Abstract:

In order to explore the effect of warm flow compaction on the forming process of iron-based powders,the behaviors of warm flow compaction of the mixture of atomized iron powders and fine ferrocarbonyl powders are analyzed by using a self-developed testing system.By comparing the room-temperature compaction with the warm flow compaction,it is found that the decrease rate of lateral pressure in the warm flow compaction with the increase of transverse distance is slow,especially,at general powder-forming pressure of 600～700MPa,warm flow compaction is of higher lateral pressure coefficient than room-temperature compaction.This means that,in the same position in a part,warm flow compaction yields higher lateral pressure and relative density.It is also found that,for polyethylene glycol（PEG） binder,the optimal compaction temperature and speed are respectively 62℃ and 240mm/min,and the suitable PEG content ranges from 2% to 3%;and that,during the warm flow compaction,binder sufficiently coats and bonds metal powders,thus improving the filling capability of powders and the supportability of binder lubrication film.As a result,the pressure transmission effect among powders becomes better,and powder metallurgy part with complicated shape and high relative density can be successfully obtained.

Key words: warm flow compaction, iron-based powder, polyethylene glycol, densification