Residual stress of ruthenium powder samples compacted by spark-plasma-sintering (SPS) determined by X-ray diffraction

Spark-plasma-sintering (SPS) experiments of cylindrical ruthenium powder samples have been performed at different sintering temperatures between 1200 degrees C and 1600 degrees C applying a comparatively short sintering time of 1 min. The compacted samples have been characterized in respect of crystallite size, phase composition, and microstructure by X-ray diffraction and scanning electron microscopy techniques. Furthermore, the stress components sigma(11), and sigma(33) directed parallel and vertical to the compaction axis have been determined by means of the sin(2)psi Method. The SPS process resulted in a significant reduction of the residual stress in the material in comparison with samples compacted by conventional hot pressing methods (HP) which were compacted at 1200 degrees C and 1400 degrees C for 60 min. This effect is also associated with an enhanced crystallite growth. (C) 2008 Elsevier Ltd. All rights reserved.