The Experts below are selected from a list of 321 Experts worldwide ranked by ideXlab platform
Guillermo Requena - One of the best experts on this subject based on the ideXlab platform.
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Peritectic Titanium Alloys for 3D printing
Nature Communications, 2018Co-Authors: Pere Barriobero-vila, Joachim Gussone, Norbert Schell, Andreas Stark, Jan Haubrich, Guillermo RequenaAbstract:3D printing of Titanium Alloys today is based on known alloy compositions that result in anisotropic structural properties. Here, the authors add lanthanum to commercially pure Titanium and exploit a solidification path that reduces texture and anisotropy.AbstractMetal-based additive manufacturing (AM) permits layer-by-layer fabrication of near net-shaped metallic components with complex geometries not achievable using the design constraints of traditional manufacturing. Production savings of Titanium-based components by AM are estimated up to 50% owing to the current exorbitant loss of material during machining. Nowadays, most of the Titanium Alloys for AM are based on conventional compositions still tailored to conventional manufacturing not considering the directional thermal gradient that provokes epitaxial growth during AM. This results in severely textured microstructures associated with anisotropic structural properties usually remaining upon post-AM processing. The present investigations reveal a promising solidification and cooling path for α formation not yet exploited, in which α does not inherit the usual crystallographic orientation relationship with the parent β phase. The associated decrease in anisotropy, accompanied by the formation of equiaxed microstructures represents a step forward toward a next generation of Titanium Alloys for AM.
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peritectic Titanium Alloys for 3d printing
Nature Communications, 2018Co-Authors: Pere Barrioberovila, Joachim Gussone, Norbert Schell, Andreas Stark, Jan Haubrich, Guillermo RequenaAbstract:Metal-based additive manufacturing (AM) permits layer-by-layer fabrication of near net-shaped metallic components with complex geometries not achievable using the design constraints of traditional manufacturing. Production savings of Titanium-based components by AM are estimated up to 50% owing to the current exorbitant loss of material during machining. Nowadays, most of the Titanium Alloys for AM are based on conventional compositions still tailored to conventional manufacturing not considering the directional thermal gradient that provokes epitaxial growth during AM. This results in severely textured microstructures associated with anisotropic structural properties usually remaining upon post-AM processing. The present investigations reveal a promising solidification and cooling path for α formation not yet exploited, in which α does not inherit the usual crystallographic orientation relationship with the parent β phase. The associated decrease in anisotropy, accompanied by the formation of equiaxed microstructures represents a step forward toward a next generation of Titanium Alloys for AM.
Mitsuo Niinomi - One of the best experts on this subject based on the ideXlab platform.
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Titanium Alloys for Biomedical Applications
Springer Series in Biomaterials Science and Engineering, 2020Co-Authors: Mitsuo Niinomi, Carl J. BoehlertAbstract:The low Young’s modulus of β-type Titanium Alloys makes them advantageous for use in medical implant devices, as they are effective in both preventing bone resorption and promoting good bone remodeling. The development of low Young’s modulus β-type Titanium Alloys for biomedical applications is described herein, along with a discussion of suitable methods for even greater modulus reductions. Since there is often occasion to remove implant devices, Titanium Alloys suitable for removable implants are also described. It has recently been noted that although patients require low Young’s modulus Titanium Alloys, a high modulus is needed by surgeons. Consequently, β-type Titanium Alloys with a self-tunable Young’s modulus are also explored. An evaluation of the effectiveness of low Young’s modulus β-type Titanium Alloys in preventing stress shielding is provided, which is based on the results of animal testing. Means of enhancing the mechanical biocompatibilities of β-type Titanium Alloys for biomedical applications are also described along with the suitability of those β-type Titanium Alloys which exhibit super-elastic and shape-memory behavior. Finally, the unique behavior of some β-type Titanium Alloys for biomedical applications is discussed.
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Mechanical Performance of Titanium Alloys with Added Lightweight Interstitial Element for Biomedical Applications
Materials Science Forum, 2018Co-Authors: Mitsuo NiinomiAbstract:Oxygen is considered to be an impurity in Titanium and its Alloys, and it enhances their brittleness. However, oxygen has also been recognized as a useful ingredient to improve the mechanical performance of Titanium Alloys for biomedical applications, because oxygen is a lightweight interstitial element that is non-toxic and non-allergenic. Some reports show that adding oxygen improves both the strength and the ductility of Titanium Alloys for biomedical applications. The effects of oxygen addition on the mechanical performance of Titanium Alloys for biomedical aplications are described.
