The interrelationships between the microstructure and electrical discharge machining (EDM) behaviour of B(4)C-TiB(2) composites with respectively 30, 40 and 60 vol.% TiB(2) are investigated. Special attention was given to the influence of the grain size on the EDM behaviour by producing composites with an ultrafine TiB(2) phase using in situ synthesis during PECS. The experimental work revealed that 40 vol.% of TiB(2) results in an optimal material removal rate while the surface roughness for rough cut EDM decreases with increasing TiB(2) content. The finer microstructure of the ultrafine composite shows higher MRR's and lower Ra values than the commercial powder based composites. The major material removal mechanism for the PECS based composites was melting. The 3 point bending strength of all composites after grinding, EDM rough cut and EDM finish cut was not statistically different and about 800 MPa. The EDM recast layer was analysed by X-ray photoelectron spectroscopy.
|Journal||Journal of the European Ceramic Society|
|State||Published - 1 Oct 2011|