TiB2 Research Articles

Constructing a Functional Fast‐Ion Conductor Interface for Vertically Aligned Titanium Boride Nanosheets to Achieve Superior Sodium‐Ion Storage Performances

AbstractDesigning excellent anode materials to enhance the sluggish interfacial kinetics of Na+ is a key challenge in improving the electrochemical performance of sodium‐ion batteries (SIBs). Herein, an ultra‐thin fast‐ionic conductor NaB5C coating TiB2 nanoflowers with vertically aligned nanosheet arrays to form yolk–shell TiB2@NaB5C (TBNBC) nanospheres as an anode material for SIBs. The unique structure creates direct and short ion/electron transfer pathways and reserves enough space to prevent the uneven electrochemical reactions from TiB2 nanosheets aggregation and stacking, thus ensuring the long‐term cycling stability of SIBs. Additionally, the NaB5C coating with fast‐ionic conductor functional interphase provides rapid Na+ transport channels and effectively reduces the Na+ de‐solvation barrier, accelerating Na+ reaction kinetics. Furthermore, a homogeneous and robust solid electrolyte interphase (SEI) film including inorganic boron species and fluorine‐rich inner layer is constructed on the TBNBC electrode to delocalize stress and induce a uniform Na+ flux, further promoting fast Na+ interphase reaction kinetics. Consequently, the optimized composites achieve ultrastable cycling performances of 173 mAh g−1 over 5000 cycles at 10 A g−1. More importantly, they also exhibit an outstanding capacity of 182.2 mAh g−1 at −20 °C. This work offers opportunities for the energy storage use of transition metal borides under extreme conditions.

Hydronium-Crosslinked Inorganic Hydrogel Comprised of 1D Lepidocrocite Titanate Nanofilaments.

When a few drops of acid (hydrochloric, acrylic, propionic, acetic, or formic) are added to a colloid comprised of 1D lepidocrocite titanate nanofilaments (1DLs)-2 × 2 TiO6 octahedra in cross-section-a hydrogel forms, in many cases, within seconds. The 1DL synthesis process requires the reaction between titanium diboride with tetramethylammonium (TMA+), hydroxide. Using quantitative nuclear magnetic resonance (qNMR), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC), the mass percent of TMA+ after synthesis is determined to be ≈ 13.1±0.1%. The TMA+ is completely removed from the gels after 2 water soak cycles, resulting in the first completely inorganic, TiO2-based hydrogels. Ion exchanging the TMA+ with hydronium results in gels with relatively strong hydrogen bonds. The hydrogels' compression strengths increased linearly with 1DL colloid concentration. At a 1DL concentration of 45gL-1, the compressive strength, at 80% deformation when acrylic acid is used, is ≈325kPa. The strengths are ≈ 50% greater after the TMA+ is removed. The removal of all residual organic components in the hydrogels, including TMA+, is confirmed by qNMR, Fourier-transformed infrared spectroscopy (FTIR), and TGA/DSC. The 1DL phase is retained after gelation, TMA+ removal, and 80% compression.

Structure and Properties of the Electroexplosive Coating of the TiB2-Ag System after Electron Beam Treatment

A coating of the TiB2-Ag system was formed through the use of sequential operations of electroexplosive spraying and electron beam processing. The values of electrical conductivity (62.0 MS/m), Vickers microhardness (0.251-0.265 GPa at the point of measurement on a silver matrix and 25-32 GPa at the point of measurement at inclusions of boride phases), nanohardness (4.48 ± 0.76 GPa) were determined), Young’s modulus (116±29 GPa), wear parameter under dry friction-sliding conditions (1.2 mm3/N • m) and friction coefficient (0.5). Switching wear resistance during accelerated tests was 7000 on and off cycles with an electrical resistance of 10.01 - 11.76 LiOhm. The thickness of the coatings is 100 microns. The coatings are formed by a silver matrix with inclusions of titanium borides located in it with three types of sizes: nanocrystalline, submicrocrystalline and microcrystalline. Quantitatively, in the structural composition among titanium borides, titanium diboride and silver (56 wt. %) are formed predominantly (41 wt. %), while other titanium borides account for 3 wt. %. Structural transformations are described using complementary methods of X-ray phase analysis, scanning and transmission electron microscopy.

