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Title
Verfahren zur roentgendiffraktometrischen, zerstoerungsfreien Bestimmung von dehnungsfreien Gitterparametern und/oder mechanischen Spannungszustaenden
Date Issued
2001
Author(s)
Kaempfe, A.
Predecki, P.
Kaempfe, B.
Eigenmann, B.
Patent No
1996-19639901
Abstract
The method involves the separate determination of the depth distributions of the expansion free grating and stress conditions using the whole diffraction spectrum. To determine the depth profile the Bragg angle qy*,f* for several diffraction maxima is measured in the expansion free direction with Y*, F* for a plane stress condition given by :- with F* optional,V an elastic constant and s11/s22 ratio of stress components. To determine the stress condition at 1/e-penetration depth T the Bragg angle q for the diffraction maxima of severAl reflections is measured. To each reflection there is allocated a tilt angle Y so that the depth T remains constant during the measurement and the stress condition for the penetration depth is given by :- where:- s1 and s2 are x-ray graphical elastic constants for each reflex (hkl)sij:=stress components. To determine depth profiles of the mechanical stress the stress in various I/e penetration depths t is determined USE - For determining characteristics o f surface layers of polycrystalline specimens which have a gradient of mechanical stresses and/or expansion free grating parameters at right angles to the specimen surface ADVANTAGE - Increases the depth of penetration for determining depth profiles of stresses and grating parameters
Language
de
Patenprio
DE 1996-19639901 A1: 19960927