The Effects of Crystalline Anisotropy on the Elastic Response of Materials

A brief account is given on the effects of single crystal anisotropy on the elastic response of polycrystalline materials. Measurements using neutron diffraction and a rig giving a controlled stress are described. These are able to measure the strain as a function of the stress for a number of crystallographic planes. The anisotropy effects predicted be the simple Reuss and Voigt theories will be described. Recent measurements on initially stress-free samples placed under defined stresses up to and beyond their yield point are shown These can give a valuable insight into both the elastic and plastic properties of metals.