Ti Al Nb Research Articles

Microstructure and mechanical properties of Ti–45Al–2W–xC alloys

The microstructure and mechanical properties of five alloys with nominal compositions of Ti–45Al–2W–xC (in at.%), where x is ranging from 0.4 to 2.0 at.%, were studied. The alloys were prepared by vacuum induction melting in graphite crucibles, followed by centrifugal casting into a graphite mould. The as-cast alloys were subjected to hot isostatic pressing and heat treatment consisting of solution annealing, cooling at a constant rate and stabilisation annealing. The microstructure of the heat-treated alloys consists of equiaxed α2(Ti3Al) + γ(TiAl) lamellar grains surrounded by γ grain boundaries with a small amount of β/B2 particles. The α2-α2 interlamellar spacing λ decreases with increasing carbon content until a solubility limit of carbon is achieved. The increase in carbon content above the solubility limit leads to the formation of primary Ti2AlC particles during solidification and an increase in the amount of γ phase at grain boundaries. Vickers microhardness of lamellar grains depends on the carbon content and interlamellar spacing λ. The studied Ti–45Al–2W–0.8C and Ti–45Al–2W–1.2C alloys show improved creep resistance at 800 °C compared to that of the reference carbon-free TiAl–W and carbon-containing TiAl–Nb based alloys with fully lamellar, nearly lamellar, convoluted or pseudo-duplex microstructure.

Liquid dripping dynamics and levitation stability control of molten Ti–Al–Nb alloy within electromagnetic fields

The dripping dynamics of the electromagnetically levitated (EML) liquid Ti–Al–Nb alloy under high temperatures was investigated by both numerical simulation based on the Arbitrary Lagrangian–Eulerian method and corresponding EML experiments. A dripping formation parameter εD was defined to describe the critical shape of alloy droplet. According to the simulated results, the high-temperature dripping phenomenon took place when εD < 0.68, which was in good agreement with experimental data. When dripping event occurred, the Lorentz force applied on alloy droplet decreased by approximately 11.7% within 0.07 s. Three typical methods were accordingly proposed to avoid the dripping failure of a bulk liquid Ti–Al–Nb alloy, which was implemented by enhancing electric current, adjusting levitation coil diameter, or increasing coil winding number. To control the droplet shape, the deformation pattern and the flow behavior of the liquid alloy were studied in a wide current range from 700 to 1400 A. With the increase in excitation current, the cone-shaped alloy melt transformed to a rhombus, and the flow behavior transformed from a typical four toroidal flow vortexes up to a complex eight toroidal flow vortexes. Moreover, the centroid position of liquid alloy rose up significantly at first and then slowly approached to levitation ceiling.

Crystallographic Origin of Phase Transformation and Lamellar Orientation Control for TiAl-Based Alloys

TiAl intermetallics are typical metallic materials involving complex solid-state phase transformations, with crystal orientations that are difficult to control due to multi-transformation variants. However, lamellar orientation control is crucial to the development of a polysynthetic twinned single crystal structure in TiAl-based alloys for jet engines or other high-temperature systems. In this study, β-solidifying TiAl alloys were used to study the relationships between the lamellar structure and the phase transformation process under directional solidification (referred to as the directional phase transformation, DPT). It was found that the β → α phase transition affects the lamellar orientations and that the subsequent process of α → α2 + γ leads to the final formation of the polysynthetic lamellar structure. Detailed analyses based on crystallography show that the β/α phase interface is responsible for the different oriented lamellar structures with the 0° or 45° orientation. With a lower interfacial energy, the 0° oriented α phase nucleates more easily but grows much more slowly than the 45° oriented α phases during DPT, which makes it feasible to control the lamellar orientations for TiAl-based alloys. The crystallographic origin for the control of lamellar orientations was then studied and confirmed by using EBSD in a β-solidifying Ti–Al–Nb alloy.

