Wear Resistance Of Titanium Alloy Research Articles

INCREASE OF THE CORROSION-MECHANICAL WEAR RESISTANCE OF TITANIUM ALLOYS BY NITRIDATION IN THE GLOW DISCHARGE: A REVIEW OF MODERN RESEARCH

In this work, a review of modern research in the field of increasing the corrosion-mechanical wear resistance of titanium alloys using glow discharge nitriding is carried out. Titanium alloys, due to their unique properties, namely high strength, lightness, exceptional corrosion resistance and excellent biocompatibility, are widely used in aviation, medicine, engineering and many other industries. However, operational conditions in some applications require even greater improvement of the wear resistance and corrosion resistance of these alloys, which makes the search for effective methods of their improvement an urgent scientific and engineering task. Among the promising technologies that can be used to improve the corrosion-mechanical properties of titanium alloys, low-temperature anhydrous nitriding in a glow discharge should be considered. The use of low-temperature anhydrous nitriding in a glow discharge eliminates the growth of the base grain and hydrogen embrittlement of the surface. Also, low-temperature nitriding in a glow discharge makes it possible to increase the wear resistance of the surface of titanium alloys, while the saturation of the surface with nitrogen is controlled, which allows predicting the results of processing, does not lead to a change in the shape of parts. The analysis of scientific research shows that increasing the corrosion-mechanical wear resistance of titanium alloys by means of nitriding in a glow discharge is a promising direction that opens up new opportunities for industry and science. Progress in this field depends on further research, innovative development and the integration of the latest technologies, which together will contribute to the creation of more durable, efficient and environmentally friendly materials for a wide range of applications. In general, increasing the corrosion-mechanical resistance of titanium alloys by the method of nitriding in a glow discharge is a promising direction of research in Ukraine, which can lead to the improvement of the properties of titanium alloys and the expansion of their use in various industries.

Properties of laser cladding (NiCoCr)94Al3Ti3-cBN-hBN hard self-lubricating ceramic coating

Titanium alloy is an essential material for preparing aerospace engines because of its excellent performance. However, the poor wear resistance of titanium alloy restricts its further development as a critical engine material. This study aimed to use laser cladding and particle enhancement technologies to enhance the surface wear resistance of titanium alloy. (NiCoCr)94Al3Ti3+hBN, (NiCoCr)94Al3Ti3+cBN, and (NiCoCr)94Al3Ti3+hBN + cBN were prepared on the surface of titanium alloy, and the wear resistance mechanism of single-phase self-lubricating particles, single-phase hard particles, and self-lubricating and hard biphasic particles was investigated. The results showed that the microhardness of the biphase-reinforced coating was 1083.8 HV0.5, which was higher than that of the self-lubricating particle-reinforced coating and hard-particle-reinforced coating by 368.4 HV0.5 and 149.8 HV0.5, respectively. The friction coefficient of the biphase-reinforced coating was 0.4208, which was lower than that of the self-lubricating particle-reinforced coating and hard-particle-reinforced coating by 0.0224 and 0.0686, respectively. The wear rate of the biphase-reinforced coating was 0.076 mm3/NM, and the wear resistance of the biphase-reinforced coating was 3.42 and 1.37 times that of the self-lubricating particle-reinforced coating and hard-particle-reinforced coating, respectively. hBN relied on its own decomposition to promote the coating to present a layered unstable structure to achieve a wear reduction effect, cBN relied on its own hardness to resist wear and played a wear-resistant role, whereas biphase-reinforced coating had a hard wear resistance and formed a lubricating film to enhance the wear resistance of the coating. The comprehensive performance of the dual-phase wear-resistant coating reinforced by hard particles and self-lubricating particles was better than that of single-phase wear-resistant coating, providing a reference for developing wear-resistant coating integrating hardness and self-lubrication.

