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Byungil Yoon,Jae Yoon Kim,Jae-Sung Lee,Hyoung Seok Jung 대한견주관절의학회 2018 대한견주관절의학회지 Vol.21 No.4
Background: The purpose of this study was to compare the radiologic results of patients who underwent surgery with a hook plate and a locking plate in distal clavicle fractures. Methods: Sixty patients underwent surgical treatment for Neer type IIa, IIb, III, and V distal clavicle fracture. Twenty-eight patients underwent fracture fixation with a hook plate and 32 with a locking plate. Coracoclavicular distance was measured on standard anteroposterior radiographs before and after the surgery, and union was confirmed by radiograph or computed tomography taken at 6 months postoperatively. Other radiologic complications like osteolysis was also checked. Results: Bony union was confirmed in 59 patients out of 60 patients, and 1 patient in the hook plate group showed delayed union. Coracoclavicular distance was decreased more in the hook plate group after surgery (p<0.01). After 6 weeks of the hook plate removal, the coracoclavicular distance was increased a little compared to before metal removal, but there was no difference compared to the contralateral shoulder. Eleven out of 28 patients (39.3%) showed osteolysis on the acromial undersurface in the hook plate group. Conclusions: Both the hook plate group and the locking plate group showed satisfactory radiologic results in distal clavicle fractures. Both hook plate and locking plate could be a good treatment option if it is used in proper indication in distal clavicle fracture with acromioclavicular subluxation or dislocation.
고속비행체 구조재물로 탄소섬유와 탄화규소섬유를 강화재로 한 SiC세라믹 복합재의 특성 연구
윤병일(Byungil Yoon),김재성(JaeSung Kim),김명주(Myeongju Kim),김정일(Jungil KIm),박홍식(Hongsik Park) 한국추진공학회 2018 한국추진공학회 학술대회논문집 Vol.2018 No.5
본 연구의 목적은 마하 5이상으로 비행하는 극초음속비행체의 열방호구조재에서 섬유 종류에 따른 특성을 비교하기 위함이다. 극초음속 비행 시에 공력가열과 충격파로 인하여 구조물의 온도가 크게 상승한다. 이 같은 환경에 적응할 수 있는 소재는 세라믹복합재(CMC)가 오늘날 가장 적절한 소재의 하나이다. 본 연구에서는 CMC의 섬유강화재로서 탄소섬유, 탄화규소섬유를 사용하였으며, 직물 일부는 탄소섬유와 탄화규소섬유를 혼합하여 제직하였다. 탄화규소섬유는 ㈜데크카본이 생산한 Goldsic-200을 사용하였다. CMC는 CVI+PIP 혼합 공정으로. Cf/SiC, Cf/SiCf/SiC, SiCf/SiC 3종류의 시편을 제작하였다. 기계적물성, 열적물성과 Oxy-Acetylene Torch에 의한 삭마 특성을 비교 분석하였다. The object of this study is to evaluate various characteristics of thermal protection ceramic composites reinforced by carbon fiber and sic fiber for hypersonic vehicle applications flying over mach 5. The temperature in vehicle structure increase significantly due to aerodynamic heating and shock wave. Today, CMC is one of the most promising candidate materials able to meet such extremely environmental conditions. In this study, Toray carbon fiber and silicon fiber(SiC) produced in DACC Carbon and co-weaved plain fabric types were used as fiber reinforcement in making CMC. 3 different kind of CMC plates were prepared by using hybrid processing, CVI and PIP. Mechanical property, thermal property and erosion rate by oxy-acetylene torch for the CMC specimens were evaluated respectively and compared.
싸이클로헥센 증기 공정에 의한 산소량이 적은 실리콘카바이드 섬유의 개발
윤병일,최우철,김명주,김재성,김정일,강홍구,Yoon, Byungil,Choi, Woo Chul,Kim, Myeong Ju,Kim, Jae Sung,Kim, Jung il,Kang, Hong Gu 한국군사과학기술학회 2017 한국군사과학기술학회지 Vol.20 No.5
A chemical vapor curing method(CVC) was developed to cure polycarbosilane(PCS) fibers by using cyclohexene vapour as a non-oxygen active reactant, instead of air in oder to prepare the silicon carbide(SiC) fiber with low oxygen content. A cross-linked PCS fibers by cyclohexene vapor showed a completely different variation in IR spectra in comparison to the air-cured PCS fiber. CVC method resulted in less than 3 wt% in oxygen content. In this experiment conditions, The average tensile strength and modulus of SiC fiber obtained by CVC had 1995 MPa and 183 GPa respectively, which is higher than that of SiC fiber prepared by air-curing process.
