Commercial Pure Titanium Alloy Research Articles

Characterization of Electrochemical and Biocompatibility of Zinc Oxide Coating Electrodeposited on Commercial Pure Titanium Alloy

This study examines how the duration of electrodeposition affects the morphology and electrochemical characteristics of zinc oxide coatings applied to a pure titanium substrate. The morphology of the coating and the phases present within it are analyzed using a scanning electron microscope and the X‐ray diffraction technique. The coating's resistance to corrosion in a phosphate‐buffered saline solution is evaluated using two electrochemical methods: impedance spectroscopy and potentiodynamic polarization tests. The surface roughness of the coated samples is assessed using interferometry. The results demonstrate that an increase in electrodeposition time, ranging from 150 to 1200 s, leads to an enhanced texture intensity in the (0002) and (010) planes of the ZnO coating. Furthermore, the thickness of the ZnO crystals and surface roughness increases by factors of 3.25 and 2.79, respectively, as the deposition time is extended. This extended duration results in the formation of larger needle‐shaped and flower‐like ZnO crystals, leading to a significantly nonuniform structure. Correspondingly, the corrosion rate also increases as the electrodeposition time is extended from 150 to 1200 s, rising from 0.001951 to 9.117 μm year−1. The lowest corrosion rate (1.654 μm year−1) is achieved in coatings deposited for 300 s using a potential of 3 V.

Ultrasonic pulsed waterjet peening of commercially-pure titanium

Commercially-pure titanium (CP-Ti) has proven indispensable in critical industries such as aerospace and automotive. To meet the ever-increasing demands of titanium applications, ultrasonic pulsed waterjet peening (UPWJ) has been evaluated for the first time on CP-Ti, as a novel method to optimise compressive surface residual stress. UPWJ offers the potential for an environmentally benign, non-contaminating peening process, paving the way for sustainable surface modification methods. UPWJ treatment involved directing a waterjet at a pressure of 69 MPa onto CP-Ti coupons, maintaining a stand-off distance of 25.4 mm and adjusting traverse speeds from 200 to 1000 mm/s. The effects of stand-off distance were also evaluated (varied from 25.4 to 44.4 mm), at a constant traverse speed of 1000 mm/s. Conventional shot peening was also applied on the same CP-Ti alloy as a baseline. The experimental results revealed relationships between the applied traverse speed and stand-off distance, and the measured surface roughness and residual stress. Furthermore, it was shown that UPWJ improves the surface mechanical behaviour, in terms of both the Rockwell hardness (HRB) and the scratch hardness. A higher stand-off distance and faster traverse speed contributed to increasing the induced compressive residual stress (to a maximum of −391 MPa), while keeping the surface roughness at moderate levels (i.e., Ra <3 μm). Comparing UPWJ with shot peening, this study highlights the potential of UPWJ for CP-Ti alloy surface modification, while removing the potential for surface contamination, which can be detrimental in many applications. Comparison of UWPJ used for peening Ti-6Al-4V (Grade 5) is also briefly discussed.

Effect of Electrically Assisted Preheating on Microstructure and Properties of Laser-Cladded Co-Based Coating on CP-Ti Alloy Substrate

Co-based coatings were prepared on commercially pure titanium (CP-Ti) with electrically assisted pre-heating (EAPH), followed by laser cladding with the assistance of pulsed current. Conventional pre-heating (CPH) laser cladding was carried out as a control to investigate the effects of a pulsed current on the phase composition, microstructure, microhardness, and wear resistance of the coatings. The results showed that periodically varied pulsed currents generate an induced magnetic field. This field fragments bottom dendrites and transforms columnar dendrites into equiaxed crystals through the influence of the Lorentz force. The phase composition of the coatings remained unchanged under the pulsed current, as well as unassisted and CPH condition, consisting of γ-Co, α-Ti, CoTi2 solid solution, and TiC, Cr7C3 hard phases. The microhardness of the coating increased at 720 A due to grain refinement, compared to unassisted and preheated coatings at the same temperature. Moreover, a suitable preheating temperature can reduce crack generation and improve the wear properties of the coating.

Low Young's Modulus TiNbSn Alloy Locking Plates Accelerate Osteosynthesis in Rabbit Tibiae.

