Claims
- 1. A gradient function material seal cap for a discharge lamp bulb, the seal cap produced by molding and thereafter firing a slurry which contains a plurality of groups of particles having different specific gravities:
- said plurality of groups of particles include at least a first group of particles and a second group of particles;
- said first group of particles comprises a group of nonmetal particles having a maximum particle diameter equal to or smaller than a deflocculation limit of about 6.0 .mu.m, said nonmetal particles being made of one or more materials selected from the group consisting of alumina, zirconia, magnesia, silica, silicon carbide, titanium carbide, silicon nitride, and AlON; and
- said second group of particles comprises a group of metal particles of a high melting point which have a specific gravity which is about 1.5 times the specific gravity of said first group of particles, and particle diameters distributed across said deflocculation limit, and said metal particles of a high melting point being made of an alloy containing at least one material selected from the group consisting of nickel, tungsten, molybdenum, tantalum, and chromium.
- 2. A gradient function material seal cap according to claim 1, wherein a sintering assistant is added to said second group of particles for sintering the second group of particles at a low temperature.
- 3. A gradient function material seal cap for a discharge lamp bulb, the seal cap produced by molding and thereafter firing a slurry which contains a plurality of groups of particles having different specific gravities;
- said plurality of groups of particles includes at least a first group of particles and a second group of particles;
- said first group of particles comprises a group of nonmetal particles having a maximum particle diameter .ltoreq. a deflocculation limit of about 6.0 .mu.m, said nonmetal particles being made of at least one material selected from the group consisting of alumina, zirconia, magnesia, silica, silicon carbide, titanium carbide, silicon nitride, and AlON;
- said second group of particles comprises a group of metal particles of a high melting point which have a specific gravity which is about 1.5 times the specific gravity of said first group of particles, and particle diameters distributed across the deflocculation limit, and said metal particles of a high melting point being made of an alloy containing at least one material selected from the group consisting of nickel, tungsten, molybdenum, tantalum, and chromium;
- a sintering assistant being added to said second group of particles for sintering the second group of particles at a low temperature; and
- said sintering assistant is added to said second group of particles in about 5 to 50 parts with respect to 100 parts (by volume) of said second group of particles.
- 4. A gradient function material seal cap according to claim 2, wherein said sintering assistant comprises powder containing at least one material selected from the group consisting of NiCr powder, Ni powder, Cr powder, Co powder, Cu powder, and Ti powder.
- 5. A gradient function material seal cap for a discharge lamp bulb, the seal cap produced by molding and thereafter firing a slurry which contains a plurality of groups of particles having different specific gravities;
- said plurality of groups of particles includes at least a first group of particles and a second group of particles;
- said first group of particles comprises a group of nonmetal particles having a maximum particle diameter .ltoreq. a deflocculation limit of about 6.0 .mu.m, said nonmetal particles being made of at least one material selected from the group consisting of alumina, zirconia, magnesia, silica, silicon carbide, titanium carbide, silicon nitride, and AlON;
- said second group of particles comprises a group of metal particles of a high melting point which have a specific gravity which is about 1.5 times the specific gravity of said first group of particles, and particle diameters distributed across the deflocculation limit, and said metal particles of a high melting point being made of an alloy containing at least one material selected from the group consisting of nickel, tungsten, molybdenum tantalum, and chromium; and
- said groups of particles have a composition continuously varying in a transverse direction of said seal cap as if in transversely superposed corrugated patterns.
- 6. A gradient function material seal cap according to claim 1, wherein said first group of particles have a specific gravity ranging from about 3 to 7.
- 7. A gradient function material seal cap according to claim 1, wherein said slurry is introduced into a porous mold to form a molded body which is then fired to form the seal cap.
- 8. A gradient function material seal cap according to claim 1, wherein said seal cap comprises an electrically conductive layer located away from a discharge space which is defined by the discharge lamp bulb sealed with the seal cap, and an inner electrode located within the discharge space and coupled to the conductive layer without being extruded externally of the seal cap.
- 9. A gradient function material seal cap according to claim 5, wherein said seal cap comprises an electrically conductive layer located away from a discharge space which is defined by the discharge lamp bulb sealed with the seal cap, and an inner electrode located within the discharge space and coupled to the conductive layer without being extruded externally of the seal cap.
- 10. A gradient function material seal cap according to claim 2, wherein said low temperature is in a range of 1270-1400.degree. C.
Priority Claims (3)
Number |
Date |
Country |
Kind |
4-279331 |
Sep 1992 |
JPX |
|
5-55991 |
Mar 1993 |
JPX |
|
5-214409 |
Aug 1993 |
JPX |
|
Parent Case Info
This is a divisional of prior pending U.S. application Ser. No. 08/564,777, filed Nov. 29, 1995, which is a divisional of prior application Ser. No. 08/246,134, filed May 19, 1994 (now U.S. Pat. No. 5,653,924), which is a continuation of PCT application PCT/JP93/01367, filed Sep. 24, 1993.
US Referenced Citations (20)
Divisions (2)
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Number |
Date |
Country |
Parent |
564777 |
Nov 1995 |
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Parent |
246134 |
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Continuations (1)
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Number |
Date |
Country |
Parent |
PCTJP9301367 |
Sep 1993 |
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