Abstract:

:Fe-2Cu-2Ni-lMo-0.8C mixed powders were rapidly consolidated via a pulsed-constant electric current sintering process, and the microstructure and fracture morphology of the alloy sintered at different pulse durations were analyzed. Moreover, the density and bending strength of the alloy were measured and the sintering consolida- tion behavior of the powders was investigated. The results indicate that   when the peak current, base current, duty cycle and frequency of the pulsed electric current are respectively 3000A, 360A, 50Hz and 50% , and when the idle constant current is chosen as 1389 A, the alloy sintered with pulsed electric current for 3 rain and with con- stant electric current for another 3 rain is of a density of 7.61 g/cm³ and a bending strength of 1540MPa;   the alloy mainly consists of pearlite, with massive or reticular ferrite and austenite as well as few nonuniformly-distributed alloy phase being also observed;   the bending fracture is in a mixed mode of cleavage, dimple and interg- ranular fracture; and   as compared with the conventional sintering, the spark plasma sintering is more effective in improving the performance and the processing efficiency.

Key words: Fe-2Cu-2Ni-1Mo-0. 8C alloy, spark plasma sintering, microstructure, bending strength