Sintered silicon nitride articles for tools and method of prepar

Details Sintered silicon nitride articles for tools and method of prepar Sintered silicon nitride articles for tools and method of prepar

1997-03-12

1999-07-13

Pitts, Andrea L.

Cutters, for shaping

Comprising tool of specific chemical composition

407118, 407120, 408144, B23B 2714

Patent

active

059217251

ABSTRACT:
Sintered silicon nitride articles for cutting tools and the like, having a high relative density, excellent wear resistance and nicking, particularly at high temperatures, and a method for preparing such articles are disclosed. The articles are made by mixing 0.25 to 3.0 vol % of magnesium oxide powder and 0.3 to 2.0 vol % of ytterbium oxide with silicon nitride starting materials, then crushing and mixing, optionally with 1.0%-vol. or less, preferably 0.5%-vol. or more of aluminum oxide powder and adding an organic binder. The article is formed using a metal press to a shape for usage as SNGN120408 tools. The sintered silicon nitride articles for tools are obtained by degasing the shaped articles, subjecting them to a primary firing at 1700 to 1900.degree. C. and 0.3 to 1.0 MPa temperature and pressure, and following with a secondary firing at a temperature which is substantially lower than the primary firing temperature, at a pressure of 100 MPa or greater.

REFERENCES:
patent: 4578087 (1986-03-01), Tanaka et al.
patent: 4640693 (1987-02-01), Bhat et al.
patent: 4919689 (1990-04-01), Pyzik et al.
patent: 5370716 (1994-12-01), Mehrotra et al.
patent: 5382273 (1995-01-01), Mehrotra et al.
patent: 5525134 (1996-06-01), Mehrotra et al.
patent: 5597272 (1997-01-01), Moriguchi et al.
patent: 5702808 (1997-12-01), Ljungberg
patent: 5712030 (1998-01-01), Goto et al.

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