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.

Provided is a surface treatment agent capable of imparting superior antifouling property as well as good and durable hydrophilicity to an inorganic substrate. The surface treatment agent is one comprising a pretreatment agent and a hydrophilizing treatment agent and being to be sequentially applied to an inorganic substrate, wherein the pretreatment agent comprises a silane compound having a reactive silyl group and an organic functional group and a polyfunctional monomer, and the polyfunctional monomer has one or more first reactive groups that react with the organic functional group and one or more second reactive groups that react with the hydrophilizing treatment agent.

An optical element includes an optical surface including a ceramic material. The optical element further includes a coating that includes a bifunctional molecule arranged on the optical surface. The bifunctional molecule includes a first functional group and a second functional group. The first functional group forms a covalent bond to the ceramic material of the optical surface, and the second functional group includes an aromatic functional group. The optical element further includes a carbon-containing material non-covalently bonded to the second functional group of the bifunctional molecule of the coating.

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.

Methods for improving the wear performance of silicon nitride and/or other ceramic materials, particularly to make them more suitable for use in manufacturing biomedical implants.

Methods for improving the wear performance of silicon nitride and/or other ceramic materials, particularly to make them more suitable for use in manufacturing biomedical implants.

The present invention provides a concrete protective agent and a preparation method thereof, and a concrete protective film and a preparation method thereof. The concrete protective agent provided in the present invention includes the following components: water, oxalic acid, a defoaming agent, and a film-forming agent. When the concrete protective agent provided in the present invention is used for concrete protection, oxalic acid in the protective agent can react with calcium ions in concrete for in situ generation of calcium oxalate monohydrate inside and on a surface of concrete to obtain a protective film with strong adhesion to concrete. The film-forming agent in the protective agent is used as a template to adjust and control growth of calcium oxalate crystals, so as to improve waterproof performance and corrosion resistance to sulfate and chloride ions of the protective film. Preparation methods provided in the present invention are simple and practical and are suitable for mass production.

The present invention provides a concrete protective agent and a preparation method thereof, and a concrete protective film and a preparation method thereof. The concrete protective agent provided in the present invention includes the following components: water, oxalic acid, a defoaming agent, and a film-forming agent. When the concrete protective agent provided in the present invention is used for concrete protection, oxalic acid in the protective agent can react with calcium ions in concrete for in situ generation of calcium oxalate monohydrate inside and on a surface of concrete to obtain a protective film with strong adhesion to concrete. The film-forming agent in the protective agent is used as a template to adjust and control growth of calcium oxalate crystals, so as to improve waterproof performance and corrosion resistance to sulfate and chloride ions of the protective film. Preparation methods provided in the present invention are simple and practical and are suitable for mass production.

The disclosure describes techniques for forming a surface layer of an article including a CMC using a cast. In some examples, the surface layer includes three-dimensional surface features, which may increase adhesion between the CMC and a coating on the CMC. In some examples, the surface layer may include excess material, with or without three-dimensional surface features, which is on the CMC. The excess material may be machined to remove some of the excess material and facilitate conforming the article to dimensional tolerances, e.g., for fitting the article to another component. The excess material may reduce a likelihood that the CMC (e.g., reinforcement material in the CMC) is damaged by the machining.

The disclosure describes techniques for forming a surface layer of an article including a CMC using a cast. In some examples, the surface layer includes three-dimensional surface features, which may increase adhesion between the CMC and a coating on the CMC. In some examples, the surface layer may include excess material, with or without three-dimensional surface features, which is on the CMC. The excess material may be machined to remove some of the excess material and facilitate conforming the article to dimensional tolerances, e.g., for fitting the article to another component. The excess material may reduce a likelihood that the CMC (e.g., reinforcement material in the CMC) is damaged by the machining.