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The further development of lithium-sulfur (Li-S) batteries is limited due to the shuttling effect caused by soluble polysulfides, which reduces the cycle stability and cycle life of batteries. A new modified separator based on MoS 2 @SiO 2 heterostructure was designed to improve Li+ diffusion and effectively suppresses the shuttling effect of polysulfides in lithium-sulfur batteries. Electrochemical results show that the rate capacity of Li-S batteries assembled with the modified separator is greatly enhanced. The initial discharge capacity at 0.1 C was 1395.44 mAh g−1. The discharge capacity reached 935.85 mAh g−1 at 2 C and 799 mAh g−1 at 3 C. After 300 cycles at 1 C, the reversible capacity remained at 620 mAh g−1. Moreover, the average Coulombic efficiency above 95% indicates stable long-term cycle performance. Density functional theory (DFT) calculations and adsorption experiments further verify that the synergistic effect between MoS 2 and SiO 2 nanotubes (SNTs) can significantly enhance the adsorption capacity of polysulfides and accelerate polysulfides conversion kinetics. This new modified separator with excellent electrochemical performance and facile synthesis process is expected to be an ideal choice for lithium-sulfur battery applications. [ABSTRACT FROM AUTHOR]

The alloying effects on the microstructure, especially precipitation of harmful phases and solvus temperature of L1 2 -structured γʹ phase, etc., are essential for alloy design and development of precipitation strengthened Co-based superalloys. Based on the newly reported Co30Ni9Al5Mo10Cr2Ta0.03B alloy, alloying elements Mo, Cr, Al, Ta and Ni are systematically changed and alloys are fabricated to investigate their microstructures in two heat treatment statuses, namely homogenization and aging, respectively. Results show that Mo and Cr are γ forming elements and have limited effect on γʹ solvus temperature, but high concentration of Mo and Cr facilitates the formation of harmful μ phase. Al, Ta, and Ni are all γʹ stabilizers and can effectively increase γʹ solvus temperature, but roles of Al, Ta and Ni are different. Increasing Al and Ta would result in other harmful phases, such as the μ phase in the 6Ta and 4Ta alloys, and μ + B2 phases in the 13Al and 11.5Al alloys. However, Ni addition significantly increases solvus temperature and area fraction of γʹ phase without occurrence of harmful phases. The current findings might provide guidelines for design and development of precipitation strengthened Co-based alloys. [Display omitted] • The alloying effects of Mo, Cr, Ta, Al & Ni are systematically investigated. • Mo & Cr are γ formers, which facilitate the formation of μ phase. • Ta is a strong γˊ former, but excessive Ta facilitates the formation of TCP phase. • Al is necessary for γˊ phase, but excessive Al results in B2 & TCP phases. • Ni stabilizes γˊ phase without forming the harmful phases in Co-based alloys. [ABSTRACT FROM AUTHOR]

The article discussed the effects of hypergravity fields on the dendrite structure, macrosegregation, and mechanical properties of Al7050 alloy. Compared to normal gravity, the average size of α-Al grains at the bottom of the sample was significantly reduced under hypergravity. The melt superheating temperature influenced atomic clusters, which, along with dendrite fragmentation, facilitated heterogeneous nucleation. Subsequently, the "crystal rain" mechanism led to the migration and accumulation of primary crystals. The emergence of coarse columnar dendrites under hypergravity may result from high-speed forced convection transferring solutes at the dendrite tips, thereby promoting dendrite growth through increased concentration gradients. Under hypergravity, Zn, Mg, and Cu elements were enriched at the bottom of the sample, possibly due to solutes expelled during α-Al dendrite growth entering the liquid phase. The denser solute-rich liquid settled at the bottom under hypergravity, precipitating numerous secondary phases. The compressive strength and strain of the hypergravity specimen increased due to its special density-dependent layered structure. • The microstructure evolution, mechanical properties, and mechanisms of Al7050 alloy under hypergravity were studied. • The heterogeneous nucleation and "crystal rain" mechanisms jointly led to grain refinement under hypergravity. • Hypergravity altered solute distribution in alloy melt, causing macrosegregation and equiaxed-to-columnar grain transition. • At 3000 g , compressive strength and strain of solidified Al7050 alloys rose by 24.3% and 47.4%, respectively, versus 1 g. [ABSTRACT FROM AUTHOR]

