Improved Manufacturing of Hardmetals and Sintered Steel via Tailored Carbon Source

Purpose and goal

Project objectives were fulfilled through the systematic study of the interaction between different carbon sources with base metal/oxide powders and processing atmospheres utilizing number of advanced characterization techniques. Results indicate that the choice of a carbon source is essential parameter in both cases. In total, eight different carbon sources were studied in a variety of the synthesis/processing conditions (temperature profile and processing atmosphere).The most effective carbon sources were identified in both cases and processing conditions proposed.

Expected results and effects

In both studied cases - synthesis of nano-structured WC and sintering of prealloyed powder metallurgy steels importance of the combination of the proper carbon source and respective processing parameters was indicated. New manufacturing routine for the synthesis of nano-WC was proposed based on utilization of fine carbon black as the carbon precursor, proper mechanical alloying/milling with following synthesis in hydrogen-rich atmosphere. Novel robust sintering process for prealloyed PM steels is proposed utilizing fine synthetic graphite grades, not used in PM nowadays.

Planned approach and implementation

Developed synthesis strategy of the nano-WC with utilization of the fine carbon black precursors and intermediate synthesis temperatures allows implementation of the project results in a small batch process during coming couple of years. Utilization of the fine synthetic graphite for the sintering of prealloyed PM steels is foreseen to be industrially applied in the short-term. Number of the project results (e.g. utilization of fine synthetic graphite for synthesis of WC and carbon black for PM processing) requires additional research to assure industrial implementation.