Korea Institute of Science and Technology

Sang Whan Park

Mi Rae Youm

Gyoung Sun Cho

Sung Il Yun

Kyoung Ran Han

Chang-Sam Kim

Sung Il Youn

Chang Sam Kim

Byung Won Cho

Sung Ho Yun

Jin Kook Yoon

Yung Chul Jo

Jung Man Doh

Sung Woon Jeon

Kyoung Ran Lim

Jin Oh Yang

Kyoung Sop Han

The present disclosure provides a boron carbide composite material having a novel composition with excellent mechanical properties, and a production method therefor. The boron carbide composite material has high fracture toughness and may be applied as a lightweight bulletproof ceramic material. The boron carbide composite material is a boron carbide/silicon carbide/titanium boride/graphite (BC&#x2014;SiC&#x2014;TiB&#x2014;C) composite material. The composite material may overcome a technical limitation on increasing the fracture toughness of the boron carbide composite material, and may be produced as a high-density boron carbide composite material using a reactive hot-pressing sintering process at a relatively low temperature. The boron carbide composite material having excellent mechanical properties may be applied to general industrial wear-resistant parts and nuclear-power-related industrial parts, and particularly, may be actively used as a lightweight bulletproof material for personal use and for military aircraft including helicopters.

Boron carbide composite and production method therefor

The present invention relates to an eco-friendly method for preparing a porous silicon carbide structure, which is capable of preparing a porous silicon carbide structure having meso- or macro-sized pores without using a harmful phenolic resin as a carbon source.

Eco-friendly method for manufacturing of porous silicon carbide structure

The present invention relates to a method for preparing a metal catalyst (Ni, Co, etc.)-supported porous silicon carbide structure having meso- to macro-sized pores, high porosity and superior mechanical properties. Unlike the existing method wherein a porous silicon carbide structure is prepared and then the metal catalyst is infiltrated therein, the preparation of the porous silicon carbide structure and the supporting of the metal catalyst occur at the same time by the mixing metal catalyst material and starting materials. As a result, the metal catalyst is distributed uniformly in the porous silicon carbide structure and it is possible to locate a desired amount of the metal catalyst inside the porous silicon carbide structure.

Method for preparing metal catalyst-supported porous silicon carbide structure

The present invention relates to a method for preparing an ultrahigh-purity silicon carbide powder, more particularly to a method for preparing an ultrahigh-purity silicon carbide granular powder by preparing a gel wherein a silicon compound and a carbon compound are uniformly dispersed via a sol-gel process using a liquid state silicon compound and a solid or liquid state carbon compound of varying purities as raw materials, preparing a silicon dioxide-carbon (SiO&#x2014;C) composite by pyrolyzing the prepared gel, preparing a silicon carbide-silicon dioxide-carbon (SiC&#x2014;SiO&#x2014;C) composite powder via two-step carbothermal reduction of the prepared silicon dioxide-carbon composite, adding a silicon metal and then conducting carbonization and carbothermal reduction at the same time by heat treating, thereby growing the synthesized silicon carbide particle with an increased yield of the silicon carbide.

Method for preparing ultrahigh-purity silicon carbide powder

The present disclosure relates to porous silicon dioxide-carbon composites and a method for preparing high-purity &#x3b2;-phase silicon carbide granular powders using the same. More particularly, it relates to a method for preparing high-purity &#x3b2;-phase silicon carbide granular powders in accordance with a first step of preparing gel wherein carbon compounds are uniformly dispersed in silicon dioxide network structures generated by a sol-gel process using a silicon compound and a carbon compound in a liquid state as raw materials, a second step of preparing porous silicon dioxide-carbon composites, in which the carbon compounds are solidified, dried and then thermally treated to have a high specific area, and a third step of conducting both of a direct reaction between carbon and metallic silicon and a carbothermal reduction between carbon and silicon dioxide through a two-step treatment process of the prepared porous silicon dioxide-carbon composites powders with the added metallic silicon, wherein the average particle size, particle size distribution and purity of the silicon carbide powder can be adjusted by controlling a heating rate, a heat treatment temperature and time during the heat treatment process.

