Mo Matrix Research Articles

Development of ICP‐OES Based Analytical Method with Prior Preferential Removal of Emission Rich Matrix by Elevated Temperature Ionic Liquid Based Extractive Mass Transfer for Determination of Metallic Constituents in U‐Mo Alloy: The Next Generation Nuclear Fuel

AbstractAn (ICP‐OES) based analytical methodology was developed for the determination of metallic constituents (Al, Ca, Co, Cr, Cu, Fe, Ga, In, Mn, Mg, Na, Ni, Si, V, W and Zn) at minor and trace level in U−Mo alloy fuel after preferential separation of emission rich major matrix using TBP‐HDBO‐NTf2 without any compromise on the determination of analytes at trace levels. Application of ionic liquid, HDBO‐NTf2 drastically reduced the time of analysis (30 min reduction per sample) and generation of toxic organic waste (20 mL per sample) containing U and Mo. The method was optimized by identification of analytical lines of the elements free from spectral interference of U and Mo, establishing the calibration curves using those lines and evaluation of analytical performances (detection limit, linear dynamic range etc.) in U−Mo matrix. The preferential separation of U and Mo were found to follow anion exchange and cation exchange mechanism involving UO2((NO)3)3.2TBP− and MoO2(NO3) TBP+ species, respectively, which differ in their conventional separation by solvation mechanism involving ML2 and ML1 neutral species, respectively. Preferential separation by HDBO‐NTf2 based system can be effectively used for determination of analytes of 10 ppm concentration at 10 % error limit. The total uncertainty in estimation of each analyte have been estimated. The real sample analyses data were compared to that obtained by n‐dodecane based ICP‐OES method and direct analysis of Energy Dispersive X‐ray Fluorescence spectroscopic (EDXRF) method. The data were found to be in good agreement with each other. The experimentally obtained results were subjected to t‐test with 95 % confidence limit and 10 degrees of freedom. The texpt was found to be less than tcrit 2.228 revealing reliability of the methods. The experimentally obtained variance values (Fexpt) were found to be less than Fcrit∼2.980 revealing the variance values are within acceptable statistical error limit.

In-situ modulating laminated microstructure of α+β+TiC in titanium composites by laser powder bed fusion of Mo2C/Ti powder mixture towards biomedical applications

Additive manufacturing offers a revolutionary pathway for customising patient-specific metal implants. However, clinical practice calls for balanced material properties besides a patient-matched geometry, including good biocompatibility, low elastic modulus, good material strength and enhanced wear resistance. This study demonstrates an in-situ microscale composition modulation method by laser powder bed fusion (LPBF) using a Mo2C/Ti powder mixture, achieving adaptive microstructure and successfully combining balanced mechanical and wear properties in the Ti-7.5Mo-2.4TiC composites. The modulation is made through partial homogenisation of raw materials, leaving entangled Mo-rich and Mo-poor streaks around the molten pool boundary and a Ti–Mo matrix at the molten pool centre. By optimising volumetric energy density to 82.3 J/mm3, the modulated composition inhomogeneity produces an alternately laminated microstructure with entangled α and β streaks around the molten pool boundary and mixed α+β phases at the molten pool centre. Such that the molten pool boundary reveals a lower elastic modulus relative to the molten pool centre. The uneven allocation of elastic moduli throughout layers of molten pools enables a step-by-step deformation mode under compressive loading, lowering the component-related elastic modulus to 90.4 ± 2.1 GPa; on the other hand, it suppresses crack propagation, extending the material's elongation to 16.4 ± 1.4%. The synergistic effect of grain refinement and dispersion strengthening provided by in-situ precipitated TiC improves yield strength (936.9 ± 19.8 MPa) and ultimate compressive strength (1415.5 ± 23.1 MPa). The hard TiC also enhances the wear property, obtaining lower wear rates (down to 8.6 × 10−4 mm3N−1m−1) than the pure Ti. The balanced mechanical and wear properties could expand the potential of this composite in clinical use. More importantly, this LPBF-based approach creates a pathway for microscale composition modulation in material design and performance customisation towards biomedical applications.