To model the centrifugal loads and complex geometries experienced by turbine blades during service, the nickel-based single crystal superalloy DD6 samples with a groove structure are designed and tested under the coupling conditions of high-speed rotating of 20,000 r/min and high temperature of 980 ℃. Scanning electron microscopy and transmission electron microscopy are used to analyze the microstructural evolution of γ-γ' phases and dislocation morphologies of 400 h and 1000 h samples. The results indicate that microstructural degradation of the γ-γ' phase attributes to the larger centrifugal tensile stress S 11 in the applied physical stress compositions until deformation occurs. Our observations suggest that a/2 < 101 > -type dislocations initiate plastic deformation by slipping within the γ phase. However, their movement is constrained at the interface between the γ and γ' phases, resulting in their tendency to aggregate at this boundary. After the formation of stable interfacial dislocation networks, these dislocations then react to generate either a< 010 > -type dislocations or a/2 < 112 > -type dislocations, which cut into the γ' phase. However, under high stress conditions, the a/2 < 101 > -type dislocations are primarily cut directly in the form of dislocation pairs. • The γ-γ' phase degradation and dislocation evolution of DD6 superalloy was investigated. • Creep tests are conducted under high-speed rotating and high temperature condition. • Microstructural degradation of the γ-γ' phase attributes to the larger centrifugal tensile stress S 11. • Interfacial dislocation networks and superdislocations accelerate the separation and disappearance of the γ phase. [ABSTRACT FROM AUTHOR]

Abstract: Electron-diffraction radial distribution function (RDF) was used as a structural probe to study the process of crystallization of Ge2Sb2Te5 (GST) films annealed in situ. The GST thin film began to crystallize after a characteristic peak of 0.52nm appeared in the RDF, indicating the formation of third nearest neighbour ordering. The GST films preferentially form uniform nanosized grains. The similarities and differences in the structures of the amorphous phases and the polycrystalline phases are described. [Copyright &y& Elsevier]

In order to make up for the deficiency that the laboratory testing of standard samples cannot approximately simulate the turbine blade geometry and service environment, the creep experiment of the nickel-based single crystal superalloy NiAlReRu components with film cooling holes (FCHs) is carried out under the coupling high-speed rotating and high temperature condition. The component with the FCHs exposed to the coupling high-speed rotating of 20000 rpm and high temperature of 1000 ℃ continuously lasts 255.92 h until it breaks. The microstructural evolution and fracture process are analyzed. The results indicate that the existence of the FCHs evidently changes the stress distribution of the region with the FCHs, which makes the microstructural evolution of γ′ phase significantly different. The component is fractured along the second row of the FCHs and the normal direction of the fracture surface is basically parallel to the centrifugal force direction. The fracture process can be divided into three typical stages. The coupling effect of temperature and stress on the failure mechanism is discussed. • The failure mechanism of NiAlReRu superalloy under high-speed rotating and high temperature was investigated. • The microscopic stress concentration induced by film cooling holes contributes to the change of rafting behavior. • Film cooling holes become the initial source of cracks and are responsible for dissociation fracture. [ABSTRACT FROM AUTHOR]

