Method for improve x-ray diffraction determinations of residual stress in nickel-base alloys

Patent · Mon Jan 01 00:00:00 EST 1990

OSTI ID:867348

Berman, Robert M ^[1]; Cohen, Isadore ^[1]

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1. Pittsburgh, PA

A process for improving the technique of measuring residual stress by x-ray diffraction in pieces of nickel-base alloys which comprises covering part of a predetermined area of the surface of a nickel-base alloy with a dispersion, exposing the covered and uncovered portions of the surface of the alloy to x-rays by way of an x-ray diffractometry apparatus, making x-ray diffraction determinations of the exposed surface, and measuring the residual stress in the alloy based on these determinations. The dispersion is opaque to x-rays and serves a dual purpose since it masks off unsatisfactory signals such that only a small portion of the surface is measured, and it supplies an internal standard by providing diffractogram peaks comparable to the peaks of the nickel alloy so that the alloy peaks can be very accurately located regardless of any sources of error external to the sample.

• Assignee: United States of America as represented by United States (Washington, DC)
• Patent Number(s): US 4918711
• OSTI ID: 867348
• Country of Publication: United States
• Language: English

Related Subjects

method
improve
x-ray
diffraction
determinations
residual
stress
nickel-base
alloys
process
improving
technique
measuring
pieces
comprises
covering
predetermined
surface
alloy
dispersion
exposing
covered
uncovered
portions
x-rays
diffractometry
apparatus
exposed
based
opaque
serves
dual
purpose
masks
unsatisfactory
signals
portion
measured
supplies
internal
standard
providing
diffractogram
peaks
comparable
nickel
accurately
located
regardless
sources
error
external
sample
nickel-base alloys
base alloy
base alloys
measuring residual
x-ray diffraction
exposed surface
residual stress
nickel alloy
uncovered portion
x-ray diffractometry
nickel-base alloy
accurately locate
/378/106/252/428/