The thermal stability of non-stoichiometric Y-Zr-O nanoparticles in oxide dispersion strengthened (ODS) Mo alloys

In our previous work, a nanostructured oxide dispersion strengthened (ODS) Mo alloy with a high density of non-stoichiometric Y-Zr-O nanoparticles was developed as fuel cladding material. Considering the hostile high-temperature condition, this study focuses on the thermal stability of non-stoichiometric Y-Zr-O nanoparticles at 1400 °C for 48 h. Results showed that non-stoichiometric Y-Zr-O nanoparticles appeared to coarsen, resulting in the loss of coherency with the Mo matrix. The core/shell structure with Y-rich Y-Zr-O oxide cores and Zr-rich shells was formed by Zr diffusion from the Mo matrix to the oxides/matrix interface. Together with Ostwald ripening, it contributed to the evolution from metastable non-stoichiometric Y-Zr-O oxides to equilibrium Y-Zr-O oxides with a partitioned Y2O3 concentration distribution. Further, the Zr addition accelerated the coarsening of Y-Zr-O oxides. Zr-rich Y-Zr-O oxides were more likely to coarsen due to the larger equilibrium solubility of the Zr element and diffusion activation energy than those of Y-rich Y-Zr-O oxides.

Investigation of microstructure and strengthening mechanism in CNTs reinforced Mo-based composites

The carbon nanotubes (CNTs) reinforced Mo-based composites were fabricated by an efficient powder metallurgy method, including acid treatment, wet dispersion, ball milling (BM) and spark plasma sintering (SPS). The sintered Mo-based composites possess high relative density (99.1%) and compressive yield strength (970 ± 10 MPa). Acid treatment and wet dispersion effectively address the problems of the agglomeration and subsequent uniform distribution of the CNTs in the composite powders. After BM and SPS, ultrafine-grained composites with a grain size of 1.84 μm and a nanoparticle size of less than 200 nm were obtained. A mechanism for purification and strengthening is proposed. On the one hand, Hf and HfC can adsorb nearby oxygen impurities and purify the Mo matrix. On the other hand, the incoherent interface between Mo and nanoparticles acts as primary dislocation nucleation and prevents the propagation of secondary dislocations, which in turn leads to strain hardening.

A novel crack-free Ti-modified Mo alloy designed for laser powder bed fusion

A novel crack-free Ti-modified Mo alloy with good mechanical properties was fabricated successfully by laser powder bed fusion (L-PBF). The micro-Ti particles dissolve homogeneously into the Mo matrix. The homogeneous mixture of Ti in Mo does not allow the formation of any new secondary phases. The presence of Ti increases the resistance to deformation within the grains and hence, eliminates the formation of hot-tearing cracks between Mo grains. The presence of high compressive properties (compressive yield strength (656 ± 9 MPa) and fracture strain (18.2 ± 1.9%)) in the L-PBF Tiμm/Mo alloy sample may be attributed to the presence of a high degree of geometrically necessary dislocations (GNDs). The doping of Ti in Mo not only helps in the successful fabrication of L-PBF Mo but also improves their mechanical properties, which paves the way for the fabrication of high-performance Mo-based alloys by L-PBF via innovative alloy design.

Preparation and in-situ strengthening mechanisms of Mo composites with the addition of WC

The strength enhancement is critical for the application exploration of Mo-based materials. In this work, a secondary phase of WC is introduced into the Mo matrix, and the corresponding phase, microstructure and mechanical properties have been studied. It is found that the addition of WC particles can significantly improve the mechanical properties, leading to a high ultimate tensile strength (UTS) of 591.5 MPa and a hardness of 242.7 HV over the sintered Mo–12%WC composite, which are about 21.2% and 49.5% higher than those of pure Mo, respectively. During the sintering, the additive WC particles react with the Mo matrix to in-situ generate W and Mo2C, and the former is dissolved into the Mo matrix to exhibit solid solution strengthening. Besides, the latter hinders the migration of grain boundaries (GBs) to limit the grain growth of Mo, resulting in smaller grain size. More importantly, the Mo2C (1‾2‾1) can gain coherent interfaces with Mo (11‾ 0) to intensify the phase boundary. This work paves a way for the design of high-performance composites through the in-situ reinforcement of decomposable additives.

Preliminary thermal and mechanical analysis on the reactor core of a new heat pipe cooled reactor applied in the underwater environment

The heat pipe cooled nuclear reactor (HPR) has great potential in the underwater applications, as a reliable energy system provider, due to its advantages in the passive heat removal capability and avoidance of single point failure. For the newly proposed HPR concept design, NUclear Silence ThermoElectric Reactor (NUSTER), the thermal and mechanical analysis is performed, on the three-dimensional detailed solid core model, through the coupling of ANSYS Fluent and Mechanical. The safety limits are preliminarily proposed for the NUSTER, based on which the paper analyzes the reactor thermal and mechanical characteristics under the normal and heat pipe failure accidents. It is found that the core components, including the fuel rods, matrix and heat pipe can operate with large thermal margin in the normal condition. The heat pipe failure accidents will cause the large temperature increase of the fuel rods, matrix and heat pipes and significantly change the thermal stress distribution in the fuel Molybdenum (Mo) cladding and matrix. The Mo matrix temperature exceeds its temperature limit and the average thermal stress increases significantly in the two adjacent heat pipes failure accident of the 1/8 reactor core, indicating the further optimization of the matrix material in the future design.

