http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
다이아몬드 grit(흑연) / Cu-13Sn-12Ti 삽입금속 진공 브레이징 접합체의 젖음성 및 계면반응
함종오,이지환,Ham, Jong-Oh,Lee, Chi-Hwan 대한용접접합학회 2010 대한용접·접합학회지 Vol.28 No.3
Various alloy system, such as Cu-Sn-Ti, Cu-Ag-Ti, and Ni-B-Cr-based alloy are used for the brazing of diamond grits. However, the problem of the adhesion strength between the diamond grits and the brazed alloy is presented. The adhesion strength between the diamond grits and the melting filler alloy is predicted by the contact angle, thereby, instead of diamond grit, the study on the wettability between the graphite and the brazing alloy has been indirectly executed. In this study, Cu-13Sn-12Ti filler alloy was manufactured, and the contact angles, the shear strengths and the interfacial area between the graphites (diamond grits) and braze matrix were investigated. The contact angle was decreased on increasing holding time and temperature. The results of shear strength of the graphite joints brazed filler alloys were observed that the joints applied Cu-13Sn-12Ti alloy at brazing temperature $940^{\circ}C$ was very sound condition indicating the shear tensile value of 23.8 MPa because of existing the widest carbide(TiC) reaction layers. The micrograph of wettability of the diamond grit brazed filler alloys were observed that the brazement applied Cu-13Sn-12Ti alloy at brazing temperature $990^{\circ}C$ was very sound condition because of existing a few TiC grains in the vicinity of the TiC layers.
용탕단조법에 의한 Alumina 단섬유강화 AC4C 기 복합재료의 인장강도에 미치는 점결제 및 가압력의 영향
여인동,이지환 ( In Dong Yeo,Chi Hwan Lee ) 한국주조공학회 1995 한국주조공학회지 Vol.15 No.2
N/A The mechanical properties of Al/Al₂O₃composites have been investigated in relation with manufacturing factors such as applied pressure of casting and binder amount of preform. It was found that tensile strength increases with an increase of applied pressure, but decreases with binder amount. Increase of tensile strength is attributable to refinement of microstructure, improvement of intefacial bonding between Al₂O₃short fiber and matrix, decrease of porosity in the matrix. Due to the high thermal stability of alumina short fiber, tensile strength of composites at 150℃ was superior to matrix alloy at room temperature. To evaluate the strength of composites, modified Kelly-Tyson`s equation was introduced. Manufacturing factor M was obtained calculating from experimental data. M values were increased with applied pressure, but decreased with binder amount. The initiation of microcrack appeared to be at interface and reinforcement colony. Amount of micro-dimple was increased with applied pressure, and interfacial debonding phenomenon was remarkable with an increase of binder amount.
다이캐스팅법에 의해 제조된 SiC 입자강화 알루미늄합금기 복합재료의 미세조직 및 인장특성
이태원,이지환 ( Tae Won Lee,Chi Hwan Lee ) 한국주조공학회 1997 한국주조공학회지 Vol.17 No.4
N/A The main objective of this study is to investigate the microstructure and tensile strength of SiC_p/Al alloy composites fabricated by die casting method. Die casting was performed using the preheated mold at the pouring temperature range of 620∼750℃ under the pressure of 1,039 kgf/㎠. The low speed and a following high injection speed were 0.4 and 2.1m/s, respectively. The microstructure of SiC_p/Al alloy composites fabricated by die casting method was found to be finer than that of composites fabricated by gravity casting. Also, SiC particulates were homogeneously distributed in refined A1 matrix due to rapid solidification. The tensile strength of SiC_p/Al alloy composites fabricated by die casting method was found to be varied with cast temperature. The maximun tensile strength of SiC_p(10 vol.% and 20 vol.%)/Al alloy composites showed 380 MPa at the cast temperature of 750℃ and 363 MPa at the cast temperature of 700℃, respectively.
용탕단조법으로 제조된 Al2O3 / AC4C 복합재료의 피로균열 전파거동에 관한 연구
여인동,이지환 ( In Dong Yeo,Chi Hwan Lee ) 한국주조공학회 1995 한국주조공학회지 Vol.15 No.4
N/A This study has been conducted with the purpose of examining the fatigue crack growth characteristics of Al₂O₃short fiber reinforced aluminum matrix composites made by squeeze casting process with different applied pressure and binder amount. Fatigue crack growth experiments have been performed under constant load amplitude method with a fixed load ratio. The rate of crack propagation was decreased with binder amount as well as applied pressure. Also fatigue crack growth path in matrix was changed from flat to rough mode with an increase of applied pressure. In the composites, fatigue crack was propagated to interface between matrix and reinforcement at 10㎫, but it was propagated to reinforcement at 20㎫. The major reason of thee result was considered that interfacial bonding force and microstructure of matrix were improved due to an increase of applied pressure. Localized ductile striation in the composites was observed at low growth rate region and such a phenominon was remarkable with an increase of applied pressure. At high growth rate region, the propensity of fracture appearance was changed from interfacial debonding to reinforcement fracture with an increase of applied pressure.
용탕단조법에 의한 δ-Alumina 단섬유강화 AC4C 기 복합재료의 계면반응에 관한 연구
여인동,이지환 ( In Dong Yeo,Chi Hwan Lee ) 한국주조공학회 1994 한국주조공학회지 Vol.14 No.4
N/A This paper has been examined for the interfacial reactions in δ-Al₂O₃short fiber-reinforced AC4C matrix composite materials after squeeze casting and thermal exposure. After squeeze casting, it was found that reaction products exist on the Al₂O₃short fiber surface in both composites with and without silica binder. After thermal exposure at 450℃ for 30min, the thickness of reaction zone was significantly increased; Al₂O₃short fiber morphology was observed to be rough due to interfacial reaction compared with squeeze cast specimen. STEM and XRD observation and analysis showed that reaction product appears to be MgAl₂O₄.