Porous silicon dioxide-carbon composite and method for preparing high-purity granular beta-phase silicon carbide powder with using the same

Disclosed is a carbon felt impregnated with inorganic particles. The impregnated carbon felt can be used together with sulfur in a cathode of a sodium-sulfur (Na&#x2014;S) battery. Also disclosed is a method for producing the impregnated carbon felt. According to exemplary embodiments, the problem of the prior art can be solved in which inorganic particles such as alumina particles are not directly adhered to carbon felts, thus necessitating complicated processes. In addition, a slurry including an inorganic binder and alumina particles can be used to directly coat the alumina particles on the surface of a carbon felt, making the production procedure very simple. Furthermore, the use of the carbon felt surface coated with the alumina particles in a Na&#x2014;S battery increases the wicking of sodium polysulfides, suppresses the accumulation of sulfur as an insulator on the surface of beta-alumina as an electrolyte, and inhibits non-uniform aggregation of sulfur or sodium polysulfides on the carbon felt, so that the concentration polarization of charges can be reduced without a significant increase in the internal resistance of the battery, achieving high utilization efficiency of sulfur as a reactant.

Carbon felt impregnated with inorganic particles and method for producing the same

Disclosed herein is a method for manufacturing SiC powders with a high purity, and more particularly, a method for manufacturing SiC powders with a high purity by reating a solid phase carbon source as raw materials with gas phase silicon sources generated from a starting material composed of metallic silicon and silicon dioxide powders and, in which it is easy to control the size and crystalline phase of the SiC powders by changing the compositions of the gas phase silicon source to the solid phase carbon source mole ratio, and the temperature and time for the heat treatment.

Method for manufacturing SiC powders with high purity

Disclosed is an alumina-coated spinel-silicon carbide refractory composition with good resistance to coal slag penetration and a method for manufacturing the same. The refractory composition refractory composition comprising 3 to 10 parts by weight of fine alpha alumina powder with respect to the weight of the refractory mixture, wherein the mixture is prepared by mixing alumina-coated spinel aggregates and silicon carbide in a ratio of 10:90 to 40:60 wt %, a dispersant, and an alumina sol as a binder.

Alumina-coated spinel-silicon carbide refractory composition with high corrosion resistance to coal slag and method for manufacturing the same

Disclosed is to a method for manufacturing a cobalt boride coating layer on the surface of iron-based metals by using a pack cementation process. In particular, the present invention relates to a method for manufacturing a cobalt boride coating layer by forming a composite coating layer on the surface of steels which is composed of an outmost layer having a composition of cobalt boride (CoB) and an inner layer having a composition of iron-cobalt boride ((Fe,Co)B). Since the cobalt boride coating layer is a compact coating layer having little defects such as pores, it can improve physical properties such as corrosion resistance, wear resistance and oxidation resistance of steels.

Methods for manufacturing of cobalt boride coating layer on surface of steels by using a pack cementation process

Disclosed are methods of producing Ni/YSZ porous anode bodies for solid oxide fuel cells. According to the methods, a small amount of a nickel compound or salt is used as a pore former. Upon heating in air, the nickel compound or salt is decomposed into nickel oxide and releases gases, resulting in volume shrinkage. Therefore, Ni/YSZ porous bodies having a uniform pore size and reduction products thereof can be produced in an economical manner.

Methods of producing anodes for solid oxide fuel cells

Disclosed is a cement-free high strength unshaped refractory in which barium aluminate and a dispersant are further added to a refractory which includes a refractory material containing AlOand SiC and an alumina sol binder to largely improve handling strength of the unshaped refractory. The unshaped refractory according to the present invention is usefully applicable to lining which contacts slag in a blast furnace or a gasifier.

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Seoul, South Korea

Sang Whan Park