Metal-intermetallic Composites Research Articles

Development of 3D bicontinuous metal–intermetallic composites through subsequent alloying process after liquid metal dealloying

This study presents a novel process for the fabrication of metal–intermetallic composites with a 3D bicontinuous structure, achieved through a combination of liquid metal dealloying (LMD) and subsequent alloying. Initially, porous Ti structures are produced using the LMD process, followed by immersion in a molten Mg–3Al (wt%) metal. Due to the higher thermodynamic miscibility of Al with Ti compared to Mg, the concentration of Al in the Ti matrix increases as the immersion time increases. This results in a sequential phase transition within the Ti matrix: α-Ti → Ti3Al → TiAl. The phase transition considerably affects the hardness and strength of the composite material, with the Mg–Ti3Al–TiAl composite exhibiting a maximum hardness nearly twice as high as that of the conventional Mg–Ti composite. This innovative process holds potential for the development of various bicontinuous metal–intermetallic composites.

Boron Enhanced Complex Concentrated Silicides – New pathway for designing and optimizing ultra-high temperature intermetallic composite materials

Refractory Metal Intermetallic Composites and Refractory Complex Concentrated Alloys have been identified as promising candidates for ultra-high-temperature applications that exceed the limits of superalloys. However, designing and developing new materials with the proper density for aerospace applications is a significant challenge. For this reason, new refractory metal-based materials are in continuous development. This study introduces a new class of materials known as Boron-Enhanced Complex Concentrated Silicides (BECCSs). By providing a balance between density and high-temperature performance, these materials with their density-optimized refractory metal silicide-borides have the potential to revolutionize high-temperature applications. Utilizing a quaternary MoNbTaW equiatomic alloy (ρ = 13.73 gcm−3) as a starting point and a computer-aided alloy modeling tool, seven alloy compositions were designed in a multi-step process aimed at lowering the material density. Through the introduction of Ti, Si, and/or B, the microstructure was transformed from a BCC solid solution to a multiphase structure comprised of silicides and borides. The proposed redesign of the alloy led to a significant reduction in density, even to 5.44 gcm−3. All seven alloys were produced by using a laboratory arc melter, and their microstructure and room-temperature mechanical properties were analyzed using SEM, EDS, EBSD, and micro-indentation. The results of structural characterization allowed us to identify specific phase constituents, and it was established that a transition from BCC solid solutions to silicides/borides-based alloys results in a substantial increase in hardness, even above 1600 H V (17 GPa).

A Perspective of the Design and Development of Metallic Ultra-High Temperature Materials: Refractory Metal Intermetallic Composites, Refractory Complex Concentrated Alloys and Refractory High Entropy Alloys

The paper is a personal perspective on the design of metallic ultra-high temperature materials (UHTMs). Specifically, the alloy design “landscape” of metallic UHTMs was considered from the viewpoint of the alloy design methodology NICE. The concepts of synergy, entanglement and self-regulation and their significance for alloy design/development were discussed. The risks, ecological challenges and material-environment interactions associated with the development of metallic UHTMs were highlighted. The “landscape” showed that beneath the complexities of alloy design lies an elegant and powerful unity of specific parameters that link logically and that progress can be made by recognising those interrelationships between parameters that generate interesting, diverse, and complex alloys.

On the Stability of Complex Concentrated (CC)/High Entropy (HE) Solid Solutions and the Contamination with Oxygen of Solid Solutions in Refractory Metal Intermetallic Composites (RM(Nb)ICs) and Refractory Complex Concentrated Alloys (RCCAs).

