Mechanical properties of biomedical titanium alloys
15 Mar 1998-Materials Science and Engineering A-structural Materials Properties Microstructure and Processing (Elsevier)-Vol. 243, Iss: 1, pp 231-236
TL;DR: Titanium alloys are expected to be much more widely used for implant materials in the medical and dental fields because of their superior biocompatibility, corrosion resistance and specific strength compared with other metallic implant materials.
Abstract: Titanium alloys are expected to be much more widely used for implant materials in the medical and dental fields because of their superior biocompatibility, corrosion resistance and specific strength compared with other metallic implant materials. Pure titanium and Ti–6Al–4V, in particular, Ti–6Al–4V ELI have been, however, mainly used for implant materials among various titanium alloys to date. V free alloys like Ti–6Al–7Nb and Ti–5Al–2.5Fe have been recently developed for biomedical use. More recently V and Al free alloys have been developed. Titanium alloys composed of non-toxic elements like Nb, Ta, Zr and so on with lower modulus have been started to be developed mainly in the USA. The β type alloys are now the main target for medical materials. The mechanical properties of the titanium alloys developed for implant materials to date are described in this paper.
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TL;DR: In this paper, the influence of alloy chemistry, thermomechanical processing and surface condition on these properties is discussed and various surface modification techniques to achieve superior biocompatibility, higher wear and corrosion resistance.
4,113 citations
TL;DR: In this article, the most critical challenges for metallic implant biomaterials are summarized, with emphasis on the most promising approaches and strategies, and the properties that affect biocompatibility and mechanical integrity are discussed in detail.
Abstract: Human tissue is structured mainly of self-assembled polymers (proteins) and ceramics (bone minerals), with metals present as trace elements with molecular scale functions. However, metals and their alloys have played a predominant role as structural biomaterials in reconstructive surgery, especially orthopedics, with more recent uses in non-osseous tissues, such as blood vessels. With the successful routine use of a large variety of metal implants clinically, issues associated with long-term maintenance of implant integrity have also emerged. This review focuses on metallic implant biomaterials, identifying and discussing critical issues in their clinical applications, including the systemic toxicity of released metal ions due to corrosion, fatigue failure of structural components due to repeated loading, and wearing of joint replacements due to movement. This is followed by detailed reviews on specific metallic biomaterials made from stainless steels, alloys of cobalt, titanium and magnesium, as well as shape memory alloys of nickel–titanium, silver, tantalum and zirconium. For each, the properties that affect biocompatibility and mechanical integrity (especially corrosion fatigue) are discussed in detail. Finally, the most critical challenges for metallic implant biomaterials are summarized, with emphasis on the most promising approaches and strategies.
1,575 citations
TL;DR: In this article, the main metallic biomaterials are stainless steels, Co-based alloys, and titanium and its alloys and they are used for replacing failed hard tissue.
Abstract: Metallic biomaterials are mainly used for replacing failed hard tissue. The main metallic biomaterials are stainless steels, Co-based alloys, and titanium and its alloys. Recently, titanium alloys are getting much attention for biomaterials. The various kinds of new high strength α+β and low-modulus β-type titanium alloys composed of nontoxic elements, such as Nb, Ta, Zr, etc., are developed for biomedical applications because of the toxicity of alloying elements and lack of mechanical biocompatibility of conventional titanium alloys, such as Ti-6Al-4V. Recent research and development in other metallic alloys, such as stainless steels and Co-based alloys, also will be discussed.
1,215 citations
TL;DR: The development of new metallic alloys for biomedical applications is described in this paper, which includes β-type titanium alloys with a self-tunable modulus, which has been proposed for the construction of removable implants.
1,154 citations
TL;DR: In this article, the microstructure-defect-property relationship under cyclic loading for a TiAl6V4 alloy processed by selective laser melting is investigated. And the results show that the micron sized pores mainly affect fatigue strength, while residual stresses have a strong impact on fatigue crack growth.
1,079 citations
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15 Aug 1996-Materials Science and Engineering A-structural Materials Properties Microstructure and Processing
TL;DR: In this paper, the comparative mechanical property data of five beta titanium alloys (TMZFTM, Ti-13Nb-13Zr, TIMETAL® 21SRx, Tiadyne 1610 and Ti-15Mo) are presented.
Abstract: The Ti-6Al-4V ELI alloy is still the main titanium alloy used for medical applications to date. To address the potential safety concerns over vanadium and aluminum, and the possible advantage of using a low modulus material to reduce stress shielding, the development of a low modulus biocompatible implant material was initiated in the United States in 1986. Five beta titanium alloys (TMZFTM, Ti-13Nb-13Zr, TIMETAL® 21SRx, Tiadyne 1610 and Ti-15Mo) are being proposed for surgical implant applications in the United States. Based on published data, the comparative mechanical property data of these beta titanium alloys are presented.
710 citations
01 Jan 1996
35 citations
TL;DR: In this paper, the effect of the microstructure on mechanical properties, fracture toughness, and rotating-bending fatigue strength in the air and simulated body environment, that is, Ringer's solution, was investigated.
Abstract: The microstructure of Ti-5Al-2.5Fe, which is expected to be used widely as an implant material not only for artificial hip joints but also for instrumentations of scoliosis surgery, was variously changed by heat treatments. The effect of the microstructure on mechanical properties, fracture toughness, and rotating-bending fatigue strength in the air and simulated body environment, that is, Ringer’s solution, was then investigated. Furthermore, the effect of the living body environment on mechanical properties and fracture toughness in Ti-5Al-2.5Fe were investigated on the specimens implanted into rabbit for about 11 months. The data of Ti-5Al-2.5Fe were compared with those of Ti-6Al-4V ELI, which has been used as an implant material mainly for artificial hip joints, and SUS 316L, which has been used as an implant material for many parts, including the instrumentation of scoliosis surgery. The equiaxedα structure, which is formed by annealing at a temperature belowβ transus, gives the best balance of strength and ductility in Ti-5Al-2.5Fe. The coarse Widmanstattenα structure, which is formed by solutionizing overβ transus followed by air cooling and aging, gives the greatest fracture toughness in Ti-5Al-2.5Fe. This trend is similar to that reported in Ti-6Al-4V ELI. The rotating-bending fatigue strength is the greatest in the equiaxedα structure, which is formed by solutionizing belowβ transus followed by air cooling and aging in Ti-5Al-2.5Fe. Ti-5Al-2.5Fe exhibits much greater rotating-bending fatigue strength compared with SUS 316L, and equivalent rotating-bending fatigue strength to that of Ti-6Al-4V ELI in both the air and simulated body environments. The rotating-bending fatigue strength of SUS 316L is degraded in the simulated body environment. The corrosion fatigue, therefore, occurs in SUS 316L in the simulated body environment. Fatigue strength of Ti-5Al-2.5Fe in the simulated body environment is degraded by lowering oxygen content in the simulated body environment because the formability of oxide on the specimen surface is considered to be lowered comparing with that in air. The mechanical property and fracture toughness of Ti-5Al-2.5Fe and Ti-6Al-4V ELI are not changed in the living body environment. The hard-surface corrosion layer is, however, formed on the surface of SUS 316L in the living body environment. The C1 peak is detected from the hard-surface corrosion layer by energy-dispersive X-ray (EDX) analysis. These facts suggests a possibility for corrosion fatigue to occur in the living body environment when SUS 316L is used. The fibrous connective tissue and new bone formation are formed beside all metals. There is, however, no big difference between tissue morphology around each implant material.
21 citations