http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
국산 지르콘사로부터 부분 안정화 지르코니아의 제조 및 그 응용에 관한 연구 I. 국산 지르콘사로부터 고순도 지르코니아 분말의 제조
김환,선우식,신건철,황규홍,Kim. H.,Sunwoo, S.,Shin, K.C.,Hwang, K.H. 한국세라믹학회 1987 한국세라믹학회지 Vol.24 No.2
ZrO2 powders having high purity were prepared from domestic zircon sand using the caustic fusion method and the soda ash sintering process. In the caustic fusion method, ZrO2 recovery was reached to 96% when 100/140 mesh zircon was reacted with NaOH at the NaOH/Zircon mole ratio 6 and at 650$^{\circ}C$ for 2 hours. And in the soda ash sintering process, ZrO2 was recovered to 88.5% when -325 mesh zircon was reacted with Na2CO3 at the Na2CO3/Zircon mole ratio 1.1 and 1050$^{\circ}C$ for 2 hours. In both cases, Zr component was extracted to ZrOCl2, subsequently crystallized to ZrOCl2$.$8H2O to increase the purity, and converted to ZrO2 by precipitation. And to increase the sinter ability of powder, Cl- ion was removed and strong agglomeration was avoided by methanol distribution of Zr(OH)4 precipitates.
국산 지르콘사를 이용한 부분 안정화 지르코니아의 제조 및 그 응용에 관한 연구 : II. 부분 안정화 지르코니아 소결체의 제조 및 그 특성
김환,선우식,강종봉,심규송,신건철,황규홍,Kim, H.,Sunwoo, S.,Kang, J.B.,Shim, K.S.,Shin, K.C.,Hwang, K.H. 한국세라믹학회 1988 한국세라믹학회지 Vol.25 No.2
The microstructural changes in partially stabilized MgO-ZrO2 alloys during heat treatment and mechanical properties of ZrO2(Y2O3)/Al2O3 systems have been studied. 9mol% MgO-ZrO2 powders were sintered at 1800$^{\circ}C$ for 4 hours and these specimens were aged at 1420$^{\circ}C$ and 1100$^{\circ}C$ secondly. These specimens have high thermal shock resistance and high toughness. The bend strength of Y-PSZ/Al2O3 composites conventially sintered were increased by HIP from 650MPa to 980MPa.
인공 고관절 골두용 세라믹 복합재료에 대한 세라믹-세라믹 접촉 마멸 특성 분석
김환(H. Kim),이권용(K.Y. Lee),김대준(D. J. Kim),이명현(M.H. Lee),서원선(W.S. Seo) 한국트라이볼로지학회 2004 한국트라이볼로지학회 학술대회 Vol.39 No.-
Ceramic femoral heads in the total hip replacement have been developed to reduce the polyethylene liner wear. Alumina and zirconia (3Y-TZP) having the excellent tribological properties are coupled against acetabular cups of polyethylene and are used in clinical application worldwide. However, alumina has a risk of catastrophic failure, and zirconia has the low temperature degradation in spite of enhanced fracture toughness. Recently, novel zirconia/alumina composite is very attractive due to the low temperature degradation (LTD)-free character and high fracture toughness. In the present study, we focus on the wear of ceramic on ceramic, which are able to be used as femoral heads and acetabular cups. Therefore, LTD-free zirconia/alumina composites with three compositions are made in a form of disk and cylinder, and the wear of the composites is performed on pin-on-disk type wear tester. The wear is conducted with or without lubricant. All the composites fabricated with the different composition show the good wear resistance.
치아 충전용 복합레진의 광중합 광원 종류에 따른 마멸 비교
김환(H. Kim),이권용(K.Y. Lee),박성호(S.H. Park),정일영(I.Y. Jung),전승범(S.B. Jeon) 한국트라이볼로지학회 2004 한국트라이볼로지학회 학술대회 Vol.39 No.-
In this study, the wear characteristics of five different dental composite resins cured by conventional halogen light and LED light sources were investigated. Five different dental composite resins of Surefil, Z100, Dyract AP, Fuji II LC and Compoglass were worn against a zirconia ceramic ball using a pin-on-disk type wear tester with 15 N contact force in a reciprocal sliding motion of sliding distance of 10 ㎜/cycle at 1㎐ under the room temperature dry condition. The wear variations of dental composite resins were linearly increased as the number of cycles increased. It was observed that the wear resistances of these specimens were in the order of Dyract AP > Surefil > Compoglass > Z100 > Fuji II LC. On the morphological observations by SEM, the large crack formation on the sliding track of Fuji ?LC specimen was the greatest among all resin composites. Dyract AP showed less wear with few surface damage. There is no significant difference in wear performance between conventional halogen light curing and light emitting diodes curing sources. It indicates that a light emitting diodes (LED) source can replace a halogen light source as curing unit for composite resin restorations.
내저온열화 특성을 갖는 지르코니아/알루미나 복합세라믹의 마멸평가
김환(Kim H),이권용(Lee KY),김대준(Kim DJ),이명현(Lee MH),서원선(Seo WS) 한국트라이볼로지학회 2003 한국트라이볼로지학회 학술대회 Vol.37 No.-
Ceramic femoral heads in the total hip replacement have been developed to reduce the polyethylene liner wear. Alumina and zirconia (3Y - TZP) are using in clinical application worldwide and there are many good test reports. However, alumina has a risk of catastrophic failure, and zirconia has the low temperature degradation in spite of enhanced fracture toughness. Recently, novel zirconia/alumina composite having low temperature degradation-free character and high fracture tough was developed and it leads the lower wear of polyethylene than alumina and zirconia. In the present study, in order to optimise the microstructure of low temperature degradation (LTD)-free zirconia/alumina composite for the best wear resistance of polyethylene, various compositions of (LTD)-free zirconia/alumina composites were fabricated, and the sliding wear of UHMWPE against these novel composites were examined and compared with that against alumina and zirconia ceramics used for total hip joint heads.