scholarly journals Porous Titanium Cylinders Obtained by the Freeze-Casting Technique: Influence of Process Parameters on Porosity and Mechanical Behavior

Metals ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 188 ◽  
Author(s):  
Paloma Trueba ◽  
Ana M. Beltrán ◽  
José Manuel Bayo ◽  
José Antonio Rodríguez-Ortiz ◽  
Diego F. Larios ◽  
...  

The discrepancy between the stiffness of commercially pure titanium and cortical bone tissue compromises its success as a biomaterial. The use of porous titanium has been widely studied, however, it is still challenging to obtain materials able to replicate the porous structure of the bones (content, size, morphology and distribution). In this work, the freeze-casting technique is used to manufacture cylinders with elongated porosity, using a home-made and economical device. The relationship between the processing parameters (diameter and material of the mold, temperature gradient), microstructural features and mechanical properties is established and discussed, in terms of ensuring biomechanical and biofunctional balance. The cylinders have a gradient porosity suitable for use in dentistry, presenting higher Young’s modulus at the bottom, near the cold spot and, therefore better mechanical resistance (it would be in contact with a prosthetic crown), while the opposite side, the hot spot, has bigger, elongated pores and walls.

2005 ◽  
Vol 19 (2) ◽  
pp. 139-143 ◽  
Author(s):  
Wagner Sotero Fragoso ◽  
Guilherme Elias Pessanha Henriques ◽  
Edwin Fernando Ruiz Contreras ◽  
Marcelo Ferraz Mesquita

Commercially pure titanium (CP Ti) has been widely applied to fabricate cast devices because of its favorable properties. However, the mold temperature recommended for the manufacture of casts has been considered relatively low, causing inadequate castability and poor marginal fit of cast crowns. This study evaluated and compared the influence of mold temperature (430°C - as control, 550°C, 670°C) on the marginal discrepancies of cast CP Ti crowns. Eight bovine teeth were prepared on a mechanical grinding device and impressions were used to duplicate each tooth and produce eight master dies. Twenty-four crowns were fabricated using CP Ti in three different groups of mold temperature (n = 8): 430°C (as control), 550°C and 670°C. The gap between the crown and the bovine tooth was measured at 50 X magnification with a traveling microscope. The marginal fit values of the cast CP Ti crowns were submitted to the Kruskal-Wallis test (p = 0.03). The 550°C group (95.0 µm) showed significantly better marginal fit than the crowns of the 430°C group (203.4 µm) and 670°C group (213.8 µm). Better marginal fit for cast CP Ti crowns was observed with the mold temperature of 550°C, differing from the 430°C recommended by the manufacturer.


2020 ◽  
Vol 142 (5) ◽  
Author(s):  
Xia’nan Li ◽  
Zhutian Xu ◽  
Jihui Huang ◽  
Linfa Peng ◽  
Ping Guo

Abstract Previous studies show that the phase transition temperature of Ti6Al4V can be effectively reduced by electropulsing treatment, which may be related to the promotion effect of current on element diffusion. In order to verify the above conjecture, the diffusion experiments of the Ti6Al4V-pure titanium system under the action of electropulsing and heat treatment are carried out. The results show that the current can effectively improve the diffusion coefficients of aluminum and vanadium, and the promotion effect has no relationship with the direction of the current. Considering the inhomogeneity of the Joule heat distribution of the microscopic scale of the material, the hypothesis of “local hot spot” is proposed to explain the experimental phenomena. It is found that the hypothesis can make effective predictions of diffusion coefficients and explain the promotion effect of electropulsing on Ti6Al4V phase transition reasonably.


Coatings ◽  
2018 ◽  
Vol 9 (1) ◽  
pp. 3 ◽  
Author(s):  
Akashlynn Badruddoza Dithi ◽  
Takashi Nezu ◽  
Futami Nagano-Takebe ◽  
Md Hasan ◽  
Takashi Saito ◽  
...  

Hydroxyapatite (HA) coatings on titanium implants enhance rapid bone formation around the implant due to their osteoconductive property. The present study aimed to achieve a thin and uniform HA film coating on titanium implants by solution plasma treatment (SPT). Commercially pure titanium and porous titanium disks were employed. A pulse plasma generator was used on the disks for 30 min. Morphologic and crystallographic features of the deposited films were examined by scanning electron microscopy (SEM) and X-ray diffractometry (XRD). To evaluate the wettability of the disks, water droplet (20 µL) surfaces were measured using a contact angle analyzer. The initial attachment of osteoblast-like cells (MC3T3E1) on the titanium substrates before and after solution plasma treatment was evaluated by counting the number of attached cells after incubation for 4 h. After immersion in the mineralizing solution for up to seven days, no crystals were observed on the polished-Ti surface. A more uniform and dense precipitation of round and grown crystals with diameters of approximately 1–5 µm was observed on Ti-SPT. XRD clearly showed that the precipitated crystals on titanium disks were HA. The contact angle of the polished-Ti increased with time (θ = 37°–51°). The surface of the Ti-SPT remained hydrophilic (θ ˂ 5°) after up to 30 days of aging. The number of attached cells on the Ti-SPT after aging for 30 days remained above 85% of that on the Ti-SPT without aging. SPT in a mineralizing solution can be used to acquire a homogenous precipitation of HA on porous-surfaced titanium implants.


