Plastic and nonmetallic article shaping or treating: processes – Forming continuous or indefinite length work – Layered – stratified traversely of length – or multiphase...
Patent
1997-06-09
1999-11-30
Derrington, James
Plastic and nonmetallic article shaping or treating: processes
Forming continuous or indefinite length work
Layered, stratified traversely of length, or multiphase...
264640, 264641, 264650, 264166, 264212, 264216, B28B 114, C04B 3581
Patent
active
059937157
ABSTRACT:
A method of unidirectionally aligning the whiskers during tape casting and a sintered silicon nitride laminate of controlled properties and microstructure through alignment of the reinforcing grains fabricated by using the method are disclosed. The whiskers are unidirectionally oriented by placing a row of guides 0.2-0.5 mm apart from each other at exit of the reservoir of the slip containing the whiskers during tape casting. The silicon nitride comprising 10-30 volume % of elongated large grains growing from the .beta.-Si.sub.3 N.sub.4 whiskers and oriented unidirectionally in the fine grained matrix is fully densified by gas pressure sintering at 1900.degree. C. It exhibits a fracture toughness value as high as 9.24 Mpa m normal to the whisker alignment according to the Evans-Charles' method disclosed in the Journal of the American Ceramic Society, 59 [7-8], 371-372 (1976).
REFERENCES:
patent: 4886767 (1989-12-01), Goto
patent: 5603877 (1997-02-01), Kato
Becher, "Microstructural Design of Toughened Ceramics," 74 J. Am. Ceram. Soc. 225-69 (1991).
Hirao et al., "Microstructure Control of Silicon Nitride by Seeding with .beta.-Silicon Nitride Particles," 77 J. Am Ceram. Soc. 1857-62 (1994).
Hirao et al., "Processing Strategy for Producing Highly Anisotropic Silicon Nitride," 78 J. Am. Ceram. Soc. 1687-90 (1995).
Muscat et al., "Microstructure of an Extruded .beta.-Silicon Nitride Whisker-Silicon Nitride Composite," 75 J. Am Ceram. Soc. 2713-18 (1992).
Goto et al., "Mechanical Properties of Unidirectionally Oriented SiC-Whisker-Reinforced Si.sub.3 N.sub.4 Fabricated by Extrusion and Hot-Pressing," 76 J. Am Ceram. Soc. 1420-24 (1993).
Geiger et al., "Flow Between Parallel Plates," Transport Phenomena in Metallurgy pp. 41-43 (1973).
Wittmer et al., "Development of .beta.-Si.sub.3 N.sub.4 For Self-Reinforced Composites," 13 Ceram. Eng. & Sci. Proc. 907-917 (1992).
Ohama, "Research and Development of Advanced Composite Materials for Gas Turbine Applications," 43 Powder and Powder Metallurgy, 407-414 (1996).
Mistler, "The principles of tape casting and tape casting applications," Ceram. Processing 147-163 (1995).
Evans et al., "Fracture Toughness Determinations by Indentation," 59 J. Am. Ceram. Soc. 371-372 (1976).
Wu et al., "Fabrication of Oriented SiC-Whisker-Reinforced Mullite Matrix Composites by Tape Casting," 77 J. Am Ceram. Soc. 2586-92 (1994).
Derrington James
Korea Institute of Machinery & Materials
LandOfFree
Method of unidirectionally aligning whiskers during tape casting does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method of unidirectionally aligning whiskers during tape casting, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method of unidirectionally aligning whiskers during tape casting will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1667524