TiB2 Phases Research Articles

In-situ synthesized multi-component particle reinforced TiAl composite with excellent mechanical properties

In order to overcome the inherent trade-off between strength and ductility of TiAl alloys, the BN nanosheets were added in Ti-48Al-2Cr-2Nb alloy. Ti-48Al-2Cr-2Nb-xBN (x = 0, 0.1, 0.5, 1, 2 wt%) alloys were prepared by vacuum arc melting (VAR), and the microstructures displayed a fully lamellar structure accompanied by simultaneous precipitation of Ti2AlN and TiB2 phases. The reaction of BN nanosheets with the Ti and Al elements resulted in formation of Ti2AlN and TiB2 phases. The lamellar colony size of TiAl composites was refined from 276.7 to 29.4 µm with BN content increasing from 0 to 2 wt%. While the lamellar spacing displayed an initial decrease followed by an increase, which was attributed to the synergistic effect of Ti2AlN and TiB2. Room temperature compression results showed that the compressive strength surged from 1653 to 2272 MPa as BN content rose from 0 to 0.5 wt%, with the highest compression strain of 34.7 % at 0.5 wt% BN. The high temperature compression results showed that the compressive strength increased from 887 to 1399 MPa as the BN content increasing from 0 to 1 wt%. Crack extension took the form of both trans-granular and inter-granular modes. The strengthening effect of TiAl composites was attributed to grain refinement strengthening and secondary phase strengthening via Ti2AlN and TiB2.

Excellent tribocorrosion resistance of additively manufactured Ti-based heterogeneous composite coating via hardening and toughening effects

To improve the tribocorrosion resistance of oil drill pipes used in deep-sea drilling, a Ti-based composite coating was successfully fabricated by laser direct energy deposition technology on the TC4 titanium alloy surface. The microstructure analysis showed that a new heterogeneous structure of multistage strengthening phases (micron-sized TiN phases and nano-sized TiB phases) distributed on the β matrix (soft Cu-rich phases and hard Mo-rich phases) was formed, and the size of β grain was refined to 2 μm with the content of Cu higher than 12 wt.%. The microhardness of the composite coating was increased to more than 700 HV0.2 due to the solution strengthening of Mo elements and the formation of hard TiN phases. At the same time, the fracture toughness of 12Cu composite coating was significantly increased to 8.37 MPa m1/2, which was attributed to the combined effect of grain refining, high-density dislocations in Cu-rich phases, and nanoscale TiB phases. The synergistic enhancement of hardness and toughness of 12Cu composite coating promoted the generation of titano-molybdenum-copper composite oxide film on the worn surface, and the tribocorrosion resistance increased more than 7 times compared with TC4.

Effect of TiB2 on properties and microstructures of Cu[sbnd]W electrical contact materials

The W skeletons were pressed by the cold isostatic pressing process, and CuW alloys with different TiB2 contents were prepared by the sintering and infiltration method. The effects of TiB2 addition on the microstructures, properties, vacuum breakdown performance, and arc motion characteristics of CuW alloys were investigated. The results show that the conductivity of CuW alloy decreases with the addition of TiB2, while the hardness increases. Compared with CuW alloy, this method improves the breakdown strength, reduces the chopping current and extends the arc life of CuW alloy. The anti-arc erosion performance of CuW alloy with the addition of TiB2 was enhanced. For CuW alloy containing TiB2, the electric breakdown occurs on the TiB2 phase at the edge of the W phase, the cathode spots are split, the arc is effectively scattered, and the ablation area after multiple breakdowns is larger, but the erosion pits are shallow and dispersed.

Electrical discharge machinable B4C–(Zr, Ti)B2 composites with enhanced mechanical properties

B4C30 vol% (ZrxTi1-x)B2 (x = 0.2, 0.4, 0.6 and 0.8) composites were fabricated via in-situ reaction by spark plasma sintering using B4C, ZrC, TiC and B powders as raw materials at 2000 °C. The effects of the Zr/Ti ratio in the (ZrxTi1-x)B2 phase on the microstructure and mechanical properties of the composites were investigated. The electrical discharge machining performance of the composites was evaluated. The formation of (Zr, Ti)B2 solid solutions was beneficial to fully dense composites with refined grains. The grain size of the (Zr, Ti)B2 phase first gradually decreased from 1.26 µm to 0.89 µm and then increased to 1.23 µm with the decreasing ZrC/TiC molar ratio. The material removal rate was slightly decreased from 6.56 mm3/min to 5.17 mm3/min with the decreasing ZrC/TiC molar ratio. The combined solid-solution and fine-grain strengthening has made the B4C30 vol% (Zr0.2Ti0.8)B2 composite enhanced Vickers hardness, flexural strength, and fracture toughness of 28.31 GPa, 772 MPa, and 6.56 MPa·m1/2, respectively, with a relative density of 99.73%.

