ZrO2 Content Research Articles

Study of the mechanical properties and toughening mechanism of ZrO2 particles toughened Si3N4 ceramics

Si3N4 ceramic has excellent properties such as high temperature resistance, high hardness, and high thermal stability, but it has the disadvantages of high hardness and brittleness and difficulty in later processing. In this paper, ZrO2 was used as toughening phase, and ZrO2 toughened Si3N4 ceramics was prepared by injection molding. The effects of ZrO2 sintering temperature and content on the mechanical properties and fracture morphology were studied. Experiments show that when the ZrO2 content is 10 wt.% and the sintering temperature reaches 1650 °C, the bending strength and fracture toughness of Si3N4 ceramics reach the maximum at the same time, which are 767 MPa and 8.7 MPa·m1/2, respectively. The density is high. XRD analysis revealed that if the sintering temperature is too high, the ZrO2/Si3N4 system will generate a large number of ZrN impurity phases that cannot be phase-transformed, which ultimately affects the ceramic properties. According to fracture morphology, the toughening mechanism of ZrO2 is stress-induced phase transition.

Mechanical and Optical Properties of ZrO2 Doped Silicate Glass Ceramics

In the present study, we report the physical and optical properties of low-cost glass (soda-lime silicate glass) fabricated from local minerals, obtained from Hazara division Khyber Pakhtunkhwa, Pakistan. Zirconium dioxide (1–3%) was added as a nucleating agent to investigate its effect on phase, density, hardness, and optical properties of soda-lime silicate glass. In the obtained glass-ceramic materials, the major crystalline phase was cristobalite. It was found that an increase in ZrO2 content and heat treatment of the samples, resulted in an increase in bulk crystallization of the samples. The mechanical properties were found to be improved with ZrO2 addition. The bandgap of the sample was in the range 3.78–4.09 eV.

Crystal growth velocities of a highly anisotropic phase obtained via surface and volume crystallization of barium–strontium–zinc silicate glasses

In the past few years, a new phase, Ba0.5Sr0.5Zn2Si2O7 with negative thermal expansion has been described in the literature. Some excess of SiO2 is necessary to produce glasses from which the Ba0.5Sr0.5Zn2Si2O7 phase can be crystallized. Unfortunately, in such glasses usually surface crystallization occurs; however, the addition of nucleating agents such as trace quantities of platinum or relatively high quantities of ZrO2 is necessary to achieve bulk nucleation. These additional components also affect the crystal growth velocity, which furthermore is different for crystal growth from the surface and in the bulk. In this paper, three different chemical compositions containing different ZrO2 concentrations, where one composition additionally contains 100 ppm platinum, are studied with respect to their crystallization behaviour. Although the compositions do not differ much, the crystallization behaviour and also the Crystal growth velocities are surprisingly different.

RETRACTED: Bioactivity, antibacterial activity and functionality of zirconia doped zinc phosphate bioglasses for application in dentistry.

Abstract Objective Zirconia incorporated zinc phosphate bioactive glasses have been developed and assessed to know the structural strength and the capacity to form new bone bond layer (Hydroxyapatite layer) essential for the production of dental and orthopaedic implants. Methods The bioglass 8ZnO–22Na2O–(24-x)CaO–46P2O5–xZrO2 (where x = 0, 0.1, 0.3, 0.5, & 0.7 mol%) was synthesized by conventional melt-quenching technique. The structural and physico-mechanical properties of glasses were investigated. For in vitro bioactivity analysis, the samples were immersed in SBF for various time periods (0, 3, 7, 14 & 21 days) and formation of hydroxyapatite layer (HAP) layer on glass surfaces was examined by X-Ray diffraction (XRD), Fourier transform infrared (FTIR) and Scanning electron microscopy- Energy dispersive X-ray spectroscopy (SEM-EDS) techniques. The dissolution behavior of the glasses was evaluated by weight loss and pH measurements. Additionally, Cytotoxicity and proliferation were analyzed by culturing rat mesenchymal stem cells (rMSC) for 24 h and 72 h using Cell counting kit (CCK-8) method and antibacterial activity was tested aginest Escherichia coli (E. coli), Staphylococcus aureus (S. aureus) and Pseudomonas aeruginosa (P. aeruginosa) at different time intervals 24 h and 48 h. Results The chosen bioglasses showing enhanced bioactivity and structural properties. The formation of hydroxyapatite layer increases with the content of ZrO2 up to 0.5 mol% and decrease further increase zirconia in the glass network. pH variation and weight loss results disclosed the controlled release of Ca2+ and Zr4+ ions. All samples displaying high proliferation good cytocompatability and antibacterial activity. In addition, physico-mechanical properties increases gradually with zirconia incorporation. Significance These findings implicate that, as-synthesized bioactive glasses are showing stimulatory effects on bone growth and lead to the development of dental and orthopeadic implants.