In as-cast (AC) or heat-treated (HT) metallic ultra-high temperature materials often "conventional" and complex-concentrated (CC) or high-entropy (HE) solid solutions (sss) are observed. Refractory metal containing bcc sss also are contaminated with oxygen. This paper studied the stability of CC/HE Nbss and the contamination with oxygen of Nbss in RM(INb)ICs, RM(Nb)ICs/RCCAs and RM(Nb)ICs/RHEAs. "Conventional" and CC/HE Nbss were compared. "Conventional" Nbss can be Ti-rich only in AC alloys. Ti-rich Nbss is not observed in HT alloys. In B containing alloys the Ti-rich Nbss is usually CC/HE. The CC/HE Nbss is stable in HT alloys with simultaneous addition of Mo, W with Hf, Ge+Sn. The implications for alloy design of correlations between the parameter δ of "conventional" and CC/HE Nbss with the B or the Ge+Sn concentration in the Nbss and of relationships of other solutes with the B or Ge+Sn content are discussed. The CC/HE Nbss has low Δχ, VEC and Ω and high ΔSmix, |ΔHmix| and δ parameters, and is formed in alloys that have high entropy of mixing. These parameters are compared with those of single-phase bcc ss HEAs and differences in ΔHmix, δ, Δχ and Ω, and similarities in ΔSmix and VEC are discussed. Relationships between the parameters of alloy and "conventional" Nbss also apply for CC/HE Nbss. The parameters δss and Ωss, and VECss and VECalloy can differentiate between types of alloying additions and their concentrations and are key regarding the formation or not of CC/HE Nbss. After isothermal oxidation at a pest temperature (800 oC/100 h) the contaminated with oxygen Nbss in the diffusion zone is CC/HE Nbss, whereas the Nbss in the bulk can be "conventional" Nbss or CC/HE Nbss. The parameters of "uncontaminated" and contaminated with oxygen sss are linked with linear relationships. There are correlations between the oxygen concentration in contaminated sss in the diffusion zone and the bulk of alloys with the parameters ΔχNbss, δNbss and VECNbss, the values of which increase with increasing oxygen concentration in the ss. The effects of contamination with oxygen of the near surface areas of a HT RM(Nb)IC with Al, Cr, Hf, Si, Sn, Ti and V additions and a high vol.% Nbss on the hardness and Young's modulus of the Nbss, and contributions to the hardness of the Nbss in B free or B containing alloys are discussed. The hardness and Young's modulus of the bcc ss increased linearly with its oxygen concentration and the change in hardness and Young's modulus due to contamination increased linearly with [O]2/3.

A Study of the Effects of Hf and Sn on the Microstructure, Hardness and Oxidation of Nb-18Si Silicide-Based Alloys-RM(Nb)ICs with Ti Addition and Comparison with Refractory Complex Concentrated Alloys (RCCAs)

In this paper, we present a systematic study of the as-cast and heat-treated microstructures of three refractory metal intermetallic composites based on Nb (i.e., RM(Nb)ICs), namely the alloys EZ2, EZ5, and EZ6, and one RM(Nb)IC/RCCA (refractory complex concentrated alloy), namely the alloy EZ8. We also examine the hardness and phases of these alloys. The nominal compositions (at.%) of the alloys were Nb-24Ti-18Si-5Hf-5Sn (EZ2), Nb-24Ti-18Si-5Al-5Hf-5Sn (EZ5), Nb-24Ti-18Si-5Cr-5Hf-5Sn (EZ6), and Nb-24Ti-18Si-5Al-5Cr-5Hf-5Sn (EZ8). All four alloys had density less than 7.3 g/cm3. The Nbss was stable in EZ2 and EZ6 and the C14-NbCr2 Laves phase in EZ6 and EZ8. In all four alloys, the A15-Nb3X (X = Al,Si,Sn) and the tetragonal and hexagonal Nb5Si3 were stable. Eutectics of Nbss + Nb5Si3 and Nbss + C14-NbCr2 formed in the cast alloys without and with Cr addition, respectively. In all four alloys, Nb3Si was not formed. In the heat-treated alloys EZ5 and EZ8, A15-Nb3X precipitated in the Nb5Si3 grains. The chemical compositions of Nbss + C14-NbCr2 eutectics and some Nb5Si3 silicides and lamellar microstructures corresponded to high-entropy or complex concentrated phases (compositionally complex phases). Microstructures and properties were considered from the perspective of the alloy design methodology NICE. The vol.% Nbss increased with increasing ΔχNbss. The hardness of the alloys respectively increased and decreased with increasing vol.% of A15-Nb3X and Nbss. The hardness of the A15-Nb3X increased with its parameter Δχ, and the hardness of the Nbss increased with its parameters δ and Δχ. The room-temperature-specific strength of the alloys was in the range 271.7 to 416.5 MPa cm3g−1. The effect of the synergy of Hf and Sn, or Hf and B, or Hf and Ge on the macrosegregation of solutes, microstructures, and properties of RM(Nb)ICs/RCCAs from this study and others is compared. Phase transformations involving compositionally complex phases are discussed.

Refractory Metal Intermetallic Composites, High-Entropy Alloys, and Complex Concentrated Alloys: A Route to Selecting Substrate Alloys and Bond Coat Alloys for Environmental Coatings.

