Influence of plastic deformation on the martensitic phase transformation in lithium

The influence of plastic deformation on the phase transition behavior of lithium is investigated by neutron scattering techniques. Plastic deformation about 30 degrees above the transformation temperature (74 K) does inhibit the phase transformation even down to low temperatures. On the other hand, below the phase transition temperature plastic deformation favors the phase transformation. The amount of the low-temperature phase is increased but the structure obtained after severe plastic deformation is no longer 9R. The diffraction data indicate the formation of a polytype where the stacking sequence of close packed planes is disordered.