The development of new materials with hierarchical frameworks and tailored band structures is an attractive approach to efficiently photocatalytic hydrogen evolution. Here, we report a visible-light active calcium titanate (CaTiO 3) photocatalyst with a hierarchical architecture constructed from single crystal nanowires, which was prepared by a one-pot hydrothermal reaction using polyvinyl alcohol (PVA) as structure directing agent. The hierarchical structure of the CaTiO 3 samples involved single-crystal nanowires growing respectively along the [110], [1 1 ¯ 0] and [001] direction and intersecting each other perpendicularly which further featured a high specific surface area and oxygen vacancies. This material was able to split water into H 2 under visible light irradiation. It was found that oxygen vacancies formed an impurity level at an energy level 0.95 eV below the conduction band acted as electron donors and promoted charge transport and separation. • A visible-light active CaTiO 3 photocatalyst was prepared by hydrothermal way • The bandgap of CaTiO 3 photocatalyst was narrowed by oxygen vacancies • The sample showed a hierarchical single-crystal like structure formed by nanowires [ABSTRACT FROM AUTHOR]

Abstract It is very challenging to synthesize perovskite oxides with controlled morphology and defect states at the same time. In this work, the BaZrO 3 hollow nanostructures with oxygen vacancies were facilely synthesized through one-step solvothermal method using ethylenediamine (EDA) as solvent. The as-synthesized BaZrO 3 could split pure water into H 2 without addition of sacrificial agent under UV light irradiation. The photocatalytic H 2 production rate is about 15 times than that of the commercial BaZrO 3 (BZO-C). It is believed that the presence of oxygen vacancies and the hollow morphology made contribution to the improvement of photocatalytic performance. This work provides a reference for microstructure and defect modification of photocatalysts at the same time to enhance the photocatalytic performance. Highlights • The BaZrO 3 with hollow structures and oxygen defects was one-step synthesized. • The as-obtained BaZrO 3 shows increased photocatalytic activities in pure water. • The special morphology and defects contribute to the improvement of properties. • The hollow structures and defects result from the presence of EDA in the reaction. • This work provides a reference for microstructure and defect modification. [ABSTRACT FROM AUTHOR]

As a photocatalyst, barium titanate (BaTiO 3 ) has shown a great potential in photocatalytic water splitting for hydrogen evolution. In this work, BaTiO 3 nanoparticles were synthesized at room temperature conditions under ambient pressure. The small particle size below 10 nm plays a key role in suppressing the recombination of photo-induced carriers, and thus promoting the photocatalytic activity. The photocatalytic hydrogen evolution rates of BaTiO 3 (BTO-R) synthesized at room temperature are 8 and 2.9 times that of commercial BaTiO 3 (BTO-C) in the presence and absence of triethanolamine (TEOA) as a sacrificial agent, respectively. This work provides a good example on size control, low-cost synthesis and photocatalysts' design. [ABSTRACT FROM AUTHOR]

A series of egg lecithin coating LiFePO 4 composites have been prepared by a simple mechanochemistry activation and sintering processes using the regenerated LiFePO 4 as raw materials. The mechanical forces of high energy ball milling have induced activation or chemical changes of different components. The as-prepared LiFePO 4 composites showed stable (C+N+P) co-coating layers with N-C and P-C bonds wrapped LiFePO 4 particles and smaller uniform particle sizes, which can shorten the diffusion distance of lithium ions and electrons, and offer a good electronic conduction between the LiFePO 4 particles. The LiFePO 4 /C composite coating with 15% egg lecithin exhibited the average specific capacities of 164.9 mAh g −1 at the low C-rate of 0.2 C; at C-rate of 5 C, the electrode can deliver the specific capacity of 120 mAh g −1 with a capacity retention of 93% after 100 cycles; even at high rate of 20 C, this electrode materials can still keep 100.7 mAh g −1 , which is 41% greater than its pristine counterpart. More interestingly, the raw material in this work is the recycled LiFePO 4 produced from the spent power batteries, which also demonstrates a greatly potential approach to utilize the regenerated LiFePO 4 from the spent batteries into high-performance cathode materials for Li-ion batteries applications. [ABSTRACT FROM AUTHOR]

