Papers by Keyword: Experimental Techniques

Abstract: Tracer diffusion is one of most reliable techniques for providing basic kinetic data in solids. In the present review, selected direct methods, in particular the radiotracer measurements as a superior technique due to its high sensitivity, Secondary-Ion-Mass-Spectroscopy (SIMS) profiling, X-Ray Diffraction measurements and Rutherford Backscattering Spectrometry are presented and discussed. Special attention is put on the radiotracer technique describing the currently used sectioning techniques in detail with a focus on the experimental applications and complications. The relevant experimental results are exemplary shown. Furthermore, the most recent developments and advances related to the combined tracer/inter-diffusion measurements are highlighted. It is shown that this approach offers possibilities to provide the concentration-dependent tracer diffusion coefficients of the constituting elements in multi-component alloys in high-throughput experiments. Possibilities of estimating the tracer diffusion coefficients following different types of diffusion couple methods in binary and multicomponent systems are briefly introduced. Finally, specificity of SIMS analysis of diffusion in fine-grained materials are carefully analyzed. If applicable, a direct comparison of the results obtained by different techniques is given.

Abstract: The mechanical properties of gas hydrate-bearing sediments are important basic parameters during natural gas hydrate drilling and exploitation. It’s very hard to get and preserve the actual gas hydrate specimens for the measurements of these characteristics. Experimental techniques for mechanical properties of gas hydrate-bearing sediments are essential and unique because of the special high pressure and low temperature conditions for the stability of gas hydrate. Qingdao Institute of Marine Geology has developed an experimental equipment (Chinese National patent No. ZL 2010 2 0253067.3) to study the variation of mechanical properties along with gas hydrate saturation in different sediments. The combination, configuration and advantages of the equipment, as well as some preliminary experimental results were introduced in this article.

Abstract: In connection with the 100^th anniversary of Stoney’s equations, some historical remarks are made with respect to the development of these equations. As an example of the extension of Stoney’s equations, a unique algorithm of the layer growing/removing methods is presented for de­termination of residual stresses in isotropic inhomogeneous coated plates. Using a computer pro­gram based on this algorithm, residual stresses are computed in the galvanic steel coating on the copper plate substrate.