MoSi2 Phase Research Articles

Effects of TiB2 contents on the microstructure and oxidation behavior of Mo-Si-B composite coatings

A novel Mo-Si-B-TiB2 composite coating was prepared on Nb-Si based ultrahigh temperature alloy by slurry sintering. The effects of TiB2 contents (1, 3, 5 and 10 wt%) on the microstructure and oxidation behavior of Mo-Si-B composite coatings were revealed. The results show that TiB2 modified Mo-Si-B composite coatings display a bilayer structure, in which the outer layer is composed of MoSi2, Mo5Si3 and TiB2 phases, and the inner layer is composed of (Ti,Nb)5Si4, (Nb,X)5Si3 and (Nb,Ti)B2 phases. The added TiB2 particles are evenly distributed in the outer layer of the coatings. By introducing TiB2 into the coating, the service life of Mo-Si-B composite coatings is extended from 50 h to 100 h at 1250 ℃, the oxidation rate of the coating is reduced from 1.62 to 0.02 mg2 cm−4 h−1. This indicates that the addition of appropriate TiB2 effectively slows down the oxidation rate and significantly improves the oxidation resistance of Mo-Si-B composite coatings. The Mo-Si-B composite coating with 3 wt% TiB2 had the lowest mass gain (3.9 mg/cm2) after oxidation at 1250 ℃ for 100 h, and it exhibited the best oxidation resistance. This is attributed to the formation of composite oxide scale with crack-free, good healing ability, suitable levels of differential thermal expansion and low oxygen permeability.

Effect of Microstructure on Oxidation and Micro-mechanical Behavior of Arc Consolidated Mo-Ti-Si-(B) Alloys

AbstractThe present study deals with the development and characterization of Mo-35Ti-10Si and Mo-35Ti-10Si-2B (wt.%) alloy for ultra-high temperature applications beyond the temperature limit of existing super alloys. The microstructural characterization using scanning electron microscopy (SEM), energy dispersive spectrometry (EDS), electron back scattered diffraction (EBSD), x-ray diffraction (XRD) revealed that the Mo-35Ti-10Si-2B alloy was consisted of three phases, namely, (Mo, Ti)ss, (Mo, Ti)5SiB2 and (Ti, Mo)5Si3; whereas, Mo-35Ti-10Si alloy was found to be consisting of (Mo, Ti)ss, and (Mo,Ti)3Si phases. Since quantification of boron is difficult by EDS, Particle Induced Gamma-ray Emission (PIGE), a nuclear reaction analysis technique was used for chemical composition analysis of boron. The oxidation behavior of the Mo-35Ti-10Si-2B alloy in the temperature regime of 825-1250 °C was studied in detail and compared with boron-free Mo-35Ti-10Si alloy. Mo-35Ti-10Si-2B alloy exhibited superior oxidation behavior at intermediate temperatures of 825 °C, and excellent oxidation resistance at higher temperatures between 1000 and 1250 °C due to the formation of the protective borosilica and double oxide layers (TiO2 and duplex borosilica-TiO2), respectively. High-temperature oxidation mechanisms were discussed using detailed microstructural cross section analysis of the oxidized alloy samples. The micro-mechanical behavior of constitutive phases of the Mo-35Ti-10Si-2B alloy were studied by microhardness, nano-indentation and micropillar compression testing. The micropillar compression of (Mo, Ti)ss phase showed fairly ductile behavior with the evidence of activation of dislocation in the form of slip lines revealed through the post-deformation fractography. Deformation studies of (Mo, Ti)5SiB2 and (Ti, Mo)5Si3 phases were also carried out which showed large strain bursts indicating possibility of activation of dislocation activities even at room temperatures imparting low level of ductility.

High-Temperature Heat Treatment of Plasma Sprayed Ti–Si–C–Mo Coatings

In this work, the effect of 800 °C and 1100 °C post-heat treatment on the plasma spraying of Ti–Si–C–xMo (x = 1.0, 1.5) composite coatings was investigated. The composite coatings were composed of TiC, Ti3SiC2, Ti5Si3 and Mo5Si3 reacted phases. After heat treatment, the Ti3SiC2 and Mo5Si3 phases increased. The coating microhardness decreased by 16% and 18% for Ti–Si–C–1.0Mo and Ti–Si–C–1.5Mo coatings, respectively, after heat treatment at 1100 °C. Fracture toughness increased by 16% for the Ti–Si–C–1.5Mo coating after heat treatment at 1100 °C, which was mainly due to the heat treatment promoting Ti3SiC2 formation, healing micro-cracks, reducing the internal stress and making the microstructure dense. The coating friction coefficient before and after heat -treatment was between 0.4 and 0.6. After heat treatment, the wear amount of the coating was first reduced and then increased, and the minimum wear loss occurred after heat treatment at 800 °C. The wear mechanism was mixed abrasive wear, adhesive wear and tribo-oxidation wear.