This paper considers metallic ultrahigh-temperature materials (UHTMs) and the alloying behaviour and properties of alloys and their phases by using maps of the parameters δ (based on atomic size), Δχ (based on electronegativity), and valence electron concentration (VEC), and discusses what connects and what differentiates material groups in the maps. The formation of high-entropy or complex concentrated intermetallics, namely 5-3 silicides, C14 Laves and A15 compounds, and bcc solid solutions and eutectics in metallic UHTMs and their co-existence with “conventional” phases is discussed. The practicality of maps for the design/selection of substrate alloys is deliberated upon. The need for environmental coatings for metallic UHTMs was considered and the design of bond coat alloys is discussed by using relevant maps.

On the Microstructure and Properties of Nb-Ti-Cr-Al-B-Si-X (X = Hf, Sn, Ta) Refractory Complex Concentrated Alloys.

We studied the effect of the addition of Hf, Sn, or Ta on the density, macrosegregation, microstructure, hardness and oxidation of three refractory metal intermetallic composites based on Nb (RM(Nb)ICs) that were also complex concentrated alloys (i.e., RM(Nb)ICs/RCCAs), namely, the alloys TT5, TT6, and TT7, which had the nominal compositions (at.%) Nb-24Ti-18Si-5Al-5B-5Cr-6Ta, Nb-24Ti-18Si-4Al-6B-5Cr-4Sn and Nb-24Ti-17Si-5Al-6B-5Cr-5Hf, respectively. The alloys were compared with B containing and B free RM(Nb)ICs. The macrosegregation of B, Ti, and Si was reduced with the addition, respectively of Hf, Sn or Ta, Sn or Ta, and Hf or Sn. All three alloys had densities less than 7 g/cm3. The alloy TT6 had the highest specific strength in the as cast and heat-treated conditions, which was also higher than that of RCCAs and refractory metal high entropy alloys (RHEAs). The bcc solid solution Nbss and the tetragonal T2 and hexagonal D88 silicides were stable in the alloys TT5 and TT7, whereas in TT6 the stable phases were the A15-Nb3Sn and the T2 and D88 silicides. All three alloys did not pest at 800 °C, where only the scale that was formed on TT5 spalled off. At 1200 °C, the scale of TT5 spalled off, but not the scales of TT6 and TT7. Compared with the B free alloys, the synergy of B with Ta was the least effective regarding oxidation at 800 and 1200 °C. Macrosegregation of solutes, the chemical composition of phases, the hardness of the Nbss and the alloys, and the oxidation of the alloys at 800 and 1200 °C were considered from the perspective of the Niobium Intermetallic Composite Elaboration (NICE) alloy design methodology. Relationships between properties and the parameters VEC, δ, and Δχ of alloy or phase and between parameters were discussed. The trends of parameters and the location of alloys and phases in parameter maps were in agreement with NICE.

The Effect of Boron on the Microstructure and Properties of Refractory Metal Intermetallic Composites (RM(Nb)ICs) Based on Nb-24Ti-xSi (x = 16, 17 or 18 at.%) with Additions of Al, Cr or Mo.

This paper is about metallic ultra-high temperature materials, in particular, refractory metal intermetallic composites based on Nb, i.e., RM(Nb)ICs, with the addition of boron, which are compared with refractory metal high entropy alloys (RHEAs) or refractory metal complex concentrated alloys (RCCAs). We studied the effect of B addition on the density, macrosegregation, microstructure, hardness and oxidation of four RM(Nb)IC alloys, namely the alloys TT2, TT3, TT4 and TT8 with nominal compositions (at.%) Nb-24Ti-16Si-5Cr-7B, Nb-24Ti-16Si-5Al-7B, Nb-24Ti-18Si-5Al-5Cr-8B and Nb-24Ti-17Si-3.5Al-5Cr-6B-2Mo, respectively. The alloys made it possible to compare the effect of B addition on density, hardness or oxidation with that of Ge or Sn addition. The alloys were made using arc melting and their microstructures were characterised in the as cast and heat-treated conditions. The B macrosegregation was highest in TT8. The macrosegregation of Si or Ti increased with the addition of B and was lowest in TT8. The alloy TT8 had the lowest density of 6.41 g/cm3 and the highest specific strength at room temperature, which was also higher than that of RCCAs and RHEAs. The Nbss and T2 silicide were stable in the alloys TT2 and TT3, whereas in TT4 and TT8 the stable phases were the Nbss and the T2 and D88 silicides. Compared with the Ge or Sn addition in the same reference alloy, the B and Ge addition was the least and most effective at 800 °C (i.e., in the pest regime), when no other RM was present in the alloy. Like Ge or Sn, the B addition in TT2, TT3 and TT4 did not suppress scale spallation at 1200 °C. Only the alloy TT8 did not pest and its scales did not spall off at 800 and 1200 °C. The macrosegregation of Si and Ti, the chemical composition of Nbss and T2, the microhardness of Nbss and the hardness of alloys, and the oxidation of the alloys at 800 and 1200 °C were also viewed from the perspective of the alloy design methodology NICE and relationships with the alloy or phase parameters VEC, δ and Δχ. The trends of these parameters and the location of alloys and phases in parameter maps were found to be in agreement with NICE.