Enhancing high-temperature fretting wear resistance of TC21 titanium alloys by laser cladding self-lubricating composite coatings

Fretting wear is one of the main factors restricting the fastener service reliability for the high-temperature titanium alloys. Enhancing the high-temperature fretting wear resistance of titanium alloys with laser cladding coatings is an effective method. Thus, in this work, a self-lubricating composite coating was designed and fabricated on the surface of TC21 titanium alloy with laser cladding. Special attentions were made to the effect of the fractions of the hard and self-lubricating phases on high-temperature fretting resistance. In addition, the contribution of laser cladding power was also concerned. The primary phases of the self-lubricating composite coatings are α-Co, CaF2, WC, TiC and Cr23C6, and the reasons for the formation of TiC and Cr23C6 are investigated from a thermodynamic point. The prepared composite coatings are dense and uniform. The crystallographic characteristics and the volume fractions of the hard phases (WC, TiC and Cr23C6) and self-lubricating phase (CaF2) were revealed, and the effect of grain size on the coating properties was analyzed. The hardness of the coatings were all maintained around 700 HV0.2, which was significantly higher than that of the substrate. The composite coating significantly improves the friction and wear resistance at 500 ℃. The hard phase was also found to be the most resistant to friction and wear. The frictional performance of the coating gets better when the hard phase and the self-lubricating phase increase. However, the hard phase contributes more to the high-temperature friction and wear resistance than the self-lubricating phase and the wear volume is 1/40 that of substrate. For the laser cladding power, the higher power can lead to a higher fraction of CaF2 but a lower fraction of hard phase, causing a decline in COF but an increase in wear volume. The wear mechanisms of the coating and the substrate were analyzed, the subsurface stress distribution state of the wear scars were further analyzed. The current results present new insights on the anti-wear design strategy to the composite coatings consist of hard and self-lubricating phase.

Wear resistance enhancement mechanism of columnar network distributed TiBw in titanium matrix composites

To improve the wear resistance of titanium alloy, TiBw/TA15 composites with different columnar network densities were fabricated. It is shown that the wear resistance of the composite increased with the density increment of the columnar network, which could be attributed to both the refinement of matrix grains and the enhancement in hardness. To investigate the wear resistance enhancement mechanism of columnar network distributed TiBw, a novel approach is proposed for reconstructing the evolution of TiBw by observing the variation trend of TiBw from the undeformed matrix to the worn surface. This verified the load transfer mechanism of TiBw and revealed the cooperative variation of columnar network distributed TiBw to resist plastic deformation during the wear process.

Effects of Graphene Oxide on Tribological Properties of Micro-Arc Oxidation Coatings on Ti-6Al-4V

This paper investigates the effect of graphene oxide (GO) particles on the friction reduction and wear resistance of coatings on a Ti-6Al-4V alloy generated using the micro-arc oxidation (MAO) technique. Different concentrations of GO were added in aluminate–phosphate electrolyte. The composition of the MAO coatings was investigated using X-ray diffraction and the energy dispersive spectrum. Measurements of the coating’s thickness, hardness, and roughness have also been conducted. Ball-on-disk friction tests under dry conditions were carried out to reveal the tribological behavior of the MAO coating. The results showed that the coating consisted of Al2TiO5 and γ-Al2O3. The addition of GO greatly reduced the friction coefficient by 25%. The coating with 5 g/L of GO particles exhibited the lowest friction coefficient (reduced from 0.47 to 0.35). Moreover, the coating thickness become thicker (from 10 to 20 μm) with an increase in GO concentration from 0 to 10 g/L. The wear mechanism was revealed via worn surface analysis. This study provides a helpful way to improve the surface wear resistance of titanium alloys.

Co-construction of microstructure evolution and wear resistance of in-situ TiBw/TA15 composites with network structure

To further improve the wear resistance of titanium alloy, titanium matrix composites with network distributed TiBw were fabricated. Microstructure evolution and wear mechanism of TA15 alloy and 5 vol% TiBw/TA15 composites were investigated at the temperature of 25 °C and 600 °C. The wear rate of TiBw/TA15 composites at 600 °C was only 7.2 × 10−5 mm3/(N·m). Compared to TA15 alloy, the wear rate of composites decreased by 17.2% at room temperature and 38.4% at high temperature. A novel approach was used to investigate the enhancement role of reinforcement on wear resistance of composites: co-construction of subsurface microstructure evolution and wear resistance through multi-angle observation. The results showed that the improvement of the wear resistance at room temperature was attributed to the TiBw, which enhanced work hardening and improved thermal conductivity. During high- temperature wear process, the TiBw effectively hindered dislocation movement and promoted the DRX, which decreased the stress concentration caused by severe plastic deformation.

