Development of Low Elastic Modulus Titanium Alloys as Implant Biomaterials
School of Materials Science and Engineering, Hebei University of Engineering, Handan, 056038, China
Hebei Engineering Research Centre for Rare Earth Permanent Magnetic Materials & Applications, Hebei University of Engineering, Handan 056038, China
Hebei Key Laboratory of Wear-resistant Metallic Materials with High Strength and Toughness, Hebei University of Engineering, Handan 056038, China
Academic Editor: Mazen Alshaaer
Received: March 20, 2022 | Accepted: April 12, 2022 | Published: April 21, 2022
Recent Progress in Materials 2022, Volume 4, Issue 2, doi:10.21926/rpm.2202008
Recommended citation: Liu KY, Yin LX, Lin X, Liang SX. Development of Low Elastic Modulus Titanium Alloys as Implant Biomaterials. Recent Progress in Materials 2022; 4(2): 008; doi:10.21926/rpm.2202008.
© 2022 by the authors. This is an open access article distributed under the conditions of the Creative Commons by Attribution License, which permits unrestricted use, distribution, and reproduction in any medium or format, provided the original work is correctly cited.
The development of biomaterial science and engineering is very important for humans to enjoy a long life. Thus, biomaterials have always been the focus of material scientists and engineers and have received much attention. As hard tissue implants, biomaterials should possess high strength, a certain degree of plasticity, should be non-toxic, the elastic modulus should be close to that of the bone, and should have good biocompatibility. Research and clinical applications have shown that Ti and its alloys are the most suitable to be used as hard tissue implant biomaterials [1,2,3]. Long-term experiments and clinical applications have shown that a mismatch of elastic modulus between implants and surrounding bones causes a “stress shielding” effect [4,5,6]. The one with a low elastic modulus bears less stress when two materials with different elastic modulus are stressed together. Wolff’s law  showed that if the bones in the human body are exposed to external pressure for a long time, the density and hardness of the bone can increase. Conversely, bones can undergo osteoporosis and resorption if they are exposed to low stress or are in a stress-free state for a long period. To decrease or avoid such an effect, researchers are committed to developing alloys with a low elastic modulus [8,9,10]. Ti and its alloys are the most studied and the most promising to be used as hard tissue implant materials. In recent decades, many Ti alloys have been developed, and some have been clinically applied [11,12]. Interestingly, some porous Ti alloys show a very low elastic modulus (0.05 ~ 5.7 GPa) . Some methods have also been developed to prepare the porous Ti alloys for biomaterials. The methods that are generally used consist of reverse freeze casting , dynamic freeze casting [15,16], HF/HNO3-treatment , powder-based additive manufacturing , etc.
This study reviewed the advancements in the application of low elastic modulus Ti alloys as a type of hard tissue implant biomaterial. The major series of low elastic modulus Ti alloys as implant biomaterials, including TiNb-based, TiMo-based, and TiZr-based alloys, were introduced, discussed, and compared. This study might be used as a reference for the development of low modulus metallic biomaterials.
2. Early Low Modulus Titanium Alloys for Biomaterials
In the early stage, stainless steel and Vitallium were used as the major hard tissue implant materials . But The elastic modulus of stainless steel is approximately 200 GPa, and that of Vitallium is close to 220 GPa [1,19,20]. The elastic modulus of these alloys is very high compared to that of the bones (10 to 30 GPa) and, thus, might result in a “stress shielding” effect. Among common metals, pure Ti has a low elastic modulus of 110 GPa, and the typical commercial titanium alloy, Ti-6Al-4V (TC4), also has a similar elastic modulus and higher strength. Thus, pure Ti and the TC4 alloy are the major Ti alloys that are used in the early application stage as hard tissue implant biomaterials [11,21]. Besides these Ti alloys, the Ti-6Al-7Nb , Ti-28Nb-7Al , and Ti-15Nb-25Zr-8Fe  alloys were also developed and can be used as an implanted biomaterial. However, clinical applications have shown that elements Al [25,26] and V [27,28,29] have some side effects on the human body. Hence, the toxicity, negative effects, cell activity, and other biocompatibilities of alloying elements are taken seriously [30,31,32]. Steineman and Kawahar summarized the toxicity and biocompatibility of various metals (see Figure 1) [33,34]. Besides Ti, elements such as Zr, Nb, Ta, Sn, Pa, Mo, etc., also have favorable biocompatibility and are suitable for being used as alloying elements for bio-Ti alloys.
Figure 1 The biocompatibility of common metals and alloys: (a) toxicity and (b) polarization resistance vs. biocompatibility.
