Sintered compact, process for production thereof, and optical element

A method for manufacturing a sintered body for manufacturing a sintered body having a predetermined shape, the sintered body having a ceramic base material, the method for manufacturing a sintered body comprising:

• preparing a ceramic preform that includes a base material selected from the group consisting of zinc sulfide, germanium, zinc selenide, calcium fluoride, and spinel, the ceramic preform being free of silicon nitride;
• using a predetermined mold having an upper die and a lower die to hot-press the ceramic preform to form a pressure-sintered body that defines an optical component;
• and
• cooling the optical component while applying a pressure load of approximately 5% or more and 100% or less of a pressure load applied during the step for forming the optical component, the optical component having an unprocessed surface that has not been subjected to mechanical processes such as cutting and polishing, the surface thereof being free of residual stress in a compressive direction and the uprocessed surface having residual stress in a tensile direction corresponding to tensile stress that is equal to or greater than 1 MPa.

An optical component comprising the sintered body manufactured by a method for manufacturing a sintered body having a predetermined shape, the sintered body having a ceramic base material, the method for manufacturing a sintered body comprising:

• preparing a ceramic preform that includes a base material selected from the group consisting of zinc sulfide, germanium, zinc selenide, calcium fluoride, and spinel, the ceramic preform being free of silicon nitride;
• using a predetermined mold having an upper die and a lower die to hot-press the ceramic preform to form a pressure-sintered body that defines an optical component;
• and
• cooling the optical component while applying a pressure load of approximately 5% or more and 100% or less of a pressure load applied during the step for forming the optical component, the optical component having an unprocessed surface that has not been subjected to mechanical processes such as cutting and polishing, the surface thereof being free of residual stress in a compressive direction and the unprocessed surface having residual stress in a tensile direction corresponding to tensile stress that is equal to or greater than 1 MPa.