Synthesis of titanium carbide coating on Ti15Mo alloy and its tribological behaviour

AbstractTi15Mo alloy has been regarded as one of the most potential biomedical materials due to its excellent performance. However, the low hardness and poor wear resistance of titanium alloy limit the further application. Therefore, high temperature solid carburising technology was performed on the surface of Ti15Mo alloys to prepare titanium carbide (TiC) coating with graphene (G) as the carburising agent. The microstructure, mechanical properties, and tribological properties of TiC coating under different lubricants were investigated. Results showed that TiC coating was closely bonded to the titanium substrate. The maximum thickness of TiC coating treated with 1150°C was approximately 184.02 μm, and the microhardness of alloys treated with 1100°C can achieve 1221.5 HV. All modified Ti15Mo alloys showed improved tribological performance compared to the original samples. The wear mechanisms of modified Ti15Mo alloys were abrasive wear and adhesive wear under the SBF lubricant, and the TiC coating was slightly peeled off. The overall friction coefficient and wear rate under 25% calf serum lubricant were lower than the SBF lubricant, and surface scratches were almost absent, and slight abrasive wear and adhesive wear occurred on the surface.

Micro-abrasive wear behavior by ball cratering on MAO coating of Ti–25Ta alloy

Surface treatments are widely used techniques to improve the wear resistance of titanium alloys for biomedical applications. Modification by micro-arc oxidation (MAO) creates an oxide ceramic coating of alloy substrate to improve wear resistance. This work investigated the micro-abrasive wear by ball cratering of MAO coatings over Ti–25Ta alloy. For this purpose, the surfaces were worn by steel balls at a load of 2 N and a rotation speed of 200 rpm. After 50 min of testing, the depth of the wear reaches the substrate, confirming that the MAO coating has a much lower wear rate. Guided by Archard's law, the wear volume, wear rate, and MAO coating thickness were calculated through wear test.

Tribological properties of Ti-N compound layer formed on Ti6Al4V by HCD assisted plasma nitriding

In order to improve the wear resistance of titanium alloy Ti6Al4V, an adherent Ti-N compound layer was formed on it by hollow cathode discharge (HCD) assisted plasma nitriding in a mixture gas of NH3 and N2 with a ratio of 1:2. After processing at 750 °C for 8 h, a 4 µm thick Ti-N compound layer with high hardness was produced. X-ray diffraction analysis showed that this layer is composed of TiN and Ti2N. Pin-on-disc wear tester in dry sliding condition was used to evaluate the tribological properties. Scanning electron microscopic examination and EDS measurement of unnitrided and nitrided samples were performed after the wear tests. The wear resistance of titanium alloy was greatly enhanced after plasma nitriding.

Wear Mechanism of TC4 Titanium Alloy with TiN Coating against Self-Lubricating Fabric

Vapor deposition technology can improve the surface wear resistance of titanium alloys, and prepare lightweight and corrosion-resistant self-lubricating spherical plain bearings made of titanium alloys. However, titanium alloys with hard films can be worn by soft self-lubricating fabrics. This paper focuses on the wear problem of TiN coating on the surfaces of self-lubricating spherical plain bearings based on titanium alloys. Ring-to-plate wear tests were carried out to study the tribological properties of TiN coating on TC4 titanium alloy against self-lubricating fabric under different working conditions (load: 500–2000 N and speed: 100–500 r/min), along with the investigation of the wear mechanism of TiN coating, and the evaluation of applicable working conditions of GE15 type self-lubricating spherical plain bearings through swing tests. The results have revealed that TiN coatings can maintain a certain friction distance without wear. Increasing friction speed and load can make TiN coatings more prone to wear. A thick transfer film can protect the TiN coating from wear. The main wear mechanism is attributed to fatigue wear induced by the repeated formation and peeling of transfer films. The GE15 bearing has achieved a self-lubricating fabric wear of approximately 0.04 mm when the swinging for 500 m (25,000 times) is under a specific condition of 27 kN and 0.2 Hz without damaging the inner ring of the bearing. The bearing is suitable for swing conditions with applied loads below 27 kN. This study provides a fundamental understanding of designing self-lubricating spherical plain bearings made of titanium alloys.

