Influence of Y2O3 on the microstructure and tribological properties of Ti-based wear-resistant laser-clad layers on TC4 alloy

Multi-track Ti-based wear-resistant composite coatings were fabricated on TC4 alloy surfaces using laser-clad TC4 + Ni45 + Co–WC mixed powders with different Y₂O₃ contents (0, 1, and 3 wt%). The microstructure, microhardness, and tribological properties of the coatings were characterised using X-ray diffraction, scanning electron microscopy, energy dispersive spectrometry, electron probe X-ray micro analyser, microhardness tester, and friction and wear testing apparatus. The results showed that the number of cracks on the coating surfaces gradually decreased with the addition of Y₂O₃ and that residual Co–WC powders existed in the coating subsurfaces. The phase composition of the coatings with different Y₂O₃ contents remained unchanged and was mainly composed of reinforcing phases of TiC, TiB₂, Ti₂Ni, and matrix α-Ti. With the addition of Y₂O₃, the coating microstructure was remarkably refined, the direction characteristic of the TiC dendrites obviously weakened, and the nucleation rate significantly increased. When the added Y₂O₃ was 3 wt%, a large amount of TiB₂–TiC-dependent growth composite phases precipitated in the coating. The two-dimensional lattice misfit between (0001)_TiB2 and (111)_TiC was 0.912%, which indicated that TiB₂ and TiC formed a coherent interface. When the amount of Y₂O₃ was increased, the microhardness of the coatings gradually decreased, and the wear volume of the coatings first increased and then decreased. Under the effect of the TiB₂–TiC composite phases, the wear resistance of the 3 wt% Y₂O₃ coating was optimal. The 3 wt% Y₂O₃ coating friction coefficient was the lowest, and the wear mechanism was abrasive wear.     

Microstructure and mechanical properties of plasma sprayed TiC/Ti5Si3/Ti3SiC2 composite coatings with Al additions

The mass production of MAX phase coatings such as Ti₃SiC₂ and Ti₃AlC₂ using the plasma spraying method is highly challenging due to its ultra-high temperature and short reaction time. In this study, agglomerate powders of 3Ti/SiC/C/xAl with various Al contents (x = 0–1.5) were prepared to form TiC/Ti₅Si₃/Ti₃SiC₂ composite coatings using the plasma spraying technique. The effect of the Al addition on the microstructures and mechanical performances of the as-sprayed coatings was investigated. The addition of Al decreased the TiC content of the coatings while increasing their Ti₃SiC₂ content significantly. The addition of even small amounts of Al improved the MAX phase fraction of the coatings from 8.95 wt% (x = 0) to 34.05 wt% (x = 0.2) and 41.60 wt% (x = 0.5). Excess Al did not affect the Ti₃SiC₂ content of the coatings. The composite coatings showed a lamellar structure with pores and microcracks. With the addition of Al, the microhardness of the coatings increased slightly, while the fracture toughness improved significantly. The composite coatings with Al showed better wear resistance than those without Al. The wear mechanism of the coatings was a combination of adhesive wear, abrasive wear, and oxidative wear.     

Repair of spline shaft by laser-cladding coarse TiC reinforced Ni-based coating: Process,microstructure and properties

To repair the surface defects of spline shaft and improve wear resistance, the coarse TiC reinforced Ni-based composite coatings were fabricated on the spline shaft surface by laser cladding with six types of precursors containing Ni45, coarse TiC, and fine TiN powder. The effects of ceramic content and fine TiN addition on the formability, microstructure, and mechanical properties of the coatings were studied comprehensively. In TiC reinforced Ni-based coatings 1–3 without fine TiN addition, the porosity decreased from 20.415 % to 0.571 % with the increase of TiC concentration. The coatings mainly consist of CrB, Cr7C3, Cr23C6, coarse TiC, and γ-Ni. With the addition of fine TiN, the length of the ceramic phases in coatings 1#–3# decreased slightly, while volume fraction and porosity increased. Moreover, the ring-shaped Ti (C, N) phases were also detected at the edges of both undissolved TiC and TiN particles, which improved the bonding force between ceramics and matrix. Besides, these ceramics inhibited the generation of columnar crystals and eliminated the heat-affected zone. The performance test results show that the coating 3# with 30 wt% TiC and 6 wt% TiN exhibits the best wear resistance despite slightly decreased hardness, and its friction coefficient of 0.409 and wear rate of 42.44 × 10⁻⁶ mm³ N⁻¹·m⁻¹ are, respectively, 0.667 and 0.307 times those of the substrate. Based on the additive/subtractive hybrid manufacturing technology, the optimized coatings were ground to obtain the finishing surface, which indicates that the coarse TiC reinforced coating can be employed in repairing the damaged parts.     

