페이스트 오펙 제조에 관한 연구 : Ⅱ. 페이스트 오펙 포세린의 금속과의 결합강도 비교 Ⅱ. Comparison on the Bond Strength of Paste Opaque Porcelain to Metal

고제만,고대진,김사학,김광만 大韓齒科器材學會 2002 대한치과재료학회지 Vol.29 No.2

Metal-ceramic system has been widely using for aesthetic dental prosthesis. Opaque porcelain is used fore the masking of the metallic color of coping and the enhancing of the bond strength between metal and porcelain for PFM system. Paste opaque is a new type of opaque porcelain to easily apply onto metal coping and to get uniform thickness and good bonding characteristics to metal. The paste opaque was prepared by mixing of powder opaque with organic substances for this study. Three kinds of paste opaque which are in market were selected to compare the particle size distribution and bond strength with the paste opaque prepared in this study. The particle size distributions of all paste opaques were measured by particle size analyser, and the bond strengths were examined by using universal testing machine. This study shows that the maximum size of all samples is under 50㎛ and Ceramco has the finest mean particle size. The bond strength of the prepared paste opaque is about 35 MPa, and it is satisfied with ISO standard(25MPa).

高速度鋼의 機械的 性質에 미치는 mischmetal의 影響

高濟晩,蘇秉粲 조선대학교 생산기술연구소 1993 生産技術硏究 Vol.15 No.1

The effect of mischmetal addition on the mechanical properties of high speed tool steel has been investigated. The results obtained are as fallows. 1. Mischmetal addition is very effective for the crystal nucleatiou during steel sol idification, accordingly it results in smaller grain size. 2. Mischmetal addition resulted in globularization of carbide. 3. Toughness and hardness after tempering are improved by mischmetal addition, owing to its refining effect on the grain structure and the primary carbides. 4. Desulfurization was raised with increasing amount of mischmetal.

Al-Zn-Mg合金의 時效特性에 따른 機械的性質 改善에 관한 硏究

高濟晩,張禹煬 조선대학교 생산기술연구소 1986 生産技術硏究 Vol.8 No.2

Al-Zn-Mg system alloys of the Al alloys have been studied as high strength age hardening alloys. But there is still little improvement in the heat treatment of these alloys, though they were invented 40years ago. Especially problems of SCC(stress corrosion cracking) susceptibility etc. have remained almost unimproved as before. Therefore it is strongly demanded that the alloys having good machinability, high strength and stability in SCC susceptibility. The improvement of SCC susceptibility by addition of Cu and Zr was also studied and summarized as follows : 1. Maximum hardness at 150℃ in the 1st stage aging is lower than that at 120℃. This is because the formation of G. P. Zone generated at 120℃ can be restricted at 150℃, since Tc temp. of homogeneous and heterogeneous precipitate is likely lower than 150℃. 2. Hardness is higher on the l st stage age at 90℃ below Tc temp. and than the 2nd stage age at 150℃ is higher than that on the 1st stage at 150℃, and aging time was also shortened by about 800 min. 3. The alloys, not adding 0.2% Cu and 0.2% Zr were fractured after about 2~4 min. at SCC fracture test, whereas adding alloys lasted about 1200~3500 min.

WO₃粉末로 부터 WC를 製造할 때 粒度 變化에 關한 硏究

高濟晩,秋現植 조선대학교 생산기술연구소 1980 生産技術硏究 Vol.1980 No.-

A continuous two-stage Carburization furnace whose first furnace has a nitrogen atmosphere and whose second one has a hydrngen atmosphere was developed. A mixture of WO₃ and C was pelletized and resuting powders were heated continuously as they moved from the first furnace to the second furnace. The grain size of WC powder could easily be controlled by the heating. temperatures of the first and the second furnaces. The grain size distribution thus obtained was uniform and narrow.

SM25C와 SM35C를 滲炭 및 熱處理 했을때 일어나는 變形量에 關한 硏究

高濟晩 조선대학교 생산기술연구소 1978 生産技術硏究 Vol.1978 No.-

渗炭用鋼으로써 -般的으로 SM25C와 SM35C가 使用된다. 이들 鋼을 NaCN : KCl = 1 : 1의 Salt bath에 750℃,800℃,900℃로 溫度를 올려가면서 渗炭을 시켰다. 이와같이渗炭된 鋼을 Salt Bath Quenching. Water Quenching. Oil Quenching. Tempering에 依한 熱處理를 했다. 이 液體渗炭과 熱處理는 彈度,硬度,Strain에 많은 影響을 주었는데 本實驗을 通하여 얻은 結果는 다음과 같다. 1. 渗炭時間이 길수록 溫度가 높을수록 材質의 Strain은 높다. 즉 溫度가 높고 渗炭時間이 길면 渗炭層의 깊이에 많은 影響을 준다. 2. Strain은 熱處理에서 보다 渗炭에서 훨씬더 많이 일어났다. 3. 900℃에서 30분간 渗炭한후 Salt Bath에 넣어 200℃에서 Tempering 했을때가 가장 효과적 이었는데 그 결과는 Tensile Strength 57㎏/㎟과 Hardness H_(B) 249 Strain 77μ이였다. SM25Cand SM35Care generally used as steel for carburizing, These steels were carburized in NaCN and KCl at tbe same ratio at gradual temperatures (750℃, 800℃, 900℃). Carburized tseels are heat-treated by salt bath quenching, by water quenching, by oil quenching, and by tempering. The liquid carburizing and heat treatments proved to effective to the hardness, tensile strength and strain. Through this experiment the following results are obtained. 1. With the long carburing time and high temperature, tbe strain of matenial was high. That is, the high temperature and long carbunizing proved to be effective to the depth of the carburizing layer. 2. The strain was much more in carburizing than in heat treatment. 3. After carburiz ing at 900℃ for 30 minutes and dipping into the salt bath, tempering was taken at 200℃. The result was as follow: Tensile strength 57㎏/㎟, Hardness H_(B)249 Strain 77μ.