The microstructure, thermal and mechanical stability of Ni-based single crystalline superalloys depend strongly on the alloying elements and their concentrations. Alloying has been the main design strategy for stabilizing the compositions, microstructures and thermal-mechanical properties. This article presents a review on the effects of some common alloying elements on the microstructural and mechanical property stability control of Ni-based superalloys. The various alloying elements are divided into four categories according to their main effects on these properties, comprising base elements, mechanical strengthening elements, long term stability elements and the oxidation resistance elements. The mechanical strengthening elements can further be divided into precipitation, solid solution and grain boundary segregation elements. The precipitation elements strengthen the alloys by forming the L1 2 structured γʹ phase. The solid solution elements strengthen primarily the γ phase, by increasing the solidus temperatures and decreasing the stacking fault energy, which in turn influences the thermal stability of the phases and the resistance of dislocation movement. The grain boundary elements strengthen the alloys by the formation of carbides and borides along the grain boundaries during solidification, which help to prevent the formation of casting pores and hot tearing and to strengthen low angle boundaries. The long-term stability elements inhibit the precipitation of topologically closed-packed phases causing deterioration of the mechanical properties. The oxidation resistance element, mainly Al, promotes the formation of protective Al 2 O 3 surface layer. [ABSTRACT FROM AUTHOR]

High-Nb-containing TiAl alloys have been considered an excellent candidate for demanding high-temperature structural components due to their attractive mechanical properties and low density. However, the intrinsic brittleness at room temperature remains a great barrier limiting its processability. Here a novel alloy design strategy was introduced to improve its ductility from the perspective of grain refinement and removal of oxygen within the matrix. A minor content of LaB 6 was introduced into Ti-45Al-8Nb alloy prepared by vacuum arc melting. La 2 O 3 and TiB ceramic phases were in-situ synthesized owing to the decomposition of LaB 6 additive. The effect of LaB 6 addition on the microstructure and compressive properties of TiAl-based alloys was investigated. The LaB 6 inoculation not only refines the lamellar colonies but also promotes the generation of single γ phases, contributing to the transformation from coarse full-lamellar to refined near-lamellar and even dual-phase colonies. The major fracture mode transformed from inter-lamellar to trans-lamellar to inter-granular with LaB 6 addition increasing. With 0.4 wt% LaB 6 addition, both the ultimate compress strength and fracture strain increased from 1065 MPa and 17.1 % to 1503MPa and 26.98 % respectively. • The (TiB+La 2 O 3)/Ti-45Al-8Nb composites were in situ fabricated by vacuum arc melting Ti, Al, Nb and LaB 6 mixed particles. • The effect of LaB 6 on the lamellar colonies size and phase constitution of Ti-45Al-8Nb was identified. • The compress strength of the composites increased by refined lamellar colonies and TiB precipitates. • An optimal addition of 0.4 wt% LaB 6 was preferred with maximum strength and fracture strain. [ABSTRACT FROM AUTHOR]

In this work, the morphology, crystallization process and crystal structure of the phase-change material TiSbTe (TST) alloy have been successfully established, which is essential for applying this alloy in phase-change memory. Specifically, atomic force microscopy (AFM) was employed to characterize the as-deposited and post-annealed thin films, and transmission electron microscopy (TEM) analyses of the films annealed in situ were used in combination with selected-area electron diffraction (SAED) and radial distribution function (RDF) analyses to investigate the structural evolution from the amorphous phase to the polycrystalline phase. Moreover, the presence of structures with medium-range order in amorphous TST, which is beneficial for high-speed crystallization, was indicated by the structure factors S(Q)s . The crystallization temperature was determined to be approximately 170 °C, and the grain size varied from several to dozens of nanometers. As the temperature increased, particularly above 200 °C, the first single peak of the rG(r) curves transformed into double shoulder peaks due to the increasing impact of the Ti Te bonds. In general, the majority of Ti atoms were doped into the SbTe lattice and tended to form structural defects, whereas the remainder of the Ti atoms aggregated, leading to the appearance of TiTe 2 phase separation, as confirmed by the SAED patterns, high-angle annular dark field scanning transmission electron microscopy (HAADF-STEM) images and corresponding energy-dispersive X-ray (EDX) mappings. [ABSTRACT FROM AUTHOR]

