Processing and Mechanical Properties of Solid Core and Porous Surface Ti-6Al-4V Implants Fabricated by Powder-Metallurgy

2007 ◽  
Vol 345-346 ◽  
pp. 1209-1212
Author(s):  
Montasser Dewidar ◽  
Jae Kyoo Lim
Keyword(s):  
Powder Metallurgy ◽  
Inner Core ◽  
Porous Surface ◽  
Full Density ◽  
Compressive Yield Strength ◽  
Solid Core ◽  
Heavy Load ◽  
Human Teeth ◽  
Joint Replacements ◽  
Porous Ti

Porous-surfaced with solid core Ti-6Al-4V implant compacts were fabricated by traditional powder metallurgy. Powder metallurgy technique was used to produce three different porous surfaced implant compacts 30, 50, and 70% in vacuum atmosphere. The solid core formed in the center of the compact shows similar microstructure of near full density of Ti-6Al-4V. The compressive yield strength was up to 270 MPa and significantly depended on the surface porosity, core size, and temperature of sintering. Selected porous-surfaced Ti-6Al-4V implant compacts with a solid core have much higher compressive strengths compared to the human teeth and sintered fully porous Ti-6Al-4V joint replacements. The ingrowth of bone tissue into the outer porous surface layer results in part fixation, while the solid inner core region provides the necessary mechanical strength for a device used for the replacement of heavy load bearing joint regions such as the hip and knee. The microstructure of sintered samples was investigated.

Ultra-Fine Grained Ti-15Mo Alloy Prepared by Powder Metallurgy

2018 ◽  
Vol 941 ◽  
pp. 1276-1281
Author(s):  
Anna Terynková ◽  
Jiří Kozlík ◽  
Kristína Bartha ◽  
Tomáš Chráska ◽  
Josef Stráský
Keyword(s):  
Powder Metallurgy ◽  
Bulk Material ◽  
Alpha Phase ◽  
Full Density ◽  
Fine Grained ◽  
Cryogenic Milling ◽  
Aircraft Manufacturing ◽  
Plasma Sintering ◽  
Beta Matrix ◽  
Spark Plasma

Ti-15Mo alloy belongs to metastable β-Ti alloys that are currently used in aircraft manufacturing and Ti15Mo alloy is a perspective candidate for the use in medicine thanks to its biotolerant composition. In this study, Ti15Mo alloy was prepared by advanced techniques of powder metallurgy. The powder of gas atomized Ti-15Mo alloy was subjected to cryogenic milling to achieve ultra-fine grained microstructure within the powder particles. Powder was subsequently compacted using spark plasma sintering (SPS). The effect of cryogenic milling on the microstructure and phase composition of final bulk material after SPS was studied by scanning electron microscopy. Sintering at 750°C was not sufficient for achieving full density in gas atomized powder, while milled material could be successfully sintered at this temperature. Alpha phase particles precipitated during sintering and their size, as well as the size of beta matrix grains, was strongly affected by the sintering temperature.

Powder metallurgy of the porous Ti-13Nb-13Zr alloy of different powder grain size

2019 ◽  
Vol 34 (8) ◽  
pp. 915-920 ◽  
Author(s):  
Tomasz Seramak ◽  
Andrzej Zielinski ◽  
Waldemar Serbinski ◽  
Katarzyna Zasinska
Keyword(s):  
Grain Size ◽  
Powder Metallurgy ◽  
Porous Ti ◽  
13Zr Alloy

Synthesis of porous Ti–50Ta alloy by powder metallurgy

2018 ◽  
Vol 142 ◽  
pp. 124-136 ◽  
Author(s):  
Grzegorz Dercz ◽  
Izabela Matuła ◽  
Maciej Zubko ◽  
Alicja Kazek-Kęsik ◽  
Joanna Maszybrocka ◽  
...  
Keyword(s):  
Powder Metallurgy ◽  
Porous Ti

scholarly journals The fate of planetary cores in giant and ice-giant planets

2019 ◽  
Vol 631 ◽  
pp. L4 ◽  
Author(s):  
S. Mazevet ◽  
R. Musella ◽  
F. Guyot
Keyword(s):  
High Pressure ◽  
Ab Initio ◽  
Inner Core ◽  
Giant Planets ◽  
Ab Initio Molecular Dynamics ◽  
Solid Core ◽  
Potential Core ◽  
Melting Temperatures ◽  
The Core ◽  
Pressure Melting

