SEM Microanalysis Research Articles

Mechanical Properties and Microanalytical Study of Concrete Reinforced with Blended Corn Straw and Scrap Steel Fibers.

Fiber concrete exhibits superior performance in various aspects compared to plain concrete and has been widely researched and applied worldwide. However, many industrially made fibers are expensive, and their cost has to be considered before use; thus, it would be economically valuable to find inexpensive fibers with excellent properties to make fiber concrete. Rural areas have many rich straw resources to be disposed of; at the same time, the rapid development of the automobile industry has introduced a large number of used tires containing steel wire with a very low reuse rate. These two low-cost materials can be processed to make fibers, making the study of mechanical properties regarding their incorporation into concrete practically significant for reducing the cost of fiber concrete. Based on this, a three-factor, three-level orthogonal test was conducted to investigate the effects of different dosages of corn straw fibers and scrap steel fibers, as well as the water-cement ratio, on the mechanical properties of concrete. The optimum level of each factor for blended straw-waste-steel-fiber concrete with different mechanical properties was obtained using the polar and ANOVA methods. It was found that the compressive strength, splitting tensile strength, flexural strength, and impact resistance of the specimens after fiber dosing were better than those of plain concrete specimens with the same water-cement ratio. The maximum improvement was 14.96% in cubic compressive strength, 42.90% in tensile strength, and 16.30% in flexural strength, while the maximum improvement in impact energy consumption at the final crack was 228.03%. Combined with SEM microanalysis, the two fibers formed a stronger whole with the C-S-H gel. When the specimen was subjected to load, the two fibers were able to withstand part of the load, thus enhancing the load-bearing capacity. Finally, the optimal mix ratio of blended straw-scrap-steel-fiber concrete was determined to be 0.8% corn straw fibers by volume, 0.6% scrap steel fibers by volume, and a 0.45 water-cement ratio by combining the weights of the levels of each factor under its four different mechanical properties through hierarchical analysis. This analysis of mechanical properties provides a reference for practical applications in future projects.

Phase equilibria in the Al–Fe–Mo system

This paper presents the results of our comprehensive study of phase equilibria in the Al–Fe–Mo system using DTA, X-ray diffraction, SEM and electron probe microanalysis. The liquidus and solidus projections were constructed. It is shown that the ternary compound Al8FeMo3 (τ) melts congruently at >1500 °C and has a homogeneity range from 2 to 9 at.% Fe and from 23.5 to 25 at.% Mo. Isostructural phases (Mo), (αFe) and AlMo (W-type structure, cI2-Im-3m) at solidus temperatures form a continuous solid solution (αFe,Mo,AlMo). Unlike the AlMo binary phase, which is not retained by quenching, the ternary (αFe,Mo,AlMo) phase is easily quenched due to its lower decomposition temperature. Among the binary based phases, the Al8Fe5 (ε) phase has the widest homogeneity region, which extends up to 24 at.% Mo at solidus temperatures. It is shown that the addition of Mo stabilizes the Al8Fe5 (ε) phase, and the temperature of its formation in the ternary system increases to 1331 °C in contrast to 1234 °C in the binary. Moreover, according to XRD data, the Al8Fe5 (ε) phase in the ternary system has a rhombohedral structure of the Al8Cr5-type (hR78-R-3m), rather than cubic Cu5Zn8-type structure (cI52-I-43m), like the binary one. A new binary compound Al45Mo7 was identified for the first time. Its crystal structure is established as monoclinic Al45V7-type (mS104-C2/m) with the lattice parameters a = 20.534, b = 7.561, c = 10.910 Å, β = 107.33. It was shown to form by peritectic reaction L + Al5Mo ⇄ Al45Mo7 at ∼800 °C. Iron additions stabilize the Al4Mo phase, which in the binary system is stable above 942 °C.

Exploration on the occurrence state of fluorine in cement hydration products mixed with high fluorine alkali free liquid accelerator.

If there was abundant fluorine in shotcrete, it might leach out and pollute the soil or migrate to corrode the reinforcement.Therefore, this research mainly investigated the basic properties of high-fluorine alkali free liquid accelerator (HF-AFA) and its occurrence forms in cement hydration products.The macro-test results showed that with the increase of HF-AFA dosage, it appeared excellent coagulation promoting property. However, when the HF-AFA dosage exceeded 7.0%, the 1d compressive strength of mortar was lower than 7.0 MPa. In addition, by measuring the early hydration heat of cement, C3A, C3S, C2S and C4AF pastes with and without HF-AFA, and combining XRD and SEM micro-analysis, the occurrence forms of fluorine in different clinker minerals were obtained.The final analysis results indicated that fluorine mainly existed in the form of CaF2, CaAlF5 and Ca2AlF7 crystals in C3A and C3S minerals, while only little CaF2 crystals appeared in C2S and C4AF minerals.

