Papers Published

1. Cocks, F.H. and Cogan, S.F., A new source of X-ray line broadening: inhomogeneous strains induced by uniform homogeneous temperature conditions in polyphase or non-cubic materials, J. Mater. Sci. (UK), vol. 11 no. 11 (1976), pp. 2061 - 7 .
   (last updated on 2007/04/10)

   Abstract:
   Thermal strains may contribute to X-ray diffraction line broadening in both single-phase non-cubic and in polyphase cubic polycrystalline materials even under uniform temperature conditions. A method is developed for calculating the magnitude of these thermally induced strains directly from the measured diffraction peak profiles. Corrections for particle-size effects can be made readily if particle-size broadening is significant, and the thermal diffuse scattering (TDS) contribution to the diffracted intensity can be taken into account experimentally. By this method, the strains in a Mg-5 wt.% Si alloy were found to be increased by as much as 35% by a 190°C temperature change. The interpretation of these isothermally induced strains in terms of crystal anisotropy, grain morphology and orientation and the relative sizes of phases and grains is discussed

   Keywords:
   deformation;grain size;magnesium alloys;silicon alloys;X-ray diffraction examination of microstructure;