Effect of Si content on the microstructure and properties of Ti–Si–C composite coatings prepared by reactive plasma spraying

In this study, Ti–Si–C composite coatings were synthesized via plasma spraying of agglomerated powders prepared by a spray drying/precursor pyrolysis technology using Ti, Si, and sucrose powders. The influence of Si content, ranging from 0 wt% to 24 wt%, on the microstructure, mechanical properties, and oxidation resistance of the composite coatings was investigated. Results show that the phase composition of the Ti–Si–C composite coatings changes with the increasing Si content. The coatings without Si addition consist of TiC and Ti₃O; the coatings with 6–18 wt% Si are composed of TiC, Ti₅Si₃, and Ti₃O; the coatings with Si content of 24 wt% form only TiC and Ti₅Si₃ phases. As the Si content increases, the hardness of the Ti–Si–C composite coatings increases first and then decreases, depending on the intrinsic hardness of the ceramic phases, the brittleness of Ti₅Si₃, and the defects such as pores and cracks. The Ti–Si–C composite coatings have high wear resistance due to the in-situ synthesized high-hardness TiC and Ti₅Si₃. Owing to the high brittleness of Ti₅Si₃, the increasing Si content leads to higher wear volume loss at room temperature, which can be partially improved in high-temperature wear tests. The oxidation resistance of Ti–Si–C composite coatings increases with the increase of Si content, and the higher the oxidation temperature, the more obvious the influence of the Si addition on oxidation resistance.     

Reinforced mechanical properties of plasma-sprayed Fe-based amorphous composite coatings by in-situ TiNx/TiOy

Ceramic particle-reinforced Fe-based amorphous coatings have received extensive attention due to their excellent strength and wear resistance. In this paper, TiN_x/TiO_y -enhanced Fe-based amorphous coatings were prepared by reactive plasma spraying technology, and the effect of eggshell-like TiN_x/TiO_y on the comprehensive mechanical properties of Fe-based amorphous coatings was systematically studied. The results showed that the hardness of the composite coating was significantly higher than that of the amorphous single-phase coating. Moreover, indentation experiments showed that TiN_x/TiO_y effectively confined crack growth in the amorphous phase. Though the bonding strength of the composite coating was lower than that of the pure amorphous coating, but still maintained a high bonding force of 20.68 MPa. Through the wear experiment, it was found that the wear scar of the composite coatings appeared plastic deformation, the friction coefficient and wear mass loss were both greatly reduced, and the optimal wear performance appeared in the composite coating with 15% Ti addition. In addition, SEM, EDS analysis, and the first-principles simulation results demonstrated the good bonding between Ti-containing compounds and Fe-based alloys.     

Optimization of microstructure and properties of composite coatings by laser cladding on titanium alloy

Recently, the current technological progress in developing laser cladding technology has brought new approaches in surface modification of titanium alloys. Herein, composite coatings were fabricated by the laser cladding process on Ti811 alloys using a coaxial powder feeding method. A comprehensive study was performed on the laser energy density (L_ed) and CeO₂ content on the structure distribution, microhardness and tribological properties of the coatings. In addition, the growth mechanism of the TiC–TiB₂ structure was studied based on the Bramfitt two-dimensional lattice mismatch theory. The results indicated that the phase composition of the coating mainly contained TiC, TiB₂, Ti₂Ni, and α-Ti. The optimized coating contributed to uniform microstructure distribution and fine grain size when L_ed was 45 J/mm² and the CeO₂ content was 2 wt%, playing an important role in the best forming quality and properties. Besides, the high matching degree of an interface between TiC (111) and TiB₂ (0001) contributed to the TiC–TiB₂ composite structure, which positively influenced the grain size and distribution of TiC. The microhardness and wear resistance of the 2Ce coating was dramatically enhanced due to the fine grain strengthening and dispersion strengthening effects of CeO₂, contributing directly to generate a high average hardness of 811.67 HV_0.5 with a lower friction coefficient.     

