Influence of molybdenum content on the microstructure of spark plasma sintered titanium alloys en en Five titanium-based alloys containing 4, 8, 12, 16, and 20 wt% molybdenum additive were fabricated by spark plasma sintering process at 1200 °C. The samples were scrutinized in terms of relative density, phase evolution, and microstructural development. The relative density reached 99.9% with the molybdenum addition up to 16 wt% but slightly dropped in the sample with 20 wt% additive. In the specimens with 4 wt% Mo, molybdenum solved completely in the matrix and three different phase morphologies were observed, namely continuous α-Ti, laminar α-Ti, and very thin laminar β-Ti. With increasing Mo content to 20 wt%, widespread single β-Ti appeared alongside remained Mo and α-Ti. Ductile fracture mode was dominant in the samples with low Mo contents whilst it changed to brittle in the specimens with higher content of molybdenum. 41 47 M. Saravana Kumar Department of Mechanical Engineering Mount Zion College of Engineering and Technology India S. Rashia Begum Department of Mechanical Engineering, College of Engineering Anna University India M. Vasumathi Department of Mechanical Engineering, College of Engineering Anna University India Chinh Chien Nguyen Laboratory of Energy and Environmental Science, Institute of Research and Development and Faculty of Environmental and Chemical Engineering Duy Tan University, Da Nang 550000 Vietnam Faculty of Environmental and Chemical Engineering Duy Tan University, Da Nang 550000 Vietnam Quyet Van Le Laboratory of Energy and Environmental Science, Institute of Research and Development and Faculty of Environmental and Chemical Engineering Duy Tan University, Da Nang 550000 Vietnam levanquyet@dtu.edu.vn Faculty of Environmental and Chemical Engineering Duy Tan University, Da Nang 550000 Vietnam Titanium Molybdenum Spark plasma sintering Microstructure Densification Vol 1 No 1 Paper 4.pdf [1] A. Sabahi Namini, M. Azadbeh, M. Shahedi Asl, Effect of TiB2 content on the characteristics of spark plasma sintered Ti–TiB w composites, Adv. Powder Technol. 28 (2017) 1564–1572. https://doi.org/10.1016/j.apt.2017.03.028. ##[2] F.F. Cardoso, P.L. Ferrandini, E.S.N. Lopes, A. Cremasco, R. Caram, Ti–Mo alloys employed as biomaterials: Effects of composition and aging heat treatment on microstructure and mechanical behavior, J. Mech. Behav. Biomed. Mater. 32 (2014) 31–38. https://doi.org/10.1016/j.jmbbm.2013.11.021. ##[3] Y. Chen, L. Xu, Z. Liu, F. Kong, Z. Chen, Microstructures and properties of titanium alloys Ti-Mo for dental use, Trans. Nonferrous Met. Soc. China. 16 (2006) s824–s828. https://doi.org/10.1016/S1003-6326(06)60308-7. ##[4] C. Leyens, M. Peters, Titanium and Titanium Alloys: Fundamentals and Applications, John Wiley and Sons, Ltd. (2003). https://doi.org/10.1002/3527602119. ##[5] N.T.C. Oliveira, G. Aleixo, R. Caram, A.C. Guastaldi, Development of Ti–Mo alloys for biomedical applications: Microstructure and electrochemical characterization, Mater. Sci. Eng. A. 452–453 (2007) 727–731. https://doi.org/10.1016/j.msea.2006.11.061. ##[6] R. Adell, U. Lekholm, B. Rockler, P.