Tribological investigations of boride layers on Ti6Al4V at room and elevated temperatures

PurposeThis paper aims to improve the wear resistance of titanium alloy using a high-hardness boride layer, which was fabricated on Ti6Al4V by a high-temperature boronizing process.Design/methodology/approachThe boride layers on Ti6Al4V were obtained at 1000°C for 5–15 h. Scanning electron microscopy, energy dispersive analysis and X-ray diffractometer were used to characterize the properties of the boride layer. The tribological performance of the boride layer at room and elevated temperatures was investigated.FindingsThe X-ray diffraction analysis showed that the boride layers were a dual-phase structure of TiB and TiB2. When the boronizing time increased from 5 h to 15 h, the microhardness increased from 1192 HV0.5 to 1619.8 HV0.5. At 25°C and elevated temperatures, the friction coefficients of the boride layers were higher than that of Ti6Al4V. The wear track areas of T-5 at 200°C and 400°C were 2.5 × 10–3 and 1.1 × 10–3 mm2, respectively, which were 6.1% and 2.6% of that of Ti6Al4V, indicating boride layer exhibited a significant wear resistance. The wear mechanisms of the boride layer transformed from slight peeling to oxidative wear and abrasive wear as the temperature was raised.Originality/valueThe findings provide an effective strategy for improving the wear resistance of Ti6Al4V and have important implications for the application of titanium alloy in a high-temperature field.

Microstructure and Wear Resistance of Ti5Si3/Ti3Al Composite Coatings Prepared by Laser Cladding on TA2 Titanium Alloy

In order to improve the wear resistance of titanium alloy, a Ti5Si3/Ti3Al composite coating with improved wear resistance was successfully prepared by laser cladding TA2 titanium alloy using the double-layer presetting method of Ti-63 wt.% Al mixed powder layer/Si powder layer. The microstructure, phase composition and wear resistance of the coating were studied using X-ray diffraction (XRD), scanning electron microscopy (SEM) and pine-disk friction and wear method. The results show that the coating is mainly composed of the Ti5Si3 primary phase and Ti5Si3/Ti3Al eutectic structure. The microhardness of the coating is higher than that of the matrix. The average microhardness of the coating is about 668 HV0.1, which is 3.34 times that of the matrix. The coating significantly improves the wear resistance of the TA2 matrix, and the mass wear rate is 1/5.79 of that of the TA2 matrix. The main wear mechanisms of the coating are abrasive wear, adhesive wear and oxidative wear, whereas the main wear mechanisms of the TA2 matrix are adhesive wear and oxidative wear.

Effect of high-speed ultrasonic vibration cutting on the microstructure, surface integrity, and wear behavior of titanium alloy

Titanium alloys are widely used in aviation, marine, automotive, offshore, and medical fields. However, their poor wear resistance reduces the safety and reliability of components during service. Few study has been previously conducted on the wear resistance enhancement of titanium alloys (including Ti–6Al–4V alloy) processed by mechanical cutting. High-speed ultrasonic vibration cutting (HUVC) is an effective approach for improving the machinability of titanium alloys. In this study, we attempted to utilize HUVC improving the wear resistance of titanium alloys. After conducting high-speed turning (cutting speed within the range of 200–300 m/min), the surface integrities (surface roughness, microstructure, in-depth micro-hardness, and residual stress) of conventional cutting (CC)- and HUVC-machined samples were characterized. Experimental results demonstrated that, compared with CC, HUVC achieved a thicker plastic deformation layer (greater than 46.93 μm), lower surface roughness, higher surface micro-hardness (greater than 433 HV0.05), and higher compressive residual stress (up to −840 MPa). Moreover, surface nanocrystallization and gradient nanostructured layer were observed in HUVC-machined Ti–6Al–4V samples. In addition, compared with CC, HUVC effectively further reduced the friction coefficient and worn volume loss (decreased by 20.98%–25.59%) and ultimately improved the wear resistance. The hardness has a higher influence on the wear resistance of the machined Ti–6Al–4V alloy than the other surface integrity factors. Therefore, the proposed mechanical cutting operation was confirmed to improve the wear resistance of titanium alloys.