Modification of barium aluminosilicate glass-ceramics with zirconium oxide additives

Barium aluminosilicate glass-ceramics modified with zirconium oxide (ZrO2) in the presence and without of stabilizing yttrium oxide was synthesized by the sol-gel method. The influence of the concentration of zirconium oxide on gelation, phase formation and sintering of materials were investigated. It was found that modification with zirconium oxide leads to a reduction in the gelation time of the initial solutions. It was shown that the introduction of ZrO2 in an amount of up to 10 wt.% leads to the intensification of sintering of glass-ceramics. However, with a further increase in the ZrO2 content to 15 wt.%, it is necessary to increase the sintering temperature to 1600°C. But this is not permissible, since it leads to not a desired metastable phase – hexacylsian becoming predominant in all samples. Only glass-ceramics modified with 10 wt.% ZrO2 contains only the monocelsian phase in the entire sintering temperature range. The use of the sol-gel method made it possible to synthesize glass-ceramics with a fine-crystalline structure and a uniform volume distribution of ZrO2 grains.

Structural evolution of high zirconia aluminosilicate glasses

We report a detailed structural investigation of Ca-Na aluminosilicate glasses containing 0–20 wt% ZrO2 using X-ray absorption spectroscopy, Raman spectroscopy and 27Al and 29Si NMR. The X-ray absorption spectroscopy data reveal that Zr is predominantly present in ZrO6 octahedra but a significant Zr coordination change occurs with increasing ZrO2 content. Though Al and Zr are competing to be surrounded by charge balancing cations, 27Al NMR data do not show the presence of high-coordinated Al species; thus charge-balancing cations are preferentially localized close to AlO4 tetrahedra rather than Zr polyhedra, explaining the increase in Zr coordination number that ultimately leads to limit Zr solubility in glasses. Raman and 29Si NMR data indicates that Zr atoms are linked to the silicate network with a trend for higher degree of network connectivity at high zirconia content. Change in network connectivity and in Zr environment provide insights to understand chemical durability or crystallization in glasses.

The influence of MgO/ZrO2/Al2O3 refractories on the refining process of Ti-containing steel based on kinetic study

Ti-containing steel is widely used in various industries, and its refining process has a significant impact on performance. The influences of refractories on the refining process were studied by the interaction between refining slag and Ti-containing steel in this paper. During the refining process with MgO and ZrO2 crucible, the content of MgO and ZrO2 in the refining slag respectively increase, and they also appear in the inclusions. MgO refractory can promote the reaction between CaO in slag and molten steel, but Al2O3 and ZrO2 refractories cannot. Al2O3 refractory significantly increases the Al2O3 content oin the inclusions by affecting the slag-metal-inclusion reaction. A kinetic model for simulating the reaction of the refractory-slag-metal-inclusion system was established, and it can be applied to predict the composition variations of the slag, the steel, and the inclusions during the refining process. According to the model and experimental results, it is obvious that MgO, Al2O3 and ZrO2 refractories have different mass transfer with refining slag. The mass transfer coefficients of all three refractories were obtained in current research (kMgO = 1.0 × 10-4 m/s, kAl2O3 = 2.0 × 10-4 m/s and kZrO2 = 1.1 × 10-4 m/s).