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biomedical Titanium Alloys with young s moduli close to that of cortical bone
Regenerative Biomaterials, 2016Co-Authors: Mitsuo Niinomi, Masaki Nakai, Hua LiAbstract:Biomedical Titanium Alloys with Young’s moduli close to that of cortical bone, i.e., low Young’s modulus Titanium Alloys, are receiving extensive attentions because of their potential in preventing stress shielding, which usually leads to bone resorption and poor bone remodeling, when implants made of their Alloys are used. They are generally β-type Titanium Alloys composed of non-toxic and allergy-free elements such as Ti–29Nb–13Ta–4.6Zr referred to as TNTZ, which is highly expected to be used as a biomaterial for implants replacing failed hard tissue. Furthermore, to satisfy the demands from both patients and surgeons, i.e., a low Young’s modulus of the whole implant and a high Young’s modulus of the deformed part of implant, Titanium Alloys with changeable Young’s modulus, which are also β-type Titanium Alloys, for instance Ti–12Cr, have been developed. In this review article, by focusing on TNTZ and Ti–12Cr, the biological and mechanical properties of the Titanium Alloys with low Young’s modulus and changeable Young’s modulus are described. In addition, the Titanium Alloys with shape memory and superelastic properties were briefly addressed. Surface modifications for tailoring the biological and anti-wear/corrosion performances of the Alloys have also been briefly introduced.
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Biologically and Mechanically Biocompatible Titanium Alloys
Materials Transactions, 2008Co-Authors: Mitsuo NiinomiAbstract:Nb, Ta, and Zr are the favorable nontoxic and allergy-free alloying elements suitable for use in Titanium Alloys for biomedical applications. Low-rigidity Titanium Alloys composed of nontoxic and allergy-free elements are receiving considerable attention. The advantage of low-rigidity Titanium Alloys in the healing of bone fracture and bone remodeling is successfully proven by using tibia of rabbit as a fracture model. Ni-free superelastic and shape memory Titanium Alloys for biomedical applications are being actively developed. The mechanical properties such as fatigue and fretting fatigue are important from the viewpoint of mechanical properties, which may be collectively referred to as mechanical biocompatibilities in the broad sense, in addition to the rigidity, i.e. Young's modulus. Bioactive surface modifications of Titanium Alloys for biomedical applications are very important for achieving further biocompatibility.
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Mechanical biocompatibilities of Titanium Alloys for biomedical applications
Journal of the Mechanical Behavior of Biomedical Materials, 2008Co-Authors: Mitsuo NiinomiAbstract:Young's modulus as well as tensile strength, ductility, fatigue life, fretting fatigue life, wear properties, functionalities, etc., should be adjusted to levels that are suitable for structural biomaterials used in implants that replace hard tissue. These factors may be collectively referred to as mechanical biocompatibilities. In this paper, the following are described with regard to biomedical applications of Titanium Alloys: the Young's modulus, wear properties, notch fatigue strength, fatigue behaviour on relation to ageing treatment, improvement of fatigue strength, fatigue crack propagation resistance and ductility by the deformation-induced martensitic transformation of the unstable β phase, and multifunctional deformation behaviours of Titanium Alloys. © 2007 Elsevier Ltd. All rights reserved.
Daniel Eylon - One of the best experts on this subject based on the ideXlab platform.
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powder metallurgy of Titanium Alloys
International Materials Reviews, 1990Co-Authors: Francis H. Froes, Daniel EylonAbstract:AbstractThe powder metallurgy of Titanium Alloys is reviewed for both the blended elemental (BE) and prealloyed (PA) approaches. The BE technique allows low cost processing with mechanical behaviou...
Chuanxian Ding - One of the best experts on this subject based on the ideXlab platform.
