Abstract
Prevention of the deformation during debinding and sintering is a key issue to produce highly complex parts in acceptable dimensional accuracy by metal injection molding(MIM), since three-dimensionally complex compacts are very sensitive to such deformation.
In this paper, the deformation behavior of the injection molded thin-wall metal compact with complex geometry during debinding and sintering has been investigated in various placement of the specimens. Based on the results obtained, the factors influencing these deformation have been considered.
Debinding deformation occurs through the release of residual stresses generated in the compact during molding as well as through the viscous creep by gravity. The amount of deformation associated with the residual stress depends on the holding pressure at molding, while that due to the viscous creep depends on the rate of binder removal.
As one of the factors influencing the sintering deformation, a time lag of sintering shrinkage within the compact due to the temperature difference caused by the contact with the ceramic substrate has been cited. It has been also considered that the compact geometry, especially the presence of discontinuity or intersection, the creep by self-weight and the friction between the compact and the substrate cause the sintering deformation.