Microwave Absorbance of Polymer Composites Containing SiC Fibers Coated with Ni-Fe Thin Films
Liu, Tian,Kim, Sung-Soo,Choi, Woo-cheal,Yoon, Byungil The Korean Powder Metallurgy Institute 2018 한국분말재료학회지 (KPMI) Vol.25 No.5
Conductive and dielectric SiC are fabricated using electroless plating of Ni-Fe films on SiC chopped fibers to obtain lightweight and high-strength microwave absorbers. The electroless plating of Ni-Fe films is achieved using a two-step process of surface sensitizing and metal plating. The complex permeability and permittivity are measured for the composite specimens with the metalized SiC chopped fibers dispersed in a silicone rubber matrix. The original non-coated SiC fibers exhibit considerable dielectric losses. The complex permeability spectrum does not change significantly with the Ni-Fe coating. Moreover, dielectric constant is sensitively increased with Ni-Fe coating, owing to the increase of the space charge polarization. The improvements in absorption capability (lower reflection loss and small matching thickness) are evident with Ni-Fe coating on SiC fibers. For the composite SiC fibers coated with Ni-Fe thin films, a -35 dB reflection loss is predicted at 7.6 GHz with a matching thickness of 4 mm.
가스터빈 엔진 적용을 위하여 RMI공정으로 제조한 SiC<SUB>f</SUB>/SiC 세라믹 복합재의 특성연구
김명주(Myeongju Kim),김재성(Jaesung Kim),김정일(Jungil KIm),윤병일(Byungil Yoon) 한국추진공학회 2018 한국추진공학회 학술대회논문집 Vol.2018 No.5
최근 SiC섬유로 강화된 세라믹 매트릭스 복합재(CMC)는 낮은 밀도, 높은 강도와 인성으로 인하여 각종 엔진에 적용되고 있다. 특히, CMC 제조공정 중에서 RMI(reactive melt infiltration)한 SiCf/SiC 복합재는 높은 열전도도, 고온 내충격성, 내크립성 및 내산화성의 특징을 갖는다. 본 연구에서는 결정성 SiC섬유로 제조한 2-D프리폼을 I-CVD로 PyC코팅을 하고 용액함침 방법으로 BN코팅을 하였다. 그리고 SiC-C 슬러리를 함침한 후 용융 Si과 반응시켜 SiCf/SiC 복합재를 제조하였다. 1,200도 공기 분위기에서 노출시간에 따른 파단강도와 파단면을 관찰하였고, 고온 열적물성을 측정하여 최종 RMI공정에 대한 적합성을 평가하였다. Recently, Silicon carbide fiber reinforced ceramic matrix composites(CMC) have been applied to variois engines due to low density, high strength, toughness. Especially, Reactive Melt Infiltrated(RMI) SiCf/SiC composites of the CMC manufacturing process are characterized by high thermal conductivity, high-temperature shock resistance, creep resistance and oxidation resistance. In the study, 2-D preform made of crystalline SiC fibers were coated with PyC and BN by using I-CVD and solution impregnation method respectively. Then, SiC-C slurry was impregnated into the preform and reacted with molten Si to prepare the SiCf/SiC composites. The fracture strength and fracture surface were observed at 1,200℃ in air atmosphere, and the thermal properties of the specimens were measured to evaluate their suitability for the final RMI process.
비정질 SiC 섬유를 강화재로 한 SiC<SUB>f</SUB>/SiC 세라믹 복합재의 엔진 적용 가능성 연구
김재성(Jae Sung Kim),김명주(Myeongju Kim),김정일(Jungil Kim),윤병일(Byungil Yoon) 한국추진공학회 2018 한국추진공학회 학술대회논문집 Vol.2018 No.5
본 연구의 목적은 비정질의 SiC 섬유로 제조한 SiCf/SiC 세라믹 복합재에 대한 가스터빈엔진 적용성에 관한 연구이다. 본 실험에서는 Tyranno ZMI 섬유를 강화재로 한 RMI 공정으로 시편을 제조하였다. 평직의 SiC 섬유 직물을 적층한 후, z축 방향으로 스티칭하여 프리폼을 제작하였다. 프리폼은 I-CVD로 PyC와 SiC코팅을 하였다. RMI공정 시 ZMI 섬유의 손상을 방지하기 위해 PCS 세라믹 프리커서로 함침, 탄화 하였다. 밀도화는 SiC분말과 Carbon Black분말로 슬러리를 제조하여 진공함침 후 RMI 공정을 하였다. 상온과 고온에서 기계적 및 열적 물성을 측정으로 ZMI 섬유의 엔진 적용성을 살펴보았다. The purpose of this study is to investigate the applicability of SiCf/SiC ceramic composites reinforced with amorphous SiC fiber for gas turbine engine. In this study SiCf/SiC ceramic composites were fabricated by RMI process using Tyranno ZMI fiber as reinforcement. The preform was coated with PyC and SiC by I-CVD. Additionally PIP process using PCS precursor was used to prevent fiber damage exposed at high temperature during the process. The preform was impregnated with SiC powder and carbonblack slurry and siliconized finally to get SiCf/SiC plate. The applicability of SiCf/SiC to engine components was discussed with Mechanical and thermal property measurement.