Design for sintering – A comprehensive study on anisotropic dimensional change on sintering

This work collects as a whole the main results obtained in the Design for Sintering project, aimed at improving the effectiveness of a design procedure accounting for anisotropic dimensional change on sintering, through a deep investigation of the related phenomena and mechanisms. The project was developed in cooperation with the main European companies producing sintered components, and it is based on a huge experimental campaign. Ring-shaped parts with different characteristics were produced in different process conditions, and dimensional changes were derived from a careful reconstruction of geometry, measured in the green and sintered state. In the first part of the project, parts characterised by different geometrical parameters and different green densities were produced, using many different powder mixes, from highly shrinking to slightly swelling. The first part of the project highlighted the importance of anisotropic dimensional change in the compaction plane, and a new anisotropy parameter was proposed accordingly. In the second part of the project, the study was then focused on the anisotropy of dimensional changes in the compaction plane, as affected by different compaction strategies. The results were implemented in the design procedure, and process conditions were highlighted ensuring good agreement between real and predicted dimensions.