To determine the influence of Re and Ru on the phase morphologies and microstructure in Ni-based superalloys, a series of model alloys derived from the 4th generation TMS-138 superalloy have been investigated with systemically changing Re and Ru additions. All alloys are subjected to solid solution and aging treatments to achieve the typical γ/γ′ two phases microstructure. Phase transition temperatures are measured by using differential scanning calorimetry. The Re is found to increase the γ′-solvus temperature with a slope of roughly 5.4 ℃ per wt% Re in Ru-free alloys and 2.3 ℃ per wt% Re in 2Ru alloys, while the Ru exhibits much weaker effect. Microstructure and composition of the two phases are examined to understand the Re and Ru effects on γ′ size, shape, volume fraction, the elemental partition behavior, and the γ/γ′ lattice misfit. The results show that the addition of Re affects size and shape of γ′ precipitates, and also reduces γ/γ′ lattice misfit significantly. Meanwhile, Re increases partition coefficients of Cr and Ru. In comparison, the addition of Ru seems to have little effect on morphology of γ′ precipitates and the γ/γ′ lattice misfit, but Ru appears to alter partitioning behaviors of other elements. Because Re and Ru are two key elements for high generation Ni-based single crystal (SX) superalloys, this work might provide guidelines for designing next generation of SX superalloys. [Display omitted] • Re effectively increases the γ′ solvus temperature of superalloys, while Ru has slight effect on the γ′ solvus temperature. • Re addition decreases the size of γ′ phase and γ/γ′ lattice misfit, facilitating cubic precipitation of γ′ phase. • Ru addition only has little effect on the γ′ morphology and γ/γ′ lattice misfit of superalloys. • Partitioning behaviors of other alloying elements depend on the Re and Ru additions, especially Ru. [ABSTRACT FROM AUTHOR]

Oxidation induced phase transformation from γ′ to γ phase can severely degrade creep properties of superalloys and has been studied by in-situ environmental transmission electron microscopy, energy dispersive spectrometer and electron energy loss spectroscopy in detail. The in-situ observation showed that, during oxidization, the ordered γ′ phase (L1 2) gradually transformed to disordered γ phase (face-centered cubic (fcc)) with the appearance of oxidation product consisted of γ-Al 2 O 3 crystallites with a strong crystallographic texture. This directly proves that γ′-γ phase transformation are induced by aluminum oxidation with aluminum depleted in γ′ phase. Furthermore, the oxygen was demonstrated to diffuse preferentially through γ′-γ phase interface which is different from previously thought (γ matrix). [ABSTRACT FROM AUTHOR]

Here, we investigate a new type of kink structure that is found at γ/γ′ interfaces in nickel-based single crystal superalloys. We studied these structures at the atomic and elemental level using aberration corrected high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM). The core of the dislocation absorbs high-Z elements (i.e., Co and Re) that adopt hexagonal arrangements, and it extrudes elements (i.e., Ni and Al) that adopt face centered cubic (fcc) structures. High-Z elements (i.e., Ta and W) and Cr, which is a low-Z element, are stabilized in body centered cubic (bcc) arrangements; Cr tends to behave like Re. High-Z elements, which migrate and adopt a hexagonal structure, induce kink formation at γ/γ′ interfaces. This process must be analyzed to fully understand the kinetics and dynamics of creep in nickel-based single crystal superalloys. [ABSTRACT FROM AUTHOR]

