METHOD FOR LEACHING COBALT FROM DIAMOND CARBIDE PLATES Russian patent published in 2024 - IPC C22B3/06 

FIELD: cutting tool manufacturing technology.

SUBSTANCE: invention relates namely to methods for manufacturing cutters with an insert made of polycrystalline diamond composite (PDC cutters). The method includes applying a protective coating to parts of the plate that are not subject to etching, placing the plates in a leaching bath, leaching at a temperature of 75±10°C, removing the plates from the leach bath and removing the protective coating. The plates, after being removed from the leach bath, are immersed sequentially in additional leach baths. In this case, a solution containing ferric chloride, hydrochloric or sulphuric acid and up to 5 wt.% of cobalt chloride is fed into the first bath, and a freshly prepared solution containing from 30 to 40 wt.% of ferric chloride, as well as 0.5 to 1 vol.% of concentrated hydrochloric or sulphuric acid. A solution containing up to 5 wt.% of divalent cobalt chloride for the first bath is obtained from a freshly prepared solution that has undergone the leaching process in the last bath.

EFFECT: increase in the depth of leaching without increasing the consumption of the leaching solution.

4 cl, 2 dwg, 1 tbl, 1 ex