TiB1.8 single layers and epitaxial TiB2-based superlattices by magnetron sputtering using a TiB (Ti:B = 1:1) target

Sputter-deposited titanium diborides are promising candidates for protective coatings in harsh and extreme conditions. However, growing these layers from TiB2 diboride targets by DC magnetron sputtering usually leads to over-stoichiometric layers with low crystal qualities. Moreover, superlattices with TiB2 as one of the constituents have been becoming popular, owing to their superior mechanical properties compared to single layer constituents in addition to their use in other applications such as neutron optics. Here, we propose the use of a TiB (Ti:B = 1:1) sputtering target in an on-axis deposition geometry and demonstrate the growth of epitaxial sub-stoichiometric TiB1.8 thin films. Furthermore, we present the growth of CrB1.7/TiB1.8 superlattices, from TiB (Ti:B = 1:1) and stoichiometric CrB2 targets, with abrupt interfaces as promising materials system for neutron interference mirrors. The high crystal quality structure with well-defined interfaces is the common feature of superlattices which, regardless of application, should be addressed during the growth process.Utilizing TiB target, all films crystallize in the hexagonal AlB2 structure. The sub-stoichiometry of the TiB1.8 films was accompanied by the presence of planar defects embedded in the films. CrB1.7/TiB1.8 superlattices exhibited a homogeneous boron distribution within the layers with no sign of B-rich tissue phases through the layers. This study demonstrates the feasibility for TiB as sputter target material, that offers a solution for deposition of TiB2-based superlattices without the need to adjust the deposition parameters. Such adjustments would otherwise be unavoidable for tuning the TiB2 composition and could affect the growth of the other constituent materials.

Effect of argon and nitrogen environments on the structure and properties of protective cermet coatings based on titanium borides obtained by electric arc surfacing

The aim of this work was to enhance the mechanical and tribological properties of an alpha titanium substrate by forming a protective cermet coating on its surface. In this study, protective cermet coatings based on titanium borides were prepared by electric arc surfacing in a protective environment. Two types of protective environment were investigated during the surfacing process: (i) inert (argon) and (ii) reactive (nitrogen). The characteristic zones of the deposited layer were established depending on the environment used, and the coating-substrate transition zone was thoroughly examined. It was demonstrated that the formation of the transition zone results from the mutual diffusion of the molten material of the electrode material and the substrate. For the first time, the formation of TiB2-TiN eutectic in the form of whiskers 4-20 μm wide and 100-300 μm long distributed in the matrix of the Ti(B,N)x solid solution was established when forming a protective cermet coating in a nitrogen environment. The presence of this TiB2-TiN eutectic led to a significant increase in the hardness of the coating, up to 4.4 times, from 350 to 1530 HV. Tribological tests of surfacing coatings were conducted, and both 2D and 3D profiles of the wear grooves are presented, providing insight into the wear mechanism. It was found that the wear resistance of the cermet coating obtained in a nitrogen environment increased by 5.2 times, while in an argon environment it increased by 3.1 times as compared to the substrate without the protective cermet coating. The results indicate the potential of the developed protective cermet coatings for use in abrasive operating conditions.

Explorations of mechanical and corrosion resistance properties of AA6063/TiB2/Cr2O3 hybrid composites produced by stir casting

Mechanical and Corrosion characteristics of composite materials made from Aluminum alloys (AA) 6063 supplanting as the material of choice for automotive, aerospace, and marine applications by systematically varying ceramic reinforcements developed through controlled stir cast technique ensuring uniform dispersion are explored. The hardness, density, impact and tensile strength, corrosion resistance, and microstructural characteristics of Aluminum Matrix Composites (AMCs) reinforced with titanium diboride (TiB2) at 7.5, 10, and 12.5 wt% and chromium oxide (Cr2O3) at 3, 6, and 9 wt% were assessed according to ASTM standards. The microstructural analysis revealed a reduction in the growth of reinforcement clusters within acceptable limits. The addition of reinforcements to the matrix resulted in improved tensile strength, ranging from 124.6 to 188.7 MPa, and hardness, increasing from 71.5 to 144.32 VHN. This improvement is attributed to the strengthening or load transfer mechanism facilitated by the reinforcements. Additionally, the impact strength of the composites increased from 11.845 to 21.16 J, while the density showed slight variations. Consistent corrosion tests demonstrated that the chemical and interfacial interactions between the matrix material and the reinforcements significantly enhanced the corrosion resistance, reducing the corrosion rate from 570 to 499 mm/year.

