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US 4,108,652 AGranted
Method for producing a sintered body of high density
AssigneeNippon Tungsten Co., Ltd.
InventorsKazuki Ogawa, Mitsue Koizumi, Mitsuhiko Furukawa, Yoshimichi Hara, Takashi Kitahira
Life of this patent
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Abstract
A new hot isostatic pressing method produces sintered material having a very fine structure as well as uniform properties by forming a unique capsule such as a titanium capsule of metal over a presintered material for sintering a ceramic cutting tool material is disclosed.
Claims30
A method for producing a sintered body of high density comprising the following steps:
- first step:
- packing a mixed body of a metal powder, a chloride salt and crushed refractory material into a mold which previously contains the pre-sintered body such that said mixed body covers the entire surface of said pre-sintered body, heating said mold until pure metal having a thickness of more than 8 micron is extracted over the surface of said pre-sintered body so that said extracted metal forms a capsule coating of said metal on said body;
- second step:
- disposing said capsule-coated body obtained from the first step into a heating furnace and filling said heating furnace with a fluid pressure medium such as a nitrogen gas or an inert gas;
- and
- third step:
- keeping the atmosphere within said furnace at a desired temperature and a desired pressure so as to compress said pre-sintered body at a high temperature by way of said metal-capsule.
4 more elements
A capsule composed of fine pure metal particles which are extracted from a chloride salt;
- said capsule formed uniformly around the entire surface of a pre-sintered body and having a thickness of more than 8 micron.
Dependencies are inferred from the claim text.