Microstructure and mechanical properties of micro-nano Ti2AlC-reinforced TiAl composites

In order to improve the mechanical properties of TiAl alloys, micro-nano Ti2AlC-reinforced TiAl composites were successfully fabricated by means of spark plasma sintering (SPS) using the ball-milled multilayer graphene oxide and Ti–48Al–2Nb–2Cr pre-alloyed powders. The micro-nano Ti2AlC phase precipitated at the interface between α2-Ti3Al and γ-TiAl phases utilizing the reaction of TiAl and high-activity graphene. Fully lamellar structure was obtained after sintering above 1300 °C, and Ti2AlC phase characteristic were depended on sintering temperature and graphene content. The compressive strength and fracture strain of TiAl-0.5G alloy were improved at room temperature and elevated temperature, which was improved by 23.61% and 5.03% compared to the TiAl-0G alloy at room temperature. The tribological properties of TiAl composites were significantly improved by micro-nano Ti2AlC at the room temperature, and the average friction coefficient of TiAl-0.5G alloy is 0.217 compared with TiAl-0G alloy is 0.312, and the wear mechanism is ploughing wear. The micro-nano Ti2AlC improves the strength and oxidation resistance of TiAl composites at 650 °C, which is detrimental to the wear resistance due to the lower ductility and the third wear by the loose oxide particles at elevated temperature.

Preparation of low-oxygen-containing Ti–48Al–2Cr–2Nb alloy powder by direct reduction of oxides

A high-purity Ti–48Al–2Nb–2Cr alloy powder with an oxygen content as low as 0.0572 wt.% and a particle size of <150 μm was produced from a mixture of TiO2, Al2O3, Nb2O5, and Cr2O3 powders through reduction with magnesium and deoxidation with calcium. The phase and composition of the products were analyzed. The final product mainly included γ-TiAl and minor α2-Ti3Al phases, and Ti, Al, Cr, and Nb were homogenously distributed in the powder with a mole ratio of 49.73:43.51:2.05:1.98. The reduction and deoxidation mechanisms were investigated by thermodynamic modeling using the HSC Chemistry software and Pandat software based on the Ti alloy database.

Evolution of Lamellar O Phase During Hot Compression in Ti2AlNb-Based Alloy

The dynamic spheroidization behavior of Ti2AlNb-based alloy with O lamellae during isothermal hot compression was investigated. The aspect ratio of lamellar O phase decreased at higher compression temperatures and lower strain rates, and more kinked or spherical O phases appeared. The results indicated that deformation conditions have a considerable effect on dynamic spheroidization behavior of Ti–22Al–25Nb alloy, and the correlation between spheroidization fraction and strain follows a Avrami-type sigmoid model. The strains for starting (εc) and finishing (εf) of the dynamic spheroidization determined with the nonlinear fit were 0.10–0.31 and 1.70–5.39, respectively. The εc was higher due to the consumption of compressed strains before the fracture of O lamellae. The kinetic rate of dynamic spheroidization is positively correlated with temperature rise and negatively correlated with strain rate. Dynamic spheroidization was achieved through a combination of shearing and diffusional process during different hot compression conditions.

Some Aspects of Oxidation and Reduction Processes in Ti-Al and Ti-Al-Nb Systems.

The oxidation of titanium and titanium aluminides has attracted the attention of scientists for many years because of their high-temperature application. The most popular method to investigate oxidation behavior is the measurement of alloy mass changes during exposure to elevated-temperature under isothermal or thermal cycling conditions. However, the thermogravimetric method is not enough to establish an oxidation mechanism. In this paper, the temperature-programmed oxidation (TPOx) and reduction (TPR) were applied for the Ti–Al and Ti–Al–Nb systems, which was a new experimental concept which revealed interesting phenomena. Although oxidation of titanium alloys is well-described in the literature, not many papers present at the same time reduction of oxidized alloys. The results presented in the paper concentrated on the first stages of oxidation, which are scarcely described in the literature, but are important to understand the oxidation mechanism. Comparison between powder and bulk samples with similar compositions revealed essential differences in the oxidation mechanism.

Microstructural stability of a two-phase (O + B2) alloy of the Ti-25Al-25Nb system (at.%) during thermal cycling in a hydrogen atmosphere

&lt;abstract&gt; &lt;p&gt;In this work, the stability of the microstructure of the experimentally obtained two-phase (O + B2) alloy of the Ti–25Al–25Nb (at.%) system were studied during thermal cycling in a hydrogen atmosphere. It was found that the two-phase structure (O + B2) of the alloy of the Ti–Al–Nb system shows high thermodynamic stability. In this case, phase transformations of secondary phases (α2, AlNb&lt;sub&gt;2&lt;/sub&gt;) are observed in the microstructure of the alloy, the volumetric content of which at all stages of testing does not exceed 2%. Thus, after the first cycle of high-temperature exposure, single inclusions of the α2 phase precipitate, while in the areas enriched in Ti and Al, due to the redistribution of Nb, a new colony of the α2 phase is observed. After five test cycles, it was found that large accumulations of the α2 colony, due to the α2 → B2 phase transformations, form new micron-sized grains of the B2 phase. A volumetric accumulation of nanosized precipitates of the AlNb&lt;sub&gt;2&lt;/sub&gt; phase was found near the triple joints of the grain boundaries of the B2 phase after 10 cycles of thermal exposure, which is caused by the supersaturation of B2 grains with niobium.&lt;/p&gt; &lt;/abstract&gt;