Boron-induced microstructure evolution and mechanical properties of in situ Ti-based bulk metallic glass composites

The effect of boron(B) on the glass-forming ability (GFA), microstructure evolution and mechanical properties of (Ti48Zr20Nb12Cu5Be15)100-xBx bulk metallic glass composites (x = 0, 0.3, 0.5, 1.0 and 3.0 at. %) alloys was investigated. With increasing boron content to 0.3 at.%, the dendrite size is refiner than that of the other alloys, the B0.3 alloy presents good ductility and high strength at ambient temperature, which is mainly attributed to the strong interaction between dislocations, shear bands and the dendrite/glass interface. When the boron content is lower or higher than the critical value of 0.3 %, multiple slide steps decrease. Once the B content exceeds its maximum solid solubility, the phase instability of β-Ti dendrites and the glass matrix decreases, and more needle-like TiB2 phases and irregular block-like ZrB2 phases within and between the dendrites suppress the initiation of shear bands, resulting in brittle fracture.

Microstructure and Mechanical Properties of In Situ Synthesized Metastable β Titanium Alloy Composite from Low-Cost Elemental Powders

The titanium matrix composite was produced through a hot compaction process at 1250 °C using the mixture of elemental powders with chemical composition of Ti-5Al-5Mo-5V-3Cr and 2 wt.% addition of boron carbide. The phase analysis via X-ray diffraction method was performed to confirm the occurrence of an in situ reaction between boron carbide and titanium. Then, the wide-ranging microstructural analysis was performed using optical microscopy as well as scanning electron microscopy along with energy-dispersive X-ray spectroscopy and electron backscatter diffraction. Based on this investigation, it was possible to describe the diffusion behavior during hot compaction and possible precipitation capabilities of TiC and TiB phases. Tensile and compression tests were conducted to determine the strength properties. The investigated composite has an ultimate tensile strength of about 910 ± 13 MPa with elongation of 10.9 ± 1.9% and compressive strength of 1744 ± 20 MPa with deformation of 10.5 ± 0.2%. Observation of the fracture surface allowed us to determine the dominant failure mechanism, which was crack propagation from the reaction layer surrounding remaining boron carbide particle, through the titanium alloy matrix. The study summarizes the process of producing an in situ titanium matrix composite from elemental powders and B4C additives and emphasizes the importance of element diffusion and reaction layer formation, which contributes to the strength properties of the material.

Fabrication and Characterization of Titanium Borides by Electron Beam Surface Alloying

This study shows the possibility of the fabrication of titanium borides by an alloying of a titanium substrate with boron powder via a scanning electron beam. During the electron beam alloying experiments, the speed movement of the specimens was varied, where it was 4 and 6 mm/s. The thickness of the alloyed zone formed by the lower velocity of the movement of the workpiece is greater than that of the coating obtained by the higher speed movement. The phase composition of the coatings is in the form of the TiB2 phase, as well as some amount of undissolved boron in both considered cases. In the case of the lower speed of the movement of the sample, the undissolved boron is within the whole volume of the alloyed zone, while at the higher speed movement, it is on the top of the specimen. The hardness of the obtained coatings by the higher speed of the specimen movement reached values of about 4500 HV. Considering the values of the surface alloy fabricated via the lower velocity movement of 4 mm/s, it is about 2500 HV, which is lower than that of the one obtained by the 6 mm/s speed of the sample movement. The result obtained for the friction coefficient (COF) for the specimen alloyed by the speed of the specimen motion of 4 mm/s is 0.40; the value for the coating obtained at a speed movement of 6 mm/s is 0.34. In both cases, these values are lower than that of the titanium substrate.