Strengthening mechanisms of combined alloying with carbon and titanium on laser beam welded joints of molybdenum alloy

Molybdenum (Mo) and its alloy have great potential in the nuclear power field, but the low strength of fusion welding joints limits its engineering application. By adding two alloying elements in combination, namely carbon (C) and titanium (Ti), this study fulfilled the goal of improving properties of the heat affected zone (HAZ) while strengthening the fusion zone (FZ) of the joint. The alloying process is as follows: the base metal (BM) was first carburized then Ti foil was preset at the welding position and finally laser welding was carried out. The scanning electron microscopy (SEM), transmission electron microscopy (TEM), electron backscatter diffraction (EBSD) and nanoindentation were utilized to analyze mechanical properties and microstructures of the FZ and HAZ of the joint obtained by combined alloying with C and Ti. Moreover, the joint obtained by combined alloying was comparatively analyzed with those alloying only by C or Ti. Combined alloying can increase the maximum tensile strength to 406.6 MPa and strain to 6.6%, respectively. TiC phases as spherical particles with diameter ranging from tens to one hundred of nanometers can be precipitated in the FZ obtained by combined alloying playing a role of second-phase strengthening in Mo. Furthermore, Mo 2 C phases can be clearly observed at the grain boundary in the HAZ of the joint obtained by combined alloying. Mo 2 C is coherent or semi-coherent with the Mo matrix and can also have the second-phase strengthening effect. Combined alloying shows a new idea to strengthen Mo and its alloy welded joints. • The tensile strength and strain of joint by combined alloying with C and Ti can reach to 406.6 MPa and 6.6%, respectively. • TiC particles are precipitated in the FZ and Mo 2 C phases are precipitated in the HAZ obtained by combined alloying. • TiC in the FZ and Mo 2 C in the HAZ can play the role of the second phase-strengthening for the joints.

Influence of minor Ti additive on the microstructure and mechanical properties of Mo based alloys

The Mo based alloys with minor Ti additive were fabricated by successive processes of simple ball-milling and low-temperature sintering. Different from traditional titanium oxides additive, the minor Ti additive will adsorb nearby oxygen impurities to form TiO2 or Ti8O15 during above process, thus purifying Mo matrix. The size of formed titanium oxides (approximately 540 nm) is also close to that reported in relevant literatures. What's more, the Ti additive could availably refine the Mo powder particles during ball-milling process and improve its sintering activity. While maintaining high densit (> 99%), the sintered Mo based alloys with minor Ti additive possess finer grain (13.17 μm → 4.44 μm) and higher hardness (249 HV0.2 → 332 HV0.2) compared with pure Mo.

Nano Mo–La–O particles strengthened Mo alloys fabricated via freeze-drying technology and low temperature sintering

This work proposed an innovative technology to fabricate Mo–La–O nanoparticles strengthened Mo alloys with ultrafine nano grains via freeze-drying and low temperature sintering. These novel nano Mo–La–O particles including La7Mo7O30, La5Mo3O16, La6Mo2O15, La5Mo4O12, La4Mo2O11 and La2(MoO6) remain coherent or semi-coherent interfaces with Mo matrix to strengthen their phase boundaries. Moreover, nano Mo–La–O particles enriched in excess oxygen absorb nearby impurity oxygen and then lead to the purification of Mo matrix. Furthermore, the low temperature sintered Mo–LaxMoyOz alloys possess high relative density (98.1%), which is due to the high sintering activities of ultrafine powders (56 nm). Comparing with available literature which involves oxide-dispersion-strengthened-molybdenum alloys (ODS-Mo), the freeze-dried Mo–LaxMoyOz alloys in our work possess the finest grain size (440 nm), the finest oxide particle size (mainly <5 nm), the highest hardness (495 HV0.2) and high strength (1201 MPa) at 30% deformation.