Polypropylene Fiber Effect on Flexural Strength, Toughness, Deflection, Failure Mode and Microanalysis of Cementitious Backfills under Three-Point Bending Conditions

Cemented tailings backfill (CTB) is continually practiced in a large number of metallic mines for re-filling underground ore extraction areas. Re-filling these areas can boost the security of mining teams during construction. Hence, CTB’s durability/ductility is extremely vital to ensure the safety of the entire mine. In this study, layered-fiber-reinforced CTB (LFR-CTB) was manufactured using polypropylene fiber (PPF) to increase the strength and flexibility of backfilling. The strength and bending features of CTB and LFR-CTB specimens were explored through a three-point bending test and SEM microanalysis. Test findings pointed out that the flexural strength of 14-day-cured CTB specimens without fiber delamination and with cement showed that a tailings ratio of 1:4 was the largest among others. Residual flexural strength of LFR-CTB was greater than those of CTB without fiber delamination. Accumulating fiber delamination effectively improved CTB’s flexural features. CTBs without fiber delamination presented the largest average flexural modulus values. LFR-CTBs presented greater average toughness index values than ordinary CTB specimens. Adding fiber facilitated the progress of CTB’s post-peak rigidity. LFR-CTBs containing high-fiber delamination dimensional height have excellent bending properties. The damage mode of all backfill specimens is chiefly tensile damage. The overall bonding of LFR-CTB specimens in the presence of interlayer interfaces is outstanding, not affecting their bending performance. Ettringite and CSH gels were found to be key hydration materials. The addition of fiber to the filling has an inhibitory impact on the extension of the cracks occurring within specimens. Finally, this study’s key consequence is to deliver a technical guideline and reference in order to reveal LFR-CTB’s enhancement and delamination mechanism for industrial applications.

A clean and efficient utilization of fly ash with a focus on the strengthening decomposition mechanism of mullite

A novel method of comprehensive disposal of low temperature and high-efficiency reduction of fly ash to produce ferrosilicon without slag under the action of Fe2O3 was proposed in this paper. In addition, the promotion of Fe2O3 on the reduction and decomposition of fly ash at a low temperature and the strengthening mechanism of the reduction and decomposition of the mullite phase were systematically studied. The thermodynamic analysis shows that the decomposition reaction of mullite can be carried out only after the free SiO2 in fly ash is exhausted. Combined with the thermodynamic prediction of the equilibrium phase concentration of reduction products, the phase evolution of reduction products and the results of SEM microanalysis, it is proposed that the carbothermal reduction process of fly ash and the decomposition mechanism of mullite are as follows: iron oxide reduction, mullite decomposition into aluminum–silicon oxide and aluminum–silicon oxide deep decomposition and complete release of Al2O3, while the final products of reduction decomposition are ferrosilicon phase and alumina. According to the mineralogical characteristics of reduction decomposition products, a novel idea of preparing ferrosilicon and alumina/calcium aluminate byproducts by electric furnace melting is proposed, which lays a theoretical foundation for the large-scale, slag-free and high-value utilization of fly ash.

Insight into the isothermal multiphysics processes in cemented paste backfill: Effect of curing time and cement-to-tailings ratio

Due to the complexity of multiphysics processes, cemented paste backfill (CPB) materials begin the “black box” curing period after placement into underground stopes. Moreover, due to the limited interference in the thermal process, CPB materials may experience locally isothermal curing conditions in underground excavations. Therefore, to yield an optimal design of CPB, it is necessary to investigate the isothermal multiphysics processes in CPB. In this study, the evolution and characteristics of isothermal multiphysics processes of CPB under the different cement-to-tailings ratios are studied. Through SEM, XRD, TGA, and MIP micro-analysis, the hydration products and pore structure of CPB at different curing times and cement-to-tailings ratios are analyzed. Moreover, an isothermal multiphysics monitoring program is implemented to quantitatively study the evolution of matric suction, volumetric water content, and electrical conductivity at various curing conditions. Based on the measured data, it has been found that the mechanical strength of CPB shows a strong dependency on matric suction, volumetric water content, and electrical conductivity. The correlation among multiphysics processes under isothermal conditions is established through regression analysis on the measured data. The findings have the potentials to improve the understanding of the complex field behavior of CPB and contribute to its optimal design.

