Etching process for improving the strength of a laser-machined silicon-based ceramic article

Title: Etching process for improving the strength of a laser-machined silicon-based ceramic article

Full Record
Other Related Research

Abstract

A process for improving the strength of laser-machined articles formed of a silicon-based ceramic material such as silicon nitride, in which the laser-machined surface is immersed in an etching solution of hydrofluoric acid and nitric acid for a duration sufficient to remove substantially all of a silicon film residue on the surface but insufficient to allow the solution to unduly attack the grain boundaries of the underlying silicon nitride substrate. This effectively removes the silicon film as a source of cracks that otherwise could propagate downwardly into the silicon nitride substrate and significantly reduce its strength.

Inventors:

Copley, Stephen M ^[1]; Tao, Hongyi ^[2]; Todd-Copley, Judith A ^[1]

Palos Verdes, CA
Covina, CA

Issue Date:: 1991-01-01

Research Org.:: LOCKHEED MARTIN ENRGY SYST INC

OSTI Identifier:: 867862

Patent Number(s):: 5022957

Assignee:: University of Southern California (Los Angeles, CA)

DOE Contract Number:: AC05-84OR21400

Resource Type:: Patent

Country of Publication:: United States

Language:: English

Subject:: etching; process; improving; strength; laser-machined; silicon-based; ceramic; article; articles; formed; material; silicon; nitride; surface; immersed; solution; hydrofluoric; acid; nitric; duration; sufficient; remove; substantially; film; residue; insufficient; allow; unduly; attack; grain; boundaries; underlying; substrate; effectively; removes; source; cracks; otherwise; propagate; downwardly; significantly; reduce; significantly reduce; silicon film; hydrofluoric acid; remove substantially; ceramic article; etching process; ceramic material; grain boundaries; silicon nitride; nitric acid; effectively removes; articles formed; based ceramic; silicon-based ceramic; move substantially; ceramic mater; machined surface; effectively remove; /216/65/134/252/

Citation Formats


                    Copley, Stephen M, Tao, Hongyi, and Todd-Copley, Judith A. Etching process for improving the strength of a laser-machined silicon-based ceramic article.  United States: N. p., 1991. 
        Web.

Copy to clipboard


                    Copley, Stephen M, Tao, Hongyi, & Todd-Copley, Judith A. Etching process for improving the strength of a laser-machined silicon-based ceramic article.  United States.

Copy to clipboard


                    Copley, Stephen M, Tao, Hongyi, and Todd-Copley, Judith A. Tue .  
        "Etching process for improving the strength of a laser-machined silicon-based ceramic article".  United States.  https://www.osti.gov/servlets/purl/867862.

Copy to clipboard


                    
@article{osti_867862,

  title        = {Etching process for improving the strength of a laser-machined silicon-based ceramic article},

  author       = {Copley, Stephen M and Tao, Hongyi and Todd-Copley, Judith A},

  abstractNote = {A process for improving the strength of laser-machined articles formed of a silicon-based ceramic material such as silicon nitride, in which the laser-machined surface is immersed in an etching solution of hydrofluoric acid and nitric acid for a duration sufficient to remove substantially all of a silicon film residue on the surface but insufficient to allow the solution to unduly attack the grain boundaries of the underlying silicon nitride substrate. This effectively removes the silicon film as a source of cracks that otherwise could propagate downwardly into the silicon nitride substrate and significantly reduce its strength.},

  doi          = {},

  journal      = {},
number       = ,

  volume       = ,

  place        = {United States},

  year         = {1991},

  month        = {1}

}

Copy to clipboard

Patent:

View Patent

Save / Share:

Export Metadata

Save to My Library

Similar Records in DOE Patents and OSTI.GOV collections:

Etching process for improving the strength of a laser-machined silicon-based ceramic article

Patent Copley, S M; Tao, H; Todd-Copley, J A

A process is disclosed for improving the strength of laser-machined articles formed of a silicon-based ceramic material such as silicon nitride, in which the laser-machined surface is immersed in an etching solution of hydrofluoric acid and nitric acid for a duration sufficient to remove substantially all of a silicon film residue on the surface but insufficient to allow the solution to unduly attack the grain boundaries of the underlying silicon nitride substrate. This effectively removes the silicon film as a source of cracks that otherwise could propagate downwardly into the silicon nitride substrate and significantly reduce its strength. 1 figure.
Process for producing silicon nitride based articles of high fracture toughness and strength

Patent Huckabee, Marvin [Marlboro, MA]; Buljan, Sergej-Tomislav [Acton, MA]; Neil, Jeffrey T [Acton, MA]

A process for producing a silicon nitride-based article of improved fracture toughness and strength. The process involves densifying to at least 98% of theoretical density a mixture including (a) a bimodal silicon nitride powder blend consisting essentially of about 10-30% by weight of a first silicon nitride powder of an average particle size of about 0.2 .mu.m and a surface area of about 8-12 m.sup.2 /g, and about 70-90% by weight of a second silicon nitride powder of an average particle size of about 0.4-0.6 .mu.m and a surface area of about 2-4 m.sup.2 /g, (b) about 10-50 percent bymore »« less
Full Text Available
Power mixture and green body for producing silicon nitride base & articles of high fracture toughness and strength

Patent Huckabee, Marvin L [Marlboro, MA]; Buljan, Sergej-Tomislav [Acton, MA]; Neil, Jeffrey T [Acton, MA]

A powder mixture and a green body for producing a silicon nitride-based article of improved fracture toughness and strength. The powder mixture includes 9a) a bimodal silicon nitride powder blend consisting essentially of about 10-30% by weight of a first silicon mitride powder of an average particle size of about 0.2 .mu.m and a surface area of about 8-12m.sup.2 g, and about 70-90% by weight of a second silicon nitride powder of an average particle size of about 0.4-0.6 .mu.m and a surface area of about 2-4 m.sup.2 /g, (b) about 10-50 percent by volume, based on the volume ofmore »« less
Full Text Available
Method for improving the toughness of silicon carbide-based ceramics

Patent Tein, Tseng-Ying [Ann Arbor, MI]; Hilmas, Gregory E [Dexter, MI]

Method of improving the toughness of SiC-based ceramics. SiC, , AlN, Al.sub.2 O.sub.3 and optionally .alpha.-Si.sub.3 N.sub.4 are hot pressed to form a material which includes AlN polytypoids within its structure.
Full Text Available
Ceramic matrix composite article and process of fabricating a ceramic matrix composite article

Patent Cairo, Ronald Ralph; Dimascio, Paul Stephen; Parolini, Jason Robert

A ceramic matrix composite article and a process of fabricating a ceramic matrix composite are disclosed. The ceramic matrix composite article includes a matrix distribution pattern formed by a manifold and ceramic matrix composite plies laid up on the matrix distribution pattern, includes the manifold, or a combination thereof. The manifold includes one or more matrix distribution channels operably connected to a delivery interface, the delivery interface configured for providing matrix material to one or more of the ceramic matrix composite plies. The process includes providing the manifold, forming the matrix distribution pattern by transporting the matrix material through themore »« less
Full Text Available

Similar Records