Abstract:
In order to characterize Fe-W-C alloys fabricated by powder metallurgy process, different
experimental techniques including: X ray diffraction, optical microscopy, differential thermal analysis,
micro-hardness and wear tests were used.
The results obtained, show that the microstructure of the sintered samples principally depends
on their chemical composition. It is mainly composed of (c.c) solid solutions in the case of
agglomerate contents equal to 5 wt % W and carbon additions lower than 1 wt%.
When contents of W and C are increased, microstructure of compacts became bainitic with a
more or less homogeneous M6C carbides.
The micrographie examination revealed the presence of a residual porosity; essentially
consisting in secondary pores characterized by irregular shapes and important sizes.
Furthermore hardness and wear tests carried out on different samples permitted to point up
the influence of different parameters (microstructure, grain size, relative density, residual porosity...)
on the properties of the sintered samples. In particular, highest values of microhardness and wear
resistance have been obtained in the case of Fe-20w-l .5%C samples.