• Journal of the Korean Society of Manufacturing Process Engineers
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• v.8 no.2
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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.

• Journal of Welding and Joining
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• v.22 no.1
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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.

• Journal of the Korean Ceramic Society
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• v.30 no.5
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• pp.357-364
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• 1993

Chemical reaction occurred in the interface of Mn-Zn ferrite and glass after bonding. Effects of the formation of reaction layer on the magnetic properties were investigated. The composition of glass was 23PbO-61SiO2-6ZnO-8Na2O-2K2O and the ferrite was chosen to have a high permeability. Toroid samples of ferrites bonded with glasses, were heat-treated at $700^{\circ}C$, 80$0^{\circ}C$ and 90$0^{\circ}C$ for 1h. The reaction was observed to increase with bonding temperature, resulting in the development of reaction layer. Subsequently the initial permeability was found to be decreased. The permeabilities decreased by 25% with increasing bonding temperature from $700^{\circ}C$ to 80$0^{\circ}C$. At the bonding temperature of 90$0^{\circ}C$, the permeability was decreased by 45%, compared to that of 80$0^{\circ}C$.

• Journal of Adhesion and Interface
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• v.13 no.1
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• pp.1-8
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• 2012

The effect of the grafting ratio on the mechanical property and adhesion property of the grafted EPDM modified with methacrylic acid (MA) was investigated. The storage modulus of MA-grafted EPDM was maintained higher than that of cross-linked EPDM vulcanizate by sulfur, but it was observed that the storage modulus was decreased at elevated temperature because of the weakened secondary bonding. When the functional group for hydrogen bonding was introduced in EPDM, it had excellent mechanical properties by the aggregate between grafted EPDM molecules and crystallinity of MA. The bonding strength between EPDM and other rubbers was very low because EPDM has nonpolar property and low molecular interaction to others. The bonding strength was increased as increasing grafting ratio and it was excellent enough to break the rubber during the peel test when the grafting ratio was more than 10%.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2004.10a
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• pp.215-222
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• 2004

We synthesized a aziridine bonding agent that play an important role in increasing the adhesion property between polymer binders and solid particles. It increases the physical properties of polymer-based propellant. Chemical reaction between two materials increase the interface adhesion. We analyzed and studied the chemical characteristics of the material and physical properties of a liner applied the aziridine bonding agent. We also studied the adhesion property of a liner/propellant applied the aziridine bonding agent. 3M was use as control group. In accordance with US MIS (Missile Interim Specification) we examined the chemical properties. As a result of our study, newly synthesized aziridine bonding agent was as good as quality of 3M HX-868.

• Korean Journal of Metals and Materials
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• v.47 no.9
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• pp.573-579
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• 2009

Titanium/aluminum/stainless steel(Ti/Al/STS) clad materials have received much attention due to their high specific strength and corrosion-resisting properties. However, it is difficult to fabricate these materials, because titanium oxide is easily formed on the titanium surface during heat treatment. The aim of the present study is to derive optimized cladding conditions and thereupon obtain the stable quality of Ti/Al/STS clad materials. Ti sheets were prepared with and without pre-heat treatment and Ti/Al/STS clad materials were then fabricated by cold rolling and a post-heat treatment process. Microstructure of the Ti/Al and STS/Al interfaces was observed using a Scanning Electron Microscope(SEM) and an Energy Dispersed X-ray Analyser(EDX) in order to investigate the effects of Ti pre-heat treatment on the bond properties of Ti/Al/STS clad materials. Diffusion bonding was observed at both the Ti/Al and STS/Al interfaces. The bonding force of the clad material with non-heat treated Ti was higher than that with pre-heat treated Ti before the cladding process. The bonding force decreased rapidly beyond $400^{\circ}C$, because the formed Ti oxide inhibited the joining process between Ti and Al. Bonding forces of STS/Al were lower than those of Ti/Al, because brittle $Fe_3Al$, $Al_3Fe$ intermetallic compounds were formed at the interface of STS/Al during the cladding process. In addition, delamination of the clad material with pre-heat treated Ti was observed at the Ti/Al interface after a cupping test.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.663-667
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• 2005