Effect of various morphology of in situ generated NbC particles on the wear resistance of Fe-based cladding

To improve the wear resistance of Fe-based cladding, NbC particles with different morphology are generated in situ by adding Nb, Cr₃C₂ and C with different content. The composition of samples and the morphology of NbC particles generated in situ are revealed by XRD, SEM and EDS. The wear resistance is studied by a reciprocating friction and wear testing machine. The wear mode and the wear mechanism of each sample are investigated. The results show that although NbC particles are generated in situ in samples with different Nb, Cr₃C₂ and C content, the morphology of NbC particles is varied. The wear resistance of samples containing cross-shaped NbC particles is more outstanding than that of samples containing only rectangular NbC particles. In addition, changing Nb, Cr₃C₂ and C content does not result in a change in wear mode, but leads to the formation of continuous lattice structure of Cr_0.19Fe_0.7Ni_0.11 and Cr₂₃C₆ compounds at grain boundaries and a change in the wear resistance. When the additions of Nb, Cr₃C₂ and C are 11.2 wt%, 8.6 wt% and 0.2 wt% respectively, the coefficient of friction of the sample is the lowest, and the wear resistance is the most outstanding.     

TiC/Ti3AlC2–Co plasma-sprayed coatings with excellent high-temperature tribological properties

In this work, TiC/Ti₃AlC₂–Co cermet coatings with varying amounts of Ti₃AlC₂ were deposited by atmospheric plasma spraying (APS) process and their wear-resistant properties were discussed. The friction coefficients and wear rates at high-temperatures were measured through a ball-on-disk type friction test at 600 °C. In addition, the corresponding wear mechanisms were elucidated through the observation of phase changes and surface microstructural evolution of the coatings. The results indicated that the as-prepared coatings consisted of TiC, Ti, TiO₂, Al₂O₃, Co and CoO phases, which were produced by the decomposition and oxidation of TiC and Ti₃AlC₂. Compared with other samples, the sample with 30 wt% Ti₃AlC₂ addition displayed the smallest friction coefficient and least wear rate. Its wear rate was about 1.26 times lower than that of reported TiC–Co cermet material and about 10 times lower than that of the typically used TiC–Ni cermet material, suggesting outstanding wear resistance at elevated temperature. The addition of Ti₃AlC₂ reduced the friction coefficient of the coating by producing more TiC and Al₂O₃ hard phases and a consequent reduction of coating porosity. When the amount of Ti₃AlC₂ in the coating was less than 30 wt%, the main wear mechanism was abrasive wear. As the content of Ti₃AlC₂ was increased in the coating, the wear mechanism changed from abrasive wear to adhesive wear and the wear pattern of the coating gradually transformed from the furrows to the debris. This transformation of mechanism was related to the synergistic effect of hardness and porosity of the coating, which resulted from the remaining content and the special layered structure of Ti₃AlC₂.     

Effect of Y2O3 addition on tribological properties of plasma sprayed Al2O3-13% TiO2 coating

The effect of Y₂O₃ addition on structure, mechanical properties and tribological properties of Al₂O₃-13 wt% TiO₂ coating was investigated. The addition of 20 wt% Y₂O₃ resulted in better densification, stabilization of alpha (α) alumina phase and improvement in fracture toughness of Al₂O₃-13 wt% TiO₂ coating. Abrasive wear tests were performed over a range of loads and sliding speeds. The stabilization of α alumina phase further increased with an increase in severity of wear test conditions, as noted from X-Ray Diffraction (XRD) and X-Ray Photoelectron Spectroscopy (XPS) analysis of worn coatings. Al₂O₃-13 wt% TiO₂-20 wt% Y₂O₃ coating displayed lower friction coefficient and lower abrasive wear rate than Al₂O₃-13 wt% TiO₂ coating, which was due to synergistic effect of α alumina phase and formation of magneli phase oxide of titanium; Ti₂O₃. Friction energy map was used to rationalize observed wear rates, to identify different regimes of wear and degradation modes of coatings.     

纳米Nb粉对等离子弧喷焊铁基合金组织与耐磨性的影响

采用等离子弧喷焊技术在Q235表面制备未添加与分别添加1wt%, 3wt%和5wt%纳米Nb粉的铁基合金喷焊层。通过X射线衍射仪(XRD)、金相显微镜(OM)、扫描电镜(SEM)和能谱仪(EDS)对喷焊层的相组成、显微组织、微区成分及磨损形貌进行分析;利用维氏硬度仪和销盘磨损仪检测喷焊层截面硬度和表面耐磨性。结果表明,铁基喷焊层主要由α-Fe, γ-Fe和Cr7C3组成,添加纳米Nb粉后原位生成NbC相,且随Nb含量增至5wt%,出现了Cr23C6相。纳米Nb粉的加入使喷焊层组织中未转变的奥氏体增多,组织形貌由近等轴晶转变为树枝晶,并且添加5wt%纳米Nb粉的喷焊层组织发生明显细化。添加纳米Nb粉使喷焊层的硬度明显提高,其中添加1wt%和3wt%纳米Nb粉的喷焊层硬度均可达约766 HV0.3。纳米Nb粉的加入同时提高了喷焊层的耐磨性,磨损机制由黏着磨损变为磨粒磨损。     

