METHOD OF MAKING ITEMS FROM ULTRAFINE GRAIN SILICONIZED GRAPHITE Russian patent published in 2019 - IPC C01B32/21 C01B32/956 C04B35/565 C04B35/532 

FIELD: manufacturing technology.

SUBSTANCE: invention relates to structural materials for machine building, chemical and metallurgical industry and can be used in production of support and thrust bearings, plain bearings, end seals of pumps intended for pumping liquids with abrasive particles, as well as facing plates. First, press mass is prepared based on graphite powder of 5–30 mcm fraction or its mixture with technical carbon, including nanosized, and polymer phenol-formaldehyde binder, in form of liquid bakelite in isopropyl alcohol solution with conditional viscosity of 16 s. Graphite powder compacted with pyrocarbon or graphite with pyrocarbon coating can be used. Then, from the obtained press-mass, the blank is formed by pressing, binder is polymerised and the obtained billet is annealed. Burnt workpiece is silicated by steam-liquid-phase method by heating and holding for 1–2 hours at 1,500–1,600 °C in silicon vapor at temperature of vapors exceeding billet temperature when heated from 1,300 to 1,500 °C by 120–10 °C, respectively. Billet is heated in range of 1,300–1,500 °C can be stepped with isothermal holding. After that, workpiece is cooled in silicon vapors in the absence of specified temperature difference. Temperature 1,500 °C corresponds to graphite powder with higher chemical reactivity to silicon, and temperature of 1,600 °C – with less.

EFFECT: improving operational characteristics of items from siliconized graphite, as well as reproducibility of obtained results.

3 cl, 1 tbl