Low Temperature Nitriding of Metal Alloys for Surface Mechanical Performance.

Metallic alloys are, by essence, ductile and stiff and can support loads without sudden rupture. This ductility becomes a disadvantage when applications require wear resistance. In this case, the hardening of the surface is required while retaining a core performance.

Relation between Mechanical Hardening and Nitrogen Profile of PBII Nitrided Titanium Alloy.

Surface treatments of Ti-6Al-4V alloys are of utmost importance for biomedical applications since they allow for tribological gain. Here, Ti-6Al-4V disks have been PBII nitrided at either 500, 600, 700 and 800 °C. A set of techniques (XRD, SEM-EDS, EBSD and GDOES) was used to characterize the surface microstructural and chemical changes.

Stress-Assisted Thermal Diffusion Barrier Breakdown in Ion Beam Deposited Cu/W Nano-Multilayers on Si Substrate Observed by GISAXS and Transmission EDX.

The thermal stability of Cu/W nano-multilayers deposited on a Si substrate using ion beam deposition was analyzed by GISAXS and transmission EDX-a combination of methods permitting the observation of diffusion processes within buried layers. Further supporting techniques such as XRR, TEM, WAXS, and AFM were employed to develop an extensive microstructural understanding of the multilayer before and during heating. It was found that the pronounced in-plane compressive residual stress and defect population induced by ion beam deposition result in low thermal stability driven by thermally activated self-interstitial and vacancy diffusion, ultimately leading to complete degradation of the layered structure at moderate temperatures.

Carbon nanotube-poly(methyl methacrylate) hybrid films: preparation using diazonium salt chemistry and mechanical properties.

Hypothesis: The poor miscibility of carbon nanotubes (CNTs) in common organic solvents and organic monomers requires their modification by suitable functional (reactive or not) groups prior to their incorporation in thermoplastic polymers.

Experiments: Dispersion behavior of carbon nanotubes and mechanical properties of various CNT-poly(methylmethacrylate) (PMMA) nanocomposites were investigated. We studied the influence of the surface chemistry through the use of diazonium salts as an elegant and environmentally friendly platform to provide a suitable sidewall functionalization by methyl methacrylate functions.

Structure-mechanical function relations at nano-scale in heat-affected human dental tissue.

The knowledge of the mechanical properties of dental materials related to their hierarchical structure is essential for understanding and predicting the effect of microstructural alterations on the performance of dental tissues in the context of forensic and archaeological investigation as well as laser irradiation treatment of caries. So far, few studies have focused on the nano-scale structure-mechanical function relations of human teeth altered by chemical or thermal treatment. The response of dental tissues to thermal treatment is thought to be strongly affected by the mineral crystallite size, their spatial arrangement and preferred orientation.

ORMOSIL thin films: tuning mechanical properties via a nanochemistry approach.

The mechanical properties (hardness and elastic modulus) of organically modified silicate thin films can be finely tuned by varying the degree of alkylation and thus the fraction of six- and four-membered siloxane rings in the organosilica matrix. This opens the way to large tunability of parameters that are of crucial practical importance for films that are finding increasing application in numerous fields ranging from microelectronics to chemical sensing.