2013 ◽  
pp. 207-215 ◽  
Author(s):  
Ivana Dimic ◽  
Ivana Cvijovic-Alagic ◽  
Marica Rakin ◽  
Aleksandra Peric-Grujic ◽  
Marko Rakin ◽  
...  

Due to their excellent characteristics, such as chemical inertness, mechanical resistance, low Young?s modulus, high corrosion resistance, and outstanding biocompatibility, titanium and its alloys are the most used metallic materials for biomedical applications. In dental practice, these materials have demonstrated success as biomedical devices which are used for repairing and replacing failed hard tissue. However, the oral cavity is constantly subjected to the changes in the pH value changes and such an environment is strongly corrosive for titanium dental implants. The objective of this study was to examine ion release from commercially pure titanium (cpTi) in artificial saliva with different pH values (4.0, 5.5 and 7.5). The concentrations of released titanium ions were determined after 1, 3 and 6 weeks using Inductively Coupled Plasma - Mass Spectrometry. The results indicate that the ion release from commercially pure titanium in the artificial saliva is dependent both on the pH of artificial saliva and duration of immersion.


2021 ◽  
Vol 10 (10) ◽  
pp. e122101018606
Author(s):  
Sandra Raquel Kunst ◽  
David de Oliveira Cerveira ◽  
Jane Zoppas Ferreira ◽  
Thaís Francine Graef ◽  
Joseane de Andrade Santana ◽  
...  

Titanium has been widely used as biomaterial, especially in implantables, in which osseointegration and corrosion resistance are needed. Studies have shown that the thickness and roughness of porous titanium oxides are related to the osseointegration. According to the literature, the best anodizing conditions for obtaining nanotubes in titanium oxide are the use of a voltage of 10V in an electrolyte containing 0.15% HF in H3PO4 (w/v). In this study, was to evaluate the corrosion capacity of simulated body fluid (SBF) over titanium samples anodized on 1 mol. L-1 H3PO4 and 0.15% HF (w/v) in 1 mol.L-1 H3PO4. To perform these evaluations samples of commercially pure titanium grade 2 were used. Samples were analyzed by scanning electron microscopy, atomic force microscopy and by electrochemical corrosion tests in healthy and simulating inflammatory conditions. The hydrophobicity of oxides was tested by sessile drop essay, also using SBF. Results show that oxides obtained in H3PO4 electrolyte, barrier type oxides, work better than the porous oxides obtained in H3PO4/HF electrolyte, suggesting that barrier oxide exhibit more biomaterial characteristics than the porous oxide. These results agree with previous studies, and stand out mainly in relation to the tests performed under inflammatory conditions, more aggressive to the biomaterial.


Alloy Digest ◽  
1979 ◽  
Vol 28 (12) ◽  

Abstract RMI 0.2% Pd is a grade of commercially pure titanium to which up to 0.2% palladium has been added. It has a guaranteed minimum yield strength of 40,000 psi with good ductility and formability. It is recommended for corrosion resistance in the chemical industry and other places where the environment is mildly reducing or varies between oxidizing and reducing. The alloy has improved resistance to crevice corrosion at low pH and elevated temperatures. This datasheet provides information on composition, physical properties, elasticity, tensile properties, and bend strength. It also includes information on corrosion resistance as well as forming, heat treating, machining, joining, and surface treatment. Filing Code: Ti-74. Producer or source: RMI Company.


Alloy Digest ◽  
2020 ◽  
Vol 69 (6) ◽  

Abstract UPM CP Titanium Grade 3 (UNS R50550) is an unalloyed commercially pure titanium that exhibits moderate strength (higher strength than that of Titanium Grade 2), along with excellent formability and corrosion resistance. It offers the highest ASME allowable design stress of any commercially pure grade of titanium, and can be used in continuous service up to 425 °C (800 °F) and in intermittent service up to 540 °C (1000 °F). This datasheet provides information on composition, physical properties, and elasticity. It also includes information on corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: Ti-167. Producer or source: United Performance Metals.


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