Porous structure obtained by anodizing niobium in NaOH

Porous structures can be produced as nanotubes, nanowires and membranes, and they can be used in gas sensors, magnetic and electronic devices, biotechnology, etc. These structures can be obtained by the anodizing process, in which the electrolyte must etch the oxide to occur the pore formation. In the case of niobium, porous oxides have been obtained successfully in electrolytes containing hydrofluoric acid (HF). However, studies have shown that niobium dissolves in electrolytes of NaOH with pH 14, and porous oxides of niobium have already been obtained by the anodizing process with the occurrence of sparking. Thus, the objective of this work is to obtain porous oxides on Nb without HF addition by studying the sparking phenomenon. Therefore, niobium was anodized at different current densities (10, 25, 50, 75 and 100 mA.cm-2). The samples were evaluated concerning morphology by SEM and chemical microanalysis by EDS. It was observed that sparking depends of the oxide barrier thickness and occurs at current densities higher than 50mA.cm-2. However, the increase of the current density, in spite of not increasing the thickness of the barrier layer, caused a greater incidence of sparking. According to the assignment proposed it was possible to obtain a porous structure in niobium with NaOH electrolyte, but this structure got an irregular aspect

Potassium content diminishes in infected cells of Medicago truncatula nodules due to the mislocation of channels MtAKT1 and MtSKOR/GORK.

Rhizobia establish a symbiotic relationship with legumes that results in the formation of root nodules, where bacteria encapsulated by a membrane of plant origin (symbiosomes), convert atmospheric nitrogen into ammonia. Nodules are more sensitive to ionic stresses than the host plant itself. We hypothesize that such a high vulnerability might be due to defects in ion balance in the infected tissue. Low temperature-scanning electron microscopy (LTSEM) and X-ray microanalysis of Medicago truncatula nodules revealed a potassium (K+) decrease in symbiosomes and vacuoles during the lifespan of infected cells. To clarify K+ homeostasis in the nodule, we performed phylogenetic and gene expression analyses, confocal and electron microscopy localization of two key plant Shaker K+ channels, AKT1 and SKOR/GORK.Phylogenetic analyses showed that the genome of some legume species, including the Medicago genus, contained one SKOR/GORK and one AKT1 gene copy, while other species contained more than one copy of each gene. Localization studies revealed mistargeting and partial depletion of both channels from the plasma membrane of M. truncatula mature nodule infected cells that might compromise ion transport. We propose that root nodule infected cells do have defects in K+ balance due to mislocation of some plant ion channels, as compared with non-infected cells. The putative consequences are discussed.

Corrosion Inhibition of Welded of X – 52 Steel Pipelines by Sodium Molybdate in 3.5% NaCl Solution

The demand for improved reliability and prolong the lifetime of piping and pipelines has led to the development of various methods to protect piping and pipelines from corrosion attack, one of which is the use of inhibitors such as molybdate. Molybdate is a corrosion inhibitor that is non-toxic and environmentally friendly. The present paper aims to study effect of molybdate on corrosion behaviors of various regions in submerged arc API 5L X-52 steel welded joints including weld metal (WM), heat affected zone (HAZ) and base metal (BM) in a 3.5% NaCl solution. In this study, corrosion characteristics of welded API 5L X-52 steel pipelines were studied using Tafel polarization method by immersing the specimens in 3.5% NaCl solution with different percentages of Na2MoO4 inhibitors, namely 0.1, 0.2, 0.3, and 0.4% combined with SEM microanalysis of corrosion products. Results show that HAZ seems to be the most susceptible region for corrosion attack, and this undesirable effect is associated with bainitic microstructure present in the region. The additions of molybdate have two effects. First, the corrosion rate decreases with increasing inhibitor concentration and secondly; the corrosion potential is shifted to the positive direction in the polarization curve. The molybdate inhibition of corrosion could be related to its ability to form passive film, and it is discussed in the present study.

