Defect subsurface

Experimental investigations on Rolling Contact Fatigue of dented surfaces using artificial defects subsurface analyses... 

The operation is quite simple One sets the frequency to the lowest value, adjusts the gain and phase to the desired sensitivity using a special calibration standard discussed below and performs a zero-compensation on a defect free zone of the standard. Now one is ready to test. As one slides the probe across the surface of an aluminum structure, a signal response will be indicative of the presence of corrosion or of the presence of a subsurface edge. 

Magnetic particles is one of the most used nondestructive testing techniques in industry. It allows detection and localization of surfacic and subsurfacic defects of ferromagnetic pieces by making conspicuous leakage fields by a magnetic developer. 

Speckle shearing interferometry, or shearography, is a full field optical inspection teclmique that may be used for the nondestructive detection of surface and, sometimes, subsurface defects. Whilst being more sensitive in the detection of surface defects, it may also be considered for pipe inspection and the monitoring of internal conoslon. In contrast, laser ultrasound and other forms of ultrasound, are point by point measurement techniques, so that scanning facilities and significant data processing is required before information on local defects is extracted from any examination of extensive areas [1 - 3]. 

As a rule, in practice, the surface defects are revealed by the magnetic-powder and capillary methods. However, in the case of nonmagnetic materials the magnetic-powder methods are not applicable and the capillary ones do not detect the subsurface defects or defects filled with the lubricant after the grinding, wire-drawing and so on. 

Ce3+ defects by XPS. Pfau and Schierbaum370 studied the partial reduction of ceria thin films by XPS. They concluded that hydrogen exposure at temperatures greater than 400 °C led to higher concentrations of Ce3 + in the surface shell (surface and subsurface), and based on the position of the Ols peak, they concluded that the OH groups coexisted with the Ce3 + surface defects, strongly interacting with them. 

Subsurface Defects in Ingots, The precipitation of REpOpS and rH as solid pariicles in the liquid steel immediately after the adSi ion is conducive to inclusion clustering, the forming of large — up to inches in diameter — spatial networks of small —... 

Figure 16. Shallow surface crack at the outer radius of a sharp V2T bend on 80,000 psi steel sheet (top). Corresponding subsurface concentration of REM oxysulfides and sulfides in a slab cross section near the surface. The parent ingot was treated with 5 lbs of rare earth silicide per ton of ingot steel (bottom). The bottom picture is from a Baumann print or sulfur print, not sensitive to the oxides and thus eliminating the argument of reoxidation as main cause of surface defects in REM treated steels. Magnification, 2.5X-...

Buildup of Surface Carbon and Subsurface Oxygen and Formation of Stabilized Defect Sites. 

Integrated circuits have been studied fairly extensively by acoustic microscopy (Miller 1983, 1985) in addition to disbonding the defects that have been reported also include resist/metal overhang, subsurface blisters and resist inclusions, hillocks shorting between metallization layers, spikes in... 

Khuri-Yakub, B. T., Reinholdtsen, P., and Chou, C.-H. (1985). Acoustic imaging of subsurface defects in composites and samples with rough surfaces. IEEE 1985 Ultrasonics Symposium, pp. 746-9. IEEE, New York. [205]... 

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