Topic
Residual stress
About: Residual stress is a research topic. Over the lifetime, 39030 publications have been published within this topic receiving 554846 citations.
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01 Feb 2010-Nuclear Instruments & Methods in Physics Research Section B-beam Interactions With Materials and Atoms
TL;DR: A global approach has been developed to analyze complex thin film structures by X-ray diffraction as mentioned in this paper, which is based on the fitting of multiple data, diffraction pattern and/or images collected at different orientation of the sample to obtain all the information needed.
Abstract: A global approach has been developed to analyze complex thin film structures by X-ray diffraction The method is based on the fitting of multiple data, diffraction pattern and/or images, collected at different orientation of the sample to obtain all the information needed It requires the knowledge of the crystal structure for the phases present in the film, or if the amount/film thickness is sufficient, the crystal structure can be also determined or refined Reflectivity patterns can be added to the global refinement to improve the accuracy of the thickness determination and when coupled with total X-ray fluorescence can give the in depth chemical concentrations In addition, it constraints the solution for the quantitative phase analysis obtained from the diffraction patterns The principles of the analysis with the main methods will be presented from the theoretical point of view These cover the models from crystal structure to texture, residual strain/stresses, crystallite sizes and microstrains To make the method more effective, some specific models have been developed in the past few years Then some experimental/analysis examples will be given to enlighten how the method works and what kind of information can be obtained Not every model suits every analysis or kind of thin film and the examples will cover different cases from multiple phases to strong texture, epitaxial thin films or multilayers
866 citations
TL;DR: In this article, the authors demonstrate the correlation between microstructure and mechanical as well as tribological properties of hard ceramic coatings and demonstrate that nanostructure dependent hardness increase (compared to hardness of the bulk counterparts) sustains higher annealing temperatures than hardness increase due to an increased density of point-and/or line-defects.
820 citations
TL;DR: In this paper, the authors examine the nature and origins of residual stresses across a range of scales, from the long range residual stress fields in engineering components and welded structures, through the interphase stresses present in composites and coatings, to the microscale interactions of phase transformations with local stresses.
Abstract: Residual stress is that which remains in a body that is stationary and at equilibrium with its surroundings. It can be detrimental when it reduces the tolerance of the material to an externally applied force, as is the case with welded joints. On the other hand, it can be exploited to design materials or components which are resistant to damage, toughened glass being a good example. This paper, the second part of a two part overview, the first part having been devoted to measurement techniques, examines the nature and origins of residual stresses across a range of scales. This extends from the long range residual stress fields in engineering components and welded structures, through the interphase stresses present in composites and coatings, to the microscale interactions of phase transformations with local stresses.
773 citations
TL;DR: In this article, a general methodology is proposed for the determination of surface residual stresses and residual plastic strains using instrumented sharp indentation, which is assumed to be equibiaxial and uniform over a depth (beneath the indented surface) which is at least several times larger than the indentation contact diameter, and the indenter load and geometry can be so chosen as to minimize or maximize the contact radius to seek the broadest range of applicability and validity of the proposed method by recourse to macro-, micro- and nanoindentation of elastoplastic
728 citations
TL;DR: In this paper, a new analysis of the deflection of square and rectangular membranes of varying aspect ratio under the influence of a uniform pressure is presented, and the influence on the residual stresses on the deformation of membranes is examined.
Abstract: A new analysis of the deflection of square and rectangular membranes of varying aspect ratio under the influence of a uniform pressure is presented. The influence of residual stresses on the deflection of membranes is examined. Expressions have been developed that allow one to measure residual stresses and Young's moduli. By testing both square and rectangular membranes of the same film, it is possible to determine Poisson's ratio of the film. Using standard micromachining techniques, free-standing films of LPCVD silicon nitride were fabricated and tested as a model system. The deflection of the silicon nitride films as a function of film aspect ratio is very well predicted by the new analysis. Young's modulus of the silicon nitride films is 222 ± 3 GPa and Poisson's ratio is 0.28 ± 0.05. The residual stress varies between 120 and 150 MPa. Young's modulus and hardness of the films were also measured by means of nanoindentation, yielding values of 216 ± 10 GPa and 21.0 ± 0.9 GPa, respectively.
680 citations