Titanium boride coating by high power diode laser alloying of amorphous boron with titanium and its surface property investigations

Present work deals with fabrication of superhard titanium boride coating on titanium surface with preplaced amorphous boron layer using high power diode laser alloying. Amorphous boron instantaneously converts into crystalline boron by the effect of high-power laser interaction, which rapidly drives the boron species into titanium liquid pool and form titanium boride precipitates by its convective flow. Negative Gibbs free energy (ΔG) and enthalpy (ΔH) of amorphous boron crystallization reaction introduces the concept of laser induced self-propagation synthesis. Gibbs free energy (ΔG) for the chemical reactions between Ti and B was calculated to confirm the spontaneous formation of titanium boride compound phases. The diffusion coefficient and activation energy were estimated to understand the phase formation and microstructural evolution. The structural phase, microstructure, microhardness and wear resistance of the laser borided titanium was investigated by XRD, optical and scanning electron microscopy, EDAX, Vickers microhardness analysis and linear reciprocating wear testing. The laser alloyed coating across the cross section shows formation of dendrites and whisker like microstructures. Average microhardness of 800–1600 HV0.2 was measured at different cross-sectional depths and an extreme hardness of about 3800–4700 HV0.2 was obtained in some regions of boron precipitates. The results showed a high negative value of Gibbs free energy of about −250 kJ/mol and −170 kJ/mol at ∼2000 °C respectively which confirms the spontaneity of TiB2 and TiB phase formation. The activation energy of the titanium boride is estimated to be 140 kJ/mol. The laser borided coating with the formation of TiB and TiB2 phases could be useful for surface engineering applications.

Microstructure and mechanical properties of in-situ B4C reinforced TC4 composites prepared by laser melting deposition

In order to satisfy the increasingly harsh service environments of modern aircrafts, the novel in-situ reinforced xB4C/TC4 (x = 0–1.5 wt%) composites were prepared by laser melting deposition (LMD) and their microstructure, mechanical properties were investigated. The dual reinforcement phases of TiC and TiB were formed after B4C addition. A more favorable microstructure of refined α-Ti grains and uniformly-distributed reinforcement phases was obtained after adding 0.5 wt% B4C. The 0.5B4C/TC4 composite exhibited a moderate anti-abrasion ability owing to its beneficial microstructure and relatively high microhardness. Furthermore, it possessed the highest strength due to the effects of grain strengthening and dispersion strengthening induced by the (TiC + TiB) phases. This work provides theoretical basis and technical guidance for the development of high-performance Ti matrix composites.

Study on improving the fluidity of Ti2AlNb alloy

In this paper, the effects of main elements like Al, Nb and trace elements like Fe, Mo, W, Co, B and Si on the fluidity of Ti–22Al–25Nb alloy were investigated. The alloy composition which is beneficial to improve the fluidity was selected by calculating the thermal property parameters affecting the fluidity of the alloy through thermodynamic software, numerical simulation test of the fluidity of the alloy and verification test of the fluidity of the preferred alloy. Finally, the improvement mechanism of the alloy fluidity was discussed. Results showed that the appropriate reduction of Nb element was better than Al element for the improvement of fluidity. The addition of trace Fe, B and Si elements was beneficial to the improvement of fluidity, the improvement effect of B element was the best, while the addition of trace Mo, W, and Co was not conducive to the improvement of fluidity. The cessation mechanism of Ti2AlNb alloy is the cessation mechanism of the alloy with a wide crystallization temperature range. The composition which was the most beneficial to improve the fluidity was Ti–22Al–24Nb-0.1B. The main reasons for the improvement of the fluidity were that on the one hand, reducing 1 at% Nb and adding 0.1 at% B not only increased the superheat and crystallization latent heat but also reduced the melt viscosity and thermal conductivity, thus improving the fluidity. And on the other hand, the TiB phase refined the grains, and the fine grains prevented the dendrites from growing into a well-developed dendritic network, inhibited the adverse effect of the increase in the width of the solidification zone on the fluidity, and further improved the fluidity.