3. TiZr-based Low Elastic Modulus Ti Alloys for Biomaterials
Due to toxicity and negative effects, researchers have realized the importance of the development of low elastic modulus Ti alloys with compatible elements. Many studies have suggested that metastable beta Ti alloys should have a low elastic modulus [8,35,36]. Nb is a non-toxic and typical beta stabilizer. Thus, Nb is preferred for developing low elastic modulus Ti alloys. Many researchers have investigated low elastic modulus TiNb-based alloys for bio-applications. The main TiNb-based alloys without toxic elements and their elastic modulus are shown in Table 1 [37,38,39,40,41], Table 2 [12,42,43,44,45,46,47,48,49,50,51,52,53], and Table 3 [12,43,44,45,50,54,55,56,57,58,59,60,61,62,63,64,65,66] based on the number of components. Based on Table 1, the elastic modulus of bulk Ti-Nb binary alloys like Ti-38Nb, Ti-40Nb, and Ti-45Nb is over 55 GPa. However, that is low to 25 GPa for microporous Ti-35Nb binary alloy and an amazing low value to 2.6 GPa for macroporous Ti-35Nb. The addition of one more alloying element in ternary TiNb-based alloys results in an elastic modulus close to the upper limit of biological bones (~30 GPa). Especially, the elastic modulus of bulk Ti-19Nb-14Zr ternary alloy is as low as 14 GPa, which is similar to that of most bones. According to the strengthening theory, the addition of alloying element can strengthen alloys. Thus, the multi-component TiNb-based alloys could have both low elastic modulus and high strength. As shown in Table 3, the bulk multi-component TiNb-based alloys have elastic modulus close to that of the bones. The elastic modulus of porous Ti-35Nb-2Ta-3Zr alloys is as low as 3.1 GPa. Thus, the TiNb-based alloys can have an elastic modulus similar to that of bones. These elastic moduli can be adjusted across a wide range of values to meet the different requirements. Overall, the porous TiNb-based alloys can have a lower elastic modulus than the bulk ones. However, the low strength can limit the application of porous alloys as hard tissue implants .
4. Major Low Elastic Modulus TiMo-based Alloys for Biomaterials
Besides Nb, Mo is another major alloying element to produce low elastic modulus Ti alloys for implant biomaterials. Mo is a typical beta stabilizer for Ti alloys. Many researchers have used the Mo equivalent to design and develop various Ti alloys containing low modulus Ti alloys for different purposes [68,69]. The major low elastic modulus of TiMo-based alloys and their modulus are listed in Table 4 [43,50,55,70,71,72,73,74,75,76,77,78,79,80,81]. The effect of Mo on biocompatibility and cell activity is controversial (Figure 1). Thus, the number of developed low elastic modulus TiMo-based alloys is considerably lesser than that of TiNb-based alloys. The elastic modulus of bulk Ti-Mo binary alloys is higher than 50 GPa, and the lowest modulus of reported bulk Ti-Mo binary alloys is 55 GPa, as shown in Table 4. Like TiNb-based alloys, the porous TiMo-based alloys also have a very low elastic modulus. The porous Ti-10Mo alloy has a very low modulus of 6.4 GPa, which is lower than that of most bones (4~30). The elastic modulus of TiMo-based alloys also can be regulated and decreased by adding other alloying elements, such as Nb, Zr, Si, Sn, etc. A series of Ti-Mo-Si-Zr alloys have an elastic modulus near the upper limit of biological bones (30 GPa). The lowest elastic modulus of the reported Ti-10Mo-1.25Si-4Zr alloy is 23.1 GPa. Compared to the composition of TiNb-based and TiMo-based alloys, the addition of Mo in low elastic modulus TiMo-based alloys is mostly below 15 wt.%, but the Nb content in low elastic modulus TiNb-based alloys can reach up to 40 wt.%. Previous studies [8,35,36] have shown that metastable beta Ti alloys have the lowest elastic modulus. The coefficient of Nb in the Mo equivalent formula is only 0.28 . This indicates that the stabilization effect of 1 wt.% Mo to beta Ti phase is equivalent to approximately 3.5 wt.% Nb. Thus, the required Mo content is lesser than that of Nb.
5. TiZr-based Low Modulus Ti Alloys for Biomaterials
The elements Zr and Ti belong to the same group in the periodic table. Hence, they have similar physical and chemical properties. Some researchers have studied the effects of Zr addition on the phase transformation, microstructure, and properties of Ti and its alloys and developed some TiZr-based alloys with high strength and toughness [82,83,84,85]. As a neutral element of Ti and its alloys, the addition of Zr has a weak stabilizing effect on the beta phase of Ti and its alloys. However, when the content of Zr exceeds 10%, it has a stabilizing effect on the beta phase of Ti alloys . Zr is also an alloying element with good biocompatibility. Therefore, many researchers have studied TiZr-based biomedical alloys, and many alloys with a low elastic modulus have been obtained from this series of elements, as presented in Table 5 [50,57,87,88,89,90,91,92,93,94,95,96,97,98,99,100,101,102]. When only a small amount of the alloying elements is added, the elastic modulus of TiZr-based alloys does not decrease much. For example, the elastic modulus of Ti-6Zr-xFe (x = 4 to 7) alloys exceeds 90 GPa. With an increase in the content of the alloying element, the elastic modulus of TiZr-based alloys decreases gradually. The Ti-30Zr-5Al-3V alloy has the lowest elastic modulus of 34 GPa of the reported bulk TiZr-based alloys. Similarly, when a TiZr-based alloy is prepared in a porous material, its elastic modulus can be reduced to 5 GPa. Therefore, the elastic modulus of this series of alloys can also be close to that of the bone. Thus, TiZr-based alloys have a great potential for being used as implant biomaterials.