Corrosion, oxidation and wear study of electro-co-deposited ZrO2-TiO2 reinforced Ni-W coatings

The pulsed electro-co-deposition process was used on mild steel substrate to develop Ni-W based composite coating which comprises of ZrO2 and TiO2 oxide nanoparticles. In the deposition bath, plating parameters and ZrO2 content were maintained constant, whereas, TiO2 content was varied. Phase constitution, morphology, and chemistry of the coatings were examined by X-ray diffraction, field emission scanning electron microscopy and energy dispersive spectroscopy respectively. Surface-mechanical properties were evaluated by wear and microhardness test. Potentiodynamic polarization technique and electrochemical impedance spectroscopy were employed to determine the corrosion resistance of the coatings in a 3.5% NaCl solution. In addition, the isothermal oxidation test was conducted on the coatings at different temperatures (600, 700 and 800 °C) to evaluate the oxidation properties. From the experimental results, it got evidenced that microstructure, microhardness, wear, oxidation and corrosion properties of coatings significantly affected by the incorporation of ZrO2 and TiO2 nanoparticles. Under constant ZrO2 content, microhardness, corrosion and wear resistance of the coatings were significantly improved with increasing TiO2 content (0–15 g/L bath). Coatings with TiO2 addition were more beneficial as compared to the Ni-W and Ni-W-ZrO2 coatings. The oxidation resistance of Ni-W coating was improved after the dispersion of ultrafine ZrO2 and TiO2 particles in the matrix. Optimum values of hardness (963 HV0.05), corrosion resistance (Rct: 6082 ± 33 Ω·cm2) and wear resistance were achieved in the case of Ni-W-5 g/L ZrO2-15 g/L TiO2 composite coating.

Chemical sensing behaviour of PVA based composite

This study is conducted to enhance the sensitivity of polymer composite films in applications such as chemical sensing. For this purpose, polyvinyl alcohol (PVA) and zirconium dioxide (ZrO2) composites based gas sensors are fabricated via spin coating technique. The concentration of PVA and ZrO2 has been varied to investigate its effect on the properties of the films. The synthesized PVZr composites are characterized by XRD, FTIR and SEM. These characterization techniques are employed to study the structure and morphology of the deposited composite films. The 0.6 wt% PVA based gas sensors demonstrate increased sensitivity as compared to the others.

Nano-Grain Ni/ZrO2 Functional Gradient Coating Fabricated by Double Pulses Electrodeposition with Enhanced High Temperature Corrosion Performance

Functional gradient materials (FGM) have many excellent properties, and high-performance gradient coating exhibits good prospective application. In this paper, the nano-grain Ni/ZrO2 gradient coating was prepared by double pulse electrodeposition (BP). The surface morphology, crystal structure and electrochemical corrosion resistance of the nano-grain Ni/ZrO2 coating and Ni coating, annealed at different temperatures (400–800 °C), have been compared. In the vertical direction to the substrate surface, the content of ZrO2 increases from 0% to 34.99%. X-ray diffraction (XRD) revealed that the average crystal size of Ni/ZrO2 gradient coating gradually increases from 13.75 to 27.75 nm, and the crystal structure is a face-centered cubic (FCC). The main crystal orientation faces are (111) and (200), while the (200) face exhibited a stronger preferred orientation. Compared with the Ni coating by scanning electron microscopy, the surface morphology of double pulse fabricated Ni/ZrO2 gradient coating was revealed as being smoother, denser, and having fewer pores, and the crystal particle size distribution became narrow. X-ray photoelectron spectroscopy (XPS) shows that the chemical binding states of elements Ni and Zr have been altered. The binding energies of 2p3/2 and 2p1/2 for Ni have been increased, resulting in a higher electron donor state of Ni. The binding energy of 3d5/2 and 3d3/2 of Zr4+ in ZrO2 is decreased, thus becoming better electron acceptors. Chemical bonding has been formed at the Ni/ZrO2 interface. This study demonstrated that double pulse electrodeposition is a promising fabrication method for functional gradient coatings for high temperature applications.

A Novel Zirconium Modified Arylacetylene Resin: Preparation, Thermal Properties and Ceramifiable Mechanism