Electrochemical silicification of Mo in molten CaCl2–CaSiO3 enhances high-temperature oxidation resistance

This work aims to demonstrate the feasibility and effectiveness of electrochemical silicification of Mo in molten CaCl2–CaSiO3. Through constant-current electrolysis at 1123 K, high-quality α-MoSi2 coatings are successfully deposited on Mo plates, following the sequential formation of Mo5Si3 and β-MoSi2 phases. Increased current density results in grain refinement and reduced surface roughness due to the increase in overpotential. The oxidation test indicates that the silicide-coated Mo plate can withstand exposure to air at 1573 K for more than 15 h with minimal damage, showcasing the excellent high-temperature oxidation resistance. These findings highlight the potential application of the electrochemical silicification process.

Experimental investigation and first-principles calculations of Nb and W alloying effects on the microstructure and properties of MoSi2 coatings fabricated via arc cladding

MoSi2 is one of the most promising refractory metal silicide materials, but its further use as a structural material is limited by its drawbacks such as poor room-temperature toughness and low high-temperature strength. The work performed a comprehensive investigation combining first-principles calculations and arc cladding experiments to explore the effects of Nb and W doping on the mechanical properties and electronic structure of MoSi2 coatings. The first-principles calculations revealed that Nb addition improved the B/G value and Poisson’s ratio of MoSi2, indicating enhanced ductility. W addition yields the opposite effect and led to a higher elastic modulus and improved hardness. Experimental results demonstrated that the arc-cladding MoSi2 coating mainly consisted of MoSi2 and Mo5Si3 phases with a dendritic microstructure. Upon doping with Nb and W, additional t-(Mo,Nb)Si2 and t-(Mo,W)Si2 phases were formed, which resulted in a denser and finer microstructure. Nb addition contributed to the solid-solution toughening of the coating, while W addition enhanced hardness but reduced toughness. Remarkably, the synergistic alloying of Nb and W significantly increased the hardness and fracture toughness of the coating by 30.7 and 70.7%, respectively, compared to pure MoSi2. The strengthening mechanism of the coating was attributed to solid-solution softening and fine-grain strengthening, while the crack extension mechanism involved the crack deflection and bridging. Furthermore, the coatings doped with 2% Nb and 4% W exhibited the lowest wear weight loss and superior wear resistance. The dominant wear mechanisms were oxidation wear and abrasive wear.

High-temperature oxidation resistance of ternary and quaternary Cr-(Mo)-Si-B2-z coatings — Influence of Mo addition

The Si-based alloying of transition metal diborides is a promising strategy to improve their limited oxidation resistance in high-temperature environments. In this study, we investigate the oxidation resistance of ternary and quaternary Cr-(Mo)-Si-B2-z coatings sputter-deposited from alloyed CrB2/TMSi2 targets (TM = Cr or Mo). The as-deposited Cr-(Mo)-Si-B2-z coatings are stabilized in the single-phased hexagonal AlB2-structure, except the high-Si containing Cr0.26Mo0.11Si0.24B0.39 presenting amorphous character. The Mo-containing Cr-Mo-Si-B2-z films exhibit relatively high hardness compared to their ternary Cr-Si-B2-z counterparts, obtaining up to 26 GPa due to the formation of (Cr,Mo)B2 solid solutions. The Si-alloying in ternary and quaternary coatings provides oxidation resistance up to 1200 °C, owing to the formation of highly protective double-layered scales consisting of SiO2 with a Cr2O3 layer on top, inhibiting oxygen inward diffusion. The quaternary Cr0.31Mo0.07Si0.15B0.47 coating is distinguished by superior oxidation resistance with lower porosity and void formation compared to the ternary Cr0.37Si0.16B0.47. Mo proved to be the key element for the higher stability and enhanced oxidation resistance due to the evolution of the MoSi2 phase at ~600 °C. This phase formation controls the Si diffusion and mobility within the microstructure, thus reducing the porosity and governing the Si supply to form SiO2 scale. The quaternary Cr0.31Mo0.07Si0.15B0.47 coating maintained an oxidation resistance up to 30 h at 1200 °C by forming a 2.5 μm dense amorphous Si-based oxide scale with a thin Cr2O3 on top.