In-situ synthesis of Al2O3-reinforced high Nb–TiAl laminated composite with an enhanced strength-toughness performance

In this work, the Al 2 O 3 -reinforced high Nb–TiAl laminated composite is successfully fabricated by an innovative way of direct-current magnetron sputtering combined with the foil-foil metallurgy, with assistance of vacuum hot-pressed sintering. Here, the Nb-coated aluminum foil and titanium foil, microstructure evolution, the lamellar plane distribution and the mechanical performances are carefully studied. Specifically, the composite is composed of the α 2 -Ti 3 Al, γ-TiAl and α-Al 2 O 3 phase, in which the high Nb–TiAl matrix has a fully lamellar microstructure and a high content (∼6.5%) of Nb. Taken the textured titanium foil as raw material, the multi-stage annealing process is proved to be an effective way to control the lamellar plane distribution in the high Nb–TiAl matrix, showing that 82.3% of the lamellar planes forms an angle less than 30° from the RD-ND plane of the composite. Moreover, the bending strength and fracture toughness of the composite reach 817 MPa and 12.41 MPa m 1/2 , respectively. Further, the toughening and strengthening mechanisms are also detailly discussed. We believe that the major findings in this work can provide a new idea to design the high strength-toughness intermetallic-ceramic composites.

Microstructure control and mechanical properties of directionally solidified large size TiAl alloy by electromagnetic confinement

Ti–48Al–2Nb–2Cr alloys with a diameter of 30 mm were prepared by electromagnetic confinement directional solidification with Ti–43Al–3Si seed under different pulling rates. The macro/microstructure evolution and mechanical properties of the directionally solidified Ti–48Al–2Nb–2Cr alloys were investigated. With increasing pulling rates, the grain sizes of the directionally solidified alloys increase to the maximum at the pulling rate of 15 μm/s and then decrease. During the process of directional solidification, the primary phase of the alloy transforms from the α phase into β phase with the increase of pulling rates. At the pulling rate of 5 μm/s, the equiaxed grains with fully lamellar microstructure are formed, and some B2 phases and massive γ phases are found at the grain boundary. The well aligned α2/γ lamellar orientation is obtained at the pulling rate of 15 μm/s, while the inclined lamellar orientation is obtained when the pulling rate increases to 20 μm/s. The interlamellar spacing (λ) decreases with increasing pulling rate (V) according to the relationship λ=6966V−0.563 and r2=0.986. For the DS samples, the nanoindentation hardness of the lamellae and the interlamellar spacing satisfy the relationship of HN=53.83d−0.309 and r22=0.96. The room-temperature tensile strength of directionally solidified alloy reaches the maximum value at the pulling rate of 15 μm/s. The fracture changes from interlamellar to translamellar mode with increasing pulling rate. The synergistic effect of nanotwins and dislocations contributes to the relatively high room-temperature tensile strength and elongation during the deformation.

Phase transformation and deformation behavior of a TiAl–Nb composite under quasi-static and dynamic loadings

To improve the high-temperature deformability of TiAl intermetallics, a TiAl–Nb intermetallic matrix composite was prepared by powder metallurgy to try to introduce the deformable β phase. The microstructure and deformation behavior of the TiAl–Nb intermetallic matrix composite under quasi-static and dynamic conditions were systematically investigated. It is found that the microstructure of the composite is composed of a near-gamma TiAl matrix and Nb-rich regions. In the Nb-rich regions a coexistence of βo, ωo and γ phases was identified where ωo and γ phases were supposed to directly precipitate in the βo matrix. The ultimate tensile strength of the composite exhibits different temperature-dependent behaviors under quasi-static and dynamic loading conditions. It increases with temperatures up to 650 °C and then declines with temperature under quasi-static loading, while it does not decrease from 650 to 850 °C under the dynamic loading. In the deformed microstructures, the Nb-rich regions at all conditions are still composed of βo, ωo and γ phases, indicating that the solvus temperature of the ωo phase could be above 850 °C. Additionally, the TiAl matrix appears to not significantly contribute to the plastic deformation of the composite, where the propensity of dislocations and mechanical twins do not significantly change when varying loading conditions. However, the γ particles formed in Nb-rich regions contain substantial mechanical twins and dislocations under both quasi-static and dynamic loading conditions. Thus, the γ particles directly transformed from the βo phase exhibit better deformability than the γ phase in the matrix. This could be probably explained by a decreased stacking fault energy for the newly formed γ phase due to a decrease in Al fraction and a significant increase in Nb fraction. Meanwhile, twin intersections occurred in the γ particles, and the induced stress concentration in the intersection regions was relieved by lattice distortion and detwinning processes. This twin intersection behavior could be beneficial for improving the composite strength without sacrificing much ductility.