With the rapid development of thermal protection systems for the aerospace industry and power electronics, polyarylacetylene (PAA) resin plays an important role because of its good mechanical properties, high glass transition temperature (Tg), low water absorption, high char yield (Yc), and the fact that there is no byproduct released in the curing process. In order to further improve the thermal property of PAA based FRP for the thermal protection field, the introduction of a zirconium element into arylacetylene is promising. In this paper, zirconium modified arylacetylene (ZAA) resin was prepared by two-step synthesis. The FTIR analysis characterized its molecular structure and confirmed the products. The viscosity of ZAA was about 6.5 Pa·s when the temperature was above 120 °C. The DSC analysis showed that the ZAA had a low curing temperature, and its apparent activation energy was 103.86 kJ/mol in the Kissinger method and 106.46 kJ/mol in the Ozawa method. The dielectric constant at 1 MHz of poly(zirconium modified arylacetylene) (PZAA) was 3.4. The TG analysis showed that the temperatures of a weight loss of 5% (Td5) and char yield (Yc) at 800 °C of PZAA were 407.5 °C and 61.4%, respectively. The XRD results showed the presence of SiO2 and ZrO2 in the PZAA residue after ablation. The XRF results showed that the contents of SiO2 and ZrO2 in PZAA residual after ablation were, respectively, 15.3% and 12.4%. The SEM showed that the surface of PZAA after ablation had been covered with a dense and rigid ceramic phase composed of ZrO2 and SiO2. Therefore, the introduction of Zr into arylacetylene greatly improved the densification of the surface after ablation, and improved the heat resistant property.

Effects of Transition Metal Oxides ZrO2, Y2O3, and Sc2O3 on Radiative Heat Transfer of Low-Reactive CaO-Al2O3-Based Mold Slag

To control heat transfer between the solidifying shell and the water-cooled mold during continuous casting, the transition metal oxides, ZrO2, Y2O3, and Sc2O3, were separately added into the developed low-reactive CaO-Al2O3-based mold slags to investigate the effect on radiation heat transfer. Two kinds of master mold slags were taken into account, one included 18 pct Al2O3 and 18 pct SiO2, and the other one included 28 pct Al2O3 and 8 pct SiO2. The slag viscosity and melting temperature were measured with rotating cylinder viscometer and hemisphere-point method, respectively. The optical parameters of the slag films having different contents of transition metal oxides were measured by Fourier transform infrared spectrometer, and an optical-process model was constructed to consider the radiation from the shell surface and hot and cold sides of the solid films to the mold plate. When ZrO2, Y2O3, and Sc2O3 contents up to 4 pct, the viscosity at 1573 K fluctuated in the range of 0.05 Pa s, the melting temperature varied within a range of 15 K, except for the case of 2 pct Sc2O3, for which the melting temperature was 27 K lower than that of the master mold slag with 8 pct SiO2 and 28 pct Al2O3. The incorporation of the three transition metal oxides up to 4 pct did not have a notable effect on the viscosity or melting temperature. The addition of ZrO2 and Y2O3 effectively decreased the radiation, whereas Sc2O3 had no direct relationship with radiation. When the ZrO2 (Y2O3) concentration was increased from 0 to 4 pct, the reduction rate of radiation transfer was 26.6 pct (13.3 pct) for the mold slag containing 18 pct Al2O3 and 18 pct SiO2. The current study provides a new direction for developing low-reactive mold slag and reducing heat transfer during continuous casting.

The activation and conversion of carbon dioxide on the surface of zirconia-promoted ceria oxides

This study reports the conversion of carbon dioxide (CO2) by ceria (CeO2)-zirconia (ZrO2) composites with various ZrO2 contents (0, 20, 50, 80 and 100 %). The modification introduced by ZrO2 altered the structural properties of the ceria samples, affecting their reducibility and subsequent activity to convert CO2. The characterisation results showed a clear relationship between the structural properties of the materials and the activity for CO2 conversion. The addition of ZrO2 was effective to improve a close interaction between CeO2 and ZrO2 and induced the formation of structural defects that further promoted oxygen transport and facilitated the creation of oxygen vacancies that were critical for CO2 conversion. All samples investigated were found to be effective in converting CO2 into carbon monoxide (CO) at 450 °C, and the addition of ZrO2 was also found to be effective in improving the thermal resistance and stabilising the crystalline structure of the samples especially when the ZrO2 content was > 50 %. When the content of ZrO2 controlled between 50 % and 80 %, the onset temperature for CO2 conversion was found to be 285 °C, which was about 80 °C lower than that required for the sample without ZrO2 modification. Thus, modifying CeO2 by ZrO2 was effective to prevent both the textural and structural alteration of the samples under a high temperature environment as well as cyclic redox operations, resulting in a constant and high degree of CO2 conversion into CO.

