David H Field

US Patent:

6462339, Oct 8, 2002

Filed:

Sep 20, 2000

Appl. No.:

09/665845

Inventors:

Christopher A. Michaluk - Gilbertsville PA
David P. Field - Pullman WA

Assignee:

Cabot Corporation - Boston MA

International Classification:

G01N 23203

US Classification:

250310, 250307, 250311

Abstract:

A method for quantifying the texture homogeneity of a polycrystalline material is described. The method involves selecting a reference pole orientation; scanning in increments a cross-section of the polycrystalline material having a thickness with scanning orientation imaging microscopy or other measuring technique to obtain actual pole orientations of a multiplicity of grains throughout the cross-section of the polycrystalline material. The orientation differences between the reference pole orientation and actual pole orientations of a multiplicity of grains is then determined. A value of misorientation from the reference pole orientation at each grain measured throughout the thickness is then assigned. The average misorientation of each measured increment throughout the thickness is then determined. A texture gradient and/or texture banding can then be obtained by determining the first and/or second derivative, respectively, of the average misorientation of each measured increment through the thickness of the sample used for evaluation.

US Patent:

54669340, Nov 14, 1995

Filed:

Jan 18, 1995

Appl. No.:

8/374214

Inventors:

Brent L. Adams - Gibsonia PA
David J. Dingley - Salt Lake City UT
David P. Field - Pleasant Grove UT

International Classification:

G01N 23203

US Classification:

250307

Abstract:

An imaging apparatus (10) includes a scanning electron microscope (12) which is controlled to bombard numerous points (62) of a material sample (24) with an electron beam (18). Backscatter diffraction patterns are collected by an image collection system (26) which may include both a slower responding video camera (32) and a faster responding diode array (40). For a baseline point (62), an electron backscatter diffraction pattern collected at the video camera (32) is analyzed to identify representative pixels which reside along Kikuchi bands (78). Backscatter images from subsequent points (62) are rapidly compared (98) with the baseline to detect changes. When changes are not detected, EBSPs are not analyzed. When changes are detected, EBSPs are analyzed to generate new baselines. The resulting collection of analyzed EBSPs are processed (104) to identify microstructure attributes and to characterize defects (64).

US Patent:

55571042, Sep 17, 1996

Filed:

Oct 24, 1995

Appl. No.:

8/547299

Inventors:

David P. Field - Pleasant Grove UT
David J. Dingley - Provo UT

Assignee:

Texsem Laboratories, Inc. - Provo UT

International Classification:

G01N 23203

US Classification:

250307

Abstract:

An apparatus for determining the reliability of crystallographic solutions of a specimen includes an electron beam generator, a stage for holding the specimen, an image collection system for obtaining diffraction images of crystals within the specimen, and processor for processing the diffraction images to obtain most probable indexing solutions for the crystals and to generate confidence factors associated with the most probable indexing solutions. The apparatus may utilize the confidence factors to determine the phase of the crystals within the specimen. The confidence factors may also be incorporated into reports representing the statistical confidence of various crystallographic characteristics of the specimen.