Effect of sintering pressure and temperature on structure and properties of Ni Al metal-intermetallic composites produced by SPS

In recent decades, spark plasma sintering (SPS) has become a widespread technique in the production of high-quality intermetallic-based materials. In this study, we used SPS to fabricate multilayer metal-intermetallic (MIL) composites from pure nickel and aluminum foils. The effect of sintering temperature and pressure on the structure and properties of the fabricated MIL composites is discussed. The sintering temperature was changed from 900 to 1100 °C, the pressure varied from 10 to 40 MPa. The structure of the materials was investigated using optical microscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray energy-dispersive spectroscopy (EDX), and X-ray diffraction (XRD). Depending on the sintering regimes the intermetallic layers in the composites consisted of Ni 2 Al 3 , Ni 3 Al, and NiAl of cubic and tetragonal modifications. Tetragonal NiAl appeared in the form of microtwinned lamellar martensite. A change in SPS temperature from 900 to 1100 °C led to an increase in the volume fraction of nickel-enriched intermetallic compounds, which was accompanied by improving composites strength. With an increase of the SPS pressure from 10 to 30 MPa, the number of pores and cracks in composites decreased. At the same time, their bending strength increased by 2 times (from 450 to 900 MPa). Fractographic studies showed that the fracture mechanism of the intermetallic layers depends on their elemental composition and varies from brittle transcrystalline to wavy “feathery”. • Multilayer metal-intermetallic composites were produced by spark plasma sintering. • Ni 2 Al 3 , NiAl, and Ni 3 Al compounds were formed in the intermetallic layers. • Increase in temperature led to an increase in the volume fraction of Ni-rich phases. • NiAl twinned lamellar martensite was formed after sintering at 1100 °C. • Increase in pressure and temperature increased tensile and bending strength.

Refractory Metal (Nb) Intermetallic Composites, High Entropy Alloys, Complex Concentrated Alloys and the Alloy Design Methodology NICE-Mise-en-scène † Patterns of Thought and Progress.

The paper reflects on the usefulness of the alloy design methodology NICE (Niobium Intermetallic Composite Elaboration) for the development of new Nb-containing metallic ultra-high-temperature materials (UHTMs), namely refractory metal (Nb) intermetallic composites (RM(Nb)ICs), refractory high entropy alloys (RHEAs) and refractory complex concentrated alloys (RCCAs), in which the same phases can be present, specifically bcc solid solution(s), M5Si3 silicide(s) and Laves phases. The reasons why a new alloy design methodology was sought and the foundations on which NICE was built are discussed. It is shown that the alloying behavior of RM(Nb)ICs, RHEAs and RCCAs can be described by the same parameters. The practicality of parameter maps inspired by NICE for describing/understanding the alloying behavior and properties of alloys and their phases is demonstrated. It is described how NICE helps the alloy developer to understand better the alloys s/he develops and what s/he can do and predict (calculate) with NICE. The paper expands on RM(Nb)ICs, RHEAs and RCCAs with B, Ge or Sn, the addition of which and the presence of A15 compounds is recommended in RHEAs and RCCAs to achieve a balance of properties.

Исследование локализации пластической деформации слоистых металл-интерметаллидных композитов при динамическом канально-угловом прессовании

The method of mathematical modeling has been used to study the processes of plastic deformation localization of layered metal-intermetallic composites under dynamic channel-angular pressing. The deformation patterns of single-phase intermetallic samples and layered composites samples with the different arrangement of layers relative to the compression axis have been compared. The calculated stress-strain curves have been obtained. Three-dimensional modeling has been carried out on the basis of an approach combining two methods for the plastic flow description through the kinetics of deformation defects storage and the solid state mechanics. The numerical solution of the model equations has been carried out by the finite element method.