Furan 自硬性鑄型에 있어서 再生砂를 使用할 때 생기는 問題点가 그 對策

高濟晩 조선대학교 생산기술연구소 1983 生産技術硏究 Vol.1983 No.-

When furan return sand was used several times, cast defects was caused by increased residual resin. For decreased residual resin, S/M ratio and L.O.I value must be low. In this experiment to use return sand, S/M ratio and L.O.I value, and compressive strength by reclaiming were tested and investigated. Through this experiment, the following results are obtained: 1. L.O.I value was fallen by low S/M ratio. 2. Because quantity of fine sand was low by reclaiming, L.O.I value was decreased and compressive strength was increased. 3. Return sand was difficult to low L.O.I value, but it is expected two times strength than new sand. Therefore quantity of new binder can be low.

양극산화법으로 제조된 이산화티타늄의 특성

고제만,한종선,장재명 조선대학교 생산기술연구소 2005 生産技術硏究 Vol.27 No.spec

TiO_(2) films were synthesized by anodizing process in which electrochemical method. The surface behaviors and photocatalystic properties of anodic oxide layers on titanium were investigated. TiO_(2) layers formed in H_(2)SO_(4) solution were consisted of anatase and rutile mixed type structure. Irregular shape of pores at the initial stage of anodization seemed to be attributed to spark discharge phenomena which heavily occurred during increasing voltages. TiO_(2) layers formed in H_(2)SO_(4) and H_(3)PO_(4) mixed solution were consisted of anatase type structure and surface morphology exhibited a porous cell structure. The surface and microstructure of anodic film formed in H_(2)SO_(4) solution differed from that of TiO_(2) films formed in H_(2)SO_(4) + H_(3)PO_(4) solution.

페이스트 오펙 제조에 관한 연구 Ⅱ. 페이스트 오펙 포세린의 금속과의 결합강도 비교

고제만,고대진,김사학,김광만 대한치과재료학회 2002 대한치과재료학회지 Vol.29 No.2

냉간 금형강 SKD11의 특성에 미치는 Mischmetal의 영향

高濟晩,蘇秉粲 조선대학교 동력자원연구소 1993 動力資源硏究所誌 Vol.15 No.2

The effect of mischmetal addition on the characteristics of JIS SKD11 type cold-working die steel has been investigated by means of the microstructural observation and analysis of laboratory scale samples. The results obtained were as follows : 1. Mischmetal addition is very effective for the crystal nucleation during solidification, accordingly it results in smaller grain size. 2. Toughness, hardness and wear resistance after quenching-tempering are improved by mischmetal addition, owing to its refining effect on the grain structure and primary carbides. 3. Dimensional changes in rolling direction and in width and thickness shrink more sharply with increasing quenching temperature. This effect resulted from increasing residual austenite, which was caused by increasing carbide solution to matrix. 4. Mischmetal addition resulted in globularization of carbide. The reason for such an unusual behavier is believed due to the fact that mischmetal inhibits the coarsening of precipitates.

철근 콘크리트 수로교 보수 및 보강을 위한 에폭시 도복장 강관 받침부재를 이용한 수로교 시공공법

고제만,박수정,이현규,박은수,최성주,김창수 한국특허학회 2009 특허학연구 : 한국특허학회지 Vol.11 No.4

본 연구는 철근 콘크리트 수로교 보수 및 보강을 위해 에폭시 도복장 강관 받침부재를 이용한 수로교 시 공공법이다. 일반적인 수로교 시공공법은 5가지 공정으로 시행된다. 본 논문에서는 5가지 공정 중 강관을 고정하는 공정을 새롭게 연구하였다. 이 기술은 강관이 내측에 안착되도록 반원형상의 받침대를 형성하고, 받침대의 양측에 수직방향으로 일정길이를 갖도록 연장부를 구비한다. 연장부의 일측에 형성된 나선공과 나선 결합되는 나선축을 장착하고, 나선축의 선단에는 강관의 외경에 맞닿아 밀착하여 고정하기 위한 밀착구를 형성한다. 이때 연장부와 밀착구의 사이에는 스프링이 구비된 강관 받침부재를 이용해 강관을 안정적이고 견고하게 고정 시킬 수 있다. 따라서 이 연구는 강관을 견고하게 고정하고 안정적으로 지지해 부실시공 및 안전사고의 원인을 사전에 해소할 수 있는 효과를 갖는다. 또한 작업자가 손쉽게 설치 및 분해할 수 있어 작업능률을 향상시키고 시공기간을 획기적으로 단축할 수 있는 장점도 지닌다.