Besides the above TiNb-based, TiMo-based, and TiZr-based titanium alloys, some other Ti-based alloys with a low elastic modulus have also been developed through composition design and process adjustment, such as the TiCr-based series [103,104,105], the TiFe-based series [106,107,108], the TiCu-based series [109,110], etc. However, these alloys contain some alloying elements with toxic and negative effects. Therefore, they are not used as implanted biomaterials and are not described here.
By comparing the abovementioned series of Ti alloys with a low elastic modulus, it is evident that although all three series of Ti alloys have a very low elastic modulus showing a great application potential as implant biomaterials, the TiNb-based alloy series is the most preferred. Furthermore, the elastic modulus of all Ti alloys can be decreased dramatically to even lower than the elastic modulus of bones by producing them in porous materials using special methods like additive manufacturing , electron beam melting , and selective laser melting . The properties of porous Ti alloys, including elastic modulus, are affected by parameters of pores  such as size, porosity, shape, etc.
6. Summary and Future
This study summarized low elastic modulus titanium with great application potential as implant biomaterials. The study mainly introduced the major series of titanium alloys with a low elastic modulus, including the TiNb-based, TiMo-based, and TiZr-based series of titanium alloys. The research status and possible factors of the low elastic modulus of these major titanium alloys were analyzed. Finally, the development prospects of the abovementioned series of low elastic modulus titanium alloys were compared. Several low elastic modulus titanium alloys have been developed to be used as implant biomaterials. However, most of these studies are still in the experimental stage. Thus, practical clinical applications need time. The development of low elastic modulus titanium alloys should mainly focus on the promotion of the clinical application of some titanium alloys with a low elastic modulus and stable performance. Especially, some advanced methods, such as additive manufacturing, electron beam melting, and selective laser melting, need to be developed for optimizing the properties and promoting the application of porous Ti alloys with a favorable low elastic modulus.
Kai-Yang Liu: Writing - Original Draft, Visualization; Li-Xia Yin: Data Curation, Project Administration; Xu Lin: Check and modify the revised manuscript; Shun-Xing Liang: Funding Acquisition, Conceptualization, Writing - Review & Editing.
The Natural Science Foundation of Hebei Province (Grant No. E2021402002, E2021402001), the Department of Education of Hebei Province (Grant No. ZD2020195, ZD2018213, QN2019040), and the Science and Technology Research and Development Projects of Handan City (Grant No. 21422111221, 19422111008-20).
The authors have declared that no competing interests exist.
- Long M, Rack HJ. Titanium alloys in total joint replacement-a materials science perspective. Biomaterials. 1998; 19: 1621-1639. [CrossRef]
- Hudecki A, Kiryczyński G, Łos MJ. Chapter 7: Biomaterials, definition, overview. In: Stem cells and biomaterials for regenerative medicine. Cambridge: Academic Press; 2019. pp.85-98. [CrossRef]
- Niinomi M. Metallic biomaterials. J Artif Organs. 2008; 11: 105. [CrossRef]
- Sumner D, Galante J. Determinants of stress shielding: Design versus materials versus interface. Clin Orthop Relat Res. 1992; 274: 202-212. [CrossRef]
- Mi ZR, Shuib S, Hassan AY, Shorki AA, Ibrahim MM. Problem of stress shielding and improvement to the hip Implat designs: A review. J Med Sci. 2007; 7: 460-467. [CrossRef]
- Kennady MC, Tucker MR, Lester GE, Buckley MJ. Stress shielding effect of rigid internal fixation plates on mandibular bone grafts. A photon absorption densitometry and quantitative computerized tomographic evaluation. Int J Oral Maxillofac Surg. 1989; 18: 307-310. [CrossRef]
- Prendergast PJ, Huiskes R. The biomechanics of Wolff’s law: Recent advances. Ir J Med Sci. 1995; 164: 152-154. [CrossRef]
- Wang P, Todai M, Nakano T. Beta titanium single crystal with bone-like elastic modulus and large crystallographic elastic anisotropy. J Alloys Compd. 2019; 782: 667-671. [CrossRef]
- Saravana Kumar G, George SP. Optimization of custom cementless stem using finite element analysis and elastic modulus distribution for reducing stress-shielding effect. Proc Inst Mech Eng H. 2017; 231: 149-159. [CrossRef]
