Non-Destructive Measurement of Plastic Deformation under the Extreme Environments

2016 ◽  
Vol 827 ◽  
pp. 31-34
Author(s):  
Radka Pernicová ◽  
Jindřich Zeman

Measuring of the non-elastic deformation of wide range of materials under extreme environments, such as high temperature, underwater or lack of space, is described in this paper. Method, called Predictive Instant Defect Analysis of Constructions for short PIDAC, is based on precise indication of defined distance change between two points before and after loading. Distance is mechanical imprinted into an indication specimen and consequently measured by microscopy analysis. The technology solves not only problem of measuring plastic length deformations but also offers the capability of predicting catastrophic failure due to the breaking, tearing, or deforming of materials.

2001 ◽  
Vol 54 (8) ◽  
pp. 487 ◽  
Author(s):  
Michael James

Neutron reflectometry has become an increasingly important technique in the characterization of thin-film surfaces and interfaces. Recent advances in instrumentation, experimental design, sample environments and methods of data analysis now make it possible to obtain an angstrom-precision depth profile of the film composition. Neutrons are non-destructive and highly penetrating which makes them ideal probes for the study of buried interfaces as well as surfaces under a wide range of extreme environments. Isotopic H/D substitution (particularly in colloidal, polymeric or biological systems) provides a unique tool for selectively labelling different components of complex planar architectures. The fundamental aspects of neutron reflectometry are discussed, and the utility of this technique is illustrated by a review of several recent studies.


2006 ◽  
Vol 128 (4) ◽  
pp. 711-717 ◽  
Author(s):  
K. Y. Lee ◽  
R. Wei

Ceramic seals are widely used in many severe applications such as in corrosive, high temperature and highly loaded situations especially in hot chemical water-based extreme environments for automobile water pumps. Presently, polymeric materials are used as the counter part for alumina ceramic seals to reduce the ceramic-to-ceramic wear. As a result, leaks are very commonly observed from water pump during services. Consequently, it is needed to improve the surface properties of the ceramic seals using a surface modification technique such as a thin film coating process to meet the increasing demand of more stability, more durability, and lower friction of coefficient in those extreme environments. To meet these challenges, we have applied DLC (diamond-like carbon) coatings on alumina using a PIID (plasma immersion ion deposition) technique intended for seal applications. The DLC-coated specimens were tested under a wide range of temperature conditions, from room temperature up to 400°C, using a high temperature pin-on-disk tribo-tester. After that, the wear-tested specimens were analyzed using SEM with EDS to characterize the worn surfaces. Morphological changes of the DLC coated surfaces before and after the wear tests were studied. Under certain deposition conditions DLC performed very well up to 400°C. However, under other conditions, DLC failed catastrophically. In this paper we will present the friction and wear characteristics of the DLC-coated alumina. Finally, we will discuss the failure mode of DLC coatings.


1958 ◽  
Vol 2 ◽  
pp. 275-281
Author(s):  
Beverley James Lowe ◽  
Payson D. Sierer ◽  
Robert B. Ogilvie

AbstractThe paper is based on a feasibility study to determine the suitability of various techniques for the non-destructive measurement of cladding thickness on uranium fuel elements. The techniques studied were: 1—the attentuation of the characteristic X-ray fluorescence from the uranium base metal by the cladding material, and 2—Compton scattering of X-rays from the cladding surface. The cladding materials used in the investigation were aluminum, 304 stainless steel and zirconium, providing a wide range of both atomic number and density.


Author(s):  
Yuri Kudryavtsev

The application of an ultrasonic non-destructive method for residual stress (RS) measurements has shown that, in many cases, this technique is very efficient and allows measuring the RS both in laboratory conditions and in real structures in field for a wide range of materials. Using this technique, one can measure the RS at the same points many times, studying for instance, the changes of RS under the action of service loading or effectiveness of stress-relieving techniques. An ultrasonic computerized complex (UCC) for non-destructive measurement of residual and applied stresses was developed recently. The complex includes a measurement unit with transducers, basic supporting software, an advanced database and an Expert System, housed in a laptop, for analysis of the influence of RS on the fatigue life of welded elements. In general, the ultrasonic method allows one to measure the RS in both cases: averaged through thickness or in surface layers. The present version of UCC allows measuring the averaged through thickness biaxial RS in plates 2–150 mm thick. The results of ultrasonic RS measurement in large scale welded specimens and structures are also discussed in this paper.


Author(s):  
J W Steeds

There is a wide range of experimental results related to dislocations in diamond, group IV, II-VI, III-V semiconducting compounds, but few of these come from isolated, well-characterized individual dislocations. We are here concerned with only those results obtained in a transmission electron microscope so that the dislocations responsible were individually imaged. The luminescence properties of the dislocations were studied by cathodoluminescence performed at low temperatures (~30K) achieved by liquid helium cooling. Both spectra and monochromatic cathodoluminescence images have been obtained, in some cases as a function of temperature.There are two aspects of this work. One is mainly of technological significance. By understanding the luminescence properties of dislocations in epitaxial structures, future non-destructive evaluation will be enhanced. The second aim is to arrive at a good detailed understanding of the basic physics associated with carrier recombination near dislocations as revealed by local luminescence properties.


Author(s):  
C. Monachon ◽  
M.S. Zielinski ◽  
D. Gachet ◽  
S. Sonderegger ◽  
S. Muckenhirn ◽  
...  

Abstract Quantitative cathodoluminescence (CL) microscopy is a new optical spectroscopy technique that measures electron beam-induced optical emission over large field of view with a spatial resolution close to that of a scanning electron microscope (SEM). Correlation of surface morphology (SE contrast) with spectrally resolved and highly material composition sensitive CL emission opens a new pathway in non-destructive failure and defect analysis at the nanometer scale. Here we present application of a modern CL microscope in defect and homogeneity metrology, as well as failure analysis in semiconducting electronic materials


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