Search

Titanium alloy Ti6Al4V possesses a range of highly interesting properties such as excellent corrosion resistance, bio-compatibility and high specific stress but suffers from poor wear resistance. The present work addresses plasma assisted surface treatment using various combinations of nitriding and oxidizing treatments for improving the surface properties of this alloy. The response to the surface treatments is investigated by hardness depth profiling in correlation with the chemical and microstructural evolution. It highlights the advantages of combined nitriding and oxidizing treatments compared to single nitriding for improving surface mechanical properties of titanium alloys.

Oxide-free bonding of III-V-based materials for integrated optics is demonstrated on both planar Silicon (Si) surfaces and nanostructured ones, using Silicon on Isolator (SOI) or Si substrates. The hybrid interface is characterized electrically and mechanically. A hybrid InP-on-SOI waveguide, including a bi-periodic nano structuration of the silicon guiding layer is demonstrated to provide wavelength selective transmission. Such an oxide-free interface associated with the nanostructured design of the guiding geometry has great potential for both electrical and optical operation of improved hybrid devices.

This article examines suburban individual housing in the Soviet city of Riga in the 1950s-1980s. It is based on a corpus of complaints concerning expropriation and destruction, processed by the municipal authorities. Its aim is to shed light on the making of the city by studying residential spaces at the time of their disappearance. While this urban fabric is unknown in the case of the Soviet Union, the requests offer an opportunity to document its material characteristics (houses and gardens) and social uses (renting, gardening...). For this purpose, residents’ descriptions made in support of the complaints are analyzed as a contribution to the negotiations engaged between citizens and the administration relating to expropriations. In particular the analysis sheds light on the property regimes that framed this type of housing and the arrangements made by inhabitants as they occupied properties that explain their attachment to this type of housing

Zirconium oxynitride thin films were deposited by dc reactive magnetron sputtering. A zirconium metallic target was sputtered in an Ar + N2 + O2 atmosphere. Argon and nitrogen flow rates were maintained constant whereas oxygen was pulsed during the deposition, implementing the reactive gas pulsing process (RGPP). A constant pulsing period T = 3 s was used following an exponential periodic signal versus time. The introduction time of oxygen was systematically changed from 17% to 83% of the period. The RGPP allowed the synthesis of ZrOxNy films with tuneable metalloid concentrations adjusting the introduction time of the oxygen. Composition and structural variations associated with mechanical, optical and electrical properties exhibited a smooth transition, from metallic-like characteristics, typical of the fcc-ZrN phase, to semi-conducting behaviour corresponding to a mixture of orthorhombic-Zr3N4(O) and g-Zr2ON2 crystalline phases. [ABSTRACT FROM AUTHOR]