Al/Ni metal intermetallic composite produced by accumulative roll bonding and reaction annealing

In this research, Al/Ni multilayers composites were produced by accumulative roll bonding and then annealed at different temperatures and durations. The structure and mechanical properties of the fabricated metal intermetallic composites (MICs) were investigated. Scanning electron microscopy and X-ray diffraction analyses were used to evaluate the structure and composition of the composite. The Al 3Ni intermetallic phase is formed in the Al/Ni interface of the samples annealed at 300 and 400 °C. When the temperature increased to 500 °C, the Al 3Ni 2 phase was formed in the composite structure and grew, while the Al 3Ni and Al phases were simultaneously dissociated. At these conditions, the strength of MIC reached the highest content and was enhanced by increasing time. At 600 °C, the AlNi phase was formed and the mechanical properties of MIC were intensively degraded due to the formation of structural porosities.

Studies on synthesis and microstructure evolution of multiphase in-situ composites based on Mo-Cr-Si system

This paper presents the results on in-situ synthesis of refractory metal-intermetallic composites (RMICs), Mo-16Cr-4Si and Mo-11Cr-9Si (wt.%) multiphase alloys and their characterization. The alloys were prepared from the oxides of molybdenum and chromium by their coreduction with Si as reductant. Exothermic nature of the synthesis reactions resulted in the formation of consolidated composite as a product in a single step. As-reduced alloys were remelted by arc melting and heat treatment was given. The evolution of phases and the microstructure were studied by XRD, SEM, and EDS analysis. The multiphase microstructure consist of the silicide phases (Mo,Cr)3Si + (Mo,Cr)5Si3 for hypereutectic and (Mo,Cr)3Si phase distributed in bcc matrix comprising essentially a solid solution of (Mo,Cr) for hypo-peritectic composition. Comparative studies of the synthesized alloys were also carried out to the composition, phases, microstructure, hardness and their oxidation behavior.

Phase Equilibria in the Nb-rich Nb-Ti-Si-Cr-Hf alloys

ABSTRACTRefractory Metal-Intermetallic Composites (RMICs) based on the Nb-Si system have been considered as candidates for the next-generation high temperature materials (i.e. >1200°C). Ti, Cr and Hf have been shown to have beneficial effects on the oxidation resistance and mechanical properties of Nb-Si alloys. The present study has determined phase equilibria in the Nb-rich region of the Nb-Si-Ti-Cr-Hf system via the Calphad approach. The alloying effects of Cr and Hf on the microstructure of Nb-Si-Ti alloys are understood based on isothermal sections, liquidus projections, and solidification curves that were calculated from the thermodynamic models of the Nb-Ti-Si-Cr-Hf system developed in the present study. This work provides important guidelines on the development of new Nb-Si-Ti-Cr-Hf alloys.

Investigation on the as-cast microstructure of Nb–Nb silicide based multicomponent alloys

Refractory metal intermetallic composites (RMICs) based on the Nb–Ti–Si–Cr–Hf quinary are candidate materials for ultra-high temperature applications beyond 1200 °C. In this investigation, minor additions of Al, B, Y and Mo were introduced into the Nb-22Ti-(15–18)Si-6Cr-4Hf (at.%) base alloy for potential enhancement of the mechanical and environmental properties. The phases, phase compositions and morphologies in the as-cast microstructure of the base alloy with or without minor Al, B, Y and Mo additions were investigated using X-ray diffraction (XRD), optical metallography (OM), scanning electron microscopy (SEM), energy dispersive X-ray spectrum (EDS) and electron probe microanalysis (EPMA). The experimental results obtained from several selected alloys were found to agree with the solidification paths calculated from the Scheil model using established thermodynamic properties of all the phases in the Nb–Ti–Si–Cr–Hf–Al system.

Effects of Ti, Zr, and Hf on the phase stability of Mo_ss + Mo 3Si + Mo 5SiB 2 alloys at 1600 ° C

Understanding the stability of the three-phase Mo_ss + Mo 3Si + Mo 5SiB 2 region is important for alloy design of Mo–Si–B-based refractory metal intermetallic composites. In this work, thermodynamic modeling is coupled with guided experiments to study phase stability in this three-phase region of the Mo–Si–B–X (X = Ti, Zr, Hf) system. Both the calculated and experimental results show that additions of Zr and Hf limit significantly the stability of the three-phase region because of the formation of the ternary phases MoSiZr and MoSiHf, while Ti addition leads to a much larger region of stability for the three-phase equilibrium.

