Evaluating the effects of PIRAC nitrogen-diffusion treatments on the mechanical performance of Ti-6Al-4V alloy

The authors would like to thank the European Regional Development Fund (Malta) for research equipment funded through the application of the project “Developing an Interdisciplinary Material Testing and Rapid Prototyping R&D Facility (Ref. no. 012)”. The authors are also greatly indebted to MATERAþ/ERA-NET Plus for funding support for this research (Project ESM-1935).Powder Immersion Reaction Assisted Coating (PIRAC) is a relatively simple nitrogen diffusion based process which has been proposed as a technique capable of considerable improvements in the tribological performance of ceramics and metals alike; however, the necessary exposure of the substrate material to high temperatures for several hours may have an adverse effect on the bulk properties of materials such as titanium alloys. The effect of PIRAC treatments on the bulk metallography and mechanical properties of Ti–6Al–4V has been studied. Following PIRAC nitrogen-diffusion treatment, studies using X-ray diffraction and cross-sectional microscopy have shown evidence of the formation of a thin (1.4 mm) TiN/Ti2N layer, together with the presence of some Ti3Al intermetallic phase. Semi- logarithmic S–N plots show a deleterious effect after PIRAC treatment in terms of material cyclic fatigue strength, particularly at higher treatment temperatures. Samples processed at 800 1C for 4 h however exhibit better fatigue performance than others treated at lower temperatures for longer nitriding times. Fractographic inspection has shown that fatigue cracks originate at (or near) the surface for the untreated Ti-alloy and from the subsurface regions following diffusion treatment, owing to the build-up of compressive stresses in the latter, which hinder crack propagation.peer-reviewe

Highlights From the Annual Meeting of the American Epilepsy Society 2022

With more than 6000 attendees between in-person and virtual offerings, the American Epilepsy Society Meeting 2022 in Nashville, felt as busy as in prepandemic times. An ever-growing number of physicians, scientists, and allied health professionals gathered to learn a variety of topics about epilepsy. The program was carefully tailored to meet the needs of professionals with different interests and career stages. This article summarizes the different symposia presented at the meeting. Basic science lectures addressed the primary elements of seizure generation and pathophysiology of epilepsy in different disease states. Scientists congregated to learn about anti-seizure medications, mechanisms of action, and new tools to treat epilepsy including surgery and neurostimulation. Some symposia were also dedicated to discuss epilepsy comorbidities and practical issues regarding epilepsy care. An increasing number of patient advocates discussing their stories were intertwined within scientific activities. Many smaller group sessions targeted more specific topics to encourage member participation, including Special Interest Groups, Investigator, and Skills Workshops. Special lectures included the renown Hoyer and Lombroso, an ILAE/IBE joint session, a spotlight on the impact of Dobbs v. Jackson on reproductive health in epilepsy, and a joint session with the NAEC on coding and reimbursement policies. The hot topics symposium was focused on traumatic brain injury and post-traumatic epilepsy. A balanced collaboration with the industry allowed presentations of the latest pharmaceutical and engineering advances in satellite symposia

Nanostructured titanium-based materials for medical implants: Modeling and development

Nanostructuring of titanium-based implantable devices can provide them with superior mechanical properties and enhanced biocompatibity. An overview of advanced fabrication technologies of nanostructured, high strength, biocompatible Ti and shape memory Ni–Ti alloy for medical implants is given. Computational methods of nanostructure properties simulation and various approaches to the computational, ‘‘virtual’’testing and numerical optimization ofthese materials are discussed. Applications of atomistic methods, continuum micromechanics and crystal plasticity as well as analytical models to the analysis ofthe reserves ofthe improvement of materials for medical implants are demonstrated. Examples of successful development of a nanomaterial-based medical implants are presented.status: publishe