- Zhang L, Song B, Choi SK, Shi Y. A topology strategy to reduce stress shielding of additively manufactured porous metallic biomaterials. Int J Mech Sci. 2021; 197: 106331. [CrossRef]
- Niinomi M, Nakai M. Titanium-based biomaterials for preventing stress shielding between implant devices and bone. Int J Biomater. 2011; 2011: 836587. [CrossRef]
- Liang S. Review of the design of titanium alloys with low elastic modulus as implant materials. Adv Eng Mater. 2020; 22: 2000555. [CrossRef]
- Lee H, Jung HD, Kang MH, Song J, Kim HE, Jang TS. Effect of HF/HNO3-treatment on the porous structure and cell penetrability of titanium (Ti) scaffold. Mater Des. 2018; 145: 65-73. [CrossRef]
- Yook SW, Jung HD, Park CH, Shin KH, Koh YH, Estrin Y, et al. Reverse freeze casting: A new method for fabricating highly porous titanium scaffolds with aligned large pores. Acta Biomater. 2012; 8: 2401-2410. [CrossRef]
- Jung HD, Yook SW, Jang TS, Li Y, Kim HE, Koh YH. Dynamic freeze casting for the production of porous titanium (Ti) scaffolds. Mater Sci Eng C. 2013; 33: 59-63. [CrossRef]
- Lee H, Jang TS, Song J, Kim HE, Jung HD. Multi-scale porous Ti6Al4V scaffolds with enhanced strength and biocompatibility formed via dynamic freeze-casting coupled with micro-arc oxidation. Mater Lett. 2016; 185: 21-24. [CrossRef]
- Jang TS, Kim D, Han G, Yoon CB, Jung HD. Powder based additive manufacturing for biomedical application of titanium and its alloys: A review. Biomed Eng Lett. 2020; 10: 505-516. [CrossRef]
- Niinomi M. Recent metallic materials for biomedical applications. Metall Mater Trans A. 2002; 33: 477. [CrossRef]
- De Meurechy N, Braem A, Mommaerts MY. Biomaterials in temporomandibular joint replacement: Current status and future perspectives-a narrative review. Int J Oral Maxillofac Surg. 2018; 47: 518-533. [CrossRef]
- Bahl S, Suwas S, Chatterjee K. Comprehensive review on alloy design, processing, and performance of β Titanium alloys as biomedical materials. Int Mater Rev. 2020; 66: 114-139. [CrossRef]
- McCracken M. Dental implant materials: Commercially pure titanium and titanium alloys. J Prosthodont. 1999; 8: 40-43. [CrossRef]
- Kobayashi E, Wang TJ, Doi H, Yoneyama T, Hamanaka H. Mechanical properties and corrosion resistance of Ti–6Al–7Nb alloy dental castings. J Mater Sci Mater Med. 1998; 9: 567-574. [CrossRef]
- Wang P, Todai M, Nakano T. ω-phase transformation and lattice modulation in biomedical β-phase Ti-Nb-Al alloys. J Alloys Compd. 2018; 766: 511-516. [CrossRef]
- Li Q, Yuan X, Li J, Wang P, Nakai M, Niinomi M, et al. Effects of Fe on microstructures and mechanical properties of Ti–15Nb–25Zr–(0, 2, 4, 8)Fe alloys prepared by spark plasma sintering. Mater Trans. 2019; 60: 1763-1768. [CrossRef]
- Martinez CS, Escobar AG, Uranga-Ocio JA, Peçanha FM, Vassallo DV, Exley C, et al. Aluminum exposure for 60days at human dietary levels impairs spermatogenesis and sperm quality in rats. Reprod Toxicol. 2017; 73: 128-141. [CrossRef]
- Verstraeten SV, Aimo L, Oteiza PI. Aluminium and lead: Molecular mechanisms of brain toxicity. Arch Toxicol. 2008; 82: 789-802. [CrossRef]
- Roy S, Majumdar S, Singh AK, Ghosh B, Ghosh N, Manna S, et al. Synthesis, characterization, antioxidant status, and toxicity study of vanadium–rutin complex in Balb/c mice. Biol Trace Elem Res. 2015; 166: 183-200. [CrossRef]
- Liu J, Cui H, Liu X, Peng X, Deng J, Zuo Z, et al. Dietary high vanadium causes oxidative damage-induced renal and hepatic toxicity in broilers. Biol Trace Elem Res. 2012; 145: 189-200. [CrossRef]
- Imura H, Shimada A, Naota M, Morita T, Togawa M, Hasegawa T, et al. Vanadium toxicity in mice: Possible impairment of lipid metabolism and mucosal epithelial cell necrosis in the small intestine. Toxicol Pathol. 2012; 41: 842-856. [CrossRef]
- Mirzajavadkhan A, Rafieian S, Hasan MH. Toxicity of metal implants and their interactions with stem cells: A review. Int J Eng Mater Manuf. 2020; 5: 2-11. [CrossRef]
- Kim KT, Eo MY, Nguyen TTH, Kim SM. General review of titanium toxicity. Int J Implant Dent. 2019; 5: 10. [CrossRef]
- Sansone V, Pagani D, Melato M. The effects on bone cells of metal ions released from orthopaedic implants. A review. Clin Cases Miner Bone Metab. 2013; 10: 34-40. [CrossRef]
- Kawara H. Cytotoxicity of implantable metals and alloys. J Jpn I Met Mater. 1992; 31: 1033-1039. [CrossRef]
- Steinemann SG. "Corrosion of surgical implants-in vivo and in vitro tests," in evaluation of biomaterials. Adv Biomater. 1980; 1: 1-34.
