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Due to its higher specific strength, superior corrosion resistance, and low density, titanium (Ti) and its alloys have found widespread application in petrochemical, aerospace, biomedical, and several other manufacturing. Throughout the years, Because of their exceptional qualities, carbon nanotubes have received attention in engineering materials research due to their outstanding and excellent properties. Owing to the demands for lightweight materials with extraordinary mechanical and thermal properties for diverse. The purpose of this study is to evaluate the effects of various percentages of multiwall carbon nanotubes(MWCNT) (0.1%, 0.2%, 0.3%, 0.4%) addition to Ti-24Nb-4Zr-8Sn(Ti2448) on phase compositions and macrostructures also mechanical properties such as wear resistance and hardness of Ti-24Nb-4Zr-8Sn- MWCNT composites fabricated by the powder metallurgy. Experimental results demonstrate the hardness increases with increases percentage of MWCNT reaching 172 HB with when addition of 0.4%, while the grain size and wet wear rate decreased with increasing the content of MWCNT reaching 23.7µm and 7.034*10-5 respectively.

A phase field model for cubic to orthorhombic martensitic transformation (MT) at the nanoscale in a β titanium (Ti) alloy Ti-24Nb-4Zr-8Sn (in wt.%) is investigated by finite element simulation. The approach is based on phase field theory, time-dependent Ginzburg-Landau theory, and mechanical equilibrium equations. Partial differential equations (PDEs) were solved using the commercial software COMSOL Multiphysics. The morphology of the product phase exhibits plate-like or needle-like shapes that reduce the elastic strain energy of the system. The simulation result for random initial order parameters is in agreement with previous experimental observations. The final volume fractions of two different orthorhombic martensitic variants are not dependent on the initial conditions. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Interconnected porous Ti-Nb-Zr-Sn scaffold is made by electron beam melting method. • Alkali treatment creates outer porous topography and inner dense layer on scaffold. • Collagen is immobilized on alkali-treated scaffold by cross-linker procyanidin. • The surface treatments enhance corrosion resistance and cell response of scaffold. • The proposed surface-treated alloy scaffold has potential as biomedical implants. Abstract We present a unique way of combining alkali treatment and natural cross-linker, procyanidin, to create submicron-porous structure (pore size 100–300 nm) and immobilize type I collagen on the surface of electron beam melted β-type Ti-24Nb-4Zr-8Sn (Ti2448) alloy scaffold with interconnected porosity. Scanning electron microscopy and transmission electron microscopy showed a hybrid layer, an outer submicron-porous layer and an inner dense layer, was formed on the interconnected Ti2448 alloy scaffold surface. X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy and Sirius red staining analysis confirmed the collagen was successfully immobilized on the scaffold. The dense inner oxide layer mainly provided Ti2448 alloy scaffold with enhanced corrosion resistance. The Ti2448 alloy scaffolds, with and without surface treatments, were potentially non-cytotoxic; particularly, the type I collagen-immobilized Ti2448 alloy scaffold via procyanidin cross-linking showed better adhesion of human bone marrow mesenchymal stem cells. The proposed simple and unique surface treatment simultaneously enhances the corrosion resistance and cell adhesion of interconnected porous Ti2448 alloy scaffold without causing cytotoxicity and shows great potential for biomedical implant applications. [ABSTRACT FROM AUTHOR]

Titanium alloys (Ti-6Al-4V and Ti-6Al-7Nb) are widely used for implants, which are characterized by high elastic modulus (∼110 GPa) with (α + β) structure and that may induce undesirable stress shielding effect and immune responses associated with the presence of toxic elements. In this regard, we have combined the attributes of a new alloy design and the concept of additive manufacturing to fabricate 3D scaffolds with an interconnected porous structure. The new alloy is a β-type Ti-24Nb-4Zr-8Sn (Ti2448) alloy with significantly reduced modulus. In the present study, we explore the biological response of electron beam melted low modulus Ti2448 alloy porous mesh structure through the elucidation of bioactivity and osteoblast functions. The cellular activity was explored in terms of cell-to-cell communication involving proliferation, spreading, synthesis of extracellular and intracellular proteins, differentiation, and mineralization. The formation of fine apatite-like crystals on the surface during immersion test in simulated body fluid confirmed the bioactivity of the scaffold surface, which provided the favorable osteogenic microenvironment for cell-material interaction. The combination of unique surface chemistry and interconnected porous architecture provided the desired pathway for supply of nutrients and oxygen to cells and a favorable osteogenic micro-environment for incorporation (on-growth and in-growth) of osteoblasts. The proliferation and differentiation of pre-osteoblasts and their ability to form a well mineralized bone-like extracellular matrix (ECM) by secreting bone markers (ALP, calcium, etc.) over the struts of the scaffold point toward the determining role of unique surface chemistry and 3D architecture of the Ti2448 alloy mesh structure in modulating osteoblasts functions. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 859-870, 2017. [ABSTRACT FROM AUTHOR]

Objectives Low modulus β-titanium alloys with non-toxic alloying elements are envisaged to provide good biocompatibility and alleviate the undesired stress shielding effect. The objective of this study is to fundamentally elucidate the biological response of novel high strength-low elastic modulus Ti2448 alloy through the study of bioactivity and osteoblast cell functions. Methods Characterization techniques such as SEM, EDX, XRD, and fluorescence microscopy were utilized to analyze the microstructure, morphology, chemical composition, and cell adhesion. The cellular activity was explored in terms of cell-to-cell communication involving proliferation, spreading, synthesis of extracellular and intracellular proteins, differentiation, and mineralization. Results The formation of fine apatite-like crystals on the surface during immersion test in simulated body fluid confirmed the bioactivity of the surface, which provided the favorable osteogenic microenvironment for cell-material interaction. The proliferation and differentiation of pre-osteoblasts and their ability to form a well mineralized bone-like extracellular matrix (ECM) by secreting bone markers (ALP, calcium, etc.) over the surface point toward the determining role of unique surface chemistry and surface properties of the Ti–24Nb–4Zr–8Sn (Ti2448) alloy in modulating osteoblasts functions. Significance These results demonstrated that the low modulus (∼49 GPa) Ti2448 alloy with non-toxic alloying elements can be used as a potential dental or orthopedic load-bearing implant material. [ABSTRACT FROM AUTHOR]

The low modulus β-type Ti-24Nb-4Zr-8Sn alloy is a promising new biomedical alloy due to its excellent mechanical biocompatibility and composition of non-toxic elements. As a biomaterial, to determine its suitability for body implant applications, the important aspect is the evaluation of corrosion behaviour and the establishment of a suitable surface state in terms of a tailored surface topography and chemistry which improves corrosion resistance and enables an optimum osseointegration of bone tissue. The goal of this review is to summary the corrosion properties of Ti-24Nb-4Zr-8Sn alloy in the basic human body environments. Meanwhile, the surface modification technology which is emphasised on surface nanocrystallisation and micro-arc oxidation are systematically discussed, the former has been confirmed to be an effective way to improve the stability and pitting resistance of Ti-24Nb-4Zr-8Sn alloy, especially in the fluoride ions containing environments; whereas the later not only increases the corrosion resistance of Ti-24Nb-4Zr-8Sn alloy, but also induces the formation of apatite on the surface to exhibit good bioactivity. [ABSTRACT FROM PUBLISHER]