Wear Resistance Of Titanium Research Articles

Generation of self-healing and sliding wear resistant titanium surfaces by different pico-second laser induced periodic surface structures

Selective and complete micro-patterning (μ-patterning) of α‑titanium surfaces were performed using a 1064 nm laser system. With a fluence of 0.6 J⋅cm−2 and a pulse duration of 10 ps, two different μ-patterns of laser induced periodic surface structures (LIPSS) were generated by mainly changing the number of pulses per spot and the spot-to-spot distance. A high number of pulses per spot and a large spot-to-spot distance of 60 μm gives selectively with LIPSS modified dimples. Their spatial period varies from 159 nm to a maximum of 620 nm inside the dimples. An increased fraction of TiO2 in the crystalline form of rutile gave improved wear resistance and a coefficient of friction COF of 0.20 ± 0.02. If the spot-to-spot distance is reduced to 6 μm and the number of pulses at one spot remains low, a completely rippled surface with slightly increased oxide fraction but still a metallic plastic behaviour was able to show volume expansion during sliding. The observed self-healing ability of this LIPSS pattern is correlated with the relief of compressive stresses in this study. As volume expansion operates against the sliding motion of the diamond tip, high COFs of 0.62 ± 0.11 for a normal load of 1.0 N and 0.45 ± 0.04 for a normal load of 0.5 N were measured. After further optimisation, such a tailored increase in COF and load stimulated volume expansion of the surface could be useful in order to act against implant loosening and undesired movements.

Expanding the applications of the wear-resistant titanium aluminum nitride thin-film to include temperature sensing

This study investigates an approach to temperature sensing by integrating Titanium Aluminum Nitride (TiAlN), originally engineered for wear and corrosion applications, as a temperature sensor within a multilayered thin film system. A nitride multilayer system was developed by physical vapor deposition (PVD) using a single four-target magnetron sputtering chamber; intermediate vacuum interruption steps were employed for masking procedures. The multilayer architecture design aimed to provide the sensor layer with mechanical protection and electrical shielding. Structural and electrical characterization of the TiAlN single layer revealed semiconductor behavior and stable electrical resistance up to 750 °C, with minimal signal stabilization requirements. Despite the higher Al content, the TiAlN temperature sensor exhibited a cubic crystal structure characterized by diffuse nanolayers, resulting from a two-fold rotational deposition and target configuration. A detailed examination of the multilayer system cross-section containing the TiAlN sensor was conducted using scanning transmission electron microscopy (STEM). The analysis revealed its columnar morphology with the presence of typical PVD growth defects, including voids and droplets. While the presence of these defects may impact the electrical characteristics of the sensor, the selected experimental conditions effectively maintained the structural integrity of the multilayer system despite the vacuum interruptions caused by masking procedures. Validation experiments confirmed the functionality of the multilayer system for temperature measurements up to 400 °C. The signal acquisition system addressed room temperature resistance variations and low sensitivity (thermistor coefficient ∼100 K), resulting in a measured error of approximately 6%. This study demonstrates promising results of TiAlN as a temperature sensor within a multilayered system, expanding its range of potential applications.

Tribological Properties of the Fast Ceramic Conversion Treated Ti-6Al-2Sn-4Zr-2Mo Alloy with a Pre-Deposited Gold Layer

Ceramic conversion treatment (CCT) is an effective way to modify the surface of titanium alloys. However, this process normally needs more than a 100-h treatment at 600–700 °C to form a hard and wear-resistant titanium oxide layer. In this paper, we pre-deposited a thin gold layer on the surface of Ti-6Al-2Sn-4Zr-2Mo (Ti6242) samples before CCT to investigate if Au can speed up the treatment. Treatments at 640/670/700 °C were carried out for 10 or 120 h. After CCT, the surface roughness, surface morphology, microstructure, elemental composition, and phase constituents were characterized. Surface hardness and the nano-hardness depth distribution were measured. Finally, reciprocating sliding tribological tests were carried out to study the friction and wear of the surface layers. Thin gold layers accelerated the CCT significantly with a much thicker oxide layer. The friction of the untreated Ti6242 alloy against the WC ball was unsteady and high, but it was much lower and stable for the CCTed samples pre-deposited with Au because of the formation of titanium oxides and lubrication effect of the gold particles. The wear resistance of the CCTed Ti6242 alloy samples with gold was reinforced significantly. By pre-depositing a thin gold layer on the surface of Ti6242, the treatment time can be cut significantly, and CCT becomes more efficient.

