In order to study the effect of electro-heating impact on powder sintering densification of micro-forming fields activated sintering technology(Micro-FAST), the die with copper powders was heated to 600 ℃ at the preset heating rate of 50 ℃/s under the pressure of 100 MPa,and the holding time was 0,then cooled down to 500 ℃.After that,the die was heated at the same heating rate and cooled again between 500 ℃ and 600 ℃,and repeating for 1 to 5 times, the effect of electro-heating impact of fast heating on the preparation of micro copper gear was studied.It was found that with the increase of electro-heating impact cycle index, the densification of sintered micro copper gears with 1.6 mm pitch diameter and 8 teeth is gradually improved. When the electro-heating impact cycle indexes are 5 times, the relative density of micro copper gear is 98.7%, and the whole preparation time is only 53 seconds. It was shown by micro analyses that the fast preparation process of micro copper gear consists of 4 stages, which are rearrangement of powder particles,powder elastoplastic deformation and crush, surface melting and bonding between particles and disappearance of particle interfaces,electro-heating impact cycle,respectively.