Effect of Cr Addition on the Multiphase Equilibria in the Nb-rich Nb-Si-Ti System - Thermodynamic Modeling and Designed Experiments

AbstractRefractory Metal Intermetallic Composites (RMICs) based on the Nb-Si system are considered as candidates of next-generation high temperature materials (i.e. >1200°C). Ti and Cr have been shown to have beneficial effects on the oxidation resistance and mechanical properties of Nb-Si alloys. Phase equilibria in the Nb-Si-Ti system have been studied in detail. The present study has investigated multiphase equilibria in the Nb-Si-Ti alloys with Cr additions via an approach of integrating thermodynamic modeling with designed experiments. The alloying effects of Cr on the microstructure of the Nb-Si-Ti alloys are described using both phase equilibria and solidification paths that were calculated from the thermodynamic description of the Nb-Cr-Si-Ti system developed in the present study.

Application of phase diagram calculations to development of new ultra-high temperature structural materials

In-situ refractory metal intermetallic composites(RMICs) based either on (Nb, Si) or (Mo, Si, B) are candidate materials for ultra-high temperature applications (>1 400 °C). To provide a balance of mechanical and environmental properties, Nb-Si composites are typically alloyed with Ti and Cr, and Mo-Si-B composites are alloyed with Ti. Phase diagrams of Nb-Cr-Ti-Si and Mo-Si-B-Ti, as prerequisite knowledge for advanced materials design and processing development, are critically needed. The phase diagrams in the metal-rich regions of multicomponent Nb-Cr-Ti-Si and Mo-Si-B-Ti were rapidly established using the Calphad (Calculation of phase diagram) approach coupled with key experiments. The calculated isotherms, isopleths, and solidification paths were validated by experimental work. The important heterogeneous multiphase equilibria in both quaternary systems identified will offer engineers the opportunity to develop materials with a balance of properties for high-temperature applications.

A review of very-high-temperature Nb-silicide-based composites

The temperatures of airfoil surfaces in advanced turbine engines are approaching the limits of nickel-based superalloys. Innovations in refractory metal-intermetallic composites (RMICs) are being pursued, with particular emphasis on systems based on Nb-Si and Mo-Si-B alloys. These systems have the potential for service at surface temperatures >1350 °C. The present article will review the most recent progress in the development of Nb-silicide-based in-situ composites for very-high-temperature applications. Nb-silicide-based composites contain high-strength silicides that are toughened by a ductile Nb-based solid solution. Simple composites are based on binary Nb-Si alloys; more complex systems are alloyed with Ti, Hf, Cr, and Al. In higher-order silicide-based systems, alloying elements have been added to stabilize intermetallics, such as Laves phases, for additional oxidation resistance. Alloying schemes have been developed to achieve an excellent balance of room-temperature toughness, high-temperature creep performance, and oxidation resistance. Recent progress in the development of composite processing-structure-property relationships in Nb-silicide-based in-situ composites will be described, with emphasis on rupture resistance and oxidation performance. The Nb-silicide composite properties will be compared with those of advanced Ni-based superalloys.

Growth morphologies and mechanism of TiC in the laser surface alloyed coating on the substrate of TiAl intermetallics

TiC-type MC carbide is an important constituent and strengthening phase for nickel-base superalloys, metal matrix composites (MMCs) and intermetallic matrix composites (IMCs). Its growth morphology, size and distribution have a strong effect on the mechanical properties of materials. In addition, TiC carbide is a typical faceted crystal due to its high Jackson factor. Therefore, the solidification behavior of TiC carbide is an important research subject. In the present study, TiC reinforced composite coatings on the surface of intermetallic alloy γ-TiAl were successfully synthesized by means of laser surface alloying, the growth mechanism and phase morphologies of TiC were investigated as a function of solidification cooling rate. The growth morphology of TiC solidified at a cooling rate of 1.0×10 2 K/s is found to be dendritic, having a platelet/catenulate growth characteristic on dendrite arms. As the solidification cooling rate increases to 2.2×10 2 K/s, the growth morphology of TiC changes to a well-developed dendrite having a three-dimensional network growth characteristic. In spite of the variety of growth morphologies under different solidification conditions, TiC still grows by the lateral growth mechanism. Moreover, the growth kinetics of TiC/Al 3Ti eutectic plays an important role in controlling the carbide growth morphologies.