title: Second-phase-dependent grain refinement in Ti-25Nb-3Mo-3Zr-2Sn alloy and its enhanced osteoblast response.
abstract: Ti-25Nb-3Mo-3Zr-2Sn (TLM) substrates, which consist of pure β phase and duplex α+β phases were achieved by different heat treatment. Different substrates with and without α phase were subjected to surface mechanical attrition treatment (SMAT) for 5 and 30 min, respectively. Investigated by transmission electron microscopy (TEM), it is found that the content and morphology of α phase in the TLM substrates play crucial roles in nanocrystallization of the alloy. During SMAT, the substrates composed of duplex α+β phases are much easier to nanocrystallized than that composed of pure β phase, and the duplex-phase substrate containing 35 vt.% α needles is more inclined to grain refinement than those substrates containing 27 vt.% α cobbles and 31 vt.% α needles. Accompanied with the nanocrystallization in the surface layers of the duplex-phase substrates, the stress induced α-to-β phase transition occurs. In addition, employing hFOB1.19 cells, the behaviors of osteoblasts on the unSMATed and as-SMATed surfaces were evaluated by examining the morphology and viability of the cells. It shows that the SMAT-induced grain refinement in the surface layer of the alloy can significantly improve the osteoblast response. Our study lays the foundation for nanostructuring β titanium alloys to be used as biomedical implants.
authors.affiliation: State-key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an 710049, China.
authors.forename: Run
authors.initials: R
authors.lastname: Huang
authors.affiliation: State-key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an 710049, China.
authors.forename: Huaye
authors.initials: H
authors.lastname: Zhuang
authors.affiliation: State-key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an 710049, China. Electronic address: yonghan@mail.xjtu.edu.cn.
authors.forename: Yong
authors.initials: Y
authors.lastname: Han
mesh_terms: D000497:Alloys / Q000138:chemical synthesis / Q000737:chemistry*; D018786:Bone Substitutes / Q000138:chemical synthesis*; D002460:Cell Line; D049109:Cell Proliferation; D002470:Cell Survival / Q000502:physiology; D006244:Hardness; D006358:Hot Temperature; D006801:Humans; D008422:Materials Testing; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure*; D010006:Osteoblasts / Q000166:cytology* / Q000502:physiology*; D010012:Osteogenesis / Q000502:physiology*; D010316:Particle Size; D044367:Phase Transition; D013499:Surface Properties
chemical_list: D000497:Alloys; D018786:Bone Substitutes; C525450:titanium molybdenum alloy
keywords: Nanocrystallization; Osteoblast response; Phase transition; Surface mechanical attrition treatment; Ti–25Nb–3Mo–3Zr–2Sn alloy