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:
Nov. 30, 1993
Filed:
Dec. 31, 1991
Ritsu Miura, Chiba, JP;
Hirokazu Madarame, Chiba, JP;
Masahiro Uchida, Chiba, JP;
Yasushi Owaki, Chiba, JP;
The Japan Steel Works Ltd., Tokyo, JP;
Abstract
The present invention relates to a process for producing sinters, including a steps of mixing a powder material with a binder, injection molding the mixture, and then dewaxing and sintering the resulting injection molded article, wherein the binder comprises at least one of: copolymer, a mixture of copolymer, paraffine wax, carnauba wax, a mixture of the paraffine wax and the carnauba wax, a plasticizer, and a lubricant. According to the present invention, the dewaxing step comprises heating the injection molded article to a temperature of 250.degree.-500.degree. C. in a heating rate of 5.degree.-100.degree. C./hour under the pressure not higher than 1 Torr in order to remove 40%-95 % by weight of the binder components. Further, the temperature elevation in the sintering step is started in a vacuum atmosphere and replacing the atmosphere with an inert gas atmosphere in the process of temperature elevation.