Microstructure and wear behavior of (ZrTaNb)C/N quaternary ceramic coatings prepared by double-cathode glow plasma surface alloying on titanium alloy

Multi-principal component coating is a new type of surface protection material developed in recent years. To improve the surface hardness and wear resistance of aviation titanium alloy, (ZrTaNb)C, (ZrTaNb)N and ZrTaNb coatings were prepared by double cathode glow plasma surface alloying. The microstructure, mechanical properties and high temperature tribological behavior of quaternary ceramic coatings were studied. The results show that the quaternary ceramic coating has an FCC cubic structure, which is different from the BCC structure of the ZrTaNb coating. Meanwhile, the solid-soluble C and N elements improve the surface hardness and toughness of the multi-principal component coating, resulting in a significant reduction in wear rate, which is only 1/10 and 1/5 of that of the substrate and pure metal coating (25 °C). When the temperature increases to 500 °C, the compliant islets of oxidized and compacted debris are gradually activated as a wear-resistant oxidation glaze layer. The gradient structure of amorphous-nanocrystalline composite is formed in the subsurface layer, which can effectively improve the surface strength and wear resistance. This study provides an effective strategy for improving the wear resistance of titanium alloy surface in a wide temperature range.

Creation and study of intermetallic coating of the Ni–Ti system reinforced with tungsten carbide to increase wear resistance of titanium alloy

The results of studying the intermetallic coating of the Ni–Ti system with the addition of tungsten carbide are presented. The coating was synthesized on the surface of titanium alloy VT6 using an integrated approach – preliminary deposition of a precursor coating from monometallic nickel by cold gas-dynamic spraying and subsequent laser processing. It is shown that the introduction of tungsten carbide into the intermetallic matrix provides an increase in hardness by a factor of three or more, as well as a decrease in wear intensity by a factor of 80 compared to the wear resistance of VT6 titanium alloy. A technology has been developed and a batch of steam turbine blades with a wear-resistant coating on the surface of shrouds has been manufactured.

Effect of linear energy density on microstructure and wear resistance of WC-Co-Cr composite coating by laser cladding

To improve the wear resistance of titanium alloy, the WC-reinforced composite coatings were prepared on Ti-6Al-4V substrate by laser cladding. The effect of linear energy density (LED: 73.3 J·mm−1-283.3 J·mm−1) on the microstructure, microhardness and wear resistance of the composite coatings were investigated. The evolution of WC during laser cladding was revealed and discussed. It is found that the WC is dissolved by the forms of releasing W and C with increasing LED, and grows into specific shapes according to the Lifshitz-Slyosov-Wagner model. As the LED increases, the retention index of WC decreases (0.91–0.80) and the grain size increases (1.89 μm–5.81 μm) in the composite coating. The microstructure differences lead to the microhardness and brittleness increasement of composite coating. Compared with the Ti-6Al-4V substrate, the maximum microhardness improvement and wear mass loss reduction are 5 times and 25 times by varying LED. The main wear mechanism of composite coatings is abrasive wear. However, additional forms of wear mass loss such as adhesive wear and WC peeling can occur due to LED variation, and further leads to the difference in wear resistance. It is expected that the evolution of WC, which can regulate the microstructure will provide an effective theoretical foundation for the wear-resistance improvement of the laser cladding coatings.

Structure and mechanical properties of MAO coatings formed on aluminum-coated titanium alloy

ABSTRACT Application of titanium alloys is restricted due to their low hardness and poor wear resistance. Duplex surface treatment consisting of depositing of Al coating by arc ion plating (AIP) plus micro-arc oxidation (MAO) was carried out on Ti6Al4V alloy to improve its tribological performance. Ceramic coating mainly composed of α-Al2O3, γ-Al2O3 and mullite was fabricated on the aluminum-coated titanium alloy after the MAO treatment, and its thickness, compactness and hardness increased with the MAO time before the titanium alloy was oxidized. After the substrate titanium alloy was locally oxidized due to oxygen anions inward migration, a thin transition layer containing titanium oxides and aluminum titanate formed and incorporation of Ti in the alumina coating occurred. Occurrence of the strong eruptible discharges at these positions was facilitated probably due to the large difference in permittivity of the alumina and the titanium oxides, which led to the formation of penetrating cracks in the MAO coating. The hardness and compactness of the ceramic coating decreased. Tensile test results showed bonding strength of MAO ceramic coating/aluminum layer/titanium alloy substrate system was more than 40 MPa, and the maximum value could reach around 68 MPa. The bonding strength of the ceramic coating/titanium alloy substrate system decreased to around 34 MPa due to the weak bonding between the alumina ceramic coating and the titanium alloy substrate. Tribological test results show wear resistance of titanium alloy was greatly improved due to the fabrication of hard alumina ceramic coating on titanium alloy.