Micro End Mill Capability Improvement Due to Processing by Fast Argon Atoms and Deposition of Wear-Resistant Coating

Micro-milling is widely used to make micro-channels in various fields. In this study, micro-milling of rectangular bronze microchannels was carried out with carbide end mills with a diameter of 1 mm, processed with fast argon atoms, and coated with anti-friction wear-resistant titanium diboride. It was shown that the removal of a 3 µm thick surface layer from a micro end mill with fast argon atoms makes it possible to reduce the cutting edge radius of the tool to 1.2 µm, which is three times lower than the minimum value of 4 µm achievable in mechanical manufacturing. The subsequent deposition of a 3 μm thick anti-friction coating results in a wear-resistant micro end mill with original geometric parameters but improved performance. The surface roughness of the machined bronze microchannel significantly decreased, and the burrs above the groove practically disappeared after micro-milling.

Computational design of corrosion-resistant and wear-resistant titanium alloys for orthopedic implants

Titanium alloys are promising candidates for orthopedic implants due to their mechanical resilience and biocompatibility. Current titanium alloys in orthopedic implants still suffer from low wear and corrosion resistance. Here, we present a computational method for optimizing the composition of titanium alloys for enhanced corrosion and wear resistance without compromising on other aspects such as phase stability, biocompatibility, and strength. We use the cohesive energy, oxide formation energy, surface work function, and the elastic shear modulus of pure elements as proxy descriptors to guide us towards alloys with enhanced wear and corrosion resistance. For the best-selected candidates, we then use the CALPHAD approach, as implemented in the Thermo-Calc software, to calculate the phase diagram, yield strength, hardness, Pourbaix diagram, and the Pilling-Bedworth (PB) ratio. These calculations are used to assess the thermodynamic stability, biocompatibility, corrosion resistance, and wear resistance of the selected alloys. Additionally, we provide insights about the role of silicon on improving the corrosion and wear resistance of alloys.

Effect of Magnetron Sputtering Deposition Conditions on the Mechanical and Tribological Properties of Wear-Resistant Titanium Carbonitride Coatings

In the present work, the titanium carbonitride coatings were deposited by the reactive magnetron sputtering method at different substrate bias: 0, −70 V, and −100 V. The effect of the substrate bias on the structure, composition, and mechanical and tribological properties of titanium carbonitride coatings was studied. Scanning electron microscopy, nanoindentation, sliding wear test (ball-on-disk method), X-ray phase, and elemental analysis methods were used to evaluate the tribological properties and microstructure of the thin coatings. The dependencies obtained resulted in the determination of the most preferred mode of deposition by magnetron sputtering at a negative substrate bias in an atmosphere of argon–acetylene–nitrogen.

Preparation and Properties of Multilayer Ca/P Bio-Ceramic Coating by Laser Cladding

In order to enhance the bioactivity and wear resistance of titanium (Ti) and its alloy for use as an implant surface, a multilayer Ca/P (calcium/phosphorus) bio-ceramic coating on a Ti6Al4V alloy surface was designed and prepared by a laser cladding technique, using the mixture of hydroxyapatite (HA) powder and Ti powder as a cladding precursor. The main cladding process parameters were 400 W laser power, 3 mm/s scanning speed, 2 mm spot diameter and 30% lapping rate. When the Ca/P ceramic coating was immersed in simulated body fluid (SBF), ion exchange occurred between the coating and the immersion solution, and hydroxyapatite (HA) was induced and deposited on its surface, which indicated that the Ca/P bio-ceramic coating had good bioactivity. The volume wear of Ca/P ceramic coating was reduced by 43.2% compared with that of Ti6Al4V alloy by the pin-disc wear test, which indicated that the Ca/P bio-ceramic coating had better wear resistance.

Wear resistance of cast dental Ti-Fe alloys.