Fabrication of Mo-Y2O3 alloys using hydrothermal synthesis and spark plasma sintering

Fine-grained Mo alloys doped with uniformly distributed nanoscale Y2O3 particles were successfully prepared by employing two powerful strategies: fabricating high-quality precursor powders using hydrothermal synthesis and subsequent powder consolidation by spark plasma sintering (SPS) technique. In this study, the effect of hydrothermal variables on the morphology and existent form of yttrium and Mo was systematically studied, and the refinement mechanism of reduced mixing powders and the densification under the different sintering parameters were investigated. The results show that spherical Y2(CO3)3·2H2O gradually replaced Y(OH)CO3 owing to the increased concentration of hydrogen bonds and CO32− at excess alcohol and urea, and lamellar (NH4)2Mo4O13 developed into large pillar-shaped h-MoO3 with decreasing pH. Due to the low calculated lattice mismatch degree of Mo/Y2O3 interfaces ~10.9%, Y2O3 particles further refined and homogenized the reduced mixing powders as heterogeneous nucleating sites. After sintering at 1700 °C for 5 min with a heating rate of 100 °C/min, Mo-Y2O3 alloys possessed fine grains of 1.80 ± 0.17 μm, a high density of 98.18% and the high indentation hardness of 314.77 ± 26.12 HV0.3 and 4.82 ± 0.53 GPa HIT. The Y2O3 particles were uniformly distributed in the Mo matrix, and semi-coherent with Mo lattice, with the orientation relationships as follows: (010)Y2O3//(011)Mo, (01-1)Y2O3//(020)Mo, and [100]Y2O3//[100]Mo.

Refined microstructure and enhanced mechanical properties in Mo-Y2O3 alloys prepared by freeze-drying method and subsequent low temperature sintering

The ultrafine Mo-Y2O3 composite powders were successfully synthesized by innovative freeze-drying method. Consequently, the freeze-dried Mo-Y2O3 composite powders with high sintering activities possess an average grain size of 54 nm. After low temperature sintering at 1600 °C, the Mo-Y2O3 alloys maintaining a high density (99.6 %) have the finest grain size (620 nm) comparing with available literature about oxide dispersion strengthened molybdenum alloy (ODS-Mo). The oxide particles remain their small size (mainly <50 nm) within Mo grains and at Mo grain boundaries. Furthermore, the Y5Mo2O12 particles were firstly observed within Mo matrix, and its formation can absorb nearby oxygen impurities, which involves the purification of Mo matrix. The mechanical properties show that Mo-Y2O3 alloy possess a high hardness of 487 ± 28 HV0.2, a high yield strength of 902 MPa, a high compressive strength of 1110 MPa, respectively. Our work suggests that freeze-drying and subsequent low temperature sintering can shed light on the preparation of ultrafine ODS-Mo alloys with high performance.

The synthesis of TiC dispersed strengthened Mo alloy by freeze-drying technology and subsequent low temperature sintering

The TiC dispersed strengthened Mo alloys were synthesized by novel freeze-drying technology and subsequent low-temperature sintering. With the introduction of TiC nanoparticles using freeze-drying technology, the sintered Mo-TiC alloys possess ultrafine grain size (2.38 μm), high density (99.3%) and high hardness (402±29 HV0.2). The agglomeration and growth of second phase particles in Mo-TiC alloys were effectively depressed by freeze-drying technology. Moreover, a theory about purification and strengthening is proposed. C-deficient TiC (Ti8C5) will adsorb nearby oxygen impurities and even form TiO2 to purify Mo matrix. Furthermore, TiC (002), Ti8C5 (0-24) and TiO2 (111) can form coherent interfaces with Mo (110) to strengthen their phase boundary and improve material strength. The stable phase interface can pin and limit the growth of these second phase particles, thus maintaining their small size (<50 nm).

Evaluating compressive property and hot deformation behavior of molybdenum alloy reinforced by nanoscale zirconia particles

