Disclosed are a silicon nitride ceramic sintered body and preparation method thereof. The silicon nitride ceramic sintered body includes a sintered bulk and a hard surface layer having a thickness of 10-1000 m, formed on a surface of the sintered bulk, wherein the sintered bulk comprises a first silicon nitride crystalline phase and a first grain boundary phase; the hard surface layer comprises a second silicon nitride crystalline phase and a second grain boundary phase; the first grain boundary phase comprises a metal tungsten phase being tungsten elementary substance and/or a tungsten alloy; the second grain boundary phase comprises tungsten carbide particles; tungsten element in the metal tungsten phase accounts for 80-100 wt % of total tungsten element in the first grain boundary phase; and tungsten element in the tungsten carbide particles accounts for 60-100 wt % of total tungsten element in the second grain boundary phase.

Disclosed are a silicon nitride ceramic sintered body and preparation method thereof. The silicon nitride ceramic sintered body includes a sintered bulk and a hard surface layer having a thickness of 10-1000 m, formed on a surface of the sintered bulk, wherein the sintered bulk comprises a first silicon nitride crystalline phase and a first grain boundary phase; the hard surface layer comprises a second silicon nitride crystalline phase and a second grain boundary phase; the first grain boundary phase comprises a metal tungsten phase being tungsten elementary substance and/or a tungsten alloy; the second grain boundary phase comprises tungsten carbide particles; tungsten element in the metal tungsten phase accounts for 80-100 wt % of total tungsten element in the first grain boundary phase; and tungsten element in the tungsten carbide particles accounts for 60-100 wt % of total tungsten element in the second grain boundary phase.

Disclosed are a silicon nitride ceramic sintered body and a-preparation method thereof. The silicon nitride ceramic sintered body includes a sintered bulk and a hard surface layer having a thickness of 10-1000 m, formed on a surface of the sintered bulk, wherein the sintered bulk comprises a first silicon nitride crystalline phase and a first grain boundary phase; the hard surface layer comprises a second silicon nitride crystalline phase and a second grain boundary phase; the first grain boundary phase comprises a metal tungsten phase being tungsten elementary substance and/or a tungsten alloy; the second grain boundary phase comprises tungsten carbide particles; tungsten element in the metal tungsten phase accounts for 80-100 wt % of total tungsten element in the first grain boundary phase; and tungsten element in the tungsten carbide particles accounts for 60-100 wt % of total tungsten element in the second grain boundary phase.

Disclosed are a silicon nitride ceramic sintered body and a-preparation method thereof. The silicon nitride ceramic sintered body includes a sintered bulk and a hard surface layer having a thickness of 10-1000 m, formed on a surface of the sintered bulk, wherein the sintered bulk comprises a first silicon nitride crystalline phase and a first grain boundary phase; the hard surface layer comprises a second silicon nitride crystalline phase and a second grain boundary phase; the first grain boundary phase comprises a metal tungsten phase being tungsten elementary substance and/or a tungsten alloy; the second grain boundary phase comprises tungsten carbide particles; tungsten element in the metal tungsten phase accounts for 80-100 wt % of total tungsten element in the first grain boundary phase; and tungsten element in the tungsten carbide particles accounts for 60-100 wt % of total tungsten element in the second grain boundary phase.

A method of manufacturing pre-formed, customized, ceramic, labial/lingual orthodontic clear aligner attachments (CCAA) by additive manufacturing (AM) may comprise measuring dentition data of a profile of teeth of a patient, based on the dentition data, creating a three dimensional computer-assisted design (3D CAD) model of the patient's teeth using reverse engineering, and saving the 3D CAD model, designing a 3D CAD structure model for one or more CCAA on various parts of each tooth, importing data related to the 3D CAD CCAA structure model into an AM machine, directly producing the CCAA in the ceramic slurry-based AM machine by layer manufacturing, enabling the provider to deliver patient-specific CCAA's by an indirect bonding method to the patient's teeth to improve the efficacy and retention of the clear aligners.

A method of manufacturing pre-formed, customized, ceramic, labial/lingual orthodontic clear aligner attachments (CCAA) by additive manufacturing (AM) may comprise measuring dentition data of a profile of teeth of a patient, based on the dentition data, creating a three dimensional computer-assisted design (3D CAD) model of the patient's teeth using reverse engineering, and saving the 3D CAD model, designing a 3D CAD structure model for one or more CCAA on various parts of each tooth, importing data related to the 3D CAD CCAA structure model into an AM machine, directly producing the CCAA in the ceramic slurry-based AM machine by layer manufacturing, enabling the provider to deliver patient-specific CCAA's by an indirect bonding method to the patient's teeth to improve the efficacy and retention of the clear aligners.

A method of manufacturing pre-formed, customized, ceramic, labial/lingual orthodontic clear aligner attachments (CCAA) by additive manufacturing (AM) may comprise measuring dentition data of a profile of teeth of a patient, based on the dentition data, creating a three dimensional computer-assisted design (3D CAD) model of the patient's teeth using reverse engineering, and saving the 3D CAD model, designing a 3D CAD structure model for one or more CCAA on various parts of each tooth, importing data related to the 3D CAD CCAA structure model into an AM machine, directly producing the CCAA in the ceramic slurry-based AM machine by layer manufacturing, enabling the provider to deliver patient-specific CCAA's by an indirect bonding method to the patient's teeth to improve the efficacy and retention of the clear aligners.

A method of manufacturing pre-formed, customized, ceramic, labial/lingual orthodontic clear aligner attachments (CCAA) by additive manufacturing (AM) may comprise measuring dentition data of a profile of teeth of a patient, based on the dentition data, creating a three dimensional computer-assisted design (3D CAD) model of the patient's teeth using reverse engineering, and saving the 3D CAD model, designing a 3D CAD structure model for one or more CCAA on various parts of each tooth, importing data related to the 3D CAD CCAA structure model into an AM machine, directly producing the CCAA in the ceramic slurry-based AM machine by layer manufacturing, enabling the provider to deliver patient-specific CCAA's by an indirect bonding method to the patient's teeth to improve the efficacy and retention of the clear aligners.

Provided is a ceramic-resin composite body that has good mass productivity and product properties (heat dissipation properties, insulation properties and adhesive properties), and particularly a ceramic-resin composite that can dramatically improve the heat dissipation properties for electronic devices. The ceramic-resin composite body includes: 35 to 70% by volume of a sintered body having a monolithic structure in which non-oxide ceramic primary particles having an average major diameter of from 3 to 60 m and an aspect ratio of from 5 to 30 are three-dimensionally continuous; and 65 to 30% by volume of a thermosetting resin composition having an exothermic onset temperature of 180 C. or more and a curing rate of from 5 to 60% as determined with a differential scanning calorimeter, and having a number average molecular weight of from 450 to 4800, wherein the sintered body is impregnated with the thermosetting resin composition.

Disclosed herein is a ceramic particle comprising a core substrate chosen from yttria-stabilized zirconia, partially stabilized zirconia, zirconium oxide, aluminum nitride, silicon nitride, silicon carbide, and cerium oxide, and a conformal coating of a sintering aid film having a thickness of less than three nanometers and covering the core substrate, and methods for producing the ceramic particle.