Highlights: [•] The structure of Al20Cu2Mn3 with a space group of Bbmm is completely determined. [•] The actual formula of Al20Cu2Mn3 is Al31Cu3Mn5. [•] Al20Cu2Mn3 is formed by a parallel tessellation of hexagon subunits. [•] Al20Cu2Mn3 is prone to twinning by an alternate tessellation of hexagon subunits. [•] The Al20Cu2Mn3 is coherent with α-Al along its longitudinal axis. [Copyright &y& Elsevier]

Abstract: The optical, dielectric, and structural characteristics of Si15Sb85 phase change memory thin films under a moving continuous-wave laser initialization are studied by using spectroscopic ellipsometry and high-resolution transmission electron microscopy. The dependence of complex refractive index, dielectric functions, absorption coefficient, and optical band gap of the films on its crystallization extents formed by the different initialization laser power are analyzed in detail. The structural change from as-deposited amorphous phase to distorted rhombohedra-Sb-like crystalline structure with the increase of initialization laser power is clearly observed with sub-nanometer resolution. The optical and dielectric constants, the relationship between them, and the local atomic arrangements of this new phase change material can help explain the phase change mechanism and design the practical phase change memory devices. [Copyright &y& Elsevier]

It is important and necessary to understand the micro-mechanism of rhenium (Re) effect in the deformation process. The in-situ tensile experiments of Ni–Al and Ni–Al-Re model single crystal superalloys have been carried out in scanning electron microscope at 750 °C. It is found that Re can promote the complex stacking fault (CSF) formation, which is similar to the previous results after tensile experiments at room temperature. The micro-mechanism of Re promoting the CSF formation has been investigated by means of advanced probe-corrected scanning transmission electron microscopy and energy dispersive X-ray spectroscopy. The local high concentration of Re is observed at CSF regions after tensile experiments both at room temperature and 750 °C. The first principles calculation results further indicate that low concentration of Re increases CSF energy, while high concentration of Re decreases CSF energy, which is consistent with the experimental results. • In-situ tensile experiments of model single crystal superalloys are carried out. • Re can promote the complex stacking fault (CSF) formation. • High concentration of Re is observed in local region along CSF. • The calculation results show high concentration of Re decreases CSF energy. [ABSTRACT FROM AUTHOR]

Plastic deformation behavior of Inconel 740H superalloy during uniaxial tension at high temperature was investigated. The self-developed in-situ high-temperature tensile stage provides a better method for the study of tensile deformation of materials under different conditions. By a joint application of in-situ SEM and EBSD techniques, the tensile mechanical properties, microstructure, orientation, and grain boundary evolutions under near-service conditions (650 °C) were experimentally investigated. The results obtained show that due to the different grain orientations of polycrystalline metals, the grains with preferable orientation begin to slip first under the external force, while those orientation of harder grains will slip until they rotate to favorable orientation. In order to ensure the continuity of the matrix, the deformation between grains must be coordinated. Meanwhile, in-situ observation of the grain rotation at high temperature shows that rotation angles and paths of different grains are related to the initial orientation. By tracing typical grains and analyzing the grain rotation during in-situ EBSD testing, it was found that some grains with randomly distributed orientation at the initial state gradually changed to the direction between [001] and [111] poles with the stress increasing. This complies with the overall trend of a single grain rotation. However, after that the grains tend to reach the [101] pole rather than the stable orientation [112]. During the total deformation process, low-angle boundaries form and accumulate at the grain boundaries with concentration of stresses. While high-angle boundaries are slightly affected by the tensile deformation, and the density of twin boundary (TB) decreases. • Lattice rotation behavior at 650 ℃ was tracked using a self-developed SEM micro tensile stage and in-situ EBSD technique. • The rotation angle and path of different grains are related to the initial orientation. • Low angle boundaries occur and accumulate at the grain boundaries where stress is concentrated. • The incomplete of annealing twin is caused by the accumulation of dislocations near grain boundaries. [ABSTRACT FROM AUTHOR]

