INTRODUCTION The aim of this study was to compare cyclic fatigue resistance of four nickel-titanium rotary systems and to evaluate their surface, fractographic, and matrix morphology. METHODS Four models of endodontic rotary files (EasyShape [Komet/Gebr. Brasseler, Lemgo, Germany], ProTaper [Dentsply Maillefer, Ballaigues, Switzerland], NRT [MANI Inc, Toshigi-Ken, Japan], and AlphaKite [Komet...

In this paper, a strain-intensity-factor-based method is proposed to calculate the fatigue crack growth under the fully reversed loading condition. A theoretical analysis is conducted in detail to demonstrate that the strain intensity factor is likely to be a better driving parameter correlated with the fatigue crack growth rate than the stress intensity factor (SIF), especially for some metall...

Using uniaxial tensile and hardness testing, we evaluated the variability and anisotropy of the mechanical properties of an austenitic stainless steel, UNS S17400, manufactured by an additive process, selective laser melting. Like wrought materials, the mechanical properties depend on the orientation introduced by the processing. The recommended stress-relief heat treatment increases the tensil...

The resistance and susceptibility of austenitic stainless steel, Type 304, exposed to strong tetraoxosulphate (VI) acids (2 and 5 M concentrations) contaminated with sodium chloride at ambient temperatures was investigated by gravimetric and metallographic/scanning electron microscopy surface characterization methods. Scanning electron microscope (SEM) was used to examine and characterize the t...

This research aimed to conduct a passive layer state study on martensitic and semi-austenitic precipitation hardening stainless steels (PHSS) passivated in citric acid nitric baths at 49 70 °C for 50 75 min subsequently exposed 5 wt.% NaCl 1 H2SO4 solutions. Corrosion behavior of the material was observed by using potentiodynamic polarization (PP) according ASTM G5-11 standard. The microstructu...