In-melt electron analysis to accelerate process exploration of ceramics: Electron beam melting of TiB2

To enhance the versatility of electron beam powder bed fusion (EB-PBF), a widely utilized additive manufacturing (AM) technique for metallic materials, we propose a novel paradigm aimed at facilitating the exploration of the process parameters for less-studied materials, such as ceramics. The high melting points and poorly understood thermal properties of ceramics have constrained the comprehension of their melting behavior. In this study, titanium diboride (TiB2) sintered bodies were subjected to spot melting under four distinct electron beam currents and four different exposure times. By introducing a novel in-melt electron analysis (IMEA) approach, the various stages of melting were clearly identified. The analysis and interpretation of IMEA signals were found to be consistent with experimental observations on the spot-melted surface of TiB2. IMEA demonstrates significant potential for real-time process window optimization and quality assurance for challenging and novel materials.

Creation of Tool Coatings Based on Titanium Diboride for Highly Efficient Milling of Chromium–Nickel Alloys

Creation of Tool Coatings Based on Titanium Diboride for Highly Efficient Milling of Chromium–Nickel Alloys

Wear behaviour of titanium diboride and zirconium carbide reinforced LM13 hybrid composite for automotive applications

Abstract This study investigates the wear behaviour of a hybrid composite material reinforced with titanium diboride and zirconium carbide in LM13. The ASTM standard is followed for conducting wear tests, utilizing a pin-on-disc setup to assess the wear rate. An empirical relationship is established to predict the wear rate using statistical tool analysis of variance, and the model’s adequacy is checked. Low wear is observed at a sliding distance of 110 mm, sliding speed of 2.5 m s−1, and sliding load of 12.5 N. The observed low wear is attributed to the optimal level of reinforcement provided by titanium diboride and zirconium carbide. From the analysis of variance, sliding speed is identified as the major contributing factor to wear rate, followed by sliding distance and load. The reinforcement materials enhance the wear resistance of the hybrid composite and their effectiveness is particularly evident under the specified sliding conditions.

Deuterium plasma induced preferential erosion in ultra-high temperature ceramics TiB2 and ZrB2*

Abstract Steady-state deuterium plasma exposures were performed on ultra-high temperature ceramics titanium diboride (TiB2) and zirconium diboride (ZrB2) using the PISCES-RF linear plasma device (LPD) as early screening for first wall, plasma-facing applications. Deuterium plasma exposures were performed using 40 eV ion energies at 240, 525, and 800 °C sample temperatures and 90 eV ion energies at 240 °C sample temperatures to analyze TiB2 and ZrB2 surface morphology and chemistry evolution behavior. Post-plasma exposure chemistry characterization of the near surface ( < 50 nm) region of the samples all show transition metal enrichment, indicating boron preferential erosion. Transition metal to boron fractions vary with plasma exposure temperature under the 40 eV ion energy; metal enrichment is maximized at 800 °C and then minimized at 525 °C. SEM micrographs of all plasma exposed sample surfaces show no significant or noticeable plasma induced damage from cracking or blistering.

Titanium boride nanosheets with photo-enhanced sonodynamic efficiency for glioblastoma treatment