Effect of deformation band on the strength of a rolled plate of intermetallic titanium alloy based on Ti–22Al–25Nb system

The influence of deformation band (DB) in a rolled plate of VTI-4 alloy of the Ti–22Al–25Nb system on the ultimate tensile strength (UTS) of this material in tensile tests has been studied. Samples subjected to heat treatment under the same conditions differ significantly in strength: 1075 MPa for the central part of the plate and 1150 MPa for the rest of the plate volume. It is shown that the spread in strength is determined by the presence of DB and the fraction of its area in the sample cross section. The presence of DB in a sample leads to reduction in its UTS by 3–6%, when the fraction of DB in a cross section of the test samples is 30–40% by area. It is found that the central part of the plate is a monograin, which has a thickness of ~1 mm and orientation 〈100〉β along the plate principal axes. The low strength of DB material is due both to the absence of grain-boundary hardening and unfavorable crystallographic orientation of monograin relative to the tensile load. The presence of the grain and texture inhomogeneity in a rolled plate leads to incorrect results of mechanical tests and could be a potential source of a fatigue failure.

Microstructure evolution and fracture mechanism of a TiAl–Nb alloy during high-temperature tensile testing

A TiAl–Nb alloy was prepared by casting, and its tensile properties and microstructure evolution at different temperatures were investigated. The results show that the brittle-ductile transition temperature (BDTT) of the alloy is 880–920 °C. At low temperatures, deformation mainly occurs in the γ lamellae and coarsening γ phase between the lamellar colonies. As the temperature increase in the transitory stage, a small number of dislocations may pass through the interface from the coarsening γ phase into the γ lamellae. During the brittle stage, the dislocation and dislocation array bow out from the phase interface, and twins are emitted from the phase interface, which may contribute to the accommodation of stress concentration. During the ductile stage, the γ lamellae coarsen due to the thinner and smaller α2 lamellae dissolving and phase boundary transfer. The dislocations interact with the dislocation walls to form subboundaries in the γ lamellae and transform into equiaxed crystals by dynamic recrystallization (DRX), which increases the plasticity of the alloy. With the transition from the brittle model to the ductile model, the fracture mode of the alloy changes from the mixed fracture mode of transgranular fracture and translaminar fracture to intergranular fracture.

Microstructure evolution and mechanical properties of high Nb–TiAl alloy/GH4169 joints brazed using CuTiZrNi amorphous filler alloy

A CuTiZrNi amorphous filler metal was fabricated and utilized for brazing high Nb–TiAl alloys and GH4169 superalloys. The microstructure and mechanical properties of the high Nb–TiAl/GH4169 joints brazed from 900 °C to 1020 °C temperature range were studied. Results showed that the high Nb–TiAl/GH4169 joints consisted of three zones. The interfacial microstructure of the joints was high Nb–TiAl alloy/Ti3Al + Al3(Ni, Cu)Ti2 + Al(Ni, Cu)2Ti/AlCu2(Ti, Zr) + (Ti, Zr)(Ni, Cu) + Ti2(Ni, Cu)/Cr-rich (Cr, Ni, Fe)ss + Ni-rich (Ni, Cr, Fe)ss/GH4169 alloy. The element diffusion between the substrates and the filler alloy was intensified as the brazing temperature increased, and the interfacial reaction layer thickened. At 960 °C, the joint exhibited a maximum shear strength which was approximately 241.9 MPa. At higher brazing temperatures, the excessive AlCu2(Ti, Zr) phase and coarse Ti2(Ni, Cu) deteriorated the joint properties due to their inherent brittleness.

