Clayton Olaf Ruud
Engineers at Cogan Cir, State College, PA

6493420, Dec 10, 2002

Jul 18, 2001

09/908659

Clayton O. Ruud - State College PA

The Penn State Research Foundation - University Park PA

G01N 2320

378 72, 378 70, 378 71, 378 86

An apparatus for in-situ measurement of residual surface stresses comprises a compact x-ray tube and a detector. X-rays emitted by the x-ray tube are diffracted from a specimen surface and intercepted by the detector. The intercepted x-rays are converted into light and transferred by a first fiber optic bundle and a second fiber optic bundle to light detection devices. Intensities of the received light are digitized by the light detection devices to generate a first ring and a second ring with common centers. The residual stress in the specimen surface is calculated based on a difference between the radii of the first ring and the second ring.

4686631, Aug 11, 1987

Feb 8, 1985

6/699992

Clayton O. Ruud - State College PA

G01C 2500, G01N 2320, G01B 530

364508

Previous methods for determining internal stress in polycrystalline solids by X-ray diffraction techniques have required that the distance between the X-ray irradiated surface of the sample under investigation and the X-ray detection surface for the diffracted X-rays be known. According to the practice of this invention, stress measurement can be made without determining the sample to detector distance as a separate step. Two or more sets of detection surfaces, i. e. , X-ray detector channels, are arranged around the incident X-ray beam, usually on opposite sides of the cone of diffracted X-rays from one another. The invention employs a calibration procedure which provides a set of calibration parameters, which, when used with X-ray stress equations, yields accurate internal stress measurement without the prior art requirement of determining the sample to detector distance.

5414747, May 9, 1995

Jan 31, 1994

8/189464

Clayton O. Ruud - State College PA
Mark E. Jacobs - Wheelersburg OH

The Penn State Research Foundation - University Park PA

G01N 23207

378 73

An accurate, real-time method for monitoring and analyzing crystalline specimens having polycrystalline platings. The method is capable of individual or simultaneous analysis of any combination of the following: 1) composition of the substrate and plating (even when the plating and substrate having common elements); 2) analysis of thickness of the plating(s); 3) analysis of the depth of the plating(s), e. g. , the thickness of any overlay; 4) analysis of the crystalline phase depth simultaneous with phase composition; 5) the preferred crystalline orientation; 6) the strain in the substrate; and (7) crystallinity and grain size. The apparatus is similar to that of U. S. Pat. No. 5,148,458 issued to Ruud, with the apparatus of this invention having the several detectors placed on different arcs and/or radial distances from the specimen surface under investigation.