Precipitate structure analysis by diffraction contrast image matching for a metastable semicoherent carbide phase in molybdenum. I. Generating inelastic strain

The formation of the thermodynamically stable incoherent Mo2C precipitates during aging of quenched carbon-doped molybdenum crystals proceeds through a sequence of metastable intermediate phases. For such a carbide with unknown structure the tensor of inelastic strain due to the phase transition from the metal to the carbide is constructed on the basis of a physically reasonable model allowing for a partial loss of coherency. From that strain tensor, which depends on several structure parameters, the elastic distortions around the particles and the electron diffraction contrast can be calculated. Most of the unknown parameters will be determined in a subsequent paper by comparing the theoretical images with corresponding electron micrographs.