Ceramic or metal powders moulded with binder - where binder is then removed by solvent vapour and liq. prior to sintering

摘要

A baked or sintered part is made from powder, using a binder removed from the moulding before sintering, without causing swelling nor exposing the green moulding to shear-or tensile forces. The binder is mixed with the powder at a temp. above the m.pt. of the binder, and the mixt. is moulded using press. and heat so the binder hardens on cooling. The moulding is heated above temp. in solvent vapuor to remove the binder, followed by immersing the moulding in a liq. solvent to remove the last trace of binder; and the moulding is then sintered. The powder is pref. ceramics, metals, or ceramics, with max. size 4 mu m, or av. size 1 mu m; the powder particles may be spherical. The ratio of powder:binder in the mixt. is pref. >=1:3. The powder and binder can be mixed without heating, and the moulding heated above the flow point of the binder in solvent vapour to remove the binder slowly so the moulding does not burst. The binder can be completely removed prior to baking or sintering.