Abstract: The present invention discloses magnesia and a method for manufacturing same, wherein the magnesia can be produced into granules of various shapes and sizes and can be improved in moisture resistance with the formation of a moisture resistant surface oxide layer by donor addition and then thermal treatment. The magnesia according to the present invention comprises a MgO granule; and a surface oxide layer formed on a surface of the MgO granule and a composition of the surface oxide layer is different from a composition of an inside of the MgO granule.

Abstract: Disclosed is a (K,Na)NbO3 (abbreviated by “KNN”)-based single crystal ceramic. The KNN-based single crystal ceramic according to the present disclosure is formulated by (K0.5?x/2Na0.5?x/2?y?y/2Mx+y/2)Nb1?x/3+yO3, wherein M indicates a metal having a different valence from Na, and ? indicates a metal vacancy. The above formulated KNN-based single crystal ceramic allows compensating for the volatilization of Na in a growing grain due to the addition of M2+ ions, and substituting M2+ ions for Na+ ions to form metal vacancies, thereby making possible the single crystal growth.

Abstract: Disclosed is a (K,Na)NbO3 (abbreviated by “KNN”)-based single crystal ceramic. The KNN-based single crystal ceramic according to the present disclosure is formulated by (K0.5?x/2Na0.5?x/2?y?y/2Mx+y/2)Nb1?x/3+yO3, wherein M indicates a metal having a different valence from Na, and ? indicates a metal vacancy. The above formulated KNN-based single crystal ceramic allows compensating for the volatilization of Na in a growing grain due to the addition of M2+ ions, and substituting M2+ ions for Na+ ions to form metal vacancies, thereby making possible the single crystal growth.

Abstract: The present invention relates to granules of a brittle material for room-temperature granule spray in vacuum, and to a method for forming a coating film using same. Particularly, particles having a size of 0.1 to 6 ?m are granulated and a coating film may be formed through room-temperature granule spray in vacuum using the granules. The granules of the brittle material according to exemplary embodiments may be used through the vacuum granule injection at room temperature and a coating process may be continuously performed. Since the granules injected through a nozzle have a relatively large mass and thus have a large amount of kinetic energy, the coating film may be formed at a low gas-flow rate, and the forming rate of the coating film may be increased. Therefore, the granules may be useful for forming a ceramic coating film.

Abstract: A method of preparing a nano-structured hydroxyapatite [Ca10(PO4)6(OH)2, HA] coating layer with improved biocompatibility is provided. The preparation method includes: (S1) putting hydroxyapatite [Ca10(PO4)6(OH)2, HA] powder in a powder chamber, placing a metal substrate in a deposition chamber, and keeping the chamber in vacuum state by using a vacuum pump; (S2) injecting carrier gas into the powder chamber and mixing with hydroxyapatite powder; (S3) spraying the mixture of the powder and the carrier gas onto the surface of metal substrate in the deposition chamber through a nozzle and depositing hydroxyapatite coating layer on the metal substrate; (S4) hydrothermal-treating the deposited hydroxyapatite coating layer; and (S5) rinsing the hydrothermal-treated hydroxyapatite coating layer and drying the layer. Additionally, a thermal-treated, nano-structured hydroxyapatite [Ca10(PO4)6(OH)2, HA] coating layer with improved biocompatibility fabricated by the above preparation method is provided.

Abstract: Disclosed is a method for manufacturing multilayer ceramics, and in particular, a method for manufacturing multilayer ceramics with improved interlayer bonding by laminating ceramic tapes manufactured from slurry under vacuum and sintering them. The method comprises the steps of: admixing an organic substance comprising a dispersion agent, a plasticizer, and a binder with ceramic powder to give slurry; defoaming the ceramic slurry under vacuum, followed by casting the defoamed ceramic slurry into ceramic tapes; laminating the ceramic tapes at room temperature to 100° C. under vacuum less than 1 atm; burning out the organic substances from the ceramic tapes laminated under vacuum; and sintering the laminated ceramic tapes free of organic substances.