In operando tomography reveals degradation mechanisms in lamellar iron foams during redox cycling at 800 °C

The lifetime of iron-based active materials in high-temperature redox applications (e.g., solid-oxide iron-air batteries, chemical looping) is limited by sintering, accelerated by oxidation/reduction volume changes. Here, in operando X-ray microtomography is used to reveal the evolution of structure, porosity, and extent of reaction in freeze-cast, lamellar iron foams during five redox cycles between Fe and FeO/Fe3O4 (via H2 and H2O) at 800 °C. Foam porosity decreases during oxidations but only partially recovers during reductions, with a net decrease from 77 to 52%. A gas-blocking surface layer, or shell, forms around the foam exterior. By correlating SEM microanalysis with in operando data, the Kirkendall effect is identified as the primary mechanism underlying these degradations. These insights suggest that material lifetime can be improved by measures that prevent the Kirkendall effect, such as combining iron with elements (in solid solution or as a second, redox-inactive phase) that lessen the imbalance of diffusional fluxes.

Investigation on sulfate activation of electrolytic manganese residue on early activity of blast furnace slag in cement-based cementitious material

Clinker, blast furnace slag (BFS) and electrolytic manganese residue (EMR) were used to make the cement-based cementitious material (CCM) in this research. The activation effect of EMR with different content on the early activity of BFS was studied. The mechanical properties were analyzed by cement mortar test. The hydration characteristics were investigated by XRD, SEM, 29Si NMR and other micro-analysis methods. The results indicate that the early strength of CCM can be greatly improved when the content of EMR is 15%. The microscopic analysis of XRD, SEM and 29Si NMR show that the secondary hydration reaction of BFS was accelerated by the sulfate, and more BFS was depolymerized, which resulted in a significant increase in ettringite (AFt) and C-S-H gel production at 3d. Meanwhile, the consumption of Ca(OH)2 increases. The pore diameter becomes smaller and the structure is more compact. Leaching test results show that NH3–N and heavy metals are well solidified in the cementitious material, which shows a good environmental performance. This research provides an effective path for the disposal of EMR and sulfate activating to pozzolanic materials.

Corrosion Behavior of GH4169 Alloy under Alternating Oxidation at 900 °C and Solution Immersion

In this paper, the corrosion behavior of GH4169 superalloy under alternating oxidation (at 900 °C) and solution immersion (in 3.5% NaCl solution, 30 ± 1 °C) has been studied by SEM, XRD, XPS, and electron probe microanalysis (EPMA). The results show that the alternating environment increases the corrosion rate of GH4169. The reaction of NaCl and Cr2O3 generates various volatile and soluble corrosion products, such as Na2Cr2O7, CrCl3, Cl2, and Na2CrO4, at a high temperature. The destruction of the protective Cr2O3 film leads to the increase of defects in the oxide scale, promoting the formation of oxides, such as NiO and Fe2O3, and changes the composition and structure of the oxide film. After repeated iterations, the mixed oxides will result in the spalling of the oxide film because they can reduce the fracture toughness of the corrosion scale. Therefore, the corrosion is comprehensively intensified.

Experimental investigation of phase transformations in the La-Fe and La-Fe-C systems

Phase equilibria in the La-Fe-C system at crystallization were studied and the binary La-Fe system was reinvestigated using DTA, X-ray diffraction, SEM and electron probe microanalysis. Using the results, the binary La-Fe phase diagram has been redrawn and liquidus and solidus projections for the La-Fe-C system constructed, for the first time, covering the whole concentration range. There is no stable miscibility gap in the liquid phase of La-Fe system, according on our results. The La-Fe system shows a simple eutectic at 88 at.% La. The eutectic temperature was measured to be 788 °C. No intermediate phases were found. In the ternary La-Fe-C system a ternary compound La3.67FeC6 (τ) was found in equilibrium with the liquid phase and to coexist with most of the other phases in the system. Additions of carbon to La-Fe alloys caused liquid immiscibility. In this investigation, the liquid separation has been proved with clear microscopic pictures of samples showing this effect. A ternary stable liquid miscibility gap marked L1 + L2 develops from a metastable liquid miscibility gap in the La-Fe binary system. None of the binary intermetallic phases show any solubility of the third component.