A new beta TiNbSn alloy with a low Young's modulus of approximately 40 GPa has been developed to resolve the stress shielding by Young's modulus divergence. In this study, the efficacy of TiNbSn alloy locking plates on bone repair is compared to that of commercially pure titanium (CP-Ti). The TiNbSn alloy and CP-Ti, which have Young's moduli of 49.1 GPa and 107 GPa, respectively, were compared. Male Japanese white rabbits were anesthetized, and osteotomy and osteosynthesis with locking plates were performed on the right tibia. The bone repair was assessed using micro-computed tomography (CT), histomorphometry, immunohistochemistry, and mechanical testing. Micro-CT, histomorphometry, immunohistochemistry, and mechanical testing were performed four weeks after osteotomy. Six weeks after surgery, micro-CT and mechanical testing were performed. Micro-CT analysis at four weeks after surgery showed that the intramedullary fracture callus in the TiNbSn alloy group had more bone volume and numerous bridging structures compared to the CP-Ti group (CP-Ti vs. TiNbSn alloy, 34.3 ± 13.1 mm3 vs. 61.3 ± 19.6 mm3, p = 0.02; mean ± standard deviation). At four weeks post-osteotomy, the healed tibia showed significantly higher strength in the TiNbSn alloy group compared with CP-Ti (CP-Ti vs. TiNbSn alloy, 81.3 ± 31.2 N vs. 133.7 ± 46.6 N, p = 0.04). TiNbSn alloy locking plates had a more positive impact on bone formation and bone strength restoration than the CP-Ti locking plates during the early phase of bone healing.

High temperature diffusion behavior between Ta-10W coating and CP-Ti and TC4 alloy

To improve high temperature properties of Titanium alloy, Ta-10W coating was deposited by multi-arc ion plating (MAIP) technique on commercial pure titanium (CP-Ti) and TC4 (Ti-6Al-4V) titanium alloy respectively. The microstructures and high temperature diffusion behavior of Ta-10W coating on CP-Ti and TC4 alloy were investigated by XRD, SEM and EDS. The results showed that the obtained Ta-10W coatings consisted of α-Ta, exhibiting an integrated and compact surface as well as excellent interface bonding. For the Ta-10W/Ti samples, a TiTa solid solution diffusion layer formed and gradually became thicker and thicker over time. After diffusion for 50 h, massive titanium element even diffused to the surface of the coating. During cooling, the β-Ti → α′-Ti martensitic phase transformation occurred, and the martensitic relief morphology appeared on the surface of the coatings. Meanwhile, α-Ta precipitated along the laminate boundary of α-Ti, which leads to the formation of white stripe-like structure in the diffusion layer. Dissimilarity, the Ta-10W/TC4 samples possessed relative high diffusion rate, but the Ti didn't reach the surface of the sample after 50 h. There was a thick diffusion layer which contained two layers formed between Ta-10W and TC4 after heat treatment of 10h, and the Kirkendall voids appeared near the interface of Ta-10W/TC4. This work is helpful to understand the high-temperature performance of refractory coating and provides a new idea for the further study of protective coatings on Titanium alloy.

Comparative analysis of the orientation dependent tensile deformation of commercially pure titanium and titanium alloy OT 4-1

Correlation of mechanical properties and tensile deformation of hexagonal commerciallypure titanium (CP-Ti) and acicular alpha titanium alloy OT 4-1 was studied in the present investigation. Tensile specimens were prepared along the rollingdirection, along 450 to the rolling direction and transverse to the rolling direction to obtain different tensile deformation from cold rolled annealed sheets of CP-Ti and titanium alloy OT 4-1. The conjoint control of essential microstructural features and the orientation of specimen on tensile properties of commercially pure titanium and the titanium alloy OT 4-1 was highlighted.

Investigations on multi-sheets single point incremental forming of commercial pure titanium alloys

ABSTRACT The rate of production in single point incremental forming (SPIF) approach for the sheet metals is comparatively low when comparing to multiple sheet incremental forming process (MSSPIF). This increase in production rate comes with a trade-off of reduced formability in MSSPIF. The aspiration of the current paper is to analyze the formability, the strain distribution, and the void coalescence variables as per the strain triaxiality during the MSSPIF process of the available commercially pure (CP) titanium sheets. The forming limit diagrams (FLDs) and the strain distribution analysis have been carried out for multiple sheets of two, three, and four sheets bunch while they were formed together. The outcomes proved that the uppermost sheets achieved the higher limiting principal true strain and the limiting values of the principal true strain of bottom sheets decreased in accordance with the position of the sheet and the same was reported in FLDs. The void coalescence in the fractured specimen exhibited an enhanced fracture resistance for CP sheets of titanium. The size of void (µm), thickness of ligament (LT), void (L/W) ratio, d-factor, strain triaxiality, and other void coalescence parameters also have been compared when two, three, and four sheets were formed together during MSSPIF process.