In situ observation of competitive growth of α grains during β → α transformation in laser beam manufactured TiAl alloys

Low ductility has long been the bottleneck for high temperature application of TiAl alloys. It is reported that grain refinement through boride could improve its mechanical property. However, this refinement is suppressed at high cooling rate. This article delineates for the first time an in situ observation by synchrotron X-ray diffraction. It illustrates the mechanism of competitive nucleation and grain growth of Burgers and non-Burgers α grains during β → α transformation in a Ti–45Al–5Nb–0.2C–0.2B alloy (TNB-V5). Comparing with those in base material, the volume fraction and size of borides are significantly reduced in the welding zone. The non-Burgers α grains nucleate earlier than Burgers α. However, Burgers α grains grow much faster than non-Burgers α during β → α transformation in the welding zone, due to a high thermodynamic driving force of Burgers α grains. No orientation relationships between α and borides or between β and borides are observed in the fast cooling.

High-temperature tensile behaviors and microstructural evolutions of a directionally solidified Ti–45Al–5Nb–2Mn alloy

Investigations on the high-temperature tensile performances and deformation behaviors of the directionally solidified Ti–45Al–5Nb–2Mn alloy revealed that an increase in the tensile temperature resulted in the occurrence of brittle-ductile transition (BDT) and the BDT temperature was beyond 1173 K. The mixed mode of inter- and trans-lamellar fracture governed the brittle fracture, and except for dimples, there were split lamellae on the ductile fracture surface. The main cracks propagated along a tortuous path and multiple secondary cracks were formed adjacent to the main cracks. The dislocation mechanism controlled the high-temperature tensile deformation. The lamellar interface remained flat at 1073 K and 1173 K, but there was significant strain existing at the lamellar interface, which made the orientation relation of α2 lath and γ lath change to be (200)γ//(011‾0)α2and [001]γ//[0001]α2. At the tensile deformation of 1273 K, the lamellae coarsened irregularly by the phase degradation reaction of α2→γ and dynamic recrystallization.

A study on strengthening and toughening mechanism of laser beam welded joint prepared between Ti–22Al–27Nb and Ti–6Al–4V with an interlayer of Nb

In this study, laser beam welding (LBW) between Ti–22Al–27Nb and Ti–6Al–4V was experimented with and without an interlayer of Nb to analyze and compare the effect of Nb on evolution of microstructure in fusion zone (FZ) and its impact on weld joint performance at room as well as high temperature (650 °C). The nucleation and evolution of phases and crystals were examined through X-ray diffraction (XRD), electron probe microanalysis (EPMA), electron back scattered diffraction (EBSD), high resolution transmission electron microscopy (HRTEM) and high angle annular dark field (HAADF) imaging, respectively. The weld joint performance was evaluated through tensile and hardness tests. The adulteration of LBW joint between Ti–22Al–27Nb and Ti–6Al–4V through pure Nb contributed an increase of 28.70% in yield strength (YS), 10.22% in ultimate tensile strength (UTS) and 12.81% in percentage elongation. The evident reason for such an improvement in joint performance was attributed to the suppression of α′ martensite and nucleation of single phase B2 with fine grained structure, which provided greater fraction of high angle grain boundaries (HAGBs) in FZ. The LBW joint between Ti–22Al–27Nb and Ti–6Al–4V with an interlayer of Nb was ruptured from the base material (BM) Ti–22Al–27Nb during tensile straining at room temperature. All the LBW joints between Ti–22Al–27Nb and Ti–6Al–4V, either prepared with or without an interlayer of Nb, were fractured from the BM Ti–6Al–4V during tensile test at 650 °C.

In Situ Investigation of the Rapid Solidification Behavior of Intermetallic γ‐TiAl‐Based Alloys Using High‐Energy X‐Ray Diffraction

Representing an attractive new processing method, additive manufacturing can be used to manufacture parts made of γ‐TiAl‐based alloys for high‐temperature applications. However, in terms of nucleation during rapid solidification and subsequent solid‐state phase transformations, the process is not yet fully understood, and research is still going on. This article focuses on a setup to study solidification processes during laser melting via in situ high‐energy X‐ray diffraction at a synchrotron radiation source. To create conditions similar to those encountered in powder bed‐based additive manufacturing processes, such as electron beam melting or selective laser melting, a thin platelet is laser‐melted on its upper edge. Phase transitions are measured simultaneously via high‐energy X‐ray diffraction in transmission geometry. The use of a thin platelet instead of the usual powder bed precludes the unfavorable contribution of solid phases from surrounding powder particles to the diffraction signal. First results of the in situ high‐energy X‐ray diffraction experiment on a Ti–48Al–2Nb–2Cr (in at%) alloy prove the applicability of the used setup for an accurate tracing of phase transformations upon rapid solidification.

