Process analysis of binder treatment on iron-based alloy powder

Binder treatment technology is a widely used method of bonding fine powders to coarse particles using a binder liquid. In this paper, binder treatment experiments were carried out for binary Fe–C mixture and multicomponent mixture (alloy powders exceeding 15 wt.%). The differences of particle size distribution and microstructural of conventional mixing and binder treatment mixing in Fe–C mixture were compared, and the fine particles were evenly bonded to the coarse iron particles surface and preferentially filled into the pits after binder treatment. The physical properties of the multicomponent mixture after binder treatment were improved, the flowrate and fine particles adhesion ratio achieved 30 s/50 g and 96%, respectively, and the segregation was obviously reduced. Further, the phenomenon of small particles bonded to large particles was explained by capillary force and snowball effect. Meanwhile, the theory that small particles migration caused by spontaneous capillary flow during drying and consolidation was proposed.