Structural and Microstructural Characterization ofNanostructured Hardmetals of WC-Co/Ti/Ti+Co

摘要

Nanosized WC, and binders Co, Ti and Ti-Co, are used to process hardmetals. Titanium was proposed to reduce and even replace the Co in these composites, verifying the effectiveness of the new binders. Samples of nanosized WC with 10wt%Co, WC-9wt%Ti-1 wt%Co, WC-10wt%Ti were cold compacted at 200MPa and sintered at 1500X during 1 hour under vacuum of 10-(-2)mbar for the processing of hardmetal were performed. The structural characterization by X-ray diffraction and microstructure by scanning electron microscopy (SEM) and EDS microanalysis of the sintered material. We observed the presence of the W-2C phase in the sintered samples, and Co-3W phases in the samples with Co content and a good distribution of binder phase, leading to formation of small "pool" of Co and Ti and small porosity and well distributed. It was proved that using Ti are as binder phase, it avoids the neta phase formation.