Effect of heat treatments on the microstructure and mechanical properties of Ti2AlNb intermetallic fabricated by selective laser melting

Ti 2 AlNb (Ti–22Al–25Nb at.%, nominal composition) intermetallic is essential to aerospace industry from a weight reduction perspective, and brings a possibility of replacing some Ni-based superalloys. Despite evaporation of element Al (from its original composition 22.8 at.% to 18.5 at.%), selective laser melting (SLM) technology offers distinct advantages in fabricating Ti 2 AlNb intermetallic with superior room-temperature properties. A full understanding of corresponding heat treatment mechanism is the key to utilize well the SLM-prepared Ti 2 AlNb at high temperatures. This study aims to clarify the relationship between the microstructure and mechanical propensities of SLM-prepared then heat-treated Ti 2 AlNb, to ultimately achieve promising mechanical performances at high temperatures. For this research purpose, a series of heat treatments were conducted, and the corresponding microstructures, mechanical properties were systematic studied by advanced characterization techniques. Results show that the mechanical properties at both room and high temperatures depend on heat treatment adopted. The samples solution-treated at 950 °C and then aged at 700 °C show promising room and high temperature strengths due to the formation of acicular O, α 2 and grain boundary α 2 phases. However, their ductility was poor. Aging at 830 °C reduces the strength, but significantly improves the ductility due to the appearance of rodlike O phase and the increase of B2/β phase proportion. The alloy possesses promising strength and ductility (611 MPa, 10.0%) and high thermal stability at 650 °C. It is further demonstrated that the heat-treated Ti 2 AlNb possesses promising specific strength, even higher than that of as-cast Inconel 718 superalloy. The developed alloy, therefore, has a high potential for the industries requiring high-temperature performance and weight reduction. • A suitable heat treatment schedule was established for the SLM-prepared Ti 2 AlNb. • Heat-treated Ti 2 AlNb has high specific strength comparable to Inconel718 at 650 °C. • The relationships between mechanical properties and microstructures were established. • Phase transition mechanism during heat treatment was clarified.

Influence of cooling rates on microstructure and tensile properties of a heat treated Ti2AlNb-based alloy

In the present study, a two-phase Ti 2 AlNb-based alloy with a nominal composition of Ti–22Al–25Nb (at%) comprising the dominant O + B2/β phase was explored. The microstructural evolution and tensile properties are studied by applying different heat treatment methods of water-cooling (WC, 140 °C/s) and furnace-cooling (FC, 0.08 °C/s) after heat treatment at 1015 °C for 40 min, followed by aging treatment at 800 °C for 1, 5, and 100 h. The results indicated that the morphologies of solution-treated alloys after different cooling methods have a significant distinction. The WC alloy consists of a continuous B2/β phase and a few remnant O phase, whereas the FC alloy comprises a mass of lath O phase and discontinuous B2/β phase. The Widmanstätten O + B2 structures were generated in the following aging treatment. The α 2 phase was not detected during the heat treatments in the present work. The B2 phase and O phase in the aged WC and FC alloys follow the classical orientation relationship: ( 110 ) B 2 / / ( 001 ) O , [ 1 ‾ 11 ] B 2 / / [ 1 1 ‾ 0 ] O . The room-temperature ultimate tensile strength (UTS) and elongation to failure (EL) of the FC and aged FC alloys are higher than the WC and aged WC alloys, except for the 100 h-aging condition. On the contrary, the high-temperature UTS and EL of the aged WC alloys are higher than the aged FC alloys. The existence of the O/O phase boundaries, the coarsening of the B2 grain boundary and discontinuous precipitation harmed the performances of the studied alloys. Beyond that, the fracture mode of the explored alloys with different heat treatment methods was also analyzed. • The morphologies of solution-treated Ti 2 AlNb-based alloys after different cooling methods have a significant distinction. • The B2 phase and O phase in the studied alloys follow the classical orientation relationship: 110B2//001O, [111]B2//[110]O. • Tensile properties and fracture mode are significantly influenced by different cooling rates and aging treatments. • The O/O boundaries, coarsening of the grain boundary and discontinuous precipitation harmed the properties of the alloys.