Silicon carbide whisker reinforced ceramic composites and method for making same

Patent · Tue Jan 01 04:00:00 EST 1985

OSTI ID:865608

Wei, George C ^[1]

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1. Oak Ridge, TN

The present invention is directed to the fabrication of ceramic composites which possess improved mechanical properties especially increased fracture toughness. In the formation of these ceramic composites, the single crystal SiC whiskers are mixed with fine ceramic powders of a ceramic material such as Al.sub.2 O.sub.3, mullite, or B.sub.4 C. The mixtures which contain a homogeneous dispersion of the SiC whiskers are hot pressed at pressures in a range of about 28 to 70 MPa and temperatures in the range of about 1600.degree. to 1950.degree. C. with pressing times varying from about 0.75 to 2.5 hours. The resulting ceramic composites show an increase in fracture toughness of up to about 9 MPa.m.sup.1/2 which represents as much as a two-fold increase over that of the matrix material.

• Research Organization: Oak Ridge National Laboratory (ORNL), Oak Ridge, TN
• DOE Contract Number: W-7405-ENG-26
• Assignee: United States of America as represented by Department of Energy (Washington, DC)
• Patent Number(s): US 4543345
• OSTI ID: 865608
• Country of Publication: United States
• Language: English

Related Subjects

/501/264/
1600
1950
28
70
75
carbide
carbide whisker
ceramic
ceramic composite
ceramic composites
ceramic mater
ceramic material
ceramic powder
ceramic powders
composites
contain
crystal
crystal sic
degree
directed
dispersion
especially
especially increased
fabrication
fine
fine ceramic
formation
fracture
fracture toughness
homogeneous
hot
hot press
hot pressed
hours
improved
improved mechanical
increase
increased
increased fracture
material
matrix
matrix material
mechanical
mechanical properties
method
mixed
mixtures
mpa
mullite
possess
possess improved
powders
pressed
pressing
pressing times
pressures
properties
properties especially
range
reinforced
reinforced ceramic
represents
resulting
resulting ceramic
sic
sic whiskers
silicon
silicon carbide
single
single crystal
temperatures
times
times varying
toughness
two-fold
two-fold increase
varying
whisker
whisker reinforced
whiskers