Binary Ti-Fe alloys with 5-25 mass% Fe were prepared, and subjected to reciprocating wear test. The aim of this study was to investigate the relationship between mechanical properties and the wear resistance of titanium and Ti-Fe alloys. The dimensions (length, width and depth) of wear marks on Ti-Fe alloys were less than those observed on pure Ti specimen. Wear resistance of Ti-Fe alloys was better than that of pure titanium. It was established that hardness was the main factor that influenced wear resistance of Ti-Fe alloys. Single β Ti-Fe alloys showed better wear resistance than α+β Ti-Fe alloys. Increase in concentration of Fe in the β phase of Ti-Fe alloys leads to improved wear resistance of the alloy. Ti-Fe alloys with 11-15 mass% Fe form ideal candidates for fabrication of dental titanium alloys with excellent wear resistance.

Microstructures and mechanical properties of wear-resistant titanium oxide coatings deposited on Ti-6Al-4V alloy using laser cladding

In this work, a freeze-dried TiO2 nano-sized powder was used as the coating material and single tracks of TiOx coating were cladded on Ti-6Al-4V substrates using a diode laser. The microstructure, chemical composition, and mechanical properties of the coatings were characterized and their relationships were explored. Coatings with structural and compositional gradients formed under a laser energy density (LED) of 20 kJ/m, while coatings with a relatively homogeneous microstructure were obtained using a LED of 30 kJ/m. The microstructure evolution was controlled by the molten pool lifetime and the intensity of convective flow during laser processing. The elastic modulus of the graded coating showed a decreasing trend from the top coating surface to the interface while that of the homogeneous coating remained constant. Our results also demonstrated that the hardness and wear resistance of the oxide coatings were up to four and ten times higher than that of the substrate.

Laser-Sustained Plasma (LSP) Nitriding of Titanium: A Review

Titanium and its alloys possess several attractive properties that include a high strength-to-weight ratio, biocompatibility, and good corrosion resistance. However, due to their poor wear resistance, titanium components need to undergo surface hardening treatments before being used in applications involving high contact stresses. Laser nitriding is a thermochemical method of enhancing the surface hardness and wear resistance of titanium. This technique entails scanning the titanium substrate under a laser beam near its focal plane in the presence of nitrogen gas flow. At processing conditions characterized by low scan speeds, high laser powers, and small off-focal distances, a nitrogen plasma can be struck near the surface of the titanium substrate. When the substrate is removed, this plasma can be sustained indefinitely and away from any potentially interacting surfaces, by the laser power and a cascade ionization process. This paper presents a critical review of the literature pertaining to the laser nitriding of titanium in the presence of a laser-sustained plasma, with the ultimate objective of forming wide-area, deep, crack-free, wear-resistant nitrided cases on commercially pure titanium substrates.

Structure and properties of titanium after nitriding in a plasma of pulsed hollow cathode glow discharge

The paper reports on a study of the structure, phase composition and mechanical characteristics of a modified surface layer of VT1-0 titanium after nitriding in the plasma of pulsed and stationary non-self-sustained glow discharge. It was revealed that after nitriding in a pulsed glow discharge, the volume fraction of nitride phase (Ti2N, TiN) in the surface layer of VT1-0 titanium is higher than that in the nitrited layer obtained by exposure to a plasma of steady glow discharge at the same nitriding temperatures, average ion current density at the surface and ion energy. As a result, the hardness of the surface layer of samples obtained by nitriding in pulsed discharge mode exceeds that of samples treated in steady glow discharge mode. Wear resistance of titanium after nitriding in the plasma of a pulsed glow discharge is approximately four times higher than that of titanium without treatment and 1.5 times higher than that achieved by nitriding in a steady glow discharge plasma.

Al2O3-TiB2 nanocomposite coating deposition on Titanium by Air Plasma Spraying

Titanium has low wear and corrosion resistance due to its low hardness. The corrosion and wear resistance of titanium are improved using various surface modification methods such as coating with sufficient materials. Al2O3 based microparticles’coatings have interesting mechanical properties. Mechanical properties of alumina can be improved with several techniques such as applications of alumina nanoparticles instead of microparticles and also adding ceramics such as TiB2. Air Plasma Spraying is a physical method for coating, which is one of the most commercial and economical coating techniques. The aim of this work is to coat TiB2-Al2O3 Nanocomposite on commercially pure titanium by Air Plasma Spraying method. Spraying process was operated at two steps. In this research, the effect of current on melting of TiB2-Al2O3Nanocomposite and microstructure of coatings was investigated. Surface characteristics were evaluated using Field Emission Scanning Electron Microscopy (FESEM(. The microstructure of the coatings consisted of two distinct regions and was completely melted and quenched as splats, and the other one was incompletely melted.