- Ozaki T, Matsumoto H, Watanabe S, Hanada S. Beta Ti alloys with low Young’s modulus. Mater Trans. 2004; 45: 2776-2779. [CrossRef]
- Chen LY, Cui YW, Zhang LC. Recent development in beta titanium alloys for biomedical applications. Metals. 2020; 10: 1139. [CrossRef]
- Panigrahi A, Sulkowski B, Waitz T, Ozaltin K, Chrominski W, Pukenas A, et al. Mechanical properties, structural and texture evolution of biocompatible Ti–45Nb alloy processed by severe plastic deformation. J Mech Behav Biomed Mater. 2016; 62: 93-105. [CrossRef]
- Guo S, Zhang J, Cheng X, Zhao X. A metastable β-type Ti–Nb binary alloy with low modulus and high strength. J Alloys Compd. 2015; 644: 411-415. [CrossRef]
- Helth A, Pilz S, Kirsten T, Giebeler L, Freudenberger J, Calin M, et al. Effect of thermomechanical processing on the mechanical biofunctionality of a low modulus Ti-40Nb alloy. J Mech Behav Biomed Mater. 2017; 65: 137-150. [CrossRef]
- Zhuravleva K, Bönisch M, Prashanth KG, Hempel U, Helth A, Gemming T, et al. Production of porous β-type Ti–40Nb alloy for biomedical applications: Comparison of selective laser melting and hot pressing. Materials. 2013; 6: 5700-5712. [CrossRef]
- de Oliveira CS, Griza S, de Oliveira MV, Ribeiro AA, Leite MB. Study of the porous Ti35Nb alloy processing parameters for implant applications. Powder Technol. 2015; 281: 91-98. [CrossRef]
- Ma LW, Cheng HS, Chung CY. Effect of thermo-mechanical treatment on superelastic behavior of Ti–19Nb–14Zr (at.%) shape memory alloy. Intermetallics. 2013; 32: 44-50. [CrossRef]
- Kuroda D, Niinomi M, Morinaga M, Kato Y, Yashiro T. Design and mechanical properties of new β type titanium alloys for implant materials. Mater Sci Eng A. 1998; 243: 244-249. [CrossRef]
- Elias LM, Schneider SG, Schneider S, Silva HM, Malvisi F. Microstructural and mechanical characterization of biomedical Ti–Nb–Zr(–Ta) alloys. Mater Sci Eng A. 2006; 432: 108-112. [CrossRef]
- Matsumoto H, Watanabe S, Hanada S. Beta TiNbSn Alloys with low Young’s modulus and high strength. Mater Trans. 2005; 46: 1070-1078. [CrossRef]
- Li P, Ma X, Wang D, Zhang H. Microstructural and mechanical properties of β-Type Ti–Nb–Sn biomedical alloys with low elastic modulus. Metals. 2019; 9: 712. [CrossRef]
- Cimpean A, Mitran V, Ciofrangeanu CM, Galateanu B, Bertrand E, Gordin D-M, et al. Osteoblast cell behavior on the new beta-type Ti–25Ta–25Nb alloy. Mater Sci Eng C. 2012; 32: 1554-1563. [CrossRef]
- Li P, Ma X, Tong T, Wang Y. Microstructural and mechanical properties of β-type Ti–Mo–Nb biomedical alloys with low elastic modulus. J Alloys Compd. 2020; 815: 152412. [CrossRef]
- Brailovski V, Prokoshkin S, Gauthier M, Inaekyan K, Dubinskiy S, Petrzhik M, et al. Bulk and porous metastable beta Ti–Nb–Zr(Ta) alloys for biomedical applications. Mater Sci Eng C. 2011; 31: 643-657. [CrossRef]
- Mohammed M, Khan Z, Siddiquee A. Beta titanium alloys: The lowest elastic modulus for biomedical applications: A review. Int J Chem Nucl Metall Mater Eng. 2014; 8: 726-731.