Microstructure and properties of Ni-WC gradient composite coating prepared by laser cladding

In this study, an Ni-based gradient composite coating reinforced with WC was prepared on a Q345R steel substrate by laser cladding. The Ni-WC composite coating was designed as a multilayer structure with gradient composition. The coating started with a layer of C276 alloy with 10 wt% WC on the substrate, and the subsequent layers were composed of Ni60 alloy with different WC contents (10, 30, and 50 wt% WC). The overall morphology, phase composition, and microstructure of the coatings were investigated. The microhardness and the wear properties of each layer of the coatings were also evaluated. The results showed that the gradient composition design was beneficial for reducing the cracking tendency. The coating was composed of an Ni-based matrix, WC, and multiple carbides and borides hard phases. With increasing WC content in the layers, the hard phases exhibited regional distribution characteristics. The WC reinforcement particles underwent different types of dissolution during the cladding process. From the surface to the substrate, the average microhardness of the coating was 1053.5 HV_0.2, 963.4 HV_0.2, 859.0 HV_0.2, 441.7 HV_0.2, and 260.5 HV_0.2. The wear tests revealed that the coefficient of friction and the wear loss values of the four layers were all lower than those of the substrate, demonstrating enhanced wear resistance.     

Synergistic effect of CeO2 and Al2O3 nanoparticle dispersion on the oxidation behavior of MCrAlY coatings deposited by HVOF

In this study, the as-received and nano-scaled oxide dispersion strengthened (ODS) MCrAlY coatings were deposited using high-velocity oxy-fuel (HVOF) spraying process. The high-energy planetary ball-milling process was utilized to prepare CeO₂ and Al₂O₃ nanoparticles. ODS-NiCoCrAlY feedstock powders were also developed using the ball-milling process. The various formulations of Al₂O₃ and CeO₂ nanoparticles (0.5 and 1.0 wt%) were chosen to apply different types of ODS-NiCoCrAlY coatings. The microstructure of the as-received and ODS coatings were evaluated by field emission scanning electron microscope (FESEM) as well as the commercial and ODS powders. Furthermore, the microhardness of different compositions of ODS coatings was accordingly investigated and the obtained results were compared with as-received coating. On account of the measurement of oxidation kinetics, the freestanding as-received and ODS coatings were exposed to air at 1000 °C up to 500 h and the thickness growth rate of the α-Al₂O₃ oxide layer was simultaneously examined. The results exemplified that NiCoCrAlY+1.0 wt% nano-CeO₂+0.5 wt% nano-Al₂O₃ coating had a better oxidation resistance and lower oxide scale growth rate under the synergistic effects of both CeO₂ and Al₂O₃ nanoparticles.     

Tribological behavior of composites fabricated by reactive SPS sintering in Ti-Si-C system

In this study, wear and friction behavior of two based-composites from the Ti-Si-C system, (40 wt% TiC; 28 wt% Ti₅Si₃; 17 wt% Ti₃SiC₂) and (18 wt% TiC; 26 wt% Ti₅Si₃; 41 wt% Ti₃SiC₂) reinforced by 15 wt% of large size SiC (100-150 µm) particles were investigated. The four-phase composites exhibited approximatively the same friction coefficient (µ ~ 0.9) under high loads (10 N and 7 N). The composite with high Ti₃SiC₂ showed higher wear rate values by one order of magnitude. However, under 1 N, the composite with high TiC content showed a higher running-in period and a lower steady state µ value (0.37 after 1000 m sliding distance). Scanning electron microscopy, Energy Dispersive X-Ray and Raman spectroscopy analysis of the worn surfaces of the two composites revealed that oxidation was the dominant wear mechanism. The oxidation process and the removal kinetics of the oxides during sliding controlled the tribological behavior of the composites. The influence of processing variables on microstructures development and wear mechanisms of the composites is discussed.     