Sonodynamic therapy (SDT) has garnered significant attention in cancer treatment, however, the low-yield reactive oxygen species (ROS) generation from sonosensitizers remains a major challenge. In this study, titanium boride nanosheets (TiB2 NSs) with photo-enhanced sonodynamic efficiency was fabricated for SDT of glioblastoma (GBM). Compared with commonly-used TiO2 nanoparticles, the obtained TiB2 NSs exhibited much higher ROS generation efficiency under ultrasound (US) irradiation due to their narrower band gap (2.50 eV). Importantly, TiB2 NSs displayed strong localized surface plasmon resonance (LSPR) effect in the second near-infrared (NIR II) window, which facilitated charge transfer rate and improved the separation efficiency of US-triggered electron–hole pairs, leading to photo-enhanced ROS generation efficiency. Furthermore, TiB2 NSs were encapsulated with macrophage cell membranes (CM) and then modified with RGD peptide to construct biomimetic nanoagents (TiB2@CM-RGD) for efficient blood-brain barrier (BBB) penetrating and GBM targeting. After intravenous injection into the tumor-bearing mouse, TiB2@CM-RGD can efficiently cross BBB and accumulate in the tumor sites. The tumor growth was significantly inhibited under simultaneous NIR II laser and US irradiation without causing appreciable long-term toxicity. Our work highlighted a new type of multifunctional titanium-based sonosensitizer with photo-enhanced sonodynamic efficiency for GBM treatment. Statement of significanceTitanium boride nanosheets (TiB2 NSs) with photo-enhanced sonodynamic efficiency was fabricated for SDT of glioblastoma (GBM). The obtained TiB2 NSs displayed strong localized surface plasmon resonance (LSPR) effect in the second near-infrared (NIR II) window, which facilitated charge transfer rate and improved the separation efficiency of US-triggered electron-hole pairs, leading to photo-enhanced ROS generation efficiency. Furthermore, TiB2 NSs were encapsulated with macrophage cell membranes (CM) and then modified with RGD peptide to construct biomimetic nanoagents (TiB2@CM-RGD) for efficient blood-brain barrier (BBB) penetrating and GBM targeting. After intravenous injection into the tumor-bearing mouse, TiB2@CM-RGD can efficiently cross BBB and accumulate in the tumor sites. The tumor growth was significantly inhibited under simultaneous NIR II laser and US irradiation without causing appreciable long-term toxicity.

Characterization of (Zr,Ti)B2-SiC composites obtained by hot press sintering of ZrB2-SiC-TiO2 powder mixtures

The ability to enhance mechanical and oxidation properties for severe environmental applications has led to substantial academic interest in multiphase ultra-high temperature ceramics (UHTC). The purpose of this work is to study the in-situ solid solution formation of (Zr,Ti)B2 from ZrB2 and TiO2 in a ZrB2-SiC composite using hot pressing reaction sintering. For this, a mixture of 10, 20, and 30 % vol% SiC with ZrB2 was mixed with 2.0 wt% TiO2. Hot pressing sintering was performed with a load of 20 MPa at a final temperature of 1850 °C/30 min in an argon atmosphere. The microstructures, crystalline phases, densities, mechanical properties, and oxidation resistance of the composites were examined and compared with ZrB2-SiC samples lacking TiO2. In samples where TiO2 was added, the matrix grain size slightly decreased, the fracture mode was mainly intergranular, and the SiC grain morphology changed the aspect ratio to be more equiaxed. The solid solution (Zr,Ti)B2 was produced, and it was demonstrated by EDS elemental map images and the XRD analysis that Ti atoms incorporate into the ZrB2 crystalline structure. The development of solid solutions showed no impact on relative densities or Vickers hardness. However, the solid solution formation favored an improvement in fracture toughness, probably owing to the smaller matrix grain size and intergranular fracture mode. Samples exhibiting (Zr,Ti)B2 formation presented lower oxidation resistance than undoped samples in the same oxidizing condition.

Synthesis of titanium diboride by electric arc plasma in air

The paper reports data that demonstrate the feasibility of vacuum-free electric arc synthesis of titanium diboride. An optimal energy mode was found to synthesize submicron titanium diboride powder with the hexagonal lattice parameters a = 3.03 ± 0.04 Å, c = 3.23 ± 0.04 Å with no impurity crystal phases in its composition. A bulk ceramic sample with relative density of 99.1 % and hardness of 18 GPa was consolidated from the synthesized powder. The powder and bulk ceramic samples were analyzed by scanning electron microscopy and transmission electron microscopy. Structure of the synthesized material has a positive effect on the densification of the material. The sintered grains already formed in the process of synthesis under the influence of external pressure and heating from the current flow sinter each other, forming a single target structure with a minimum number of pores, of oxide impurities. Raman spectroscopy was employed to analyze the homogenized precursor mixture, synthesized powder, and TiB2-based bulk ceramic sample. The obtained Raman spectrum of sintering powder is characteristic of TiB2-based materials with a low concentration.