The microstructure and high-temperature oxidation resistance of Si-rich Mo-Si-B coatings prepared by ultrasonic vibration assisted laser cladding

Si-rich Mo-Si-B powders (Mo-62Si-5B at%) were deposited on Nb-Si based alloy by laser cladding assisted with ultrasonic vibration. The obtained coatings mainly consist of MoSi2 and (Mo, X)5Si3 (X = Nb and Ti). With the introduction of ultrasonic vibration during laser cladding, the lath-shaped MoSi2 phase transforms into cellular gradually. Meanwhile, the discrepancy on the microstructure of the top region and the bottom region is eliminated gradually, indicating that the cavitation and acoustic streaming of ultrasonic vibration not only refines the microstructure, but also homogenizes the element and phase distribution in the coatings. High-temperature oxidation experiment at 1250 ℃ were conducted to assess the oxidation resistance of the coatings. Compared with Nb-Si alloy, the coated specimens have much lower oxidation weight increase. Furthermore, with the assistance of ultrasonic vibration, the oxidation resistance of the coating is enhanced further. The oxide scales on the coatings consist of two layers: an upper amorphous aluminoborosilica with TiO2 particles dispersed and a lower crystalline SiO2 layer. With the introduction of ultrasonic vibration, the microstructure of the coatings is refined, resulting in more phase and grain boundaries in the coatings. Therefore, the diffusion of the elements to the surface is accelerated and the protective oxide scale can be formed quickly.

Effects of air plasma flame on the ZrB2-based UHTC coatings: Microstructure, phase evolution and ablation resistance

As for the air plasma sprayed ZrB2-based coatings, B content change caused by inevitable oxidation is predictable but commonly ignored. Affected by air plasma flame, the B element loss and residual B2O3 in the sprayed ZrB2 coating were observed. Moreover, how the B content change affects the microstructure, phase evolution, and ablation resistance (2.4 MW/m2, 60 s) of ZrB2-based coatings with different secondary phases (SiC, MoSi2, and TaC) was investigated. The B element loss contributed to the increase in surface temperature and the decline in the sintering degree of the ZrO2 layer. The evaporation of residual B2O3 caused damage to the coating structure in the form of pores, whose negative effect was enhanced and reduced by MoSi2 and TaC secondary phases, respectively. This work will provide some insight into thermally sprayed non-oxide ceramic coatings in the atmosphere.

Effect of pre-oxidation on the electrochemical corrosion behavior of Ni-based coating reinforced by ceramic particles

Based on the widely use of the NiCr coating, we investigated the electrochemical corrosion behavior of the NiCr coating reinforced by MoSi2 and AT40 ceramic phases which has the potential of application in seal coating. The composite coating was prepared on the surface of the nickel-based alloy with approximately 150 μm thick by using atmospheric plasma spraying (APS). The composite coatings were exposed in air at 650 °C, 900 °C, 1050 °C and 1100 °C for 24 h respectively and then the corrosion behavior of the coatings were analyzed by electrochemical workstation. Scanning electron microscopy (SEM), X-ray diffraction (XRD) and energy dispersive X-ray spectroscopy (EDX) were used to analyze the microstructure and phase composition. The results show that the pre-oxidation improved the corrosion resistance substantially compared to the original coating. It was shown that the coating with ceramics addition which was pre-oxidized at 900 °C presents the best corrosion resistance. The influence of the ceramics particles addition and elements diffusion were discussed.