Oxidation of TaB2-SiC coatings prepared by spark plasma sintering and effect of pre-oxidation treatments

To suppress the oxidation of TaB₂-SiC coatings, the effects of pre-oxidation temperature on the oxygen hindering properties of TaB₂-SiC coatings were investigated to prepare TaB₂-SiC coatings with enhanced oxidation behavior. The addition of 40 wt% TaB₂ made the oxygen permeability of the coating decrease by 62.16%. However, excessive TaB₂ weakened the oxygen hindering ability of the coating due to the large ion complex ability of Ta⁵⁺. The pre-oxidation temperature at 1500 °C led to a homogeneous dispersion of Ta-oxide nanocrystal particles in the Ta-B-Si-O complex-phase glass layer. In contrast with the untreated samples, the active factor and inert factor values of the TaB₂-SiC coating after pre-oxidation treatment at 1500 °C decreased by 43.12% and 17.33%, respectively, which improved the dynamic stability of the coating during oxidation.     

Comparison of the anti-coking performance of CVD TiN,TiO2 and TiC coatings for hydrocarbon fuel pyrolysis

Previous work has shown that both TiN and TiO₂ coatings can inhibit the metallic catalytic coking effectively, but both of them have their own shortage. In this work, TiC coating was prepared on the surface of SS304 tube using TiCl₄-CH₄-H₂ by CVD method. Its morphology, elemental composition, thickness and oxidation resistance were characterized by SEM, EDX, metalloscopy and TPO tests, respectively. The results show that CVD TiC coating is gray, homogeneous, and dense without cracks or holes. The TiC coating presents a cuboid particle structure with the sizes of about 1.0 µm for the cuboid crystals, and the Ti/C ratio close to 1:1, while the average thickness is about 11.62 µm. TPO results show that the TiC coating begins to react with O₂ and release CO₂ at about 810 °C. Compared with the TiN coating (The initial oxidation temperature of TiN is about 350 °C), the oxidation resistance of TiC coating is improved substantially. As a conclusion, the high oxidation resistance order is TiO₂ coating>TiC coating>TiN coating. Furthermore, the temperature programmed cracking of RP-3 Chinese jet fuel was employed to compare the anti-coking performance of TiN, TiO₂ and TiC coatings. The results show that each of TiN, TiO₂ and TiC coating has obvious anti-coking effect, and the anti-coking performance order is TiN coating=TiC coating>TiO₂ coating.     

In situ TiBX/TiXNiY/TiC reinforced Ni60 composites by laser cladding and its effect on the tribological properties

Ni-based composite coatings reinforced by TiB_X/Ti_XNi_Y/TiC with different Ti6Al4V contents were precipitated on a 35CrMoV substrate via laser cladding. The phase composition, elemental distribution, and precipitated phases of the coatings were characterised using X-ray diffraction, energy dispersive X-ray spectroscopy, scanning electron microscopy, and transmission electron microscopy. The mechanical and tribological properties of the cladding layer were also characterised. The results showed that the coating contained TiB₂, TiC, TiB, Ni₃Ti, and NiTi₂ phases with uniform elemental distribution and grain refinement. A schematic of the growth model and precipitation sequence of the reinforced phases was generated. The microstructure, elemental segregation, hardness, and friction behaviour of the cladding layer were significantly influenced by the addition of Ti6Al4V. The optimal microstructure and best mechanical properties were obtained by the addition of 4 wt% Ti6Al4V, with that coating possessing a hardness, average friction coefficient, and wear volume of 770.8 HV₁, 0.180 and 6132 um³, respectively.     

Design and development of TiC-reinforced 410 martensitic stainless steel coatings fabricated by laser cladding

AISI 410 martensitic stainless steel (MSS) coatings, reinforced with TiC ceramic particles of varying contents (0, 5%, 10% and 15%), have been fabricated by laser cladding technology for the first time in this study. The microstructure evolution and properties of the laser-cladded specimens are carefully investigated by advanced techniques, including XRD, SEM, TEM, EDS, a micro-hardness tester and a ball-on-disc tribological tester. The obtained results show that the as-cladded 410 MSS coating is mainly composed of coarse lath martensite (M), a few austenite (A) and M₂₃C₆. After addition of TiC ceramic particles, the lath-shaped M is significantly refined, meanwhile the nano-sized Ti-enriched ceramic precipitates (TiC and Ti(C,N)) are formed in the composite coatings. However, microcracks and pores occur in the laser-cladded coating with addition of TiC up to 15%. It is found that both the microhardness and wear resistance of the coatings are enhanced with an increasing TiC content, and the 10% TiC-reinforced coating exhibits the optimal comprehensive performance, with much higher microhardness and wear resistance in comparison to the TiC-free MSS coating. The remarkable properties of the TiC-reinforced 410 MSS coatings can be mainly ascribed to the synergistic effects of microstructural refinement, nano-precipitation hardening and second-phase strengthening.     

