| 摘要 |
The invention relates to a process for manufacturing plumbagineous materials designed for making electrode-tools for electro-erosion machining. According to the invention, the process consists in using as raw materials calcined petroleum coke ( having an ash content of maximum 0.8 % raw material ) where the share of electro-graphite in the mixture is of maximum 25 %, raw materials of 100 % granulation under 0.2 mm, 90 ...98 % under 0.07 mm, 30 ...80 % between 0.04 to 0.07 mm, which are mixed with coke-chemical pitch acting as a binder, the shares amounting to 60 ...66 parts of the above-mentioned raw materials and 34 ...40 parts of the pitch binder. The raw materials and the binder are subjected to hot alligation for homogenization at a temperature equal to the pitch softening temperature (KS) plus 70 ..80 ° C, and after cooling, the mixture is ground to 100 % granulation under 0.4 mm and is subjected to isostatical or extrusion hot mould pressing at a pressure of minimum 2,000 bars. The green products have an apparent density of minimum 1.7 g/ cm 3. Then the pressed products are baked at a temperature of minimum 950° C, are impregnated with impregnating pitch, are baked again at a temperature of minimum 700° C and are graphitized at a temperature of minimum 2,000° C.
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