Improving properties of boron carbide (B4C) with silicon doping and titanium diboride addition

In this research, B4C-TiB2 composites were successfully fabricated via the spark plasma sintering method. First, the TiB2 source effect on the B4C-TiB2 composites was investigated using commercially available TiB2 and in-house synthesized TiB2. Subsequently, the effect of Si/B co-doped B4C on composite ceramics was studied, followed by examining the samples' microstructure and elastic and mechanical properties. The results showed that B4C-TiB2 composites made with in-house TiB2 powder obtained higher relative density and more desirable elastic and mechanical properties than samples made with commercial TiB2. In-house TiB2 and Si/B-B4C composites provided more properties improvement overall. The elastic modulus, Vickers hardness, and fracture toughness values of Si/B co-doped samples were 493 GPa, 30.09 ± 1.97 GPa, and 4.31 ± 0.74 MPa m1/2, respectively. Additionally, the amorphization of the TiB2-B4C composite decreased with Si/B co-doping.

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

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

Characterization of Wear Resistance and Corrosion Resistance of Plasma Paste Borided Layers Produced on Pure Titanium.

Commercially pure titanium was plasma paste borided using various temperatures of the process. An increase in the boriding temperature resulted in an increase in the thickness of the borided layer. All the layers produced consisted of an outer compact TiB2 zone and an inner TiB zone in the form of whiskers penetrating into the substrate. The presence of hard titanium borides resulted in a significant increase in wear resistance compared to non-borided pure titanium. However, the thickness of the layer produced strongly influenced the wear behavior, in respect of the time required for complete destruction of the layer. Higher wear resistance was characteristic of the TiB2 layer due to its compact nature, whereas the specific morphology of TiB whiskers resulted in their lower wear resistance compared to the outer TiB2 layer. Plasma paste boriding of pure titanium also had an advantageous effect on corrosion resistance compared to non-borided pure titanium. Simultaneously, due to the higher thickness of TiB2 layer, the specimen borided at a higher temperature showed higher corrosion resistance.

Development of high hard TiB–TiB2 coatings on Ti implants for bio-tribological applications; applying Box-Behnken design and actual wear analyzing in simulated body fluids

This research focuses on the enhancement of the tribological behavior of commercial pure titanium (Cp-Ti) in a simulated body fluid (SBF) via surface reinforcement by titanium borides. The protective boride coatings were formed through the pack cementation process at two different temperatures (950 and 1050 °C) to create diverse hard compositions of TiB and TiB–TiB2 in the coating, with hardness of 1032 and 1291 Hv, respectively. The roughness and wettability of top surfaces were evaluated before the tribology studies due to their impacts on the tribology behavior. Box-Behnken design (BBD) was applied to investigate the effects of the wear parameters in dry and SBF environments. The duration of the wear tests was 53, 35, and 26 min for low, medium, and high speed. It was found that the abrasion wear type was dominant at the beginning of sliding, and then changed to the plastic deformation in the dry conditions, while there is no sign of the abrasion and adhesion wear features at the surface of the reinforced samples abraded in the SBF solution. Results confirmed a high coincidence between BBD predictions and actual findings. The released debris from the coatings was also investigated to find origins. Results showed that majority of the debris in the SBF solution belonged to the calcium phosphate particles demonstrating the bioactivity of the TiB–TiB2 coatings. According to findings, hard TiB–TiB2 coatings could significantly improve the tribological behavior of the Ti implants, which could in turn result in expanding the biological application of Cp-Ti.