Microstructure and Wear Resistance of FeCuNiTiAl High-Entropy Alloy Coating on Ti6Al4V Substrate Fabricated by Laser Metal Deposition

In order to improve the hardness and wear resistance of titanium alloys, an equimolar ratio high-entropy alloy (HEA) FeCuNiTiAl coating was fabricated on the surface of titanium alloy Ti6Al4V by means of laser metal deposition for the first time. The microstructure and composition of the HEA coating and the transition zone were observed by scanning electron microscopy (SEM) and energy dispersive spectrometer (EDS). The results show that HEA coating and Ti6Al4V have suitable metallurgical bonding, and no defects, such as cracks, are found at the interface. The hardness of the HEA coating is between 450 and 500 HV0.5, which is about 1.5 times that of the Ti6Al4V substrate. Wear tests show that the wear rate of HEA coating is 0.89 × 10−5 mm3/(N·m), while that of Ti6Al4V reaches 53.97 × 10−5 mm3/(N·m), and the wear resistance of substrate is increased 60 times by the HEA coating. The wear mechanism of the Ti6Al4V substrate is mainly abrasive wear, and the wear mechanism of FeCuNiTiAl HEA coating is mainly adhesive wear, accompanied by slight oxidation wear and abrasive wear.

MICROSTRUCTURE AND TRIBOLOGICAL PERFORMANCE OF SELF-LUBRICATE CLADDING PRODUCED BY TUNGSTEN INERT GAS AND MICROWAVE HYBRID HEATING TECHNIQUES

The wear reduction of moving components is highly desirable because wear limits their reliability and service life, mainly at elevated temperatures. This study produced thick clads of NiCrSiB/WC/MoS2/BaF2 by tungsten inert gas (TIG) and microwave hybrid heating (MHH) cladding techniques, which were compared for microstructural and high-temperature tribological properties. The clad samples were subjected to sliding contact using a pin on disc tribometer at 200∘C, 400∘C, 600∘C under 20 and 40[Formula: see text]N load. The worn surface was analyzed using FESEM, XRD and three-dimensional (3D) profilometer. The experimental results revealed a significant effect of the TIG current and MHH exposure time on the microhardness value, which predominantly depends on the morphological characteristics. The average hardness of TIG clads was found to be 1.2 times higher than the MHH clad. Because of the MoS2 and BaF2 encapsulation, the continuous lubricant layer formation compensated for improved wear resistance with good reliability and longer service life. This work provides significant insights into the wear behavior of TIG and MHH clads at elevated temperatures and the prospective applications in turbines, where inadequate wear resistance of titanium alloy is the major concern for its use.

Self-lubricating coating design strategy for titanium alloy by additive manufacturing

Lowering the coefficient of friction (COF) and improving the wear resistance of titanium alloys are critical for expanding their industrial applications. Herein, we report a novel strategy endowing titanium alloys with superior tribological performance by combining surface texture and solid lubricant: a coating with honeycomb structure was prepared by laser powder-bed fusion and incorporated with polytetrafluoroethylene (PTFE) as solid lubricant. The hybrid coating exhibits stable low COF and zero-wear properties under various service environments: atmosphere, deionized water, seawater, and corrosive acid medium. Under the action of friction force, wear debris can be continuously captured by the hybrid coating while releasing equal volume PTFE lubricant to repair the damaged lubricating film, thereby achieving excellent tribological properties of the coating in various environments. Our findings provide a new approach to improve the friction and wear properties of metal and alloy components.