SiC-Based Composite Material Reinforced with Molybdenum Wire

Silicon carbide (SiC) possesses a unique combination of properties such as high mechanical strength at elevated temperatures, wear resistance, low thermal expansion coefficient, high temperature oxidation resistance, corrosion stability, radiation hardness, high chemical inertness, and thermal conductivity. Unfortunately, SiC is very brittle and cannot, therefore, be used “as is”. SiC’s crack resistance, due to the prevention of crack propagation, can be increased by the reinforcing of SiC. In this paper, a novel method for manufacturing SiC-based composites reinforced with Mo wire is developed. The composites are produced by infiltrating porous carbon blanks with molten silicon. The molten silicon reacts with the molybdenum wire embedded in the carbon blanks. As a result, a complex interfacial silicide layer with a predominant MoSi2 phase is formed on the surface of the Mo wire. In addition, a thin layer of Mo5Si3 is formed between the residual metal in the core of the wire and the disilicide. A stable bond of the interfacial layer with both the residual metal and the SiC-based ceramic matrix is observed. Mechanical tests on the obtained samples for three-point bending at 20 and 1500 °C showed quasi-plastic damage. The reinforcing elements act as stoppers for propagating cracks in the event of a matrix failure. The developed method for producing composites with a ceramic matrix reinforced with metal wire makes it possible to reduce the cost of machining and manufacturing products with complex geometric shapes. It also opens the way for broader applications of SiC-based composites.

MoSiBTi by powder metallurgy

The molybdenum silicon boron, MoSiB, material system is considered as a promising candidate to be able to increase exhaust temperature and thereby efficiency in aero and industrial gas turbines. In the MoSiB system, the Berczik triangle has been established to describe a three-phase field to form tough and strong high temperature materials. However, adding titanium may lead to a different phase field favoring the formation of the Mo5Si3 phase over Mo3Si phase promising better creep resistance and oxidation resistance. Additionally, Ti5Si3 precipitates may increase the ductility of the alloy by reducing the silicon content in the molybdenum solid solution and at the grain boundaries. Synthesizing the material by powder metallurgy offers both new prospects and challenges towards phase formation. A thermodynamic equilibrium state, like for example a chemical homogeneous melt is never reached. In contrast local diffusion couples and the resulting phase transformations define the microstructure of the alloy.

Self-propagating high-temperature synthesis of heterophase materials in the Zr–Mo–Si–B system. Kinetics and mechanisms of combustion and structure formation

The paper focuses on the study of the combustion kinetics and mechanisms of elemental mixtures in the Zr–Mo–Si–B system, as well as the analysis of phase and structural transformation stages in the combustion wave. A thermodynamic analysis of potential chemical reactions occurring in the combustion wave was carried out. The reaction of ZrB2 formation is preferred in the range of 298–2500 K. Above 2200 K, the formation of MoB becomes more thermodynamically advantageous as compared to MoSi2. Phase stability estimates of combustion products showed that ZrB2, MoSi2 and MoB phases are in equilibrium. Experimental dependences Тc(Т0) and Uc(Т0) are linear, which implies an unchanged combustion mechanism at T0 = 298÷800 K. Preheating leads to an increase in Uc. Similarly, an increase in the proportion of Zr and B in the mixture has a similar effect, i.e. an increase in heat emission and Tc. With a minimum content of Zr and B, the interaction between Mo and Si with the formation of MoSi2 by the reaction diffusion mechanism is decisive. As the proportion of Zr and B increases, the rise of T0 to 750 K does not affect the Tc. Eeff values (50–196 kJ/mol) confirm the significant influence of liquid-phase processes on the combustion kinetics. The mechanism of structure formation was studied. A Si–Zr–Mo melt is formed in the combustion front. The primary grains of ZrB2 and MoB crystallize from this melt as it is saturated with boron. At the same time, the melt spreads over the surface of Zr and Mo particles. This leads to the formation of ZrSix, MoSix films. Core-shell structures are formed behind the combustion front, which disappear as they move towards the post-combustion zone. The phase composition of products is formed in the combustion front in less than 0.25 s.

Performance analysis of Mo(Si, Al)2 solid solutions based on valence electron structure

In the present study, the valence electron structures (VESs) of Mo(Si1-xAlx)2 solid solution alloys were calculated according to the empirical electron theory (EET) of solids and molecules, and the relationship between VESs and their properties was determined. The results indicated that the hardness of the phases with the C11b crystal structure could be compared using the quantity of covalent electrons (CEs) and bonding energy on the strongest bonds, the strength by the ratio of the quantity of CEs to the total quantity of valence electrons, and the plasticity by the quantity of lattice electrons (LEs). It was found that the dissolution of Al in the MoSi2 phase could reduce the quantity of CEs, bonding energy, percentage of the total quantity of CEs relative to the total quantity of valence electrons and increase the quantity of LEs in Mo(Si1-xAlx)2 alloyed materials. These results indicated that alloying Al with MoSi2 would decrease the hardness value (HV) and strength and increase the plasticity of Mo(Si1-xAlx)2 solid solutions. Based on these results, samples of Mo(Si1-xAlx)2 solid solutions were prepared; when the Al content reached 12 at%, the hardness and bending strength of Mo(Si1-xAlx)2 solid solutions decreased by 24.84% and 14.96%, respectively, and the fracture toughness increased by 119.94% compared to that of the unalloyed MoSi2.