Effects of laser shock peening on the micro-hardness, tensile properties, and fracture morphologies of CP-Ti alloy at different temperatures

This study investigated the effects of laser shock peening (LSP) on the micro-hardness distribution and fractural morphologies of tensile specimens manufactured from commercial pure titanium (CP-Ti) at four different temperatures. The micro-hardness distributions and fractural morphologies of the as-machined and LSPed tensile specimens were characterized and analyzed. The relationship between the micro-hardness and microstructures of CP-Ti along the gauge length direction was also discussed. Results indicated that LSP significantly improved the micro-hardness of CP-Ti alloy; however, the high temperature negatively affected the micro-hardness but enhanced the plasticity of the product. Furthermore, LSP significantly increased the ultimate tensile strength (UTS), the area reduction of fracture surface, and the elongation rate of CP-Ti alloy. The high temperature induced tensile necking on the fracture surface and significantly promoted grain growth, thereby decreasing the UTS.

Synergistic erosion-corrosion behavior of commercially pure titanium at various impingement angles

The characteristics of commercially pure titanium (CP-Ti) in erosion and erosion–corrosion conditions have been studied. The erosion-corrosion tests were carried out using a slurry impingement rig in a 3.5% NaCl solution containing 60g/l SiO2 particles with average size of 250–500μm at a jet velocity of 4m/s under impingement angles of 20–90°. The pure erosion tests were also performed by applying a potential of −1V versus open circuit potential. The corrosion behavior of CP-Ti alloy in both stagnant and the erosion-corrosion conditions were studied using polarization technique and the synergy values were calculated. Erosion and erosion-corrosion mechanisms were determined using scanning electron microscopy. The results showed that the maximum erosion and erosion-corrosion rates occurred at an impingement angle of 40°. The impact of particles during the erosion-corrosion increased the corrosion rate to a maximum of about 2300 times compared with the stagnant condition. The results also showed positive synergisms at all impingement angles with the rates significantly higher than the pure erosion rates. It was found that about 75–90% of the removal rate in erosion-corrosion was related to the effect of corrosion on erosion.

Deformation Behaviour of a Commercial Pure Titanium Alloy during Hot Compression Testing

The flow curve behavior and microstructure evolution of commercially pure titanium (CP-Ti) through uniaxial hot compression was investigated at 850 °C and a strain rate of 0.1/s. Electron back scattered diffraction (EBSD) was employed to characterize the microstructure and crystallographic texture development for different thermomechanical conditions. The stress-strain curves of CP-Ti alloy under hot compression displayed a typical flow behavior of metals undergoing dynamic recrystallization (DRX), which resulted in grain refinement. The critical strain for the onset of DRX was 0.13 using the double differentiation analysis technique. It was also revealed that the texture was markably altered during hot deformation.

Zr61Ti2Cu25Al12 metallic glass for potential use in dental implants: Biocompatibility assessment by in vitro cellular responses

In comparison with titanium and its alloys, Zr61Ti2Cu25Al12 (ZT1) bulk metallic glass (BMG) manifests a good combination of high strength, high fracture toughness and lower Young's modulus. To examine its biocompatibility required for potential use in dental implants, this BMG was used as a cell growth subtract for three types of cell lines, L929 fibroblasts, human umbilical vein endothelial cells (HUVEC), and osteoblast-like MG63 cells. For a comparison, these cell lines were in parallel cultured and grown also on commercially pure titanium (CP-Ti) and Ti6–Al4–V alloy (Ti64). Cellular responses on the three metals, including adhesion, morphology and viability, were characterized using the SEM visualization and CCK-8 assay. Furthermore, real-time RT-PCR was used to measure the activity of integrin β, alkaline phosphatase (ALP) and type I collagen (COL I) in adherent MG63 cells. As indicated, in all cases of three cell lines, no significant differences in the initial attachment and viability/proliferation were found between ZT1, CP-Ti, and Ti64 until 5d of incubation period. It means that the biocompatibility in cellular response for ZT1 BMG is comparable to Ti and its alloys. For gene expression of integrin β, ALP and COL I, mRNA level from osteoblast cells grown on ZT1 substrates is significantly higher than that on the CP-Ti and Ti64. It suggests that the adhesion and differentiation of osteoblasts grown on ZT1 are even superior to those on the CP-Ti and Ti64 alloy, then promoting bone formation. The good biocompatibility of ZT1 BMG is associated with the formation of zirconium oxide layer on the surface and good corrosion-resistance in physiological environment.