Electrochemical behavior and corrosion resistance of IrO2-ZrO2 binary oxide coatings for promoting oxygen evolution in sulfuric acid solution

In this study, we prepared Ti/IrO2-ZrO2 electrodes with different ZrO2 contents using zirconium-n-butoxide (C16H36O4Zr) and chloroiridic acid (H2IrCl6) via a sol-gel route. To explore the effect of ZrO2 content on the surface properties and electrochemical behavior of electrodes, we performed physical characterizations and electrochemical measurements. The obtained results revealed that the binary oxide coating was composed of rutile IrO2, amorphous ZrO2, and an IrO2-ZrO2 solid solution. The IrO2-ZrO2 binary oxide coatings exhibited cracked structures with flat regions. A slight incorporation of ZrO2 promoted the crystallization of the active component IrO2. However, the crystallization of IrO2 was hindered when the added ZrO2 content was greater than 30at%. The appropriate incorporation of ZrO2 enhanced the electrocatalytic performance of the pure IrO2 coating. The Ti/70at%IrO2-30at%ZrO2 electrode, with its large active surface area, improved electrocatalytic activity, long service lifetime, and especially, lower cost, is the most effective for promoting oxygen evolution in sulfuric acid solution.

Study of structural and mechanical behaviour of Al-ZrO2 metal matrix nanocomposites prepared by powder metallurgy method

(1-x)Al + xZrO2 (x = 0, 2, 4 and 6 wt%) metal matrix nanocomposites (MMNCs) have been prepared by the powder metallurgy method with Aluminium (Al) metal powder as a matrix material and ZrO2 nanoparticles synthesised by co-precipitation method was used as a reinforcement material. ZrO2 crystallizes in monoclinic structure with an average crystallite size of 22.28 nm. In MMNCs both Al and ZrO2 phase appears separately and intensity of ZrO2 phase increase with the increase in ZrO2 concentration. ZrO2 nanoparticles were finely dispersed into Al MMNCs as confirmed by Scanning Electron Microscope (SEM). Mechanical properties of ZrO2 reinforced MMNCs has been significantly improved as compared to pure Al. The maximum hardness value of Al-ZrO2 MMNCs is improved by 9.57% and wear resistance is improved by 63.91% for 6 wt% of ZrO2 in Al metal matrix. The nanocomposites containing the highest concentration of ZrO2 i.e. 6 wt% shows maximum corrosion resistance efficiency i.e. 70% as compared to 2 wt% and 4 wt% which were showing 35.55% and 41.20% respectively.

On the Differentiation of Heterocoagulation and Coagulation Processes Processing in Binary Mixed Sol

Results of turbidimetry study of aggregate stability of binary SiO2–ZrО2 sol and its components in 10–3–10–1 M KCl solutions at рН 3.4 when ZrO2 particles have a high positive charge and SiO2 particles are slightly (close to zero) negatively charged are presented. The ratio of numerical concentrations of sol particles ZrO2 to SiO2 was 7.8 : 1. It was found that in binary SiO2–ZrО2 sol both the process of heterocoagulation (mutual coagulation) of sols and coagulation of the same oxide particles occur throughout the studied range of KCl concentrations. The way of differentiation of processes of dissimilar SiO2 and ZrO2 particles heterocoagulation and coagulation of components is proposed. It is shown that at pH 3.4 the increase in the concentration of KCl solutions in binary SiO2–ZrО2 sol leads to a decrease in the intensity of the process of ZrO2 and SiO2 particles mutual coagulation, which is explained by the decrease in the radius of action of attraction of dissimilar particles.

High Velocity Impact Response of Aluminum- Carbon Fibers-Epoxy Laminated Composites Toughened by Nano Silica and Zirconia

This research work investigated the effects of SiO2 and ZrO2 nanoparticles type and content incorporated into an epoxy matrix on the high velocity impact behavior of carbon fiber reinforced aluminum laminates (CARALL). CARALL specimens consisted of a 0/90/90/0 stacking sequence of a carbon-epoxy composite containing 0, 1, 3, 5 and 7 wt% of each of nanoparticles sandwiched between two layers of aluminum 2024-T3. To observe the toughening effects of the nanoparticles on the fracture surface of the impacted CARALL, a typical field emission scanning electron microscope (FESEM) was employed. Impact energy absorption of CARALL was at most increased by 18 % and 12 % with the nanoparticles content of 5 wt% SiO2 and 3 wt% ZrO2, respectively. Overloading of the nanoparticles content up to 7 wt% resulted in the creation of nanoparticles aggregated sites associated with loss in the energy absorption capacity. FESEM fractography procedure also showed that the crack deflection and pinning were the most recognizable toughening mechanisms exhibited by nanoparticles. Overall, the controlled addition of SiO2/ZrO2 rigid nanoparticles to CARALL was found to be a promising method for improving the high velocity impact energy absorption of CARALL.