TiO2–ZnO/Ni–5wt.%Al composite coatings on GH4169 superalloys by atmospheric plasma spray techniques and theirs elevated-temperature tribological behavior

Ni–based composite coatings with different amounts of TiO₂–ZnO were fabricated by atmospheric plasma spraying (APS) to protect GH4169 superalloy substrates against excess wear and friction at elevated temperatures. In addition, the influence of the simultaneous addition of the oxides on the microstructure, microhardness, and wear behaviour was investigated. According to the results, the simultaneous addition of TiO₂/ZnO provides anti-friction and wear inhibition over 600 °C. In particular at 800 °C, the TiO₂–ZnO/Ni–5wt.%Al composite coating (10 wt% TiO₂ and 10 wt% ZnO were incorporated within Ni–5wt.%Al matrix) exhibits a superior lubricity and wear resistance compared to the Ni–5wt.%Al based coatings. The XRD, Raman, and TEM characterisations reveal the formation of a glaze oxide layer consisting of NiO, TiO₂, ZnO and the in-situ production of ternary oxide (Zn₂TiO₄), which was primarily responsible for the tribological performance of the sliding wear contacts at the specific temperature.     

Tribological properties of polyimide coatings filled with PTFE and surface‐modified nano‐Si3N4

Polyimide (PI) coatings filled with PTFE and nano‐Si₃N₄ were prepared by a spraying technique and successive curing. Nano‐Si₃N₄ particles were modified by grafting 3‐aminopropyltriethoxysilane to improve their dispersion in the as‐prepared coatings. Friction and wear performances and wear mechanisms of the coatings were evaluated. The results show that the incorporations of PTFE and modified nano‐Si₃N₄ particles greatly improve the friction reduction and wear resistance of PI coating. The friction and wear performance of the composite coating is significantly affected by the filler mass fraction and sliding conditions. PI coating incorporated with 20 wt % PTFE and 5 wt % modified nano‐Si₃N₄ displays the best tribological properties. Its wear rate is more than one order of magnitude lower and its friction coefficient is over two times smaller than that of the unfilled PI coating. Differences in the friction and wear behaviors of the hybrid coatings as a function of filler or sliding condition are attributed to the filler dispersion, the characteristic of transfer film formed on the counterpart ball and the wear mechanism of the coating under different sliding conditions. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40410.     

A comparative investigation on microstructure evolution and wear resistance of in situ synthesized NbC,WC, TaC reinforced Mo2FeB2 coatings by laser cladding

To improve the microhardness and wear resistance of Mo₂FeB₂ coatings, composite coatings were prepared by laser cladding using in situ synthesized NbC, WC, and TaC. The influence of different carbides on the morphology, microstructure, microhardness, residual stress, and tribological properties of the composite coatings was investigated. The results showed various microstructural morphologies in different composite coatings. Apparent herringbone structures were observed in most coatings except for the Mo₂FeB₂/TaC composite coating and a eutectic structure was formed in the Mo₂FeB₂/WC composite coating. In addition, the heat-affected zone was typically composed of acicular martensite and lath martensite. The microhardness of the Mo₂FeB₂/WC composite coating increased to 1543.6 HV_0.5 compared with 985.7 HV_0.5 observed for the Mo₂FeB₂ coating. Tensile stress existed in the coating, bonding zone, and heat-affected zone, whereas the substrate exhibited compressive stress. The Mo₂FeB₂/WC composite coating exhibited the lowest tensile stress (298 MPa). The Mo₂FeB₂/WC composite coating containing WC and the W₂C phase had the lowest coefficient of friction (0.38) and wear rate (3.90 × 10^?5 mm³/Nm), indicating its excellent tribological properties. Moreover, the wear mechanism of the Mo₂FeB₂ coating is severe adhesive and abrasive wear. The adhesive wear mechanism was mitigated by the formation of in situ synthesized NbC, WC, and TaC. The wear mechanism of the Mo₂FeB₂/WC composite coating was only a slight abrasive wear.