Predictive model development for PM gear rolling

In combination with existing processing methods for powder metallurgy (PM) gear manufacturing, transverse gear rolling has the potential to deliver high dimensional precision and increased performance. In order to effectively design the sintered gear preform, the rolling tools, and finally the rolling process, a constitutive understanding of both the kinematical boundary conditions and the densification behavior of different PM materials is necessary as the foundation elements of a predictive model for PM gear rolling. A process design strategy, based on kinematical simulation, as it relates to PM gear rolling for both improved precision and selective densification, is described. The successful application of this design strategy is illustrated for the precision rolling of a helical pump gear, and the surface densification of a standard gear.