scholarly journals Dissimilar Brazing of Ti–15Mo–5Zr–3Al and Commercially Pure Titanium Using Ti–Cu–Ni Foil

Materials ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 5949
Author(s):  
Gui-Lin Yue ◽  
Tai-Cheng Chen ◽  
Ren-Kae Shiue ◽  
Leu-Wen Tsay

Dissimilar brazing of Ti–15Mo–5Zr–3Al (Ti-1553) to commercially pure titanium (CP-Ti) using Ti–15Cu–15Ni foil was performed in this work. The microstructures in different sites of the brazed joint showed distinct morphologies, which resulted from the distributions of Mo, Cu, and Ni. In the brazed zone adhered to the Ti-1553 substrate, the partitioning of Mo from the Ti-1553 into the molten braze caused the formation of stabilized β-Ti without Ti2Cu/Ti2Ni precipitates. In the CP-Ti side, the brazed joint displayed a predominantly lamellar structure, composed of the elongated primary α-Ti and β-transformed eutectoid. The decrease in the Mo concentration in the brazed zone caused the eutectoid transformation of β-Ti to Ti2Cu + α-Ti in that zone. The diffusion of Cu and Ni from the molten braze into the CP-Ti accounted for the precipitation of Ti2Cu/Ti2Ni in the transformed zone therein. The variation in the shear strength of the joints was related to the amount and distribution of brittle Ti2Ni compounds. Prolonging the brazing time, the wider transformed zone, consisting of coarse elongated CP-Ti interspersed with sparse Ti2Ni precipitates, was responsible for the improved shear strength of the joint.

2012 ◽  
Vol 548 ◽  
pp. 174-178 ◽  
Author(s):  
Chong Yang Gao ◽  
Wei Ran Lu

By using a dislocation-based plastic constitutive model for hcp metals developed by us recently, the dynamic thermomechanical response of an important industrial material, commercially pure titanium (CP-Ti), was described at different temperatures and strain rates. The constitutive parameters of the material are determined by an efficient optimization method for a globally optimal solution. The model can well predict the dynamic response of CP-Ti by the comparison with experimental data and the Nemat-Nasser-Guo model.


Author(s):  
Karibeeran Shanmuga Sundaram ◽  
Gurusami Kiliyappan ◽  
Senthil Kumaran Selvadurai

Laser shock peening (LSP) is one of the innovative technique that produces a compressive residual stress on the surface of metallic materials, thereby significantly increasing its fatigue life in applications where failure is caused by surface-initiated cracks. The specimens were treated with laser shock waves with different processing parameters, and characterization studies were made on treated specimens. The purpose of the present study was to investigate the influence of Nd:YAG laser on commercially pure titanium (CP-Ti) used in prosthetic dental restorations. The treatment influenced change in microstructure, micro hardness, surface roughness, and wear resistance characteristics. Though CP-Ti is considered as an excellent material for dental applications due to its outstanding biocompatibility, it is not suitable when high mastication forces are applied. In the present study, pulsed Nd:YAG laser surface treatment technique was adopted to improve the wear resistance of CP-Ti. The wear test pin specimens of CP-Ti were investment cast with centrifugal titanium casting machine. The wear properties of specimens were evaluated after LSP on a “pin-on-disc” wear testing tribometer, as per ASTM G99-05 standards. The results of the wear experiment showed that the treated laser surface has higher wear resistance, micro hardness, and surface roughness compared to as-cast samples. The improvement of wear resistance may be attributed due to grain refinement imparted by LSP processes. The microstructure, wear surfaces, wear debris, and morphology of the specimen were analyzed by using optical electron microscope, scanning electron microscope, and X-ray diffraction (XRD). The data were compared using ANOVA and post-hoc Tukey tests. The characteristic change resulted in increase in wear resistance and decrease in wear rate. Hence, it is evident that the more reliable and removable partial denture metal frameworks for dental prostheses may find its applications.


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.


2010 ◽  
Vol 654-656 ◽  
pp. 2172-2175
Author(s):  
Kyosuke Ueda ◽  
Hajime Suto ◽  
Kaori Nakaie ◽  
Takayuki Narushima

The surface modification of commercially pure titanium (CP Ti) by pack cementation treatment at 973 K using tetracalcium phosphate (Ca4(PO4)2O, TTCP) slurry was investigated. An HAp phase and a CaTiO3 phase were observed on the reaction layer of the CP Ti substrate after pack cementation treatment at 973 K for 86.4 ks. TTCP powder decomposed to HAp and CaO, and CaO reacted with TiO2 to form CaTiO3. The reaction layer on the CP Ti substrate consisted of inner and outer layers and the particles were in the outer reaction layer. The pores observed on the reaction layer were formed by the detachment of particles from the outer layer. The bonding strength of the reaction layer was 68.1 MPa. Apatite completely covered the surface of the pack-cementation-treated CP Ti after immersion in Kokubo solution for 21.6 ks; such rapid apatite formation suggests that pack cementation treatment improves the biocompatibility of titanium.