Preparation and microstructural evolution of spherical B-modified MoSi2 powders by induction plasma spheroidization

In order to improve and consolidate the properties of boron (B)-modified molybdenum disilicide (MoSi2) powders applied in selective laser melting and make them attractive candidate for selective laser melting, in this study, induction plasma spheroidization (IPS) was conducted to spheroidize Mo–62Si–5B (at.%) powders. Mo–62Si–5B powders prepared by mechanical crushing exhibited polygonal morphology and consisted of MoSi2 and MoB2 phases. Subsequently, spherical B-modified MoSi2 powders with the size in the range of 45–100 μm were obtained via IPS. The effect of plasma power on the spheroidization rate, flowability, and oxygen content of the powders was investigated, which improved obviously with the increase of the plasma power. Powders spheroidized at the largest plasma power of 40 kW exhibited the highest spheroidization rate (89%) and the best flowability (25 s/50 g). Furthermore, morphological evolution and microstructural evolution of particles were systematically explored based on melting and solidification processes of powders. With the increase in heat absorption, the morphology of particles gets gradually converted from polygonal to spherical. The microstructure of spherical particles transforms from original hypoeutectic structure to cellular eutectic structure with the decrease in the powder size.

High temperature oxidation behavior of MoSi2–Al2O3 composite coating on TZM alloy

A novel MoSi2–Al2O3 composite coating was prepared on Mo-based TZM alloy by slurry sintering method. The oxidation behavior of the coating was evaluated at 1600 °C in static air. Microstructure and phase composition of the as-prepared and oxidized coatings were characterized, and the antioxidant mechanism of the coating at high temperature was discussed. A three-layer structure was observed in the as-prepared coating, consisting of a ∼2 μm thick Mo5Si3 diffusion layer, a ∼65 μm thick MoSi2 inner layer and a ∼36 μm thick outer layer of mixture of MoSi2 and Al2O3. After oxidation at 1600 °C for 5 h, all MoSi2 phases were completely converted to intermediate silicide Mo5Si3 by solid-state diffusion, and the formed Mo5Si3 phase would be transformed into Mo3Si phase with further extending the oxidation time. Furthermore, a dense oxide layer of SiO2-mullite was formed on the specimen surface, which can effectively protect the material to further oxidation. The MoSi2–Al2O3 coating could protect the substrate effectively at 1600 °C for 20 h without failure. The enhanced oxidation resistance of MoSi2–Al2O3 coating is due to the formation of multi-layer structure containing a SiO2-mullite composite oxide outer layer with high thermal stability and low oxygen permeability.

Oxidation Behavior and Microstructural Evolution of ZrB2–35MoSi2–10Al Composite Coating

The problem of creating and implementing high-temperature coatings for the protection of carbon–carbon (C/C) composites remains relevant due to the extremely low or insufficient heat resistance of C/C composites in an oxygen-containing environment. In the present work, detonation spraying was used for preparing new ZrB2–35MoSi2–10Al coatings on the surface of C/C composites without a sublayer. As a stabilizer of high-temperature modification of zirconia, and to increase the wettability of the surface of C/C composites, 5 wt.% Y2O3 and 10 wt.% Al were added to the initial powder mixture, respectively. The structure of the as-sprayed coating presents many lamellae piled up one upon another, and is composed of hexagonal ZrB2 (h- ZrB2), tetragonal MoSi2 (t-MoSi2), monoclinic ZrO2 (m-ZrO2), tetragonal ZrO2 (t-ZrO2), monoclinic SiO2 (m-SiO2), and cubic Al phases. The oxidation behavior and microstructural evolution of the ZrB2–35MoSi2–10Al composite coating were characterized from RT to 1400 °C in open air. During oxidation at 1400 °C, a continuous layer of silicate glass was formed on the coating surface. This layer contained cubic ZrO2 (c-ZrO2), m-ZrO2, and small amounts of mullite and zircon. The results indicated that a new ZrB2–35MoSi2–10Al composite coating could be used on the surface of C/C composites as a protective layer from oxidation at elevated temperatures.

