Ceramic powder, method of manufacturing the same, and method for laser sinter molding

Patent metadata

Field	Value
Publication number	US-9850172-B2
Application number	US-201514883235-A
Country	US
Kind code	B2
Filing date	Oct 14, 2015
Priority date	Oct 23, 2014
Publication date	Dec 26, 2017
Grant date	Dec 26, 2017

Abstract

Disclosed is a method of manufacturing a ceramic powder, which includes forming a slurry by mixing of first ceramic particles, binder and water, spraying and drying the slurry to form a first ceramic core portion, and thermally treating and shaping the first ceramic core portion. The first ceramic core portion has a first flexural strength and a first coefficient of thermal expansion. The method further includes forming another slurry to form a second ceramic shell portion formed by second ceramic particles and covering the first ceramic core portion. The second ceramic shell portion has a second flexural strength and a second coefficient of thermal expansion. The ceramic powder is formed by thermally treating and shaping the first ceramic core portion and the second ceramic shell portion.

First claim

What is claimed is:

1. A ceramic powder, comprising:
a first ceramic core portion having a first flexural strength of 350 MPa to 700 MPa and a first coefficient of thermal expansion of 7.0×10 −6 /° C. to 11.0×10 −6 /° C.; and
a second ceramic shell portion covering the first ceramic core portion and having a second flexural strength of 50 MPa to 350 MPa and a second coefficient of thermal expansion of −1.0×10 −6 /° C. to 3.0×10 −6 /° C.

2. The ceramic powder of claim 1 , wherein a weight ratio of the first ceramic core portion to the second ceramic shell portion is in the range of 90:10 to 60:40.

3. The ceramic powder of claim 1 , wherein the first ceramic core portion has a size of 10 μm to 20 μm, and the ceramic powder has a size of 14 μm to 28 μm.

4. The ceramic powder of claim 1 , wherein the first ceramic core portion further includes aluminum oxide or zirconium oxide doped with yttrium oxide, and the second ceramic shell portion further includes Li 2 O·Al 2 O 3 ·2SiO 2 , Li 2 O·Al 2 O 3 ·4SiO 2 or 2MgO·2Al 2 O 3 ·5SiO 2 .

5. The ceramic powder of claim 1 , wherein the first ceramic core portion is formed by a plurality of first ceramic particles, and the first ceramic particles have a size of 40 nm to 5 μm.

6. The ceramic powder of claim 1 , wherein the second ceramic shell portion is formed by a plurality of second ceramic particles, and the second ceramic particles have a size of 1 μm to 3 μm.

7. A method for laser sinter molding, comprising:
forming a ceramic powder layer including a ceramic powder of claim 1 ;
applying a laser to a first region of the ceramic powder layer and sintering the ceramic powder; and
removing a second region of the ceramic powder not applied the laser.

8. The method of claim 7 , wherein the ceramic powder layer after a laser sintering has a crack width of 0 μm to 1 μm.

9. The method of claim 7 , wherein the laser is a CO 2 laser with a wavelength of 10640 nm, and has a power of 3 W to 30 W and an energy density of 150 pulses/inch to 1400 pulses/inch.

10. A method of manufacturing a ceramic powder, comprising:
providing a first ceramic core portion having a first flexural strength of 350 MPa to 700 MPa and a first coefficient of thermal expansion of 7.0×10 −6 /° C. to 1.0×10 −6 /° C.;
forming a first slurry by mixing the first ceramic core portion, a plurality of second ceramic particles, a first binder and water;
spraying and drying the first slurry to form a second ceramic shell portion formed by the second ceramic particles and covering the first ceramic core portion, wherein the second ceramic shell portion has a second flexural strength of 50 MPa to 350 MPa and a second coefficient of thermal expansion of −1.0×10 −6 /° C. to 3.0×10 −6 /° C.; and
forming the ceramic powder by thermally treating and shaping the first ceramic core portion and the second ceramic shell portion.

11. The method of claim 10 , wherein the first ceramic core portion has a size of 10 μm to 20 μm, and the second ceramic particles have a size of 1 μm to 3 μm.

12. The method of claim 10 , wherein a weight ratio of the first ceramic core portion to the second ceramic shell portion is in a range of 90:10 to 60:40.

13. The method of claim 10 , wherein in the step of forming the first slurry, the first binder has a weight percentage of 1% to 3% based on a total weight of the first ceramic core portion and the second ceramic particles, and the first ceramic core portion and the second ceramic particles have a total solid content of 30% to 60% based on the first slurry.

14. The method of claim 10 , wherein the step of providing the first ceramic core portion further includes:
forming a second slurry by mixing a plurality of first ceramic particles, a second binder and water, wherein the first ceramic particles have a size of 40 nm to 5 μm;
spraying and drying the second slurry to form the first ceramic core portion formed by the first ceramic particles; and
thermally treating and shaping the first ceramic core portion.

15. The method of claim 14 , wherein in the step of forming the second slurry, the second binder has a weight percentage of 1% to 3% based on the first ceramic particles, and the first ceramic particles have a solid content of 30% to 60% based on the second slurry.

Assignees

• Ind Tech Res Inst

Inventors

• Wu Yu-Han
• Chiu Kuo-Chuang

Classifications

• C04B2235/3418

  Silicon oxide, silicic acids or oxide forming salts thereof, e.g. silica sol, fused silica, silica fume, cristobalite, quartz or flint · CPC title

• C04B2235/3203

  Lithium oxide or oxide-forming salts thereof · CPC title

• C04B2235/3246

  Stabilised zirconias, e.g. YSZ or cerium stabilised zirconia · CPC title

• C04B2235/665

  Local sintering, e.g. laser sintering · CPC title

• C04B2235/96

  Properties of ceramic products, e.g. mechanical properties such as strength, toughness, wear resistance · CPC title