Process for producing sintered body and magnet base

• US 5,487,773 A
• Filed: 10/04/1994
• Issued: 01/30/1996
• Est. Priority Date: 10/18/1991
• Status: Expired due to Fees

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Shimizu, Yutaka, Seyama, Yoshihiko
• Primary Examiner(s): Mai, Ngoclan
• Assistant Examiner(s): Jenkins, Daniel J.
• Application Number:
  US08/317,361
• Time in Patent Office: 483 Days
• Field of Search: 75/228, 75/950, 428/544, 428/611, 428/681, 428/900, 428/682
• US Class Current: 75/228
• CPC Class Codes: B22F 2998/00 Supplementary information concerning processes or compositions relating to powder metallurgy
• CPC Class Codes: B22F 3/225 by injection molding
• CPC Class Codes: B22F 7/06 of composite workpieces or articles from parts, e.g. to form tipped tools B22F7/002 takes precedence
• CPC Class Codes: H01F 3/10 Composite arrangements of magnetic circuits
• CPC Class Codes: Y10S 75/95 Consolidated metal powder compositions of >95% theoretical density, e.g. wrought
• CPC Class Codes: Y10T 428/12 All metal or with adjacent metals
• CPC Class Codes: Y10T 428/12958 Next to Fe-base component

Abstract

A process for producing a sintered body, comprising inserting a separately formed first molded article in a mold for injection molding, injection-molding a material identical to or different from that of the first molded article in the mold so that the injected material and the first molded article form together a second molded article, degreasing the second molded article, sintering the degreased article thereby obtaining a sintered body having a difference in shrinkage during the sintering between the first molded article and the injection molded portion of the second molded article other than the first molded article portion being 5% or less. The resulting sintered body is useful as a magnet base.

Claims

1. A magnetic base comprising:

a first portion, comprising one of a core portion or a core-containing peripheral portion, of an Fe-50% Co alloy; and

a second portion integral with the first portion and comprising a magnetic circuit-constituting portion of an Fe-Si alloy.

2. A magnetic base comprising:

a first portion, comprising one of a core portion or a core-containing peripheral portion, of an Fe-6.5% Si alloy; and

a second portion integral with the first portion and comprising a magnetic circuit-constituting portion, of an Fe or an Fe-0-3% Si alloy.

3. A magnetic base comprising:

a first portion, comprising one of a core portion or a core-containing peripheral portion, of a sintering density of 90% or more; and

a magnetic circuit-constituting portion integral with the first portion and having a sintering density of 80 to 90%.