WO-2026094659-A1 - POWDER COMPACT, SINTERED BODY, AND METHOD FOR PRODUCING SINTERED BODY

Abstract

This powder compact is obtained by molding a powder composition, wherein the powder composition contains zirconia powder and glass powder.

Inventors

• Hokii, Yusuke
• ABE, YOSHIFUMI
• ONODERA, Mizuho
• AKIYAMA, Shigenori

Assignees

• 株式会社ジーシーR&D

Dates

Publication Date

20260507

Application Date

20251017

Priority Date

20241031

Claims (6)

1. A powder molded article formed from a powder composition, The aforementioned powder composition includes zirconia powder and glass powder. Powdered molded body.
2. Glass powder contains silicon dioxide. The powder molded body according to claim 1.
3. The aforementioned glass powder is an aluminum-free glass powder. The powder molded body according to claim 1.
4. It is for dental use. The powder molded body according to claim 1.
5. Obtained by sintering the powder molded body according to any one of claims 1 to 4, Sintered body.
6. The process comprises sintering a powder molded body according to any one of claims 1 to 4 while increasing the temperature from 1000°C to 1500°C. A method for manufacturing a sintered body.

Description

Powder molded body, sintered body, and method for manufacturing a sintered body This disclosure relates to powder molded articles, sintered articles, and methods for manufacturing sintered articles. A technique for sintering molded bodies formed by press-molding zirconia powder is known (see, for example, Patent Document 1). This figure shows a SEM image of a cross-section of a sintered body obtained from an example of a powder molded body according to this embodiment.This figure shows an SEM image of a cross-section of a sintered body obtained from another example of the powder molded body of this embodiment.This figure shows an SEM image of a cross-section of a sintered body obtained from a comparative example of a powder-molded body.This figure shows an SEM image of a cross-section of a sintered body obtained from another comparative example of a powder molded body. Next, embodiments for carrying out the present invention will be described. <Powder molded product> The powder molded article of this embodiment is a powder molded article obtained by molding a powder composition. The powder composition includes zirconia powder and glass powder. Zirconia powder is granular or powdered zirconia ( ZrO₂ ). Zirconia ( ZrO₂ ) is monoclinic at room temperature, but its crystal structure undergoes a phase transition to tetragonal and then cubic as the temperature increases. This phase transition is accompanied by a volume change, and the sintered body will eventually fracture due to repeated heating and cooling. Therefore, it is preferable to use partially stabilized zirconia, in which a stabilizer such as a rare earth oxide is dissolved in the zirconia to form oxygen vacancies in the crystal structure, thereby suppressing fracture due to heating and cooling. Examples of such stabilizers include yttria ( Y₂O₃ ), scandia ( Sc₂O₃ ), calcia ( CaO ), magnesia (MgO), ceria ( CeO₂ ), praseodia ( Pr₂O₃ ), neodia ( Nd₂O₃ ), tria ( ThO₂ ), urania ( UO₂ ), titania ( TiO₂ ), manganese oxide ( MnO₂ ), strontia ( SrO ), barrier (BaO), nickel oxide ( NiO ), cobalt oxide ( Co₂O₄ ), chromium oxide ( Cr₂O₃ , CrO₃ ), alumina ( Al₂O₃ ), and hafnia ( HfO₂ ) . Among these, yttria ( Y₂O₃ ) is preferred as a stabilizer. The content of the stabilizer is not particularly limited, but preferably it is 1 mol% to 8 mol% in the zirconia powder, more preferably 1.5 mol% to 6 mol%, and even more preferably 2 mol% to 5 mol%. By including 1 mol% to 8 mol% of the stabilizer in the zirconia powder, the resulting zirconia sintered body contains tetragonal zirconia particles and exhibits excellent toughness due to stress-induced phase transition. The particle size of the zirconia powder is not particularly limited, but is preferably 0.01 μm to 1.0 μm, more preferably 0.1 μm to 0.9 μm, and even more preferably 0.2 μm to 0.7 μm. Here, particle size refers to the average particle size defined by the median diameter (d50). When the particle size of the zirconia powder is 0.01 μm to 1.0 μm, the zirconia powder disperses easily in the mixture when mixed with a binder, etc., resulting in a uniform mixture. Glass powder is glass in the form of granules or powder. The types of glass are not particularly limited, and examples include silicate glass (also called silicate glass or silicate-based glass), strontium glass, lanthanum glass, barium glass, zinc borate glass, aluminum fluoride-zirconium fluoride glass, and zirconium fluoride-based glass (ZBLAN: ZrF₄ -BaF₂- LaF₃ - AlF₃ -NaF). Specific examples of silicate glass include lithium silicate glass, lithium disilicate glass, lithium metasilicate glass, strontium boroaluminosilicate glass, strontium fluoroaluminosilicate glass, barium boroaluminosilicate glass, barium fluoroaluminosilicate glass, lanthanum boroaluminosilicate glass, lanthanum fluoroaluminosilicate glass, zinc silicate glass, zinc borosilicate glass, zinc fluorosilicate glass, potassium feldspar glass, and soda feldspar glass. Note that lithium disilicate glass ceramics are formed by crystallizing lithium silicate glass. These glasses may be used individually or in combination of two or more types. Among these, lithium disilicate glass, barium glass, and zinc fluorosilicate glass are preferred. The particle size of the glass powder is not particularly limited, but is preferably 0.01 μm to 1.0 μm, more preferably 0.1 μm to 0.9 μm, and even more preferably 0.2 μm to 0.7 μm. When the particle size of the glass powder is 0.01 μm to 1.0 μm, the glass powder disperses easily within the powder composition constituting the powder molded body, resulting in a homogeneous powder molded body. The glass powder content is not particularly limited, but preferably it is 0.01% to 5% by mass in the powder composition constituting the powder molded body, more preferably 0.05% to 3% by mass, even more preferably 0.08% to 1% by mass, and even more preferably 0.08% to 0.5% by mass. Including 0.01% to 5% by mass of glass powder in the powder composition constituting the