Diffusion Saturation by Titanium from Liquid-Metal Media as Way to Increase Carbide-Tipped Tool Life

The analysis of the strengths and weaknesses of the existing technologies aimed at improving the performance properties of carbide-tipped tools is presented. The results of studies into the process of diffusion metallization by titanium of a carbide-tipped tool TK type from the media of fusible liquid-metal solutions is given. The influence of titanium diffusion coatings on the durability of carbide tools is investigated. A method of providing formation on hard alloys for wear-resistant titanium high-quality functional coatings is described. The thickness of the coating varies depending on the temperature and exposure time, and ranges from 4 to 6 μm. The hardness of the coatings obtained depends on the temperature of the coating and modes of pre-carburizing, and varies from 24100 to 30000 MPa. The microstructure of the coatings is investigated. The coating consists of two layers: the coating and the transition zone, the size and hardness of which depends on the conditions of pre-carburization and modes of application of the coating. The dependence of the coatings thickness on the duration of the plates exposure in the melt, the temperature of coating composition from the coated hard alloy is investigated.

Microstructure and Wear Properties of Laser-Cladded cBN/Ti $$_{3}$$ 3 Al on Pure Titanium

In order to improve the tribological properties of titanium alloys at high temperature, the possibility of producing Ti\(_{3}\)Al intermetallic with the addition of ceramic (cBN) coatings on titanium substrate using laser technique cladding was investigated. cBN is generally known for its high hot hardness, wear resistance and chemical stability. Laser cladding is an emerging material processing technique which is an efficient and cost-effective technique for improving the surface properties of general metallic materials. This paper presents the effects of laser cladding on the phase combination, microstructure, hardness and wear resistance of titanium aluminide/cBN IMC composites at different variations in quantity of cBN in the composite. Optical microscopy, X-ray diffraction and scanning electron microscopy with EDX were used for characterising the microstructure of the coating. In addition, the composite coating was subjected to wear testing using the ball-on-disc, friction and wear apparatus. The XRD results revealed phases with small cBN, \(\hbox {Ti}_{2}\hbox {N}\) and \(\hbox {TiB}_{2}\) peaks in addition to the rich \(\gamma \)-Ti, \(\alpha 2\hbox {-Ti}_{3}\hbox {Al}\) and TiAl intermetallics phases in the coatings after cladding process, whereas the microstructure of the cBN cladded layer contained partially melted cBN grains evenly dispersed within the laths of alpha Widmanstatten phase in the form of dendrites, precipitate of \(\alpha _{2}\hbox {-Ti}_{3}\hbox {Al}\) and spherical-shaped pure titanium. The effect of the addition of cBN into \(\hbox {Ti}_{3}\hbox {Al}\) alloy at increasing weight percentages showed an improvement in the hardness and wear resistance of the coatings. The increase is attributed to reacted boron nitrides particles with titanium, being distributed uniformly in the intermetallic matrix.

A new method for production of titanium vapor and synthesis of titanium nitride coatings

It is proposed to synthesize on machine parts and cutting tools wear-resistant titanium nitride coatings with the help of the hollow-cathode glow discharge, a molybdenum crucible for titanium evaporation being used as the anode of the discharge and a process vacuum chamber being used as the hollow cathode. The research revealed that at the anode surface area less than a critical value S* = (2 m / M ) 1/2 S , where S is the area of the chamber walls, m is the mass of electrons and M is the mass of ions, the anode fall of potential is positive and grows from ∼50 V at argon pressure p = 0.2 Pa to ∼2 kV at p = 0.02 Pa. At the discharge current I = 0.6 A electrons accelerated by the anode fall of 0.9 kV transport into the crucible with the inner diameter of 12 mm the power of ∼0.54 kW, which allows the titanium evaporation and the coating deposition rate of 5 µm·h −1 on a substrate distanced from the crucible at 100 mm. After the argon is replaced with the nitrogen, titanium nitride coating without titanium droplets is synthesized the deposition rate amounting to about the same value.

