• Journal of Welding and Joining
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• 제22권1호
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• pp.77-82
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• 2004

The effect of bonding condition on tensile properties of joints diffusion bonded spheroidal graphite cast iron, FCD60 to Cr-Mo steel, SCM 440 was investigated. Diffusion bonding was performed with various temperatures, holding times, pressures and atmospheres. All tensile specimens were fractured at the bonding interface. The tensile strength and elongation was increased with increasing bonding temperature. Especially, tensile strength of joints bonded at 1123K was higher than that of a raw material, FCD60, and tensile strength of joints bonded at 1173K was equal to that of a raw material, SCM440, but elongation of all joints was lower than those of raw materials. There was little the effect of holding time on the tensile properties. In comparison with bonding atmosphere, the difference of tensile strength was not observed, but elongation of joint bonded at vacuum(6.7mPa and 67mPa) was higher than that of Ar gas. Higher the degee of vacuum, elongation increased. Tensile properties of diffusion bonds depended on microstructures of cast iron at the interface and void ratio. Microstructures of cast iron at interface changed with temperature, because decarburizing and interdiffusion at the interface occurs and transformation of austenite-1 ferrite + graphite occurs on the cooling process. The void ratio decreased with increasing temperature, especially, effected on the elongation.

• 한국기계가공학회지
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• 제8권2호
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• pp.76-82
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• 2009

In this papers, Study on the Bonding property and Strength Evaluation in Bonding interface Joints of Dissimilar material using DOE. We found optimal condition that uses experimental design method (Response Surface Analysis, DOE) used temperature, pressure, time on experiment factor. And we could get bonding condition and strength that break and crack do not happen in mechanical processing about united dissimilar material. And progress 3 point bending tests and verified result.

• 한국재료학회지
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• 제2권4호
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• pp.241-247
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• 1992

본 연구에서는 $Cu-Cu_2$O의 공정반응에 의한 구리와 알루미나의 직접접합에 대하여 연구 하였다. $1.5{\times}10^{-1}$torr, $1015^{\circ}C$에서 산화시킨 후 $10_{-3}$torr, 107$5^{\circ}C$에서 접합시킨 시편의 접합력과 계면특성을 인장시험, SEM, EDS 및 XRD를 통하여 분석하였다. 3분 산화시켜 접합하면 우수한 접합강도를 보이며 산화시간이 이보다 짧거나 길면 결합력은 저하하였다. 과단은 알루미나 공정조직 계면에서 발생하였으며 파단후 $Al_2O_3$표면에는 Cu쪽에서 빠져나간 $Cu_2$O nodule의 존재하였는 바 접합력은 $Cu_2$O-A$l_2O_3$계면보다는 $Cu-Cu_2$O계면에 좌우됨을 보여주고 있다. 접합력은 접합시간에 따라 완만한 증가를 보였으며 CuA$l_2O_4$및 $CuAlO_2$의 반응생성물이 접합중 형성되었다.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2016년도 추계 학술논문 발표대회
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• pp.81-82
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• 2016

The present study aims to derive optimal interface treatment conditions for emulating a monolithic construction. The joints in this construction are formed through the bonding shear evaluation method during the placement of ultra-high-performance concrete (UHPC) and normal strength concrete (NSC). The evaluation items include push-off tests for homogeneous UHPC + UHPC and heterogeneous NSC + UHPC. The experimental samples comprised a monolithic placement as the baseline, two levels for the separated placement according to the compression strength of concrete, and five levels for the interface treatment. The increase in the number of grooves and their cross-sectional areas only slightly influenced the bonding shear performance. The optimal interface treatment method for the homogeneous UHPC + UHPC construction grooves was at least 30mm. The heterogeneous NSC + UHPC construction should utilize waterjet roughening to expose the aggregate for the increased roughness.

• Journal of Welding and Joining
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• 제23권5호
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• pp.55-60
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• 2005

A precise bonding technique, transmission laser bonding using energy transfer, for polymer micro devices is presented. The irradiated IR laser beam passes through the transparent part and absorbed on the opaque part. The absorbed energy is converted into heat and bonding takes place. In order to optimize the bonding quality, the temperature profile on the interface must be obtained. Using optical measurements of the both plates, the absorbed energy can be calculated. At the wavelength of 1100nm $87.5\%$ of incident laser energy was used for bonding process from the calculation. A heat transfer model was applied for obtaining the transient temperature profile. It was found that with the power of 29.5 mW, the interface begins to melt and bond each other in 3 sec and it is in a good agreement with experiment results. The transmission IR laser bonding has a potential in the local precise bonding in MEMS or Lab-on-a-chip applications.

