Microstructural evolution of NiTi shape memory alloy (SMA) with a nominal composition of Ni50.9Ti49.1 (at %) is investigated on the basis of heat treatment and severe plastic deformation (SPD). As for as-rolled NiTi SMA samples subjected to aging, plenty of R phases appear in the austenite matrix. In terms of as-rolled NiTi SMA samples undergoing solution treatment and aging, Ni4Ti3 precipitate...

Nanocrystalline TiN/NiTi thin films have been grown on silicon substrate by dc magnetron sputtering to improve the corrosion and mechanical properties of NiTi based shape memory alloys without sacrificing the phase transformation effect. Interestingly, the preferential orientation of the TiN films was observed to change from (1 1 1) to (2 0 0) with change in nature of sputtering gas from 70% Ar...

A process was developed for fabricating arrays of micro-channels in shape-memory NiTi for bone implant applications, with a tailorable internal architecture expected to improve biomechanical compatibility and osseointegration. Ni-51.4 at.% Ti with 24-34 vol.% porosity was fabricated by electrochemical dissolution of parallel layers of steel wire meshes embedded within a NiTi matrix during hot p...

Room temperature monotonic and cyclic stress–strain curves for single crystal and polycrystalline NiTi shape memory alloys containing Ti3Ni4 precipitates are presented. The tensile and compressive single crystal results illustrate the importance of crystallographic texture, the unidirectional nature of the martensitic transformation, and martensite detwinning on tension-compression stress–strai...

Differences in mechanical properties between endodontic instruments might be related to the chemical composition, phase constitution, or fabrication process of nickel–titanium (NiTi) endodontic instruments. An awareness and knowledge of the mechanical properties of NiTi endodontic files and their association with the metallurgical properties is useful for clinicians to understand the behavior o...

Porous NiTi alloys were prepared by microwave sintering using ammonium hydrogen carbonate (NH4HCO3) as the space holder agent to adjust the porosity in the range of 22-62%. The effects of porosities on the microstructure, hardness, compressive strength, bending strength, elastic modulus, phase transformation temperature and superelasticity of the porous NiTi alloys were investigated. The result...

INTRODUCTION The aim of this study was to assess the extent of adoption, application and the associated issues with the nickel-titanium (NiTi) rotary instruments and techniques amongst endodontists and general dentists in Tehran. MATERIALS AND METHODS A total of 33 questions classified in six categories of demographics, frequency rate of NiTi rotary instrumentation and information. The sample...

INTRODUCTION The performance and mechanical properties of nickel-titanium (NiTi) instruments are influenced by factors such as cross-section, flute design, raw material, and manufacturing processes. Many improvements have been proposed by manufacturers during the past decade to provide clinicians with safer and more efficient instruments. METHODS The mechanical performance of NiTi alloys is s...

NiTi alloy has been used as the raw material for making endodontic files. The interest in NiTi instrument research has not waned with time. In fact, there is a renewed interest in this field, notably through the application of modern research tools and techniques from other fields, making it a truly cross-disciplinary area of research. In 1988, Walia and colleagues introduced nickeltitanium (Ni...