-I. Brånemark, A 15-year study of osseointegrated implants in the treatment of the edentulous jaw, Int. J. Oral Surg. 10 (1981) 387–416. https://doi.org/10.1016/S0300-9785(81)80077-4. ##[7] M. Abdel-Hady Gepreel, M. Niinomi, Biocompatibility of Ti-alloys for long-term implantation, J. Mech. Behav. Biomed. Mater. 20 (2013) 407–415. https://doi.org/10.1016/j.jmbbm.2012.11.014. ##[8] W. Ho, C. Ju, J. Chern Lin, Structure and properties of cast binary Ti–Mo alloys, Biomaterials. 20 (1999) 2115–2122. https://doi.org/10.1016/S0142-9612(99)00114-3. ##[9] E.-B. Lee, M.-K. Han, B.-J. Kim, H.-J. Song, Y.-J. Park, Effect of molybdenum on the microstructure, mechanical properties and corrosion behavior of Ti alloys, Int. J. Mater. Res. 105 (2014) 847–853. https://doi.org/10.3139/146.111092. ##[10] Y. Li, C. Yang, H. Zhao, S. Qu, X. Li, Y. Li, New Developments of Ti-Based Alloys for Biomedical Applications, Materials (Basel). 7 (2014) 1709–1800. https://doi.org/10.3390/ma7031709. ##[11] M. Niinomi, M. Nakai, Titanium-Based Biomaterials for Preventing Stress Shielding between Implant Devices and Bone, Int. J. Biomater. 2011 (2011) 1–10. https://doi.org/10.1155/2011/836587. ##[12] P. Rocher, L. El Medawar, J.-C. Hornez, M. Traisnel, J. Breme, H. Hildebrand, Biocorrosion and cytocompatibility assessment of NiTi shape memory alloys, Scr. Mater. 50 (2004) 255–260. https://doi.org/10.1016/j.scriptamat.2003.09.028. ##[13] E. Eisenbarth, D. Velten, M. Müller, R. Thull, J. Breme, Biocompatibility of β-stabilizing elements of titanium alloys, Biomaterials. 25 (2004) 5705–5713. https://doi.org/10.1016/j.biomaterials.2004.01.021. ##[14] D.R.N. Correa, F.B. Vicente, R.O. Araújo, M.L. Lourenço, P.A.B. Kuroda, et al., Effect of the substitutional elements on the microstructure of the Ti-15Mo-Zr and Ti-15Zr-Mo systems alloys, J. Mater. Res. Technol. 4 (2015) 180–185. https://doi.org/10.1016/j.jmrt.2015.02.007. ##[15] X. Zhao, M. Niinomi, M. Nakai, J. Hieda, Beta type Ti–Mo alloys with changeable Young’s modulus for spinal fixation applications, Acta Biomater. 8 (2012) 1990–1997. https://doi.org/10.1016/j.actbio.2012.02.004. ##[16] Y.-L. Zhou, D.-M. Luo, Microstructures and mechanical properties of Ti–Mo alloys cold-rolled and heat treated, Mater. Charact. 62 (2011) 931–937. https://doi.org/10.1016/j.matchar.2011.07.010. ##[17] W. Zhang, Y. Liu, H. Wu, M. Song, T. Zhang, et al., Elastic modulus of phases in Ti–Mo alloys, Mater. Charact. 106 (2015) 302–307. https://doi.org/10.1016/j.matchar.2015.06.008. ##[18] Y.L. Zhou, M. Niinomi, T. Akahori, Effects of Ta content on Young’s modulus and tensile properties of binary Ti–Ta alloys for biomedical applications, Mater. Sci. Eng. A. 371 (2004) 283–290. https://doi.org/10.1016/j.msea.2003.12.011. ##[19] M. Niinomi, Recent metallic materials for biomedical applications, Metall. Mater. Trans. A. 33 (2002) 477–486. https://doi.org/10.1007/s11661-002-0109-2. ##[20] E. Delvat, D.M. Gordin, T. Gloriant, J.L. Duval, M.D. Nagel, Microstructure, mechanical properties and cytocompatibility of stable beta Ti–Mo–Ta sintered alloys, J. Mech. Behav. Biomed. Mater. 