The Applications of Solid-State X-Ray Detectors in Diffraction Techniques.

A Si li solid state x-ray detector has been evaluated for its potential application in x-ray residual stress and retained austenite measurements. For fixed angle diffraction of low 2 theta values the inherent errors in determining peak positions coupled with the limited resolution of the detector made it impossible to achieve the degree of accuracy characteristic of the standard high 2 theta scanning technique for measuring residual stresses. However, there may be particular repetitive applications where the ability to measure stresses to plus or minus 10,000 psi in a few minutes time may warrant the use of the solid state detector. A technique was developed for measuring retained austenite by means of analyzing the intensities of four diffraction lines, two from austenite and two from martensite, recorded simultaneously at a fixed low 2 theta angle. For a standard specimen with 4 austenite the reproducibility was plus or minus 0.3 for counting times as low as 3 - 5 minutes. Since the solid state detector can also be used for fluorescent and structural analyses it can increase the versatility of a standard diffractometer. Author