Fibre laser nitriding of titanium and its alloy in open atmosphere for orthopaedic implant applications: Investigations on surface quality, microstructure and tribological properties

Laser nitriding is known to be an effective method to improve the surface hardness and wear resistance of titanium and its alloys. However, the process requires a gas chamber and this greatly limits the practicability for treating orthopaedic implants which involve complex-shaped parts or curved surfaces, such as the tapered surface in a femoral stem or the ball-shaped surface in a femoral head. To tackle this problem, a direct laser nitriding process in open atmosphere was performed on commercially pure titanium (grade 2, TiG2) and Ti6Al4V alloy (grade 5, TiG5) using a continuous-wave (CW) fibre laser. The effects of varying process parameters, for instance laser power and nitrogen pressure on the surface quality, namely discolouration were quantified using ImageJ analysis. The optimised process parameters to produce the gold-coloured nitride surfaces were also identified: 40W (laser power), 25mm/s (scanning speed), 1.5mm (standoff distance) and 5bar (N2 pressure). Particularly, N2 pressure at 5bar was found to be the threshold above which significant discolouration will occur. The surface morphology, composition, microstructure, micro-hardness, and tribological properties, particularly hydrodynamic size distribution of wear debris, were carefully characterized and compared. The experimental results showed that TiG2 and TiG5 reacted differently with the laser radiation at 1.06μm wavelength in laser nitriding as evidenced by substantial differences in the microstructure, and surface colour and morphology. Furthermore, both friction and wear properties were strongly affected by the hardness and microstructure of titanium samples and direct laser nitriding led to substantial improvements in their wear resistant properties. Between the two types of titanium samples, bare TiG2 showed higher friction forces and wear rates, but this trend was reversed after laser nitriding treatments.

Design of friction and wear resistant titanium- and cobalt-modified nickel-base repair alloys by spray forming

Powder injection molding (PIM) is a newly developed method for repairing gas turbine components in recent years. However, the PIM method needs a sacrificial binder, which increases working procedure and cost. To overcome this disadvantage, a new method of maintenance, i.e. spray forming (SF) technique, is put forward in this study. Three kinds of Ni-base repair alloys have been designed and prepared by the SF process. And these alloys were subjected to friction, wear and material analysis tests. Results reveal that the alloy with high titanium and cobalt content has the best friction and wear resistance. The increase in titanium and cobalt content will result in the increase of γ/γ′ misfit, grain size, and coherent γ′ size, and enhance the formation of good oxides lubricants, which leads to a decrease of the coefficient of friction. Moreover, with increasing titanium and cobalt content, the predominant wear mechanism changes from delamination wear to abrasive wear and adhesive wear. The high titanium and cobalt content give a large improvement in wear resistance by strongly hindering dislocations motion and reducing crack growth rate, which resists delamination wear.

DESTRUCTION OF BLADES SURFACE COATING

The article discusses a change of impact elasticity (a crack resistance or other value characterizing a resistance to rupture) depending on the cutting blade heating temperature. The test results showed that high temperature impact resistance strengthening of the hard alloy blade structure by treatment of its surface with wearresistant refractory titanium nitride coating proved its effectiveness at 500 0C and at 600 0C. At temperature of 900 0C a deterioration occurs resulted from generation of defects in the coating and in the hard alloy surface layer which become the sites of destructive impact crack initiation.

Diffusional titanium coatings on cast iron

The application of diffusional titanium coatings on cast iron from metal melts is investigated. The proposed technology ensures the formation of wear-resistant titanium coatings on cast iron. The composition, structure, and properties of the titanium coatings and the subsurface layer are studied, as well as the process of coating formation on cast iron.

A Comparative Study: Effects of Two Different Surface Engineering Technologies on Tribological Properties of Pure Titanium

Two different surface engineering technologies, plasma nitriding and titanium nitride (TiN) film deposition by closed-field unbalanced magnetron sputtering (CFUBMS), were used to improve the tribological properties of pure titanium. Surface characteristics were evaluated by microhardness tester, scanning electron microscopy(SEM), X-ray diffraction (XRD) and pin-on-disc tribotester. The influence of the two surface treatments on wear resistance of titanium was investigated. After plasma nitriding or TiN film deposition by CFUBMS, the microhardness of the surface increased approximately 3 to 5 times when compared with that of untreated pure titanium and the wear resistance was improved significantly. The wear resistance of TiN film deposited titanium specimens was higher than that of plasma nitrided ones.