- Hou YP, Guo S, Qiao XL, Tian T, Meng QK, Cheng XN, et al. Origin of ultralow Young׳s modulus in a metastable β-type Ti–33Nb–4Sn alloy. J Mech Behav Biomed Mater. 2016; 59: 220-225. [CrossRef]
- Tan MHC, Baghi AD, Ghomashchi R, Xiao W, Oskouei RH. Effect of niobium content on the microstructure and Young’s modulus of Ti-xNb-7Zr alloys for medical implants. J Mech Behav Biomed Mater. 2019; 99: 78-85. [CrossRef]
- Liu J, Ruan J, Chang L, Yang H, Ruan W. Porous Nb-Ti-Ta alloy scaffolds for bone tissue engineering: Fabrication, mechanical properties and in vitro/vivo biocompatibility. Mater Sci Eng C. 2017; 78: 503-512. [CrossRef]
- Vieira Nunes AR, Borborema S, Araújo LS, Malet L, Dille J, Henrique de Almeida L. Influence of thermo-mechanical processing on structure and mechanical properties of a new metastable β Ti–29Nb–2Mo–6Zr alloy with low Young’s modulus. J Alloys Compd. 2020; 820: 153078. [CrossRef]
- Li YH, Shang XY. Recent progress in porous TiNb-based alloys for biomedical implant applications. Mater Sci Technol. 2020; 36: 385-392. [CrossRef]
- Hao YL, Li SJ, Sun SY, Yang R. Effect of Zr and Sn on Young’s modulus and superelasticity of Ti–Nb-based alloys. Mater Sci Eng A. 2006; 441: 112-118. [CrossRef]
- Yang F, Li Z, Wang Q, Jiang B, Yan B, Zhang P, et al. Cluster-formula-embedded machine learning for design of multicomponent β-Ti alloys with low Young’s modulus. NPJ Comput Mater. 2020; 6: 101. [CrossRef]
- Jiang B, Wang Q, Wen D, Xu F, Chen G, Dong C, et al. Effects of Nb and Zr on structural stabilities of Ti-Mo-Sn-based alloys with low modulus. Mater Sci Eng A. 2017; 687: 1-7. [CrossRef]
- Joshi T, Sharma R, Mittal VK, Gupta V, Krishan G. Dynamic analysis of hip prosthesis using different biocompatible alloys. ASME Open J Eng. 2022; 1: 011001. [CrossRef]
- Stráský J, Harcuba P, Václavová K, Horváth K, Landa M, Srba O, et al. Increasing strength of a biomedical Ti-Nb-Ta-Zr alloy by alloying with Fe, Si and O. J Mech Behav Biomed Mater. 2017; 71: 329-336. [CrossRef]
- Hafeez N, Liu J, Wang L, Wei D, Tang Y, Lu W, et al. Superelastic response of low-modulus porous beta-type Ti-35Nb-2Ta-3Zr alloy fabricated by laser powder bed fusion. Addit Manuf. 2020; 34: 101264. [CrossRef]
- Liang SX, Feng XJ, Yin LX, Liu XY, Ma MZ, Liu RP. Development of a new β Ti alloy with low modulus and favorable plasticity for implant material. Mater Sci Eng C. 2016; 61: 338-343. [CrossRef]
- Vishnu J, Sankar M, Rack HJ, Rao N, Singh AK, Manivasagam G. Effect of phase transformations during aging on tensile strength and ductility of metastable beta titanium alloy Ti–35Nb–7Zr–5Ta-0.35O for orthopedic applications. Mater Sci Eng A. 2020; 779: 139127. [CrossRef]
- Acharya S, Panicker AG, Laxmi DV, Suwas S, Chatterjee K. Study of the influence of Zr on the mechanical properties and functional response of Ti-Nb-Ta-Zr-O alloy for orthopedic applications. Mater Des. 2019; 164 :107555. [CrossRef]
- Stráský J, Preisler D, Seiner H, Bodnárová L, Janovská M, Košutová T, et al. Achieving high strength and low elastic modulus in interstitial biomedical Ti–Nb–Zr–O alloys through compositional optimization. Mater Sci Eng A. 2022; 839: 142833. [CrossRef]
- Mavros N, Larimian T, Esqivel J, Gupta RK, Contieri R, Borkar T. Spark plasma sintering of low modulus titanium-niobium-tantalum-zirconium (TNTZ) alloy for biomedical applications. Mater Des. 2019; 183: 108163. [CrossRef]
- Yu G, Li Z, Li S, Zhang Q, Hua Y, Liu H, et al. The select of internal architecture for porous Ti alloy scaffold: A compromise between mechanical properties and permeability. Mater Des. 2020; 192: 108754. [CrossRef]
- Abdelrhman Y, Gepreel MAH, Kobayashi S, Okano S, Okamoto T. Biocompatibility of new low-cost (α + β)-type Ti-Mo-Fe alloys for long-term implantation. Mater Sci Eng C. 2019; 99: 552-562. [CrossRef]
- Li H, Cai Q, Li S, Xu H. Effects of Mo equivalent on the phase constituent, microstructure and compressive mechanical properties of Ti–Nb–Mo–Ta alloys prepared by powder metallurgy. J Mater Res Technol. 2022; 16: 588-598. [CrossRef]
- Moshokoa NA, Raganya ML, Machaka R, Makhatha ME, Obadele BA. The effect of molybdenum content on the microstructural evolution and tensile properties of as-cast Ti-Mo alloys. Mater Today Commun. 2021; 27: 102347. [CrossRef]
