Particle-size, size distribution and dislocations in nanocrystalline tungsten-carbide

Ball-milled WC powder has been compacted and sintered. The particle size ha s been determined by transmission and scanning electron microscopy and high resolution X-ray diffraction. The X-ray diffraction profiles were evaluate d for particle size and dislocation densities by the recently developed pro cedures of modified Williamson-Hall plot and modified Warren-Averbach metho d. Log-normal particle size distributions have been obtained by a newly dev eloped numerical method from the size parameters provided by X-ray line pro file analysis. The size distributions obtained by TEM and X-rays are compar ed and discussed. The dislocation density was found to be 1.9 x 10(17) m(-2 ) in the ball-milled powder which decreases to 2.0 x 10(15) m(-2) after ann ealing. (C) 1999 Acta Metallurgica Inc.