Solid-state reaction mediated microstructural evolution in a spark plasma sintered in situ Ti–B4C composite

A novel porosity-free in situ Ti–B4C composite was fabricated via spark plasma sintering (SPS). Detailed analysis of the phase evolution, coupling results from XRM, XRD and SEM-EBSD-EDS, indicate that primarily TiB2 precipitates formed due to the in-situ reactions between the boron-carbide and titanium powders. The precipitation of TiB2 resulted in the formation of a graphitic C-rich thin layer circumscribing the partially reacted B4C particles. Further progression of the in-situ reaction leads to the out-diffusion of the excess carbon from the B4C particles, across the graphite and TiB2 phases, forming TiC upon reacting with the titanium matrix. Therefore, the final microstructure primarily consisted of TiB2, TiC, and partially reacted B4C phases, with small amounts of TiB, α-Ti, and graphite. Furthermore, the microstructure in these SPS processed in situ composites appeared to be the product of a solid-state Ti–B4C diffusion couple, substantially different from their fusion-based additively manufactured counterparts. Nano-indentation tests revealed a remarkably high average hardness of ∼25 GPa for this SPS-processed Ti–B4C composite and comparable (with literature) phase-specific hardness and modulus values for the constituent TiB2, TiC, and B4C phases.

Microstructure and tribological properties of in-situ MxB reinforced CoCrFeNi HEA composites prepared by laser cladding

The CoCrFeNiTixB2x (x = 0, 0.1, 0.2, and 0.3) high entropy alloy (HEA) composite coatings were prepared on Q235 substrates by laser cladding. The microstructure, grain orientation, precipitated phase and tribological properties of the coatings were investigated by scanning electron microscopy (SEM), electron backscatter diffraction (EBSD), X-ray diffraction (XRD), transmission electron microscopy (TEM) and high-speed reciprocating wear friction tester, respectively. The results show that TiB, Cr2B, FeCrB and (FeCr)2B phases were in-situ formed in the composite coatings. The microstructures of the coatings are refined and the hardness increases with the addition of Ti and B elements. The grain orientation of all coatings is random. The orientation relationships between the HEA matrix and Cr2B is HEA matrix (002) // Cr2B (1̅3̅1̅), HEA matrix [5̅10] // Cr2B [013̅]. The composite coating exhibits the best wear resistance when the x of CoCrFeNiTixB2x is 0.2. The primary strengthening mechanisms of Ti and B doped CoCrFeNi HEAs are the synergistic effect of solid solution strengthening, second phase strengthening and fine grain strengthening.

Engineering fine grains, dislocations and precipitates for enhancing the strength of TiB2-modified CoCrFeMnNi high-entropy alloy using laser powder bed fusion

TiB2 nano-particle reinforced CoCrFeMnNi composite has been additively manufactured by using laser powder bed fusion (LPBF) technique. In comparison with the matrix CoCrFeMnNi sample, the average grain size of the TiB2 doped CoCrFeMnNi (CoCrFeMnNi + TiB2) sample reduces from 26.27 μm to 7.51 μm, appearing a morphological transformation from columnar grains to fine equiaxed grains and fine dendritic grains. Correspondingly, the compressive yield strength (σy) sharply increases from 484.41 ± 57.81 MPa of CoCrFeMnNi HEA to 952.62 ± 38.15 MPa of CoCrFeMnNi + TiB2, and the tensile yield strength increases from 480.27 ± 1.25 MPa to 834.21 ± 15.93 MPa, revealing a substantial enhancement of mechanical properties. The structural analysis unveils that the CoCrFeMnNi + TiB2 sample formed a tetragonal σ phase beside the FCC matrix and TiB2 phases compared with the single FCC phase of CoCrFeMnNi HEA. Especially, atomic resolution scanning transmission electron microscopy discloses that the TiB2 nanoparticles epitaxially grow onto the FCC matrix phase with [01–10]TiB2//[011]FCC orientation relationship. Theoretical calculations indicate that the enhancement mechanism of the CoCrFeMnNi + TiB2 sample should originate from a synergistic strengthening effect which is induced by grain refinement, TiB2 particles, σ phases and dislocations. Our work should provide a new view to utilize the rapid solidification process of LPBF and ceramic nano-particle reinforcement for the enhanced mechanical properties of HEAs with great potential.