Surface modified carbon nanotubes were applied into the epoxy composites to investigate its tribological property. Carbon nanotubes reinforced epoxy composites were fabricated by casting. Effects to the tribological property of loading concentrations and types of surface modification of carbon nanotubes were investigated under sliding condition using linear reciprocal sliding wear tester. The results show that the small amount of carbon nanotubes into the epoxy exhibited lower weight loss than the pure epoxy. It is concluded that the effect of an enormous aspect ratio of carbon nanotubes surface area which wider than conventional fillers that react as interface for stress transfer. As increased the contents of carbon nanotubes, the weight loss from the wear test was reduced. And the surface modified carbon nanotubes show better tribological property than as produced carbon nanotubes. It is due that a surface modification of carbon nanotubes increases the interfacial bonding between carbon nanotubes and epoxy matrix through chemical bonding. Changes in worn surface morphology are also observed by optical microscope and SEM for investigating wear behaviors. Carbon nanotubes in the epoxy matrix near the surface are exposed, because it becomes the lubricating working film on the worn surface. It reduces the friction and results in the lower surface roughness morphology in the epoxy matrix as increasing the contents of the carbon nanotubes.

• Transactions of Materials Processing
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• v.27 no.5
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• pp.267-275
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• 2018

The clad sheet material is produced by a roll-bonding process of one or more materials with different properties. Good formability of clad sheet material is an essential property in to deform a clad metal sheet into a part or component. Performance of the clad sheet material largely depends on interfacial bond strength between different materials. In this study, interfacial bond strength of STS/Al clad sheet was analyzed by varying experimental parameters using a blanking process. Experimental parameters are the punching speed, clearance, and stacking order of plate materials. In addition, blanking test results were compared with bond strengths measured by the T-peel test, that analyzes interface bonding strength of the standard clad sheet. The blanking process was analyzed by the finite element method under the sticking condition of interface of different materials, and experimental results and analysis results were compared.

• Journal of Welding and Joining
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• v.18 no.3
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• pp.106-113
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• 2000

Single crystallization behavior ad high temperature tensile properties of TLP bonded joints of Ni-base single crystal superalloy, CMSX-2 were investigated using MBF-80 and F-24 insert metals. CMSX-2 was bonded at 1523~1548K for 1.5~1.8ks in vacuum. The (100) orientation of bonded specimen was aligned perpendicular to the joint interface. Crystallographic orientation analyzed points over the bonded region possessed the almost same orientation across the joint interface and misorientation $\Delta^{\theta}$ was negligibly small in as-bonded and post-bond heat-treated situations. It was confirmed that single crystallization could be readily achieved during TLP bonding. The tensile strengths of all joints at elevated temperatures were equal to or greater than those of base metal the range of testing temperature between 923K and 1173K. The elongation and reduction of area in values were almost the same as those of base metal. SEM observation of the fracture surfaces of joints after tensile test revealed that the fracture surface indicated the similar morphologies each other, and that the fracture of joints occurred in the base metal in any cases.

• Journal of the Microelectronics and Packaging Society
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• v.28 no.2
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• pp.65-70
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• 2021

In this study, interfacial properties and mechanical properties of joints were reported after Cu pads finished with organic solderability preservative (OSP) on flame retardant-4 (FR-4) printed circuit board (PCB) and electronic components were joined with a Sn-57Bi-1Ag solder paste by using a laser bonding process. The laser bonding process was performed under various bonding conditions with changing a laser power and a bonding time and effects of bonding conditions on interfacial and mechanical properties of joints were analyzed. In order to apply for industry, properties of bonding joints using a reflow bonding process which are widely used were compared. When the laser bonding process were performed, we observed that Cu₆Sn₅ intermetallic compounds (IMCs) were fully formed at the interface although the bonding times were very short about 2 and 3 s. Furthermore, void formations of the joints by using the laser bonding process were suppressed at the joints with comparing to the reflow bonding process and shear strengths of bonding joints were higher than that by using the reflow bonding process. Therefore, in spite of a very short bonding time, it is expected that joints will be stably formed and have a high mechanical strength by using the laser bonding process.