| 摘要 |
<p>A sealing member 48 for location in a structure 42 for supporting a polycrystalline diamond (PCD) element 10 during leaching residual catalyst/binder from interstices in the PCD element 10 is configured to prevent a portion 30 of the PCD element 10 being leached. The sealing member 48 is formed from or coated with one or more of a peroxide-cured terpolymer, a fluorocarbon polymer or a fluoropolymer elastomer comprising copolymers of hexafluoropropylene and vinylidene fluoride, terpolymers of tetrafluoroethylene, vinylidene fluoride and hexafluoropropylene and/or perfluoromethylvinylether. The sealing member 48 can be an o-ring seal. The PCD element 10 can be located in a recess 44 of the support structure 42 which is coated with a polyketone based plastics material such as PEEK, PEK or PEEKK. Leaching can be performed in water comprising 2-5 weight % nitric acid and one or more of hydrochloric acid, sulphuric acid, phosphoric acid and/or hydrofluoric acid at up to 7M concentration.</p> |
