Revisiting Cu-based shape memory alloys: Recent developments and new perspectives

Cu-based shape memory alloys belong to one important class of functional alloys, presenting shape memory effect and superelasticity due to their reversible martensitic transformation. Although they have been extensively studied since the middle of the last century, there are still many challenges to be solved. In the last decades, these alloys were extensively studied regarding new compositions, processing routes, phase transformation, mechanical and functional properties. Aspects of the thermoelastic phase transformation have been described using thermodynamic and thermo-mechanical studies, while the role of metallurgical features (such as grain size and morphology, ordering, precipitates and second phases) have been described mainly by phenomenological approach. In this sense this review discusses the advances in the general fundamentals of Cu-based shape memory alloys, the recent developments in processing routes, compositions, and applications in the last years. Graphical abstract

Preliminary Study of the Rhenium Addition on the Structure and Mechanical Properties of Tungsten Heavy Alloy

The results of structure and mechanical property investigations of tungsten heavy alloy (THA) with small additions of rhenium powder are presented. The material for the study was prepared using liquid phase sintering (LPS) of mixed and compacted powders in a hydrogen atmosphere. From the specimens, the samples for mechanical testing and structure investigations were prepared. It follows from the results of the microstructure observations and mechanical studies, that the addition of rhenium led to tungsten grain size decreasing and influencing the mechanical properties of W-Ni-Fe-Co base heavy alloy.

DNA Studies: Latest Spectroscopic and Structural Approaches

This review looks at the different approaches, techniques, and materials devoted to DNA studies. In the past few decades, DNA nanotechnology, micro-fabrication, imaging, and spectroscopies have been tailored and combined for a broad range of medical-oriented applications. The continuous advancements in miniaturization of the devices, as well as the continuous need to study biological material structures and interactions, down to single molecules, have increase the interdisciplinarity of emerging technologies. In the following paragraphs, we will focus on recent sensing approaches, with a particular effort attributed to cutting-edge techniques for structural and mechanical studies of nucleic acids.

Development of Alternative Method for Manufacturing Structural Zirconium Elements for Nuclear Engineering

Zirconium is used as a structural material for use in aggressive environments, including the core of nuclear reactors. The traditional technology of manufacturing the structural elements of zirconium nuclear reactors is characterized by a long technological process and a significant amount of waste in the form of metal shavings. The paper presents the results of an alternative technology, spark plasma sintering, for manufacturing zirconium products. A complex of microstructural and mechanical studies of the obtained samples was carried out according to the ASTMB-351 standard. The sintering of zirconium powder and options for subsequent processing by various methods, including non-standard ones such as radial shear rolling, are justified.