Complex utilisation of ekibastuz brown coal fly ash: Iron & carbon separation and aluminum extraction

Fly ash landfills that accumulate a by-product of coal combustion and gasification represent a permanent threat to the surrounding environment due to many factors (air and water pollution, soil contamination, wildlife poisoning, etc). Moreover, disposed coal fly ash may contain significant amounts of valuable elements that are not extracted and potentially wasted. To improve the above situation, a combined ash treatment process was developed for utilisation of the coal fly ash waste from coal-fired power stations. The ash treatment includes three stages: 1) magnetic separation of an iron-containing fraction, 2) carbon separation by floatation, and 3) extraction of aluminum by the autoclave hydrochloric acid leaching. The lab-scale results of the ash treatment applied to the Ekibastuz brown coal fly ash from the Omsk power stations (Russia) were presented and discussed. The XRD analysis showed that the fly ash consists primarily of quartz, mullite and magnetite. It was found that the magnetic fraction separated at the first stage is enriched in magnetite (over 20 wt %), the carbon content in the concentrate after flotation increases to 27 wt %, and 90–95% of aluminum can be extracted during the autoclave acid leaching. The SEM analysis showed that the magnetite phase is grown on the surface of alumosilicate spheres as ∼1 μm cubic crystals. The effect of the autoclave temperature and exposure time on the Al extraction efficiency was also investigated and analysed in the present paper. The optimal autoclave temperature and exposure time were found to achieve the maximum Al extraction efficiency. It was also found by the SEM microanalysis that further extraction of aluminum is not economically feasible since the remaining Al is evenly surrounded by SiO2 in the fly ash particles.

Artificial arenite from wastes of natural sandstone industry

An artificial arenite was developed from the waste of the sandstone industry. The waste sandstone was treated to obtain different grain sizes that were recombined to reproduce the natural texture. An unsaturated polyester resin was added to the mixture of grains and the cement polymerization was initiated with methyl ethyl ketone peroxide. The product was compacted under pressure of 1.5 to 9.7 MPa and cured at 70 °C. The result was a new material with the appearance of the natural rock. Artificial sandstones were studied by SEM microanalysis, petrography study and XRF analysis. Measurements of flexural strength (9.9 MPa), apparent density (2110 kg/cm3), open porosity (7.6%), water absorption (1.2%), abrasion resistance (19 mm) and photostability (AE * = - 0.009) were carried out. The influence of the design of the mixture and its composition (fraction of aggregates, resin content and pressure) on the texture and the mechanical properties was studied.

Mineralogical and geochemical characterization of mining wastes: remining potential and environmental implications, Muteh Gold Deposit, Iran.

Muteh Gold Deposit is the biggest active gold district in Iran consisting of two mines, Senjedeh and Chah-Khatoun, and seven mineral occurrences. Senjedeh has been mined about 20years ago and was recently closed because of the depletion of the reserves. Chah-Khatoun went into operation few years ago. During the previous decades, more than 22Mt of low-grade wastes has been produced from both mines. The wastes are assumed to be a possible source of gold, especially with recent increase in the world gold prices. In this research, 62 surface and subsurface samples were taken from four waste dumps in Senjedeh and two dumps in Chah-Khatoun mines. The optical mineralogy, XRD, ICP-MS analysis, SEM, and electron probe microanalysis (EPMA) studies were carried out to investigate the mineralogical and geochemical characteristics of the waste rocks. In addition to identification of major and minor primary and secondary phases, the mode of occurrence of minerals and also the content of precious and economic elements have been studied. The main opaque mineral was found to be pyrite. Among the economic elements, Au was recognized in the pyrite lattice as well as electrum. The Au grades are higher than 0.5mg/kg in some waste piles. Zinc and Cu revealed concentrations above 5000 and about 1400mg/kg, respectively. It is for the first time that electrum is reported in Muteh. Therefore, regarding the economically recoverable content of Au, the studied waste rocks may be considered as potential ores of coming years. Among the environmentally significant elements, As showed concentrations of up to 25mg/kg which may be of pollution concerns.

Experimental investigation of solidification and isothermal sections at 1000 and 1100 °C in the Al-Fe-Mn-C system with special attention to the kappa-phase

Phase equilibria in the Al-Fe-(10-20)Mn-C system upon solidification and at 1100 and 1000 °C were studied using DTA, X-ray diffraction, SEM and electron probe microanalysis. The partial liquidus and solidus projections and the isothermal sections at 1100 and 1000 °C for the Al-Fe-10Mn-C and Al-Fe-20Mn-C systems were constructed. The compound Al(Fe,Mn)3C (κ-phase) (antiperovskite structure CaTiO3-type, ≿Р5-Pm-3m) melts congruently at ∼1300 °C. The liquidus surfaces in the studied regions are characterized by the regions of primary crystallization of γ, α, κ, M3C and graphite (C). The solidus surfaces and isothermal sections at 1100 and 1000 °C of the Al-Fe-10Mn-C system in the studied region are defined by the co-existence of the κ-phase with almost all phases of the binary subsystems, except M3C: γ, α and graphite (С). The solidus surfaces and isothermal sections at 1100 and 1000 °C of the Al-Fe-20Mn-C system in the studied region are defined by the co-existence of the κ-phase with all phases of the binary subsystems, including M3C.