Context. The Juno probe that currently orbits Jupiter measures its gravitational moments with great accuracy. Preliminary results suggest that the core of the planet may be eroded. While great attention has been paid to the material properties of elements constituting the envelope, little is known about those that constitute the core. This situation clutters our interpretation the Juno data and modeling of giant planets and exoplanets in general. Aims. We calculate the high-pressure melting temperatures of three potential components of the cores of giant planets, water, iron, and a simple silicate, MgSiO3, to investigate the state of the deep inner core. Methods. We used ab initio molecular dynamics simulations to calculate the high-pressure melting temperatures of the three potential core components. The planetary adiabats were obtained by solving the hydrostatic equations in a three-layer model adjusted to reproduce the measured gravitational moments. Recently developed ab initio equations of state were used for the envelope and the core. Results. We find that the cores of the giant and ice-giant planets of the solar system differ because the pressure–temperature conditions encountered in each object correspond to different regions of the phase diagrams. For Jupiter and Saturn, the results are compatible with a diffuse core and mixing of a significant fraction of metallic elements in the envelope, leading to a convective and/or a double-diffusion regime. We also find that their solid cores vary in nature and size throughout the lifetimes of these planets. The solid cores of the two giant planets are not primordial and nucleate and grow as the planets cool. We estimate that the solid core of Jupiter is 3 Gyr old and that of Saturn is 1.5 Gyr old. The situation is less extreme for Uranus and Neptune, whose cores are only partially melted. Conclusions. To model Jupiter, the time evolution of the interior structure of the giant planets and exoplanets in general, their luminosity, and the evolution of the tidal effects over their lifetimes, the core should be considered as crystallizing and growing rather than gradually mixing into the envelope due to the solubility of its components.

Fabrication and Characterization of Bioactive Cancellous-Like Surface on Titanium

2008 ◽  
Vol 368-372 ◽  
pp. 1370-1373
Author(s):  
Yi Ping Tian ◽  
Shan Shan Wei ◽  
Hui Li ◽  
Ling Hong Guo
Keyword(s):  
Rietveld Method ◽  
Sol Gel ◽  
Porous Surface ◽  
Main Attention ◽  
X Ray ◽  
Metal Implants ◽  
Porous Ti ◽  
Particle Coating ◽  
Ha Coating

Bioactive porous surface on metal implants are benefit for forming the continuous interface with “mechanical interlocking” and “chemical bonding” between implants and bones. In the present study, the main attention was concentrated on fabricating a porous bioactive surface on Ti substrate. Porous surface was first fabricated by two-step etched. Then thin HA coating was deposited on the pre-treated porous Ti surface by sol-gel method and immediately sintered at 500°C for 1 hour. The structure and morphology of HA coating formed on the porous surface were characterized by thin-film X-ray diffrac- tion and scanning electronic microscopy, respectively. Rietveld method and Warren-Averbach Fourier Transfer Analysis were employed to determine the lattice parameters, crystallite size and micro-strain of HA coating. The SEM results indicated that an interconnecting porous surface with cancellous structure and mean diameter about 1/m was etched on the Ti substrate, and the surface was covered by a thin particle coating. The TF-XRD results testified that the thin coating was poor crystalline HA.

scholarly journals On shear wave velocity in the top of the Earth’s inner core

2019 ◽  
Vol 488 (4) ◽  
pp. 434-438
Author(s):  
D. N. Krasnoshchekov ◽  
V. M. Ovtchinnikov ◽  
O. A. Usoltseva
Keyword(s):  
Shear Wave ◽  
Wave Velocity ◽  
Shear Wave Velocity ◽  
Inner Core ◽  
Solid Core ◽  
The Earth ◽  
Inner Surface ◽  
Core Boundary ◽  
Standard Models ◽  
Earth’S Inner Core

Analysis of PKIIKP waves reflected off the inner surface of the solid core boundary and recorded close to the antipode indicates the shear wave velocity in its top can be by 10-60% below 3.5 km/s envisaged by standard models of the Earth.

Sign in / Sign up

Export Citation Format

Share Document