SiAlON composites and method of preparing the same

Patent · Tue Jul 13 04:00:00 EDT 1993

OSTI ID:6352234

Hwang, Chinmau J; Beaman, D R

A multi-phase SiAlON ceramic material having at least a first, second and third phase is described, comprising: (a) a first phase of alpha-SiAlON having the general formula M[sub x], (Si,Al)[sub 12] (0,N)[sub 16], wherein 0 < x [le] 2 and M is a multicationic mixture of (i) a compound selected from the group consisting of oxides and nitrides of Sr; (ii) at least one compound selected from the group consisting of oxides and nitrides of Ca, Mg, Li and Na; and (iii) at least one compound selected from the group consisting of oxides and nitrides of rare earth elements or yttrium; (b) a second phase of beta-SiAlON having the general formula Si[sub 6[minus]y]Al[sub y]O[sub y]N[sub 8[minus]y], wherein 0 < y [le] 4.3; and (c) a third phase of an intergranular amorphous morphology containing Si, Al, O, and N, combined with a mixture of (i) a compound selected from the group consisting of oxides and nitrides of Sr; (ii) at least one compound selected from the group consisting of oxides and nitrides of Ca, Mg, Li and Na; and (iii) at least one compound selected from the group consisting of oxides and nitrides of rare earth elements or yttrium, such that said ceramic material exhibits high hardness, excellent strength at elevated temperatures and good oxidation resistance.

• Assignee: Dow Chemical Co., Midland, MI (United States)
• Patent Number(s): US 5227346; A
• Application Number: PPN: US 7-847522
• OSTI ID: 6352234
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360201* -- Ceramics
Cermets
&amp; Refractories-- Preparation &amp; Fabrication
360202 -- Ceramics
Cermets
&amp; Refractories-- Structure &amp; Phase Studies
360203 -- Ceramics
Cermets
&amp; Refractories-- Mechanical Properties
ALKALI METAL COMPOUNDS
ALKALINE EARTH METAL COMPOUNDS
ALUMINIUM COMPOUNDS
ALUMINIUM OXIDES
AMORPHOUS STATE
CALCIUM COMPOUNDS
CERAMICS
CHALCOGENIDES
CHEMICAL COMPOSITION
CORROSION RESISTANCE
CRYSTAL STRUCTURE
DISPERSIONS
FABRICATION
HARDNESS
LITHIUM COMPOUNDS
MAGNESIUM COMPOUNDS
MECHANICAL PROPERTIES
MIXTURES
MORPHOLOGY
NITRIDES
NITROGEN COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PNICTIDES
RARE EARTH COMPOUNDS
SILICON COMPOUNDS
SILICON NITRIDES
SODIUM COMPOUNDS
STRONTIUM COMPOUNDS