The paper deals with the fabrication of molybdenum alloy bars with different ZrO2 content via a series of processes, involving hydrothermal synthesis, co-precipitation, co-decomposition, powder metallurgy and rotary swaging. The compressive properties of molybdenum alloy bars were tested at various temperatures from room temperature to 1400 °C, and hot deformation behavior at different temperatures and strain rates was studied. The results show that ZrO2 particles with the size of tens of nanometers are evenly dispersed in Mo matrix, and ZrO2(110) and Mo(110) have a non-coherent interface due to a larger lattice misfit 13.57%. ZrO2 particles could significantly reduce grain size of molybdenum alloy and improve its compressive properties. When the volume content of zirconia increases from 0% to 2.0%, the grain size of molybdenum alloys annealed at 1200 ℃ decreases sharply from 55.9 µm to 3.5 µm. The compressive yield strength (CYS) of Mo-2.0 vol%ZrO2 annealed at 1200 °C is 674 MPa at room temperature, which is 65.6% higher than that of pure Mo. The high temperature CYS of Mo-2.0 vol% ZrO2 at 1400 °C is 176 MPa, increasing 49.6% higher than that of pure Mo. Compared with the previous works, the peak flow stress of the new Mo-2.0 vol%ZrO2 has been significantly improved. Adding of 2.0 vol%ZrO2 increases the initial temperature of dynamic recrystallization to 1200 °C, and effectively prevents the grain growth of dynamic recrystallization even at the increased deformation temperature of 1400 °C.

Separation and determination of ultratrace rhenium quantities in molybdenum matrix

ABSTRACT The production of very pure molybdenum, free of Re even at ultratrace levels, is extremely important in meeting target purity specifications during the production of 99Mo for medical applications. Here we propose two methods for separating ultratrace levels of Re from a bulk Mo matrix using either solvent extraction or extraction chromatography, combined with inductively coupled plasma quadrupole mass spectrometry (ICP-MS) detection. Re is extracted (D > 70) from solutions in sulfuric acid as a complex with tri-n-butyl phosphate. Scrubbing and washing steps result in total decontamination factors for Mo up to 1,700 for solvent extraction and 3,500 for extraction chromatography. Re is stripped into a 3 M NH4OH matrix and analyzed by ICP-MS. Detection (LD ) and quantification (LQ ) limits were optimized by matrix-matching to allow detection of Re in strip solutions at levels of LD = 0.1 ng Re/g-Mo and LQ = 0.3 ng Re/g-Mo in Mo powder samples. By employing these two extraction methods, excellent recoveries of Re from bulk Mo are achieved, and the LQ is improved by a factor of 5 × 104.

Microstructure and compression properties of fine Al2O3 particles dispersion strengthened molybdenum alloy

Abstract The Mo alloys reinforced by Al2O3 particles were fabricated by hydrothermal synthesis and powder metallurgy. The microstructures of Mo−Al2O3 alloys were studied by using XRD, SEM and TEM. The results show that Al2O3 particles, existing as a stable hexagonal phase (α-Al2O3), are uniformly dispersed in Mo matrix. The ultrafine α-Al2O3 particles remarkably refine grain size and increase dislocation density of Mo alloys. Moreover, a good interfacial bonding zone between α-Al2O3 and Mo grain is obtained. The crystallographic orientations of the interface of the Al2O3 particles and Mo matrix are [ 1 ¯ 11 ] α - Al 2 O 3 / / [ 1 ¯ 11 ] Mo and [ 1 1 ¯ 2 ] α - Al 2 O 3 / / [ 0 1 ¯ 1 ] Mo . Due to the effect of secondary- phase and dislocation strengthening, the yield strength of Mo−2.0vol.%Al2O3 alloy annealed at 1200 °C is approximately 56.0% higher than that of pure Mo. The results confirm that the addition of Al2O3 particles is a promising method to improve the mechanical properties of Mo alloys.

Ultrasmall Mo2C in N-doped carbon material from bimetallic ZnMo-MOF for efficient hydrogen evolution

The exploration and development of cost-effective and highly stable electrocatalysts with the highest possible energy efficiency remain a constant pursuit in the catalyst design and synthesis for electrocatalytic hydrogen evolution reaction (HER). In this work, a convenient approach is proposed to synthesize a type of ultrafine Mo2C nanoparticles in average sizes of 3–4 nm embedded in hierarchically porous N-doped carbon material calcined from bimetallic ZnMo-MI (MI = 2-methylimidazole) is obtained at 1000 °C, denoted as ZnMo-MI-1000. First of all, the crystalline hybrid metal-organic framework of ZnMo-MI is fabricated from zeolitic imidazolate framework of Zn-MI precursors via solvothermal reaction, in which the conversion from Zn-MI to ZnMo-MI occurs gradually over time. After calcination, the as-obtained ZnMo-MI-1000 sample shows a satisfying HER performance with the small overpotential of 83.0 mV in 0.5 M H2SO4 and 100.1 mV in 1.0 M KOH to reach a current density of 10 mA cm−2, which is attributed to ultrasmall Mo2C, Mo and N-doped graphitic carbon matrix. The multiporous network of ZnMo-MI-1000 can provide continuous mass transportation with a minimal diffusion resistance that produce effective electrocatalytic kinetics in both acidic and alkaline media, which is utilized as a highly active and durable nonprecious metal electrocatalyst for HER.

