Is there scientific evidence favoring the substitution of commercially pure titanium with titanium alloys for the manufacture of dental implants

Ti-Nb base alloys have been proposed as prospective candidates for Ni-free biomedical superelastic alloys due to their excellent mechanical properties with good biocompatibility, and many kinds of Ti-Nb base alloys exhibiting shape memory effect or superelasticity have been developed up to now. However, typical Ti-Nb base superelastic alloys show a small recovery strain which is less than one third of the recovery strain of practical Ti-Ni superelastic alloys. Over the last decade there have been extensive efforts to improve the properties of Ti-Nb base superelastic alloys through microstructure control and alloying. Low temperature annealing and aging are very effective to increase the critical stress for slip due to fine subgrain structure and precipitation hardening. The addition of interstitial alloying elements such as O and N raises the critical stress for slip and improves superelastic properties. In this paper, the roles of alloying elements on the martensitic transformation temperature, crystal structure, microstructure and deformation behavior in the Ti-Nb base alloys are reviewed and the alloy design strategy for biomedical superelastic alloys is proposed. [doi:10.2320/matertrans.M2014454]

https://www.jstage.jst.go.jp/article/matertrans/56/5/56_M2014454/_pdf

Martensitic Transformation and Superelastic Properties of Ti-Nb Base Alloys

Microwave absorbing properties of the ferrite composites based on graphene

Shape memory alloys (SMAs) are a class of smart materials characterized by shape memory effect and pseudo-elastic behavior. They have the capability to retain their original form when subjected to certain stimuli, such as heat or a magnetic field. These unique properties have attracted many researchers to seek their application in various fields including transportation, aerospace, and biomedical. The ease process adaption from semiconductor manufacturing technology provides many opportunities for designing micro-scale devices using this material. This paper gives an overview of the fabrication and manufacturing technique of thin-film and bulk micromachined SMAs. Key features such as material properties, transformation temperature, material composition, and actuation method are also presented. The application and micromechanism for both thin-film and bulk SMA are described. Finally, the microactuator devices emphasized for biomedical applications such as microgrippers and micropumps are highlighted. The presented review will provide information for researchers who are actively working on the development of SMA-based microscale biomedical devices.

https://www.mdpi.com/2072-666X/6/7/879/pdf

Micromachined Shape-Memory-Alloy Microactuators and Their Application in Biomedical Devices

Simultaneous enhancements of remanence and (BH)max in BaFe12O19/CoFe2O4 nanocomposite powders

Superelastic behaviour of Ti–Nb–Al ternary shape memory alloys for biomedical applications

Exchange coupling and magnetic behavior of SmCo5-xSnx alloys

Indentation fracture toughness of (Fe0·5Co0.5)69 − xNb6B25 + x (x = 0, 2, 4) bulk metallic glass alloys in the partially crystalline (intrinsic composite) state has been studied. Corner cracking was observed on indentation in all the compositions above a certain critical load. High hardness with values in excess of 1100HV was obtained for all the alloy compositions. Indentation fracture toughness measured through various empirical relations was found to be

Indentation fracture toughness behavior of FeCo-based bulk metallic glass intrinsic composites

FeCo-based bulk metallic glass with the compositions (Fe0.5Co0.5)69−xNb6B25+x (x=0, 2, 4) were cast using electric arc melting and suction casting technique. The samples were tested and analyzed in as-cast, sub-Tg annealed and partially crystalline conditions. Vicker’s microhardness was found to increase after annealing and partial crystallization. For high boron content hardness values approaching 1400 HV were obtained in partially crystalline samples. A compressive strength value of 4776 MPa was calculated using hardness data. Sub-Tg annealing resulted in a decrease in the size of deformation zone formed underneath the hardness indenter after indentation. The bulk metallic glass alloys were embrittled by the partial crystallization treatment. It resulted in the formation of corner cracks during indentation. The size of the deformation zone increased with an increase in load. Semicircular and radial type of shear bands were observed as in the deformation zone with a higher number of radial shear bands observed in the annealed samples compared to as-cast samples. A comparison is made between the size of the deformation zone obtained experimentally and that predicted by the available models.

Hamid Zaigham

Papers

Superelastic behaviour of Ti–Nb–Al ternary shape memory alloys for biomedical applications

Exchange coupling and magnetic behavior of SmCo5-xSnx alloys

Indentation fracture toughness behavior of FeCo-based bulk metallic glass intrinsic composites

Indentation and deformation behavior of FeCo-based bulk metallic glass alloys

Characterisation of Sm–Co–Sn alloys