Anisotropic microstrain broadening in cementite, Fe₃C, caused by thermal microstress: comparison between prediction and results from diffraction-line profile analysis

The microstrain broadening in X-ray diffraction patterns of polycrystalline Fe₃C powder particles prepared at and cooled from 873 K to ambient measuring temperature is pronouncedly anisotropic. The broadening can be quantitatively interpreted as being caused by thermal microstresses as a result of the anisotropic thermal shrinkage in conjunction with the elastic anisotropy of Fe₃C.