Boosted mechanical properties of sintered MoLa alloys with ultrafine-grains by the nanostructuring of secondary phase

The secondary phase particles of La2O3 play a crucial role in the determination of the yield strength over MoLa alloys, but few work focuses on their intrinsic modulation of shape and size. Herein, a nanostructuring strategy of the secondary phase particles is proposed to enhance the mechanical performances of MoLa alloys, in which the shape and size effects of secondary phase particles have been discussed. Moreover, the strengthening mechanism is also analyzed. It is found that the La2O3 nanospheres with a small size of 84 nm exhibit the best strengthening ability, leading to a high yield strength of 765 MPa in the sintered state. Smaller particles are easily involved into the Mo matrix interior to be intragranular, which are beneficial for the further strengthening. The strengthening contributions are quantitatively calculated, providing a predicted yield strength value, which is in good agreement with the measured one.

In-situ construction of conducting alloy interphase towards modulating Li-ion storage kinetics

Abstract Interface engineering strategy shows great promise in promoting the reaction kinetic and cycling performance in the field of electrochemical energy storage application. In this work, an in-situ interface growth strategy is proposed to introduce a robust and conducting MoGe2 alloy interphase between the electrochemical active Ge nanoparticle and flexible MoS2 nanosheets to modulate their Li-ion storage kinetics. The structural evolution processes of the Ge@MoGe2@MoS2 composite are unraveled, during which the initially-generated Ge metals serve as a crucial reduction mediator in the formation of MoGe2 species bridging the Ge and MoS2. The as-generated MoGe2 interface, chemically bonding with both Ge and MoS2, possesses multi-fold merits, including the maintaining stable framework of electrochemically inactive Mo matrix to buffer the strain-stress effect and the “welding spot” effects to facilitate the efficient Li+/e− conduction. As well, the introduction of MoGe2 interface leads to a unique sequential lithiation/de-lithiation process, namely in the order of the electrochemically active MoS2-MoGe2-Ge during lithiation and vice versa, during which the electrode strain could be more effectively released. Benefited from the robust and rigid MoGe2 interface, the delicately designed Ge@MoGe2@MoS2 composite exhibits an improved charge/discharge performances (866.7 mAh g−1 at 5.0 A g−1 and 838.5 mAh g−1 after 400 cycles) while showing a high tap density of 1.23 g cm−3. The as-proposed in-situ interface growth strategy paves a new avenue for designing novel high-performance electrochemical energy storage materials.

Hot Compression Mechanism and Comparative Study on Constitutive Models of Mo–3 vol%Al2O3 Alloys

The hot compression tests for Mo–3 vol.%Al2O3 alloys were conducted on a Gleeble-1500D thermo-mechanical simulator in the temperatures range of 1000–1300 °C and strain rates range of 0.005–1 s−1. The hot deformation behavior, mechanism associated with microstructure evolution of Mo–3 vol.%Al2O3 alloys was investigated by electron backscattering diffraction analysis. Three types of stress–strain curves were analyzed by quantifying the work hardening rate. The deformation mechanism at 1000–1300 °C mainly included the plastic deformation of Mo–3 vol.%Al2O3 alloy, as well as the dynamic recovery and recrystallization of Mo matrix. The modified Arrhenius, Modified Johnson–Cook and modified Zerilli–Armstrong constitutive equations were established and evaluated by the correlation coefficient (Rc) and average absolute relative error ( $${\bar{\text{e}}}$$ ). The flow stress of Mo–3 vol.%Al2O3 alloys could be well predicted by those three constitutive models, but modified Arrhenius constitutive model had a higher predicated accuracy. The hot deformation behavior, mechanism associated with microstructure evolution of Mo–3 vol.% Al2O3 alloys has been investigated by EBSD analysis. Three types of stress–strain curves were analyzed by quantifying the work hardening rate. The deformation mechanism at 1000–1300 °C mainly included the plastic deformation of Mo–3 vol.% Al2O3 alloy, as well as the dynamic recovery and recrystallization of Mo matrix. Moreover, modified Arrhenius constitutive model had a higher predicated accuracy for Mo–3 vol.% Al2O3 alloys than modified JC and modified ZA constitutive models.