Summary of the technology
The preferential production method of the composite material involves the sputtering for the modification of the particle surface by coating them with a nanocrystalline layer of iron-rich metallic binder with variable thickness. The rest of the processing follows the traditional powder metallurgy routes with pressing and sintering in a vacuum furnace. After processing, the composite contains tungsten carbide phase, eta-phase and iron rich binder.
Description of the technology
A group of researchers has developed a tungsten carbide (WC) based composite with iron-rich binders, using new technologies. The invention aims to obtain composites presenting a phase composition after sintering, such as, apart from the WC and the metallic binder phase, there are substantial amounts of eta carbide phase dispersed in the matrix. The advantages of the applied technology to the production of those composites are mainly reflected on a significant increment of the mechanical properties, particularly toughness, comparatively with other carbide based composites available in the market. The university is looking for companies of powder metallurgy industry interested in these technologies, namely the hardmetal industry.
The invention describes a method to obtain a composite material which comprises the following steps: - Process to modify the powder surfaces through chemical and physical coating technologies; -Uniaxial and/or isostatic pressing of the coated powders; - Sintering in vacuum or inert atmospheres.
Main advantages of its use
- The present invention has the following advantages over the existing technologies:to obtain WC-based composites with toughness values between 30 to 35% higher than the corresponding degrees of WC-Co composites, maintaining the hardness values, and superior resistance to oxidation and corrosion;
- the possibility to enlarge the range of applications of hardmetals, such as in cutting and drilling tools subjected to particularly high efforts even in corrosive environments.
- to apply new binders, namely iron rich binders, which results in economic and environmental moderations;
- The obtained composite, containing phases of WC + eta phase+ metallic binder can be applied in tools or other components whenever high toughness, hardness and corrosion/oxidation resistance are required, such as drill bits, dies, punches and seals for the oil industry, mining, etc.