The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 11, 1997
Filed:
Apr. 04, 1995
Nobuyuki Kitagawa, Hyogo, JP;
Toshio Nomura, Hyogo, JP;
Sumitomo Electric Industries, Ltd., Osaka, JP;
Abstract
Disclosed is a method of preparing a cemented carbide or a cermet alloy by mixing and kneading cemented carbide powder or cermet alloy powder with an organic binder, shaping this mixed powder into a prescribed configuration by an injection molding method and thereafter removing the organic binder from this compact and sintering the same, in order to obtain a dense alloy. Removal of the organic binder is performed in a first step in an inert gas atmosphere as a first removal step, and then continued in a second step in a vacuum of not more than 1 Torr. In the first removal step, the pressure is held in excess of the atmospheric pressure, to prevent the formation of imperfections in the compact. After continuous pores are formed in the interior of the compact, the atmosphere pressure is brought close to a vacuum, thereby facilitating the evaporation of gas from the surface and desorption of gas generated in the interior of the compact.