Physicomechanical Properties of Composite Electrochemical Coatings and Foils Based on Nickel and Reinforced with Al2O3

We describe an electrochemical method for the formation of composite electrochemical coatings and foils based on nickel and reinforced with nanosized aluminum oxide from a sulfamate electrolyte. We propose a mechanism of formation of composites and a mathematical model that reflects the relationship between the content of the hardening phase in composite electrochemical coatings and the concentration of Al2O3 hydrosol in the electrolyte. The influence of Al2O3 nanoparticles on the morphology and grain sizes of the composites is established by the methods of SEM and X-ray microanalysis. We determine the topography of composite electrochemical coatings and foils by the method of atomic force microscopy and establish the formation of a uniformly globular structure after the addition of Al2O3. The incorporation of nanosized particles of Al2O3 into the matrix of the base metal promotes a decrease in the grain size and the improvement of the mechanical properties of the composites: the microhardness and ultimate strength of the composites become 1.5–2 times higher and a substantial increase in the yield strength (as compared with nickel coating) is observed. The corrosion resistance of the composite electrochemical coatings increases as a result of the incorporation of aluminum oxide particles and, according to the depth index of corrosion k h = 10- 3 mm/yr we can attribute Ni–Al2O3 to the group of corrosion-resistant materials.

Vitis vinifera leaf litter for biosorptive removal of nitrophenols

Vitis vinifera (grape) leaf litter, an abundant agricultural waste in South Africa was chemically modified with H3PO4 and carbonized for use as biosorbent. Characterization and the potential application of the adsorbent in simultaneous removal of 4-nitrophenol and 2-nitrophenol from aqueous solutions were investigated. The adsorbent was characterized using FTIR, SEM and EDX elemental microanalysis. The EDX and FTIR analysis revealed the presence of surface oxygen moieties capable of binding to adsorbate molecules while the SEM micrographs showed the development of pores and cavities in the adsorbent. Batch adsorption experiments were conducted at a varying contact time, adsorbent dosage, pH and initial adsorbate concentration to investigate optimal conditions. The maximum adsorption capacity of the adsorbent was 103.09 and 103.10 mg/g for 4-nitrophenol and 2-nitrophenol, respectively. The adsorption process was best fitted into Freundlich isotherm while the adsorption kinetics followed a pseudo-second-order model. Liquid film and intra-particle diffusion contributed to the adsorption process. Thermodynamic parameters of ΔG°, ΔH° and ΔS° were evaluated. The adsorption was exothermic, feasible and spontaneous. The results suggest a possible application of grape leaf litter as a precursor for activated carbon and for cheaper wastewater treatment technologies.

Experimental investigation of the Al-Mn-C system: Part I. Phase equilibria at 1200 and 1100 °C

Phase equilibria in the Al-Mn-C system at 1200 and 1100 °C were studied using DTA, X-ray diffraction, SEM and electron probe microanalysis. Using the results the isothermal sections at 1200 and 1100 °C for this system were constructed covering the whole concentration range. It was shown that the ternary compound Mn3AlC (κ-carbide) (antiperovskite structure CaTiO3-type, ≿Р5-Pm-3m) is stable at these temperatures and has a wide homogeneity range. It co-exists with the majority of solid phases (γMn), εAlMn, Mn5C2, Mn7C3, C and Al4C3 at 1200 °C, and at 1100 °C also with the phase εMn4С1-х. In addition to the κ-carbide also (γMn), εAlMn, εMn4С1-х and Mn5C2 show appreciable homogeneity ranges. The Mn5C2 carbide, which in the binary Mn-C system is stable below 1167 °C, participates in equilibria in the ternary system at 1200 and 1100 °C. The character of the phase equilibria at 1100 °C is practically similar to those at 1200 °C. The main difference involves the fact that the equilibrium (γMn) + Mn5C2 which is present in the Al-Mn-C system at 1200 °C, is absent at 1100 °C. Instead, the alternative equilibrium κ + εMn4C1-x is present at 1100 °C.