Nickel-based single crystal superalloys (Ni-SXs) are of great interests in aircraft industry due to their excellent high temperature creep strength deriving from the rigid gamma/gamma prime (γ/γ′) microstructure and the single crystal nature. The creep properties of Ni-SXs depend strongly on the degradation rate of the original rigid γ/γ′ microstructure with the dislocation movements in the microstructure. Since the applied temperature and stress strongly affect the dislocation movements, the different creep mechanisms are displayed to Ni-SXs during low temperature (∼750 °C), mid-temperature (∼950 °C) and high temperature (∼1100 °C) creep. The creep deformation during low temperature creep is mainly caused by the shearing of γ′ phase by a limited number of dislocations, while high temperature creep mainly occurs to the accumulation of creep strains with the increased dislocation activities in γ phase. To enhance the creep properties of alloy, a variety of strategies of the microstructural optimization need to be considered. One is to increase the volume fraction of γ′ phase to enhance the precipitation strengthening effects. But excessive amounts of γ′ phase are disadvantageous to low temperature strength of alloy. The coarsening of γ′ phase and the rafting process strongly correlates to dislocation movements. It is of importance to discuss the specific mechanisms of coarsening and rafting as well as their influence to the creep properties of alloy. The lattice misfit between the γ and γ′ phase plays an important role in influencing the coarsening of γ′ phase and the creep properties of alloy. A proper lattice misfit helps to form the cubic γ′ phase which is advantageous to alloy. But a too large lattice misfit can promote the coarsening of γ′ phase that damages the structural stability of alloy at high temperatures. The increased additions of refractory elements in alloy promote the formation of topologically close-packed (TCP) phase. TCP phase facilitates the nucleation and propagation of micro-cracks around it that damages the creep properties of alloy. This review aims to summarize some aspects of microstructural evolution during creep of alloy with considering their effects to creep properties. To guide the design of Ni-SXs in future, some perspectives about the microstructural optimization are properly provided. • The creep properties of Nickel-based superalloys are greatly decided by the microstructural evolution during creep. • The creep mechanisms are determined by the intrinsic dislocation activities occurred in the microstructure. • The coarsening of γ′ phase is emphasized, especially the rafting process. • Lattice misfit strongly affects the formation of dislocation networks and coarsening of γ′ phase. • The formation of TCP phase which is detrimental to creep properties need to be strictly restricted in superalloy design. [ABSTRACT FROM AUTHOR]

Titanium alloy was extensively used in aerospace industrial field. It has a great significance to directly reveal the deformation process as a function of application conditions. This work investigates the real-time deformation behavior of laser direct metal deposited (LDMD) Ti–6Al–4V alloy at 200 °C, using self-developed high temperature in-situ scanning electron microscope (SEM) tensile stage with a controlled heating system. The results showed that the microstructure of the sample comprised of columnar β grains with zigzag grain boundaries decorated by tilted α plates along the building direction. During uniaxial tensile, slip bands develop along the grain boundaries between α plates with increasing stress. Grain boundary sliding contributes to the high tensile elongation. Compared the mechanical properties along transvers tensile with those at room temperature, the tensile stress decreased and displacement increased at 200 °C. Therefore, higher elongation and reduction in cross-sectional area were identified at 200 °C than those at room temperature. The fracture of specimen at 200 °C shows obvious necking character and deep dimples with thin rims. Coalescence of slip bands at α/α interface creates voids and the coupling of voids nucleates micro-crack. α/α grain boundary interface constitutes path to the crack propagation. The high misorientation angle at columnar β grain boundary hinders the cracks propagation. Finally, the cracks accumulate along the columnar β grain boundary leading to fracture. • The microstructure deformation of LDMD Ti–6Al–4V alloy is studied by high temperature in-situ SEM tensile stage at 200 °C. • Slip bands development, cracks propagation, and columnar β GB hindering at 200 °C are investigated. • Temperature effect on the deformation mode and corresponding mechanical properties have been revealed. [ABSTRACT FROM AUTHOR]