• Journal of Welding and Joining
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• 제15권6호
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• pp.32-40
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• 1997

Solid state diffusion bonding is the joining process performed by creep and diffusion, which is accelerated by heating below melting temperature and proper pressing, in vacuum or shielding gas atmosphere. By this process we can obtain sufficient joint which can't be expected from the fusion welding. For Ti-6Al-4V alloy, the optimum solid state diffusion bonding condition and mechanical properties of the joint were found, and micro void morphology at bond interface was observed by SEM. The results of tensile test showed sufficient joint, whose mechanical properties are similar to that of base metal. 850$^{\circ}$C, 3MPa is considered as the optimum bonding condition. Void morphology at interface is long and flat at the initial stage. As the percentage of bonded area increases, however, small and round voids are found. Variation of void shape can be explained as follows. As for the void shrinkage mechanism, at the initial stage, power law creep is the dominant, but diffusion mechanism is dominant when the percentage of bonded area is increased.

• 열처리공학회지
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• 제16권1호
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• pp.2-9
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• 2003

The aluminum alloy which is light and has excellent thermal conductivity and iron base alloy that is remarkable heat-resistece and wear resistence properties were bonded together. The bond was created between a stationary and a rotating member by using the frictional heat generated between them while subjected to high normal forces on the interface of Al alloy and iron base alloy. The microstructure of the bonded interface of friction welding and the strength in the bonded interface formed under various bonding conditions were examined through TEM, SEM with EDX and triple bending test. In interface of bonding materials formed after various heat treatment, bonding strength was substantially different, resulting from formation of intermetallic compound or softening during annealing.

• 대한금속재료학회지
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• 제49권5호
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• pp.380-387
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• 2011

Wire brushing, which is a typical surface preparation method for roll bonding, has recently been highlighted as a potentially effective method for surface nanocrystallization. In the present study, the microstructure evolution and hardness of the wire-brushed surface and roll-bonded interface of a 1050 aluminum sheet were investigated. Wire brushing formed protruded layers with a nanocrystalline structure and extremely high surface hardness. After roll bonding, the protruded layers remained as hard layers at the interface. Due to their hardness and brittleness the interface hard layers, can affect the interface bonding properties and also play an important role determining the mechanical properties of multi-layered clad sheets.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 1996년도 특별강연 및 춘계학술발표 개요집
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• pp.6-9
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• 1996

The Joining of copper rod and zirconia tube was carried out in Ar gas atmosphere. There are two type of the joining. The one is the reaction bond consisting of Cu and zirconia was dominated by surface reaction wi th a undetctable very thin layer. It was found that copper elements were diffused to zirconia side, but that most of Z $r^{4+}$ ions were not diffused to copper side. This result means application of a DC voltage to migrate oxygen to the copper/zirconia interface can oxidize metal at the copper /zirconia interface, and the bonding reaction between zirconia and copper oxide may occur. The other is the reaction bonding was dominated by interdiffusion with a very thick interface layer. This result means application of a DC voltage can reduce zirconia at the interface. The bonding reaction is to be an alloying between Zr and Cr.

• 한국정밀공학회지
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• 제16권1호통권94호
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• pp.227-237
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• 1999

As the interface bonding phenomenon between the matrix and the reinforcements has a large effect on the mechanical properties of MMCs, a sugestion of the strength analysis technique considering the residual stress and the interface bonding phenomenon is very important for the design of pans and the estimation of fatigue behavior. In this paper the three dimensional finite element anaysis is performed during the elasto-plastic deformation of the particulate reinforced metal matrix composites. It was analyzed with the volume fractions in view of microscale. Bonding strength. interface separation and matrix void growth between the matrix and the reinforcements will be predicted on deformation under tensile loading. An interface seperation is estimated by the fracture criterion which is a critical value of generalized plastic work per unit volume. The shape of the reinforcement is assumed to be a perfect sphere. And the type of the reinforcement distribution is assumed as FCC array. The thermal residual stress in MMCs is induced by the heat treatment. It is included at the simulation as an initial residual stress. The element birth and death method of the ANSYS program is used for the estimation of the interface bonding strength, void generation and propagation. It is assumed that the fracture in the matrix region begin to occur under the external loading when the plastic work per unit volume is equal to the critical value. The fracture strain will be defined. The experimental data of the extruded $SiC_p$>/606l Al composites are compared with the theoretical results.