Boron carbide ceramic and manufacturing method thereof
View Patent ↗Boron carbide ceramics produced by spark sintering methods have more desirable mechanical properties than conventionally produced carbides. The boron carbide ceramics include amorphous boron, amorphous carbon, and Al 2 O 3 powder as a sintering aid. The boron carbides may also contain a carbon nano fiber in a nearly homogeneously dispersed state. The sintered compact has a relative density of a boron carbide ceramic of approximately not less than 99%. The boron carbide ceramics are prepared preferably by subjecting a mixed powder of the starting raw materials and the carbon nano fiber to simultaneous synthesis and sintering using the spark plasma sintering method.
1. A material comprising a boron carbide ceramic and nearly homogenously dispersed carbon nanofibers throughout the boron carbide ceramic.
2. The material of claim 1 , wherein the boron carbide ceramic contains 3% to 15% by volume of the carbon nano fibers.
3. The material of claim 1 , wherein the boron carbide ceramic has a relative density of not less than 99%.
4. The material of claim 1 , wherein, the material is prepared from a raw material mixture comprising an amorphous boron powder, an amorphous carbon powder, an aluminum oxide powder, and carbon nano fibers.
5. The material of claim 4 , wherein the boron carbide ceramic is prepared via spark plasma sintering.
6. A method for manufacturing a boron carbide ceramic comprising carbon nanofibers, the method comprising:
mixing an amorphous boron powder, an amorphous carbon powder, and an aluminum oxide powder to form a powder mixture;
dispersing carbon nanofibers in water or alcohol to form a dispersion;
mixing the powder mixture and the dispersion mixture to form a third mixture;
drying the third mixture to obtain a raw material powder mixture;
pressing the raw material powder mixture; and
heating the raw material powder mixture to raise a temperature thereof by spark plasma sintering to form the boron carbide ceramic comprising carbon nanofibers.
7. The method of claim 6 , wherein the boron carbide ceramic comprising carbon nanofibers contains from 3% to 15% by volume of the carbon nanofibers.
8. The method of claim 6 , wherein the spark plasma sintering comprises heating the raw material powder mixture in a near vacuum of not more than 10 Pa while pressing the raw material powder mixture at a pressure of 10 MPa to 100 MPa at a temperature of 1,500° C. to 1,900° C. for 1 min. to 60 min.
9. The method of claim 6 , wherein the boron carbide ceramic comprising carbon nanofibers has a relative density of not less than 99%.