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Method of preparing a metal body by means of injection molding

Assignee: King Invest Co Ltd
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Filing: 1990-08-10
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Granted: 1991-05-14
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Expires: 2010-08-10
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Abstract

Abstract A manufacturing method for a metal body by means of injection molding that comprises the steps of mixing and kneading a metal powder with short fibers such as metallic fibers, carbon fibers and an organic binder, injection-molding the kneaded mixture to form a green body, removing the organic binder from the green body, and sintering the brown body. The short fibers are added in an amount ranging from about 0.1 to 20 wt. % against 100 wt. % of the metal powder and have a melting point of at least 350 DEG C., and at the time of sintering the fibers not less than 30 vol. % become fused and then integrated with the metal. The short fibers act as a reinforcement, strengthening the brown body as well as preventing deformation and cracking of the green body during debinding.

Inventors

  • 👤 Takuo Toda
  • 👤 Masao Tsuda

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-25 16:21
CPC Classifications
B; B22; B22F; B22F3/00; B22F3/22; B22F3/225; B22F1/00; B22F1/10; B22F1/103; C; C22; C22C; C22C47/00; C22C47/14; B22F2998/00

Claims Analysis

Total Claims: 15
Claim 1
Independent Claim 127 words
In a method of preparing a metal body by means of injection molding wherein, a metal powder with short fibers and an organic binder, are mixed and kneaded, the kneaded mixture is injection molded to form a green body, the organic binder is removed from said green body to form a brown body, and the brown body is sintered, the improvement which comprises the short fibers have a melting point of about at least 350° C., are being added in an amount ranging from about 0.1 to 20 wt. % based on 100 wt. % of the metal powder, and such that at the time of sintering the shortened fibers, not less than 30 vol. % become fused with the metal powder and integrate with the metal.
Claim 2
Dependent Claim 127 words
In a method of preparing a metal body by means of injection molding wherein, a metal powder with short fibers and an organic binder, are mixed and kneaded, the kneaded mixture is injection molded to form a green body, the organic binder is removed from said green body to form a brown body, and the brown body is sintered, the improvement which comprises the short fibers have a melting point of about at least 350° C., are being added in an amount ranging from about 0.1 to 20 wt. % based on 100 wt. % of the metal powder, and such that at the time of sintering the shortened fibers, not less than 30 vol. % become fused with the metal powder and integrate with the metal.
Claim 3
Dependent Claim 17 words
The method of claim 1 wherein said short fibers are a mixture of metallic and carbon fibers.
Claim 4
Dependent Claim 20 words
The method of claim 1 wherein said metal powder has a mean particle size of about 20 μm or less.
Claim 5
Dependent Claim 20 words
The method of claim 1 wherein said metal powder has a mean particle size of about 10 μm or less.
Claim 6
Dependent Claim 28 words
The method of claim 1 wherein said short fibers have a diameter of about 20 μm or less and a length from about 2 mm to 10 mm.
Claim 7
Dependent Claim 22 words
The method of claim 1 wherein said organic binder is selected from the group consisting of polyethylene, polystyrene, polyamide, and paraffinic wax.
Claim 8
Dependent Claim 30 words
The method of claim 1 wherein said organic binder is present in an amount from about 6 to 15 wt. % based on 100 wt. % of the metal powder.
Claim 9
Dependent Claim 20 words
The method of claim 1 wherein said injection-molding is carried out at a pressure from about 400 to 2000 kg/cm2.
Claim 10
Dependent Claim 21 words
The method of claim 1 wherein said injection-molding is carried out at a temperature of from about 120° to 160° C.
Claim 11
Dependent Claim 23 words
The method of claim 1 wherein the organic binder is removed by heating the green body to the melting of the binder point.
Claim 12
Dependent Claim 27 words
The method of claim 1 wherein the organic binder is removed by heating the green body at a rate of from about 10° C. to 200° C./hr.
Claim 13
Dependent Claim 21 words
The method of claim 1 wherein the sintering is carried out at a temperature of from about 1100° to 1500° C.
Claim 14
Dependent Claim 20 words
The method of claim 1 wherein the sintering is carried out at a time from about 0.5 to 4 hours.
Claim 15
Dependent Claim 10 words
A sintered body formed by the process of claim 1.

References Cited (Backward Citations)

US4699763A Cited
US4919719A Cited
US4921665A Cited
US4964907A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1994-05-13 1994-11-12 1995-05-14 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1998-05-13 1998-11-12 1999-05-14 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2002-05-13 2002-11-12 2003-05-14 $7700.00 Window Closed / Lapsed

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