Engineering Commons^™

Effect Of Hydrogen On The Nucleation And Motion Of Dislocations, Mohammad Zamanzade, Jorge Velayarce, Christian Motz, Oscar Torrents Abad, Afrooz Barnoush

Nanomechanical Testing in Materials Research and Development V

Conventional mechanical tests are costly, time consuming, and due to their large scale, not very successful in obtaining mechanistic information. In contrast, the local method like nanoindentation, compression or bending test of micro pillars have comprehensive ranges of possibilities to achieve an essential understanding about the influence of substitutional atoms and/or interstitial atoms (e.g., hydrogen and nitrogen) on the mechanical properties like Young´s modulus, Gibbs free energy for homogeneous dislocation nucleation, dislocation line energy and also friction stress. These methods allow us to measure the mechanical behavior in simulated environments and atmospheres close to the routine industrial applications.

Nanoindentation was …

Nanoindentation Cartography In Al/Al-Cu-Fe Composites: Correlation Between Chemical Heterogeneities And Mechanical Properties, Christophe Tromas, Aurelie Joseph, Veronique Gauthier, Anne Joulain, Sylvain Dubois, Joel Bonneville, Dominique Evidi, Jean-Phillippe Monchoux

Nanomechanical Testing in Materials Research and Development V

During the last two decades, nanoindentation testing has become a commonly used technique for measuring surface mechanical properties such as hardness or elastic modulus. With devices equipped with a motorized X-Y table, it is now possible to perform large regular nanoindentation arrays in order to make an accurate statistics of the mechanical properties. This method is particularly interesting to study heterogeneous materials. The statistical analysis, associated to mathematical deconvolution methods allows identifying the properties of each individual phase. Furthermore, hardness or elastic modulus maps can be then established and compared to other local properties such as microstructure, crystallographic orientation or …

Mechanical And Optical Properties Of Silicon Nitride Thin Films On Glass, Lukas Simurka, Selen Erkam, Tuncay Turutoglu

Nanomechanical Testing in Materials Research and Development V

Optical thin films have been widely used in glass coating industry for various energy saving applications such as solar control and low emissivity glasses. However, handling and processing of these systems can lead into various mechanical defects decreasing its lifetime and optical performance. Therefore, understanding and control of the mechanical properties plays an important role in thin films production. Silicon nitride is one of the most commonly used materials in the optical systems. Its high refractive index and good mechanical properties provide different functionalities. It can be used as a buffer layer for tuning of the optical performance or as …

Free Energy Function Of Dislocation Densities By Large Scale Atomistic Simulations, Cristoph Begau, Godehard Sutmann, Alexander Hartmaier

Nanomechanical Testing in Materials Research and Development V

The energy of complex dislocation microstructures is a fundamental property of continuum plasticity on the nanoscale. The question how the energy depends on the characteristic of a dislocation network is still not fully answered, although various - and often contradicting - models have been proposed in the literature.

In this talk, this question is addressed using large scale Molecular Dynamics simulations of nanoindentation, which have been conducted to gain insight into the relationship between dislocation microstructures and the associated free energy from an atomistic level. Several single crystalline samples of aluminum are indented using varying tip radii to study possible …

Mechanical Scaling Behavior Of Nanoporous Gold Based On 3d Structural Analysis And Indentation-Based Testing, Erica Lilleodden, Kaixiong Hu, Markus Ziehmer

Nanomechanical Testing in Materials Research and Development V

The strength of nanoporous gold (npg) has been shown to be strongly dependent on the length-scale of the gold ligaments, an observation consistent with countless micromechanical experiments that show the typical trend of “smaller is stronger”. Such size-dependent strength can be exploited in npg through targeted annealing in order to tailor the structures for specific applications. However, this approach to structural optimization requires adequate scaling laws for the prediction of strength as a function of structural length-scale, an approach reliant on the assumption of self-similarity of the coarsened structure. Here we present evidence from high resolution 3D structural characterization that …

Development And Application Of An In-Situ Nanoindenter Coupled With Electrical Measurements, Solene Comby, Fabien Volpi, Florence Robaut, Rachel Martin, Francine Roussel, Frederic Roussel, Didier Pellerin, Marc Verdier

Nanomechanical Testing in Materials Research and Development V

The increasing demand for multifunctionality has become a recurring challenge for a wide panel of application fields such as microelectronics, microsystems, energy harvesting or structural applications.

This generally implies a smart combination of materials with tailored geometries, thus leading to ever more complex structures. The complexity of these new materials requires the development of higher performance characterization tools.

In that purpose, a multifunctional characterization set-up is developed in SIMaP laboratory, mainly based on electrical and mechanical coupling. This set-up is tailored for advanced measurements at the micrometer scale of structural and functional materials displaying small scale microstructure such as multiphase, …

Micromechanical Behavior Of Thermal Barrier Coatings After Isothermal Oxidation, Carlos Serna, Deiby Maya, Alejandro Toro, Juan Meza

Nanomechanical Testing in Materials Research and Development V

Thermal protection of metallic components by using ceramic coatings like thermal barrier coatings (TBCs) is widely used, in rocket engines, aircraft industry and gas turbines for power generation to reduce the substrate temperature up to 165°C. This technology diminishes the heat transfer in combustor, initial rotor blades and nozzles guide vanes, so that turbines have taken special advantage of these coatings to meet increasing demands for greater fuel efficiency, lower NOx emissions and higher power and thrust [1]. Thermal barrier coatings, apart from thermal protection are also used to protect against abrasion, oxidation and corrosion [2].

The understanding of the …