloy for Marine Application

AA6063 alloy is a common materials used in boat and ship construction due to its lightweight and good strength. However, its strength is lower than steel's strength. For that reason, an improvement in strength is needed. In this work, an attempt has been made to improve the tensile strength of AA6063 alloy by adding manganese (Mn) element. From 0.5 to 2.5 wt.% of Mn was added to AA6063 alloy and melted together before being cast into a cylindrical steel mould. The alloy was solutionised at 535oC for 6 hours and followed by water-quenching. The alloy was then artificially aged at 200oC for 5 hours and followed by natural aging for 14 days. Tensile tests were carried out according to ASTM E8M-03 procedures. The combination of artificial and natural aging has increased the ultimate tensile strength of all AA6063 alloys (with and without Mn). The ultimate tensile strength of the alloys increased with the increase of Mn content. An addition of 2.5 wt% Mn has increased the ultimate tensile strength of AA6063 alloy to 189.55 MPa after solution treatment and artificial aging followed by 14 days natural aging compared to as-cast AA6063 alloy which has the ultimate tensile strength of 61.33 MPa.

Effect of manganese additions on the corrosion behavior of an extruded Mg–5Al based alloy

The effect of manganese on the corrosion properties of Mg–5Al alloy was investigated by electrochemical techniques in 0.6M NaCl solution and surface analyses. The electrochemical tests indicated that the corrosion rate and hydrogen evolution of the Mg–5Al specimens decreased with increasing Mn content. Surface analyses indicated that Mn promoted the formation of the corrosion products in the absence of Mn products. In addition, to this Mn addition also resulted in reduction of grain size and increase of Mn in the Mg matrix.

Effect of manganese addition on the tensile properties of cold-rolled and recovery-annealed aluminum alloy sheets

Abstract This study investigated the influence of manganese addition on the tensile properties of recovery-annealed aluminum alloy sheets. These alloys exhibit age-hardening phenomenon after annealing in the temperature range of 200–220 °C, which is mainly due to the presence of Si. In general, after annealed at the same temperature, alloys with higher Mn content exhibited higher tensile strength. These recovery annealed aluminum alloy sheets exhibited increased tensile elongation with increasing annealing temperature, which is mainly because of the contribution of post-uniform elongation. The plastic deformation during post-uniform elongation is associated with the development of fine slip bands distributed in the gauge length of the specimen. After recovery annealing, the alloy with 0.74 wt.% Mn exhibited a superior combination of strength and ductility as compared to alloys with lower Mn content.

Effect of manganese addition on the microstructure and electromagnetic properties of YIG

Y 3Mn xFe 4.85- x O 12 ( x=0, 0.02, 0.04, 0.06, 0.08 and 0.1) garnet ferrites (YMnIG) were prepared by conventional solid-state reaction method in air atmosphere. The effect of Mn addition on the microstructure and electromagnetic properties of YIG were investigated by means of techniques such as X-ray diffraction, scanning electron microscopey, network analyzer, hysteresigraph, magnetic balance and electron paramagnetic resonance spectrometry. Pure garnet phase of Y 3Fe 5O 12 was identified for all the samples, except for minor YFeO 3 phase appearing in the sample with x=0.06. The addition of Mn showed little influence on the dielectric constant of YIG, which varied between 14.2 and 14.5. Substituting Mn n+ for Fe n+ in YIG decreased the total amount of Fe ions, inhibited the reduction of Fe 3+ and promoted the grain growth of garnet phase, which led to the decrease in dielectric loss and coercivity. Because the amount of Mn 3+ ions in octahedral sites increased with Mn concentration, the saturation magnetization showed a slight decrease firstly and then increased notably. The addition of Mn could also increase the remanence ratio of YIG ferrites by decreasing the magnetostriction constant γ 111. Therefore, doping Mn into YIG ferrites with proper quantity could improve electromagnetic properties of YIG significantly. The YMnIG ferrite with x=0.08, i.e., Y 3Mn 0.08 Fe 4.77O 12, showed the optimum electromagnetic properties: ɛ r=14.2, tan δ e=1.5×10 −4, H c=36 A/m, 4π M S=192 mT, B r/ B s=0.84, Δ H=6.8 KA/m.