| The following work has been done in order to clarify and improve our understanding of part forming by powder compaction. The goal of many projects already done in this area was to create a numerical simulation software that wilus to predict and sophisticate this shaping process. The objectives of this study are: (1) to obtain experimental results that will describe part of the densification surface for eight powders; (2) to underline the influence of the size, morphology and hardness of the powder particles on the densification behaviour; (3) to propose a way of integrating the powder characteristics in a densification function.; To achieve the experimental goal, a die allowing triaxial pressing has been fabricated and instrumented. The experimental results obtained are judged to be accurate, reproducible and of great use in this field of study.; Analytically, we succeeded to enhance the influence of the powder particles characteristics on densification by using two newly propose powder parameters. The first is the relative gain in density, (H) and the second is the logarithmic shrinkage, (K). By plotting the compressibility curves using this last parameter, we were able to underline the different densification mechanisms that are affected by powders characteristics. These preliminary results lead to the conclusion that a small particle size and very irregular particle morphology will increase the intensity of the friction forces. (Abstract shortened by UMI.)... |