1 (2008) 345–351. https://doi.org/10.1016/j.jmbbm.2008.01.006. ##[21] P.L. Ferrandini, F.F. Cardoso, S.A. Souza, C.R. Afonso, R. Caram, Aging response of the Ti–35Nb–7Zr–5Ta and Ti–35Nb–7Ta alloys, J. Alloys Compd. 433 (2007) 207–210. https://doi.org/10.1016/j.jallcom.2006.06.094. ##[22] G. He, J. Eckert, Q.L. Dai, M.L. Sui, W. Löser, et al., Nanostructured Ti-based multi-component alloys with potential for biomedical applications, Biomaterials. 24 (2003) 5115–5120. https://doi.org/10.1016/S0142-9612(03)00440-X. ##[23] Y. Takemoto, I. Shimizu, A. Sakakibara, M. Hida, Y. Mantani, Tensile Behavior and Cold Workability of Ti-Mo Alloys, Mater. Trans. 45 (2004) 1571–1576. https://doi.org/10.2320/matertrans.45.1571. ##[24] M. Sabeena, S. Murugesan, R. Mythili, A.K. Sinha, M.N. Singh, et al., Studies on ω Phase Formation in Ti-Mo Alloys Using Synchrotron XRD, Trans. Indian Inst. Met. 68 (2015) 1–6. https://doi.org/10.1007/s12666-014-0426-3. ##[25] J.L. Murray, The Mo−Ti (Molybdenum-Titanium) system, Bull. Alloy Phase Diagr. 2 (1981) 185–192. https://doi.org/10.1007/BF02881476. ##[26] C.H. Wang, M. Liu, P.F. Hu, J.C. Peng, J.A. Wang, et al., The effects of α″ and ω phases on the superelasticity and shape memory effect of binary Ti-Mo alloys, J. Alloys Compd. 720 (2017) 488–496. https://doi.org/10.1016/j.jallcom.2017.05.299. ##[27] G. Dercz, I. Matuła, M. Zubko, A. Liberska, Structure Characterization of Biomedical Ti-Mo-Sn Alloy Prepared by Mechanical Alloying Method, Acta Phys. Pol. A. 130 (2016) 1029–1032. https://doi.org/10.12693/APhysPolA.130.1029. ##[28] Z. Gao, H. Luo, Q. Li, Y. Wan, Preparation and Characterization of Ti-10Mo Alloy by Mechanical Alloying, Metallogr. Microstruct. Anal. 1 (2012) 282–289. https://doi.org/10.1007/s13632-012-0045-5. ##[29] H. Hosokawa, K. Kato, K. Shimojima, A. Matsumoto, Microstructural Evolution of Ti-Mo-Ni-C Powder by Mechanical Alloying, Mater. Trans. 50 (2009) 117–122. https://doi.org/10.2320/matertrans.MRA2008280. ##[30] M.T. Jovanović, B. Dimčić, I. Bobić, S. Zec, V. Maksimović, Microstructure and mechanical properties of precision cast TiAl turbocharger wheel, J. Mater. Process. Technol. 167 (2005) 14–21. https://doi.org/10.1016/j.jmatprotec.2005.03.019. ##[31] Y. Liu, W. Wei, K. Zhou, L. Chen, H. Tang, Microstructures and mechanical behavior of PM Ti-Mo alloy, J. Cent. South Univ. Technol. 10 (2003) 81–86. https://doi.org/10.1007/s11771-003-0043-5. ##[32] J. Campbell, Entrainment defects, Mater. Sci. Technol. 22 (2006) 127–145. https://doi.org/10.1179/174328406X74248. ##[33] B. Nayebi, A. Bahmani, M. Shahedi Asl, A. Rasooli, M. Ghasemi Kakroudi, M. Shokouhimehr, Characteristics of dynamically formed oxide films in aluminum–calcium foamable alloys, J. Alloys Compd. 655 (2016) 433–441. https://doi.org/10.1016/j.jallcom.2015.09.200. ##[34] A. Sabahi Namini, M. Shahedi Asl, S.A. Delbari, Influence of Sintering Temperature on Microstructure and Mechanical Properties of Ti–Mo–B4C Composites, Met. Mater. Int. 27 (2019) 1092–1102. https://doi.org/10.1007/s12540-019-00469-y. ##[35] S.A. Delbari, A. Sabahi Namini, M. Shahedi Asl, Hybrid Ti matrix composites with TiB2 and TiC compounds, Mater. Today Commun. 20 (2019) 100576. https://doi.org/10.1016/j.mtcomm.2019.100576.