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surface modification of Titanium Titanium Alloys and related materials for biomedical applications
Materials Science & Engineering R-reports, 2004Co-Authors: Chuanxian DingAbstract:Abstract Titanium and Titanium Alloys are widely used in biomedical devices and components, especially as hard tissue replacements as well as in cardiac and cardiovascular applications, because of their desirable properties, such as relatively low modulus, good fatigue strength, formability, machinability, corrosion resistance, and biocompatibility. However, Titanium and its Alloys cannot meet all of the clinical requirements. Therefore, in order to improve the biological, chemical, and mechanical properties, surface modification is often performed. This article reviews the various surface modification technologies pertaining to Titanium and Titanium Alloys including mechanical treatment, thermal spraying, sol–gel, chemical and electrochemical treatment, and ion implantation from the perspective of biomedical engineering. Recent work has shown that the wear resistance, corrosion resistance, and biological properties of Titanium and Titanium Alloys can be improved selectively using the appropriate surface treatment techniques while the desirable bulk attributes of the materials are retained. The proper surface treatment expands the use of Titanium and Titanium Alloys in the biomedical fields. Some of the recent applications are also discussed in this paper.
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Surface modification of Titanium, Titanium Alloys, and related materials for biomedical applications
Materials Science and Engineering R: Reports, 2004Co-Authors: Xuanyong Liu, Paul K Chu, Chuanxian DingAbstract:Titanium and Titanium Alloys are widely used in biomedical devices and components, especially as hard tissue replacements as well as in cardiac and cardiovascular applications, because of their desirable properties, such as relatively low modulus, good fatigue strength, formability, machinability, corrosion resistance, and biocompatibility. However, Titanium and its Alloys cannot meet all of the clinical requirements. Therefore, in order to improve the biological, chemical, and mechanical properties, surface modification is often performed. This article reviews the various surface modification technologies pertaining to Titanium and Titanium Alloys including mechanical treatment, thermal spraying, sol-gel, chemical and electrochemical treatment, and ion implantation from the perspective of biomedical engineering. Recent work has shown that the wear resistance, corrosion resistance, and biological properties of Titanium and Titanium Alloys can be improved selectively using the appropriate surface treatment techniques while the desirable bulk attributes of the materials are retained. The proper surface treatment expands the use of Titanium and Titanium Alloys in the biomedical fields. Some of the recent applications are also discussed in this paper. © 2004 Elsevier B.V. All rights reserved.
F H Froes - One of the best experts on this subject based on the ideXlab platform.
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hydrogen as a temporary alloying element in Titanium Alloys thermohydrogen processing
International Materials Reviews, 2004Co-Authors: F H Froes, O N Senkov, J I QaziAbstract:AbstractThermohydrogen processing is a technique in which hydrogen is used as a temporary alloying element in Titanium Alloys to control the microstructure and improve the final mechanical properties. Thermohydrogen processing can also be used to enhance the processability/fabricability of Titanium products including sintering, compaction, machining, and hot working (forging, rolling, superplastic forming, etc.). In the case of near net shapes, such as castings and powder metallurgy products, thermohydrogen processing is the only method available for significant microstructural modifications and consequent enhancement in mechanical properties. This paper reviews the status of the methods and applications of thermohydrogen processing to Titanium Alloys. Principles of thermohydrogen processing, based on the hydrogen induced alterations of the phase compositions and the kinetics of phase reactions in hydrogenated Titanium Alloys, are overviewed. Stable and metastable phase diagrams of several Titanium Alloys...
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thermohydrogen processing of Titanium Alloys
International Journal of Hydrogen Energy, 1999Co-Authors: O N Senkov, F H FroesAbstract:Use of hydrogen as a temporary alloying element in Titanium Alloys is an attractive approach for enhancing processability including working, machining, sintering, compaction, etc., and also for controlling the microstructure and thereby improving final mechanical properties. In this article, the status of the methods and applications of thermohydrogen processing (THP) to Titanium Alloys is reviewed. Effects of hydrogen alloying on the phases present, their composition, and the kinetics of phase reactions are considered. The effect of hydrogen on the hot workability, composite- and powder-metallurgy-product processing, and microstructure modification of wrought and cast conventional Alloys and intermetallics, including production of nanocrystalline structures is discussed. Two recently discovered effects, i.e. hydrogen-induced softening of α Titanium and hydrogen-induced hardening of β Titanium are also discussed. Thermohydrogen processing has clear advantages in the development of improved microstructures and mechanical properties. In the case of near net shapes it is the only method for significant microstructural modification. It allows energy savings in processing to final products by improving the workability. © 1999 International Association for Hydrogen Energy.
