Fixed-super-abrasive tool and method of manufacture thereof

A method of grinding and polishing toric and other curvilinear lenses comprising the steps of:

• a. forming a super-abrasive grinding tool comprising:
• i. a substantially-rigid, non-abrasive backing member having a curved support surface determinative of the curvature of said toric and curvilinear lenses and having peripheral dimensions adapted to the motion of the optical grinding apparatus with which it is to be used by determining the area swept out by a lens in motion during the grinding of said lenses and shaping said backing member to match but not to exceed the area swept by said tool during grinding of said lens with the area swept by said lens,
• ii. a substantially malleable, multi-layered, integrally-formed abrasive wafer of predetermined thickness conformed to the curvature of and releasably secured to said backing member of (i), said abrasive wafer comprising
• 1. a super-abrasive-containing layer comprising abrasive particles having a Knoop Hardness in excess of about 3000 kg/mm.sup.2 and selected from the group consisting of diamonds, cubic boron nitride, and mixtures thereof interspersed and bound in a powdered metal matrix for binding said super-abrasive particles and,
• 2. a layer substantially free of super-abrasive particles secured to said super-abrasive-containing layer of (1);
• said wafer being formed by subjecting said super-abrasive-free layer and said super-abrasive-containing layer to sintering conditions of pressure and temperature for the metals to form said multi-layered abrasive wafer, said wafer being conformed to said backing member by interposing said wafer between said support surface and an opposed surface conformable to the predetermined desired conformation and thereafter bringing said support surface and said opposed surface towards one another with sufficient force to accomplish such conformation;
• b. mounting said grinding tool of (a) in an optical grinding machine and employing said tool to grind an optical lens while simultaneously pumping a fluid to cool, lubricate, and flush said lens during said grinding;
• c. periodically restoring during its useful life the curvature of said super-abrasive-containing layer of (a) (ii) to the curvature of said backing member of (a) (i) until said super-abrasive-containing layer has been substantially consumed;
• d. releasing said wafer having a substantially consumed super-abrasive-containing layer from said backing member and thereafter securing a replacement wafer to said backing member and
• e. representing steps (b), (c), and (d).