Developed borated austenitic stainless steel alloys as nuclear reactor control rods

Modified austenitic stainless steel alloys reinforced with B and B/Ti were fabricated and their suitability as nuclear reactor control rods was tested. A standard stainless steel AISI 316L was used as a base alloy and inlaid by 0.58 wt% of B (SSB). The structural examination of the modified SSB stainless steel, which was conducted through the Schaeffler diagram, optical micrographs (OM), and X-ray diffraction (XRD) patterns had referred to the domination of the austenite phase with the appearance of boride (M2B) and carboborides (M23X6) phases along the grain boundaries. Mechanically, an augmentation in the hardness, yield strength (YS), and ultimate tensile strength (UTS) values was observed with the incorporation of B into the AISI 316L stainless steel. However, the addition of B led to a reduction in the values of elongation (El), reduction area (RD), and impact energy. Then, the SSB stainless steel was reinforced by 0.33 wt% of Ti (SSTiB1). The structural examination showed the formation of M2B, M23X6, TiC, TiN, and TiB2 phases along the grain boundaries of the austenite matrix as well as little ferrite phases. Ti led to a significant increase in hardness, YS, UTS, El, RD, and impact energy of the SSB steel. Finally, a further addition of B and Ti (1.13 & 1.77 wt% of B & Ti, SSTiB2) was tested, as this increase led to the more enhancement of hardness, YS, UTS, and impact energy but reduced the El slightly. Due to the high slow neutrons absorption cross-section of B, the slow neutrons attenuation ability of the modified stainless steel increased effectively with increasing boron concentrations. The obtained distinctive mechanical properties and high attenuation efficiency of slow neutrons of the produced SSBTi2 stainless steel, make it a suitable choice for use as control rods in nuclear reactors.

Microstructural evolution and wear properties of in-situ (TiB + TiC)-reinforced Ti6Al4V matrix composite coating by laser melting deposition

In this study, a laser melting deposition (LDM) process was employed to deposit titanium matrix composite (TMC) coatings on a titanium alloy substrate by adding 1–5 wt% nanosized B4C particles, which were annealed at 900 °C. The microstructure and dry sliding friction behavior of TMC coatings were studied before and after the annealing treatment. The experimental results show that the TiB + TiC hybrid reinforced phase formed by the in-situ reaction of B4C and Ti matrix mainly precipitated at the grain boundary, providing the grain boundary and second-phase strengthening. Specific orientation relationships of TiB and TiC phases with the matrix phase were revealed, which had an essential effect on the microhardness distribution along the coatings. The annealing treatment promoted the diffusion of hybrid reinforcement into the matrix, strengthening their interface bonding, and has an significant impact on the wear properties of TMC coating. The room temperature friction coefficient (COF) of all the coatings remained relatively constant at 0.3–0.6. With increasing B4C content, the wear loss of the as-deposited coatings continually increased from 0.024 mm3 to 0.054 mm3, while the wear loss of the annealed TMC coatings are much lower than before, from 0.032 mm3 (TMC1) to 0.020 mm3 (TMC2) and then rise to 0.023 mm3 (TMC3). Scanning electron microscopy (SEM) morphologies determined that annealing reduced the abrasive and adhesive wear of TMC composite coating and improved its wear resistance.

Effects of Aluminum Addition on Microstructure and Properties of TiC-TiB2/Fe Coatings In Situ Synthesized by TIG Cladding.

This study focuses on the synthesis of TiC-TiB2/Fe coatings with varying amounts of aluminum (Al) using tungsten inert gas (TIG) cladding and investigates the impact of Al addition on microstructure refinement and performance enhancement of the coatings. The coatings were prepared on a mild steel substrate using TIG cladding. X-ray diffraction (XRD) analysis revealed the presence of TiC, TiB2, AlxTi, and AlxFe phases in the coatings. Scanning electron microscopy (SEM) images showed that the addition of Al improved the microstructure, reducing defects and enhancing the distribution of reinforcing phases within the coatings. The particle size of the reinforcing phases was significantly refined by the addition of Al. The micro-hardness of the coatings was significantly higher than that of the substrate, with the maximum micro-hardness of the coating reaching 955.5 ± 50.7 HV0.1, approximately six times that of the substrates. However, excessive Al addition led to a reduction in hardness due to a decrease in the quantity of hard phases. The wear tests showed that all the coatings had lower wear loss compared to the substrate material, with the wear loss initially decreasing and then increasing with the increasing Al content. Samples with a 28.57 wt.% Al addition exhibited the best wear resistance, with approximately 16.8% of the wear volume loss compared to mild steel under the same testing conditions, attributed to the optimal combination of reinforcement phase quantity and matrix properties.