2018 ◽  
Vol 53 (9) ◽  
pp. 6872-6892 ◽  
Author(s):  
S. Khayatzadeh ◽  
M. J. Thomas ◽  
Y. Millet ◽  
S. Rahimi

Author(s):  
F Reshadi ◽  
S Khorasani ◽  
G Faraji

This study investigated the surface characteristics of ultrafine-grain commercially pure titanium (UFG CP-Ti) substrates produced by equal channel angular pressing (ECAP), compared with those of coarse-grain commercially pure titanium (CG CP-Ti) and Ti–6Al–4V (Ti-64) substrates. All Ti surfaces were sandblasted and acid-etched (SLA-treated) to produce micro-rough surfaces. Tensile and microhardness tests were carried out to measure the mechanical properties of fabricated samples. Then the surface characteristics of samples including contact angle measurements, surface morphology and in vitro cell response were evaluated after polishing, sandblasting and acid etching procedures. The results showed that after applying four passes of ECAP, the average grain size of microstructure decreased from 25 µm to 170 nm, while the ultimate tensile strength increased from 545 ± 24 MPa to 971 ± 38 MPa. Investigation of surface morphologies carried out by scanning electron microscopy indicated that ECAP-processed substrate exhibits nano-topography compared with CG CP-Ti and Ti-64 substrates after applying SLA process. In addition, the contact angle of SLA-treated CG CP-Ti and UFG CP-Ti substrates decreased from 68.3° to 9.5° and 51.9° to 7.4°, respectively, indicating a significant improvement of surface wettability. The morphologies of MG63 cells cultured on the developed surfaces proved the potential superior osteoblast cell compatibility of the micro-roughened surface made of UFG CP-Ti substrates over CG CP-Ti and Ti-64 substrates.


2019 ◽  
Vol 7 (4) ◽  
pp. 109 ◽  
Author(s):  
Tetsuhiro Tsujino ◽  
Akira Takahashi ◽  
Taisuke Watanabe ◽  
Kazushige Isobe ◽  
Yutaka Kitamura ◽  
...  

Recent progress in the industrial development of dental implants has improved their surface bio-affinity, while clinical implantologists attempt to improve it through coating with various compounds, including platelet-rich plasma (PRP) in clinical settings. However, it is poorly understood how PRP acts on titanium surfaces. To validate this surface modification method and demonstrate how platelet-derived soluble biomolecules released from the activated adherent platelets act on plain, commercially pure-titanium (cp-Ti) plates, we evaluated the distribution of biomolecules by immunofluorescence. PPARγ, PDGF-B, and TGFβ1 were similarly released at immunofluorescence levels from activated adherent platelets, retained in the surrounding extra-platelet spaces for a while, and did not immediately diffuse away to distant spaces. Exogenously added CaCl2 augmented release and retention of those biomolecules along with activation and aggregation. Taken together with our previous data regarding platelet adhesion, these findings suggest that especially when treated with CaCl2, platelets immediately adhere on cp-Ti plates to release their stored biomolecules in the absence of plasma proteins and that these biomolecules do not diffuse away, but stay longer in extra-platelet spaces around the platelets by newly formed, immature fibrin fiber fragments. Consequently, these retained biomolecules are anticipated to cooperatively stabilize implants by stimulating alveolar bone regeneration and integration.


2010 ◽  
Vol 148-149 ◽  
pp. 659-663
Author(s):  
Chun Huan Chen ◽  
Rui Ming Ren

Commercially pure Titanium (CP-Ti) TIG weld joint was treated by means of high energy shot peening (HESP) using a shot peening equipment commonly used in industry. The nanostructured surface layer was characterized by XRD, TEM, SEM and Microhardometer. The results showed that surface nanocrystallization of CP-Ti TIG weld joint were realized by high energy shot peening treatment. The finest grain size in the top surface layer is about 40nm. The hardness of the surface layer is enhanced significantly after shot peening compared with that of the as-welded joint, which resulted in a remarkable surface hardening effect. Surface welded defects such as air pores are eliminated successfully so that relative uniform surface layer was obtained.


2020 ◽  
Vol 6 (1) ◽  
Author(s):  
Masayuki Nakamura ◽  
Hachidai Aizawa ◽  
Hideo Kawabata ◽  
Atsushi Sato ◽  
Taisuke Watanabe ◽  
...  

Abstract Background Platelet-rich plasma (PRP) is often used to improve surface biocompatibility. We previously found that platelets rapidly adhere to plain commercially pure titanium (cp-Ti) plates in the absence, but not in the presence, of plasma proteins. To further expand on these findings, in the present study, we switched titanium plates from a plain surface to a rough surface that is blasted with calcium phosphate (CaP) powder and then examined platelet adhesion and activation. Methods Elemental distribution in CaP-blasted cp-Ti plates was analyzed using energy-dispersive X-ray spectroscopy. PRP samples prepared from anticoagulated blood samples of six healthy, non-smoking adult male donors were loaded on CaP-blasted cp-Ti plates for 1 h and fixed for examination of platelet morphology and visualization of PDGF-B and platelet surface markers (CD62P, CD63) using scanning electron microscopy and fluorescence microscopy. Plain SUS316L stainless steel plates used in injection needles were also examined for comparison. Results Significant amounts of calcium and phosphate were detected on the CaP-blasted cp-Ti surface. Platelets rapidly adhered to this surface, leading to higher activation. Platelets also adhered to the plain stainless surface; however, the levels of adhesion and activation were much lower than those observed on the CaP-blasted cp-Ti plate. Conclusions The CaP-blasted cp-Ti surface efficiently entraps and activates platelets. Biomolecules released from the activated platelets could be retained by the fibrin matrix on the surface to facilitate regeneration of the surrounding tissues. Thus, PRP immersion could not only eliminate surface air bubbles but also improve the biocompatibility of the implant surface.


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