- Nnamchi PS, Obayi CS, Todd I, Rainforth MW. Mechanical and electrochemical characterisation of new Ti–Mo–Nb–Zr alloys for biomedical applications. J Mech Behav Biomed Mater. 2016; 60: 68-77. [CrossRef]
- Zhao C, Zhang X, Cao P. Mechanical and electrochemical characterization of Ti–12Mo–5Zr alloy for biomedical application. J Alloys Compd. 2011; 509: 8235-8238. [CrossRef]
- Raganya L, Moshokoa N, Obadele B, Makhatha E, Machaka R. Microstructure and mechanical properties of Ti-Mo-Nb alloys designed using the cluster-plus-glue-atom model for orthopedic applications. Int J Adv Manuf Technol. 2021; 115: 3053-3064. [CrossRef]
- Nunes ARV, Borborema SG, Araújo LS, Nunes CA, de Almeida LH. Electrochemical behavior of hot treated Ti-12Mo-8Nb alloy. Mater Sci Forum. 2018; 930: 368-373. [CrossRef]
- Ho WF, Ju CP, Chern Lin JH. Structure and properties of cast binary Ti–Mo alloys. Biomaterials. 1999; 20: 2115-2122. [CrossRef]
- Zhang WD, Liu Y, Wu H, Song M, Zhang TY, Lan XD, et al. Elastic modulus of phases in Ti–Mo alloys. Mater Charact. 2015; 106: 302-307. [CrossRef]
- Zhan Y, Li C, Jiang W. β-type Ti-10Mo-1.25Si-xZr biomaterials for applications in hard tissue replacements. Mater Sci Eng C. 2012; 32: 1664-1668. [CrossRef]
- Xu W, Lu X, Zhang B, Liu C, Lv S, Yang S, et al. Effects of porosity on mechanical properties and corrosion resistances of PM-fabricated porous Ti-10Mo alloy. Metals. 2018; 8: 188. [CrossRef]
- Ehtemam-Haghighi S, Attar H, Okulov IV, Dargusch MS, Kent D. Microstructural evolution and mechanical properties of bulk and porous low-cost Ti–Mo–Fe alloys produced by powder metallurgy. J Alloys Compd. 2021; 853: 156768. [CrossRef]
- Shinohara Y, Matsumoto Y, Tahara M, Hosoda H, Inamura T. Development of <001>-fiber texture in cold-groove-rolled Ti-Mo-Al-Zr biomedical alloy. Materialia. 2018; 1: 52-61. [CrossRef]
- Moshokoa N, Raganya L, Obadele BA, Olubambi P, Machaka R. The effect of solution treatment on the microstructure and mechanical properties of as-cast Ti-Mo alloys. Mater Today Proc. 2021; 38: 1049-1053. [CrossRef]
- Li Y, Cui Y, Zhang F, Xu H. Shape memory behavior in Ti–Zr alloys. Scr Mater. 2011; 64: 584-587. [CrossRef]
- Liang SX, Ma MZ, Jing R, Zhang XY, Liu RP. Microstructure and mechanical properties of hot-rolled ZrTiAlV alloys. Mater Sci Eng A. 2012; 532: 1-5. [CrossRef]
- Liang SX, Ma MZ, Jing R, Zhou YK, Jing Q, Liu RP. Preparation of the ZrTiAlV alloy with ultra-high strength and good ductility. Mate Sci Eng A. 2012; 539: 42-47. [CrossRef]
- Liang SX, Yin LX, Zhou YK, Feng XJ, Ma MZ, Liu RP, et al. Abnormal martensitic transformation of high Zr-containing Ti alloys. J Alloys Compd. 2014; 615: 804-808. [CrossRef]
- Liang S, Zhou Y, Yin L. Strengthening/weakening action of Zr on stabilizers of Ti alloys and its effect on phase transition. J Mater Eng Perform. 2021; 30: 876-884. [CrossRef]
- Qi P, Li B, Wang T, Zhou L, Nie Z. Microstructure and properties of a novel ternary Ti–6Zr–xFe alloy for biomedical applications. J Alloys Compd. 2021; 854: 157119. [CrossRef]
- Zhao X, Niinomi M, Nakai M, Miyamoto G, Furuhara T. Microstructures and mechanical properties of metastable Ti–30Zr–(Cr, Mo) alloys with changeable Young’s modulus for spinal fixation applications. Acta Biomater. 2011; 7: 3230-3236. [CrossRef]
- Zhao X, Niinomi M, Nakai M, Ishimoto T, Nakano T. Development of high Zr-containing Ti-based alloys with low Young’s modulus for use in removable implants. Mater Sci Eng C. 2011; 31: 1436-1444. [CrossRef]
- Amigó-Mata A, Haro-Rodriguez M, Vicente-Escuder Á, Amigó-Borrás V. Development of Ti–Zr alloys by powder metallurgy for biomedical applications. Powder Metall. 2022; 65: 31-38. [CrossRef]
- Wang P, Feng Y, Liu F, Wu L, Guan S. Microstructure and mechanical properties of Ti–Zr–Cr biomedical alloys. Mater Sci Eng C. 2015; 51: 148-152. [CrossRef]
- Wang P, Wu L, Feng Y, Bai J, Zhang B, Song J, et al. Microstructure and mechanical properties of a newly developed low Young’s modulus Ti–15Zr–5Cr–2Al biomedical alloy. Mater Sci Eng C. 2017; 72: 536-542. [CrossRef]
- Yan XH, Ma J, Zhang Y. High-throughput screening for biomedical applications in a Ti-Zr-Nb alloy system through masking co-sputtering. Sci China Phys Mech. 2019; 62: 996111. [CrossRef]