Fracture Resistance and Crack Growth Mechanisms in Functionally Graded Ti–TiB

This paper presents the results of fracture tests and crack path observations for a layered functionally graded material (FGM) consisting of Ti and TiB phases. The composition varied in a nearly linear manner from a TiB-rich layer at the bottom to commercially pure (CP) Ti at the top. Elastic properties of the mixed phase interlayers were measured using nanoindentation testing, demonstrating a linear variation with composition. These results differ significantly from approximations calculated in previous studies using a non-linear rule-of-mixtures approach. Fracture tests were conducted on single edge notch bend [SEN(B)] specimens with the notch aligned orthogonal to the direction of the composition gradient. For this crack orientation, "average" R-curve behavior based on the J-integral was investigated to understand the mechanics of crack growth. The value of J was found to be minimal (less than 1 N/mm) below 47 pct volume fraction of TiB compared to a reported value of approximately 150 N/mm for pure Ti. These results indicate that a steeper transition to high concentrations of the metallic phase is necessary to achieve adequate fracture resistance in this metal/ceramic FGM. Observations on the specimen surface indicate crack path toughening mechanisms of this functionally graded material include crack bridging, branching, and deflection.

Microstructure, wear and corrosion properties of B–C composite layers on pure titanium

In this work, TA2 pure titanium was treated by borocarburizing (BC), boriding first and then carburizing (B + C), and carburizing first and then boriding (C + B), and morphology and wear and corrosion properties of these layers were investigated. The results show that the BC layer and B + C layer are composed of TiB, TiB2, and TiC phases, while the C + B layer consists of TiC and TiB2 phases. The wear type of these treated samples is abrasive wear, and wear resistance is in the sequence of B + C layer > BC layer > C + B layer. In 3.5 wt.% NaCl solution, corrosion resistance is in the order of B + C layer > C + B layer > BC layer > TA2. In 5.0 vol.% H2SO4 solution, corrosion resistance is in the order of C + B layer > B + C layer > BC layer > TA2. The B + C treatment can form a layer with gentle hardness gradient, excellent wear properties, and good corrosion resistance, which is most conducive to the bonding between layer and matrix.

Synthesis of B<sub>4</sub>C–TiB<sub>2</sub> composition powder mixtures by carbidobor reduction using nanofibrous carbon for ceramic fabrication

The results of the researching process of obtaining composition powder material B4C–TiB2 by carbide reduction of titanium dioxide, using carbon reducing agent – carbon nanofibers, are presented. Furthermore, the results of studying of some properties of ceramics made using the synthesized powder are presented. The synthesis of composite materials was carried out in an induction crucible furnace for 20 min in the temperature range of 1200–1900 °C in an argon atmosphere. It has been established that the optimum temperature of the synthesis is 1650 °C, irrespective of the batch composition. The characteristics of the composite powders containing 10–30 mol. % of the TiB2 phase have been studied. X-ray electron microscopy has revealed that the particles of the powder are predominantly aggregated. There are two peaks in the particle size distribution histograms. The part of the histogram with a smaller particle size mainly characterizes the B4C phase. The part of the histogram with a larger particle size characterizes the TiB2 phase. The average particle size of the B4C phase is in the range of 5.3–5.5 µm, and that of the TiB2 phase is in the range of 33.6–41.9 µm. The average size of 50 % of composite powder’s particles for these contents does not exceed 13.4 μm. The surface area of the samples does not exceed 5 m2/g. The oxidation of the composite powder materials by atmospheric oxygen begins at a temperature of approximately 500 °C. At the same time, when the temperature reaches 1000 °C, no more than 45 wt. % of the studied powders is oxidized. Ceramics made with the synthesized powder mixture B4C + 30 mol. % TiB2 by hot pressing has shown rather high values of relative density (99.0±1.1 %) and fracture toughness (5.0±0.2 MPa∙m0.5).

The tribocorrosion resistance of TiN+TiB /TC4 composite coatings and the synergistic strengthening effects of multi-level reinforcements

The Ti-based composite coating of TiN + TiB /TC4 is successfully fabricated by laser cladding. The results show that the addition of BN promotes the in-situ formation of an elliptic TiN phase at the micron level and fibrous TiB phase at the nanometer level, forming a new structure of the hard TiN surrounded and pinned by coherent TiB. No obvious plastic deformation occurs with the increase of TiN and TiB phases, and the dense TiO2-MoO3 oxide film forms during tribocorrosion. The tribocorrosion rate is much reduced and drops to the lowest rate of 246.93 ± 14 µm/yr.