Antiferroelectricity in ZrO<sub>2</sub> and Ferroelectricity in Zr, Al, La Doped HfO<sub>2</sub> Nanoparticles

The dependence of the polarization P in Hf1-xZrxO2 nanoparticles on electric field, dopant concentration x, size and temperature are studied using the transverse Ising model and the Green’s function method. Pure ZrO2 shows at high electric fields an antiferroelectric behavior. Pure HfO2 is a linear dielectric in the monoclinic phase. With increasing ZrO2 content the of HZO shows a ferroelectric behavior. The composition dependence x of the remanent polarization Pr(x) has a maximum for x = 0.5. For x = 0, pure HfO2, and x = 1, pure ZrO2, Pr=0. P increases with decreasing HZO nanoparticle size. The influence of Al and La doping on Pr in HfO2 nanoparticles is also studied. The exhibiting of the ferroelectricity in ion doped HfO2 is due to a phase transformation and to an internal strain effect. The observed results are in good qualitative agreement with the experimental data.

Synthesis of Ni–Fe and Ni–Fe/ZrO2 composite coating and evaluation of its structural and corrosion resistance

Ni–Fe/ZrO2 nanocomposite coating was fabricated by pulse electrodeposition in the presence of suspending ZrO2 nanoparticles. Ni–Fe alloy coating were also prepared for comparison. The effects of electrodeposition parameters, Fe2+ ions and ZrO2 concentration on the nanocomposite coating were examined with various methods. All coatings exhibit dense, compact and crack-free structures. The morphology slightly altered at different conditions. Fe content is more sensitive to the deposition parameters and greatly affects the chemical composition and phase structure of Ni–Fe matrix. Current density affects the composition rather than the texture of Ni–Fe matrix. The texture, composition and properties of Ni–Fe/ZrO2 composite coating were influenced by pulse frequency, duty cycle and ZrO2 concentration. The Ra of Ni–Fe/ZrO2 nanocomposites are about 6.2–37.1 nm, depending on the process parameters. The preferred orientation is (200) texture and the process parameters influenced the RTC value. The higher content of ZrO2 results in the rougher surface. 12.5 g L−1 FeSO4·7H2O and 4 A dm−2 was the suitable parameters for the optimal composition and corrosion resistance of Ni–Fe alloys. The optimal composition of Ni–Fe/ZrO2 deposits was 74.7 ± 0.4 at.% Ni, 16.8 ± 0.5 at.% Fe and 8.5 ± 0.2 at.% ZrO2.

Wear studies of spark plasma sintered ZrO2 reinforced Ti-6Al-4V alloy

The aim of this paper is to investigate wear and tribological properties of powder metallurgy processed Ti-6Al-4V with additions of ZrO2 to produce Ti-6Al-4V/ZrO2 composites consolidated via spark plasma sintering. The spark plasma sintered compacts were examined using optical microscopy (OM) and scanning electron microscopy (SEM) techniques. Dry sliding wear tests were carried out at 5 N and 10 N using a pin-on-disk tribometer. Optical micrographs showed that additions of ZrO2 to Ti-6Al-4V promoted the formation of agglomerated ZrO2-rich particles in the matrix of Ti-6Al-4V. The friction coefficient values were very similar for all compositions, with values ranging between 0.35 and 0.55, with the lowest COF value recorded for Ti6Al4V/5ZrO2 composite at 10 N applied load. Wear and microhardness results indicate that the hardness and the wear resistance improved with increasing content of ZrO2. The lowest surface degradation was observed for Ti-6Al-4V with 10% ZrO2. The low wear resistance of Ti-6Al-4V in comparison to Ti-6Al-4V/ZrO2 composites can be attributed to the low hardness of this alloy. Adding ZrO2 to Ti-6Al-4V was found to significantly improve the wear and hardness properties of Ti-6Al-4V and may therefore potentially broaden the scope of application and performance of Ti-based materials in critical applications; particularly where wear and friction are critical concerns.