- Hu S, Li T, Su Z, Liu D. Research on suitable strength, elastic modulus and abrasion resistance of Ti–Zr–Nb medium entropy alloys (MEAs) for implant adaptation. Intermetallics. 2022; 140: 107401. [CrossRef]
- Cai D, Zhao X, Yang L, Wang R, Qin G, Chen Df, et al. A novel biomedical titanium alloy with high antibacterial property and low elastic modulus. J Mater Sci Technol. 2021; 81: 13-25. [CrossRef]
- Wu CT, Chang HT, Wu CY, Chen SW, Huang SY, Huang M, et al. Machine learning recommends affordable new Ti alloy with bone-like modulus. Mater Today. 2020; 34: 41-50. [CrossRef]
- Marczewski M, Miklaszewski A, Maeder X, Jurczyk M. Crystal structure evolution, microstructure formation, and properties of mechanically alloyed ultrafine-grained Ti-Zr-Nb Alloys at 36 ≤ Ti ≤ 70 (at.%). Materials. 2020; 13: 587. [CrossRef]
- Shi YD, Wang LN, Liang SX, Zhou Q, Zheng B. A high Zr-containing Ti-based alloy with ultralow Young’s modulus and ultrahigh strength and elastic admissible strain. Mater Sci Eng A. 2016; 674: 696-700. [CrossRef]
- Kim KM, Al-Zain Y, Yamamoto A, Daher AH, Mansour AT, AlAjlouni JM, et al. Synthesis and characterization of a Ti–Zr-based alloy with ultralow Young’s modulus and excellent biocompatibility. Adv Eng Mater. 2022; 24: 2100776. [CrossRef]
- You L, Song X. A study of low Young’s modulus Ti–Nb–Zr alloys using d electrons alloy theory. Scr Mater. 2012; 67: 57-60. [CrossRef]
- Zhang Y, Liu Z, Zhao Z, Ma M, Shu Y, Hu W, et al. Preparation of pure α”-phase titanium alloys with low moduli via high pressure solution treatment. J Alloys Compd. 2017; 695: 45-51. [CrossRef]
- Aguilar C, Arancibia M, Alfonso I, Sancy M, Tello K, Salinas V, et al. Influence of porosity on the elastic modulus of Ti-Zr-Ta-Nb foams with a low Nb content. Metals. 2019; 9: 176. [CrossRef]
- Nakai M, Niinomi M, Zhao X, Zhao X. Self-adjustment of Young’s modulus in biomedical titanium alloys during orthopaedic operation. Mater Lett. 2011; 65: 688-690. [CrossRef]
- Murayama Y, Sasaki S, Kimura H, Chiba A. Phase stability and mechanical properties of Ti-Cr based alloys with low Young’s modulus. Mater Sci Forum. 2010; 654: 2114-2117. [CrossRef]
- Liu H, Niinomi M, Nakai M, Hieda J, Cho K. Deformation-induced changeable Young’s modulus with high strength in β-type Ti–Cr–O alloys for spinal fixture. J Mech Behav Biomed Mater. 2014; 30: 205-213. [CrossRef]
- Li P, Ma X, Jia Y, Meng F, Tang L, He, et al. Microstructure and mechanical properties of rapidly solidified β-type Ti–Fe–Sn–Mo alloys with high specific strength and low elastic modulus. Metals. 2019; 9: 1135. [CrossRef]
- Haghighi SE, Lu HB, Jian GY, Cao GH, Habibi D, Zhang LC. Effect of α” martensite on the microstructure and mechanical properties of beta-type Ti–Fe–Ta alloys. Mater Des. 2015; 76: 47-54. [CrossRef]
- Li P, Zhang H, Tong T, He Z. The rapidly solidified β-type Ti–Fe–Sn alloys with high specific strength and low elastic modulus. J Alloys Compd. 2019; 786: 986-994. [CrossRef]
- Sharma A, Mishra P. Microstructure and mechanical behaviour of Ti-Cu foams synthesized via powder metallurgy technique. Mater Res Express. 2021; 8: 035402. [CrossRef]
- Tao SC, Xu JL, Yuan L, Luo JM, Zheng YF. Microstructure, mechanical properties and antibacterial properties of the microwave sintered porous Ti–3Cu alloys. J Alloys Compd. 2020; 812: 152142. [CrossRef]
- Wang P, Li X, Luo S, Nai MLS, Ding J, Wei J. Additively manufactured heterogeneously porous metallic bone with biostructural functions and bone-like mechanical properties. J Mater Sci Technol. 2021; 62: 173-179. [CrossRef]
- Wang P, Li X, Jiang Y, Nai MLS, Ding J, Wei J. Electron beam melted heterogeneously porous microlattices for metallic bone applications: Design and investigations of boundary and edge effects. Addit Manuf. 2020; 36: 101566. [CrossRef]
- Li X, Tan YH, Wang P, Su X, Willy HJ, Herng TS, et al. Metallic microlattice and epoxy interpenetrating phase composites: Experimental and simulation studies on superior mechanical properties and their mechanisms. Compos Part A Appl Sci Manuf. 2020; 135: 105934. [CrossRef]
- Niinomi M. Mechanical biocompatibilities of titanium alloys for biomedical applications. J Mech Behav Biomed Mater. 2008; 1: 30-42. [CrossRef]