The Effect of Cold-Work Distortion on X-Ray Patterns

Abstract

With modern experimental technique, it is possible to measure a peak shape with sufficient accuracy to justify an interpretation based on the precise shape of the reflection. The corrected shape is represented by a cosine Fourier series and a set of A_n coefficients determined. A plot of the A_n coefficients vs. n will distinguish between distortion and particle size broadening. From the A_n coefficients, root mean square values of strain averaged over lengths na₃ are obtained. The decrease in these values for increasing length na₃ is a direct indication of the non‐uniform nature of the strains in cold‐worked metal. By measuring several orders of a given plane, it is theoretically possible to obtain a distribution function of the strains directly from a Fourier transform of the A_n coefficients.