Comparison of mechanical and tribological performance of the ZrB2 to (Ta, Zr, Ti, V, Hf)B2 borides system

Borides are promising wear-resistant materials. The mechanical and tribological properties of ZrB2, (Ta, Zr)B2, (Ta, Zr, Ti)B2, (Ta, Zr, Ti, V)B2 and (Ta, Zr, Ti, V, Hf)B2 synthesized by spark plasma sintering were compared to examine the elemental dependence. The results indicated that the hardness and fracture toughness of borides increased with the increase of entropy. (Ta, Zr, Ti, V, Hf)B2 obtained the highest hardness and fracture toughness of 23.14 GPa and 5.13 Mpa·m1/2 due to the pores and second phases that change the path of crack propagation. In terms of wear, all the Ta-contained borides have a lower wear rate than that of ZrB2. It is almost one order of magnitude lower for (Ta, Zr, Ti, V, Hf)B2 than that of ZrB2. This is mainly due to the formation and action of tribofilm rich of amorphous Ta2O5. Thermodynamic calculation indicates that the Ta atoms in borides are more prone to being oxidized resulting in the formation of a layer of Ta2O5 on the surface, which is beneficial to wear resistance improvement. This work provides guidelines for the composition-design of high-entropy borides for wear-resistant material applications.

Tailoring molecular structure and electromechanical properties of polydimethylsiloxane elastomer for enhanced energy conversion efficiency

AbstractThe molecular structure of dielectric elastomers dictates their mechanical, electrical, and properties to react under external stimuli, influencing their suitability for applications such as actuators, sensors, and energy harvesting devices. The molecular structure of polymers can be tailored by incorporating plasticizers and particulate fillers to achieve multifunctional properties. However, achieving a balance between flexibility and maintaining mechanical strength due to incorporation of fillers induced phase separation and compromised intermolecular interactions remains challenging. In the present work, polydimethylsiloxane (PDMS) composites are synthesized using plasticizer and particulate fillers, polyethylene glycol (H‐(OCH2CH2)nOH) and titanium diboride (TiB2) respectively in various concentrations using shear mixing and doctor blade casting technique. Molecular structure of synthesized PDMS composite is confirmed by observing peaks of Raman spectra sift, which exhibits robust CO bonds dominating for both fillers. Chain entanglement due to filler incorporation significantly affects the crosslink density of PDMS composite, it increases with the concentration of plasticizer and possesses inverse relation for particulate. Furthermore, interdependence of the filler types and concentration are found on the mechanical as well as electrical properties. The specific deformation energy exhibits a significant increase of 118.9% when comparing particulate to the plasticizer at concentration of 8 wt.%. Although plasticizer increases the actuation strain and energy conversion efficiency but decreases the electrical breakdown voltage in comparison to particulate. By systematically varying fillers concentration, subtle changes in multifunctional properties are achieved. Overall, this investigation provides a framework for tailoring dielectric elastomer composites with desired electromechanical characteristics through the amalgamation of filler types and crosslinking densities, all intricately tied to the molecular architecture for electromechanical sensors.Highlights Filler incorporation changes DE molecular structure and materials properties. Formation of additional bonds and micro‐capacitors in DE enhances capacitance. Actuation strain in DE depends on filler type and concentration. Energy conversion efficiency varies with the concentration of filler.

Tribological behavior of medium entropy boride (Ta,Zr,Ti)B2 densified at a relatively low temperature of 1600 °C

Medium and High entropy borides with high hardness and corrosion resistance are promising wear resistant materials. High temperature (>2000 °C) is always necessary for the densification of medium and high entropy borides. Using a mixture of 10 vol% metallic cobalt and 20 vol% SiC as additives, medium entropy (Ti,Zr,Ta)B2 ceramics were prepared at a relatively low temperature of 1600 °C by SPS. The reduced sintering temperature is attributed to the synergistic effect of Co and SiC that wet the grain boundary and promote the interdiffusion. The prepared (Ti,Zr,Ta)B2 obtains the microhardness of 22.54 ± 0.92 GPa, comparable with other medium entropy boride ceramics prepared at 2000 °C. The tribo-tests results of (Ti,Zr,Ta)B2 sliding against steel suggests that the tribological performance are load dependent. As the load increases, the friction coefficient first rises and then falls at a load of 10 N, which is associated with the chemical differences of the tribofilm. The tribofilm is primarily composed of O and Fe, along with Zr, Ti and Ta oxides. The iron oxide in the tribofilm will deteriorate the tribological performance. Abrasive wear is the main wear mechanism at lower load of 1 N, while adhesive wear is the predominant wear mechanism at 10 N.