HIGH-PRESSURE TRIAXIAL CELL FOR METAL-POWDER

A triaxial press was developed to study the mechanical behaviour of me tal powders. This press is numerically controlled and it allows differ ent load paths with stress and/or strain control: isotropic, conventio nal triaxial tests, and loading-unloading cyclic tests. The confining pressure limit is equivalent to a specimen radial stress of 400 MN m(- 2) whereas the maximum axial stress is 1250 MN m(-2). Experiments on a n iron powder showed that there was reproducibility of the results and only a small error in measurement. With respect to the mechanical beh aviour of this powder, the important influence of deviatoric stress on the densification was observed but no dilatancy effects were observed .