Preferred orientation of beta-phase and its mechanisms in a fine-grained silicon-nitride-based ceramic

A quantitative texture analysis, including calculations of the orientation distribution function, is applied to investigate the preferred orientation of beta -Si3N4 in a fine-grained material containing almost equiaxed grains that has been hot-pressed, annealed, and plane-strain compressed. The resu lts show that (i) plane strain compression can produce relatively strong te xtures that were dependent on the compressive strain: (ii) the basal plane of hexagonal beta -Si3N4 was normal to the hot-pressing direction for the h ot-pressed and annealed samples, whereas it was parallel to the stress axis for deformed samples: and (iii) the mechanisms for texture development wer e preferred grain growth for the annealed sample and grain rotation for the hot-pressed and deformed samples, respectively.