• Proceedings of the KWS Conference
• /
• 2000.10a
• /
• pp.305-307
• /
• 2000

• Proceedings of the KWS Conference
• /
• 1994.10a
• /
• pp.163-165
• /
• 1994

• Proceedings of the KWS Conference
• /
• 1994.10a
• /
• pp.166-168
• /
• 1994

• Proceedings of the KWS Conference
• /
• 1996.10a
• /
• pp.56-57
• /
• 1996

• Proceedings of the Materials Research Society of Korea Conference
• /
• 1993.05a
• /
• pp.107-107
• /
• 1993

• Journal of Welding and Joining
• /
• v.9 no.3
• /
• pp.26-33
• /
• 1991

As it takes very long time for the Transient Liquid Phase(TLP) bonding, we tried to reduce the bonding time by changing insert material for the high diffusivity element. On this study boron powder was doped as a insert material on the bonding surface of Rene 80 superalloy, and diffusion treated at 1150.deg.C under vacuum. On this method differently from the TLP bonding the insert material was not melted during bonding but only the base metal reacted with the boron was inducedly melted. Therefore, as this bonding mechanism is different from the existing ones, it is suggested as a Melting Induced Diffusion Bonding. When this process was used for the diffusion bonding, the bonding time including homogenization decreased greatly compared to the conventional TLP bonding.

• Korean Journal of Materials Research
• /
• v.29 no.4
• /
• pp.258-263
• /
• 2019

Since the directly bonded interface between TiAl alloy and SCM440 includes lots of cracks and generated intermetallic compounds(IMCs) such as TiC, FeTi, and $Fe_2Ti$, the interfacial strength can be significantly reduced. Therefore, in this study, Cu is selected as an insert metal to improve the lower tensile strength of the joint between TiAl alloy and SCM440 during friction welding. As a result, newly formed IMCs, such as $Cu_2TiAl$, CuTiAl, and $TiCu_2$, are found at the interface between TiAl alloy and Cu layer and the thickness of IMCs layers is found to vary with friction time. In addition, to determine the relationship between the thickness of the IMCs and the strength of the welded interfaces, a tensile test was performed using sub-size specimens obtained from the center to the peripheral region of the friction-welded interface. The results are discussed in terms of changes in the IMCs and the underlying deformation mechanism. Finally, it is found that the friction welding process needs to be idealized because IMCs generated between TiAl alloy and Cu act to not only increase the bonding strength but also form an easy path of fracture propagation.

• Transactions of Materials Processing
• /
• v.19 no.8
• /
• pp.460-467
• /
• 2010

It was studied that two plates of aluminum can be welded by extru-riveting experiments with extru-rivet welding dies, and that the welding strength and metal flow on the welding section were analyzed by computer simulation according to the welding variable such as the diameter of extrusion insert dies. It was known by computer simulation that welding strength on the welding section of plates could be influenced by the diameter of extrusion insert dies. And it was known by experiments that two plates of aluminum can be welded on a spot point on aluminum plate by extru-rivet welding process, and that welding strength is higher and higher if the diameter of extrusion insert die is smaller and smaller, and that welding strength is the highest when diameter of extrusion insert dies is ${\emptyset}4.2$mm in the case that the diameter of rivet is 5 mm, when aluminum 5052 two plates with 1.5 mm thickness and one plate with 3mm thickness for rivet plate are used as welding material.

• Journal of Welding and Joining
• /
• v.21 no.1
• /
• pp.87-92
• /
• 2003

JLF-1 steel (Fe-9Cr-2W-V-Ta), reduced activation ferritic steel, is one of the promising candidate materials for fusion reactor applications. Tensile properties of JLF-1 base metal and its TIG weldments has been investigated at the room temperature, $400^{\circ}C$ and $600^{\circ}C$. The tensile strength of base metal (JLF-1) showed the level between those of weld metal and the Heat Affected Zone (HAZ). When the test temperature was increased from room temperature to high temperature ($400^{\circ}C$ and $600^{\circ}C$), both strength and ductility decreased or base metal, weld metal and the HAZ. The longitudinal specimens of base metal represented similar strength and ductility at room temperature and high temperature, compared to those of transverse specimens. Little anisotropy for the rolling direction was observed in the base metal of JLF-1 steel.

• Proceedings of the Optical Society of Korea Conference
• /
• 1990.02a
• /
• pp.257-259
• /
• 1990

In the design of waveguide E-plane bandpass filter, it is very important to characterize the K-inverters. In the analytical method. losses arising from the metal and the dielectric are ignored for the simplicity of design process. In this paper, based on the new measurement method, characteristics of inverters are measured and compared with those calculated based on mode-matching analysis.