2005 Volume 46 Issue 9 Pages 2073-2076
A traveling-zone sintering method prototype machine was designed and built to fabricate high-density homogeneous long rods from powder materials. A thin zirconia rod was fabricated using this prototype machine with the aim of verifying its performance. Electric power was successfully transmitted to the cylindrical mold by inserting a graphite sheet between the electrodes and the mold, even during the movement of the heating zone, allowing the sintering temperature to be controlled precisely to the desired value at any position. The distribution of density in the produced zirconia rod was examined. The relative density near both ends indicated over 99%, while that around the central section remained at 95%. The problem seemed to be caused by the insufficient load transferring to the central section due to the friction between the material and the mold. A modified zone sintering process, in which the applied load was compensated for each sintering section taking into account the frictional loss, was able to improve the density in the central section and successfully produced a zirconia rod with dimensions of φ8×51 mm. The above result suggests that our traveling-zone sintering machine has good potential to produce homogeneously densified thin zirconia rods with an aspect ratio of more than 6.