Microstructure evolution and growth mechanism of Si-MoSi2 composite coatings on TZM (Mo-0.5Ti-0.1Zr-0.02 C) alloy

The Si-MoSi2 composite coatings with a high silicon concentration were prepared on TZM alloy through a hot dip siliconizing method (HDS). The evolution behavior of microstructure and phase composition of Si-MoSi2 composite coatings with different diffusion times were studied. The Si-MoSi2 composite coatings have a very dense and uniform microstructure with a submicron roughness, and the lowest Sa, Sq, and Sz are only 0.258, 0.312, and 5.08 µm, respectively. A typical three-layer diffusion structure is observed at cross-section of coatings, the MoSi2 phase and carbide phases form in the outer layers, and the intermediate layer only consists of MoSi2 phase. Whereas the transition layer mainly consists of Mo5Si3 phases. The formations of globular SiO2 and carbide dispersion particles on coating surface are due to the reduction reaction between Si and (Ti,Zr)O2 dispersion phase, and the carbonation reactions. The growth process of silicide ceramic coating can be divided into four different stages: wetting stage, initial diffusion stage, stratification stage of diffusion layer, and final stage of diffusion layer formation.

High temperature oxidation behavior of molybdenum borides by silicon pack cementation process

In this study, high temperature oxidation behavior of molybdenum borides by pack cementation process was investigated. Silicon (Si) pack cementation process of molybdenum borides was performed at 1100 °C for 5 h. Silicide layers including MoSi2 phase were formed on the surface of molybdenum borides by Si pack cementation process. The thickness of silicide layer was about 70.12 μm. Molybdenum borides and pack cemented Molybdenum borides was oxidized at 1000 °C for up to 50 h. Molybdenum borides without pack cementation process was severely oxidized and its weight was reduced by approximately 87% compared to the initial weight due to the evaporation of MoO3 phase. On the other hand, pack cemented molybdenum borides were much less oxidized. In pack cemented molybdenum borides, dense borosilicate layer was formed at the surface, and this layer effectively suppressed continuous oxidation and evaporation of MoO3 phase. Based on these results, we demonstrated that the cause of this difference depends on the coating layer formed on the surface by pack cementation process, and Si pack cementation process is effective in improving the oxidation resistance of molybdenum borides.

Densification, solid solution formation, and microstructural investigation of reactive pressureless sintered HfB2-TiB2-SiC-MoSi2 quadruplet composite

Dense HfB2-TiB2-SiC-MoSi2 quadruplet composite was produced by a reactive pressureless sintering method at 2050 °C for 5 h. The relative density was improved and reached 98% by in situ formation of SiC and MoSi2 phases. Microstructural studies proved that SiC and MoSi2 second phases were mostly formed during the sintering process. Moreover, the Sintering mechanism of the composite was investigated by HSC software. TiB2 co-matrix was improved the sinterability of the composite by the formation of (Hf,Ti,Mo)–B and (Hf,Ti,Mo)–C solid solutions.Mechanical properties such as Vickers hardness (23.2 GPa), fracture toughness (5.4 MPa m1/2), and elastic modulus (430 GPa) were effectively enhanced by tailoring the composite.

Comprehensive Phase Field Study on Directionally-Solidified MoSi<sub>2</sub>/Mo<sub>5</sub>Si<sub>3</sub> Eutectic Alloy

MoSi2/Mo5Si3 eutectic composites have been considered as one of the promising candidates for ultra-high temperature structural applications owing to their high melting point, good oxidation resistance, and low mass density. Their mechanical properties can be improved by controlling the eutectic structure (i.e. script lamellar structure) in directional solidification. It is important to elucidate the dominant factors underlining the unique pattern formation. We conducted a comprehensive phase field study to examine the influence of various factors on the MoSi2/Mo5Si3 eutectic microstructure with complicated morphology. First, the inclined lamellae have been attributed to the minimization of elastic strain energy due to the lattice mismatch between MoSi2 and Mo5Si3, which are partially relaxed by forming semi-coherent phase boundaries. Second, the maze-like pattern on the horizontal cross-section appeared when a two-fold anisotropy of interfacial energy is superimposed on the MoSi2/Mo5Si3 boundary. Third, the random and intersected lamellae have been obtained by assuming the instability of the solid-liquid interface and introducing successive nucleation of Mo5Si3 phase. These findings provide guidance for manipulating the eutectic structure and act as footsteps for further theoretical investigation.