• Journal of Welding and Joining
• /
• v.13 no.3
• /
• pp.106-115
• /
• 1995

To know the bonding phenomena of Ti/Cu brazed joint, a characteristic of microstructures in bonding interlayer of vacuum brazed pure Ti to Cu has been studied in the temperature range from 1088 to 1133K for various bonding times using Ag-28wt%Cu filler metal. Also intermediate phases formed in bonded interlayer and behavior of layer growth have been investigated. The obtained results in this study are as follows: 1) Liquid insert metal width at the each brazing temperature was proportional to the square root of brazing time, and it was considered that the liquid insert metal width was controlled by the diffusion rate process of primary .alpha.-Cu formed at the Ti side. 2) Intermediate phases formed near the Ti interface were .betha.-Ti and intermetallic compounds TiCu, Ti$_{2}$Cu, Ti$_{3}$Cu, and TiCu. 3) .betha.-Ti formed in Ti base metal durig brazing transformed to lamellar structure, .alpha.-Ti + Ti$_{2}$Cu. The structure came from the eutectoil decomposition reaction in cooling. And the width of .betha.-Ti layer was proportional to the square root of brazing time, and it was considered that the growth of .betha.-Ti layer was controlled by interdiffusion rate process in .betha.-Ti. 4) The layer growth of TiCu, Ti$_{3}$Cu$_{4}$ and TiCu, phases formed near the Ti interface was linerface was linearly proportional to the brazing time, and it was considered that the layer growth of these phases was controlled by the chemical reaction rate at the interface.

• Proceedings of the KWS Conference
• /
• 2006.10a
• /
• pp.231-233
• /
• 2006

• Journal of the Korean Society for Heat Treatment
• /
• v.22 no.2
• /
• pp.95-100
• /
• 2009

In this study, the casting process using forged insert was investigated to characterize the manufacturing process by which good mechanical properties can be obtained when compared with existing casting products. Process analysis for the casting design was performed by using FVM (Finite Volume Method) software. In pouring process, three kinds of candidate gating systems are considered and analyzed respectively. The molten metal behavior in gating system is so important that it affects the solidification behavior of the cast. The results show that as the number of gates is increased, hardness of cast was increased and gaps of cast with forged insert were decreased.

• Journal of the Korean Society for Precision Engineering
• /
• v.27 no.4
• /
• pp.72-78
• /
• 2010

Textile machinery affects various industry, such as sport leisure industry, metal and chemistry material, electric electron, mechanical energy, packing and printing industry. In case of design of textile machine, the very important fact is absorbing the minute vibration induced by spinning thread and insert which is the part of spindle plays a role of reduction of impact caused by oscillation of thread bobbin. Therefore, Optimal design was executed by design of experiments and kriging optimal design methods to prevent fracture of spindle insert under the fatigue condition and deduced the best value of design parameter to improve the stability of the products. The highest sensitivity is showed at the design parameter A and D. As the spiral number of insert is increase, tension force applied its edge is distributed at whole model and the stress concentration is reduced.

• Journal of Welding and Joining
• /
• v.13 no.3
• /
• pp.125-133
• /
• 1995

Rene80 superalloy was liquid phase diffusion bonded by using pure boron (B) as an insert material. As a basic study for the possibility of practical application of this bonding method, hardness and high temperature tensile strength of the bonded joint and metallurgical analysis were investigated. As experimental results, hardness of the bonded joint was homogenized after bonding and the tensile strength at 1144K was obtained to 90% of that of base metal. But there were some problems to be improved also, that means the joint was hardened after bonding due to increase of B content and elongation was much lower than that of base metal. Flat area and (Mo, Cr, W) boride, which should be harmful for bonding strength, were observed on the fractured surface of the tensile tested specimen.

• Proceedings of the KWS Conference
• /
• 1997.05a
• /
• pp.198-200
• /
• 1997

• Proceedings of the KWS Conference
• /
• 1997.05a
• /
• pp.204-210
• /
• 1997

• Proceedings of the KWS Conference
• /
• 1999.10a
• /
• pp.103-106
• /
• 1999

• Proceedings of the KWS Conference
• /
• 1999.10a
• /
• pp.263-266
• /
• 1999

• Proceedings of the KWS Conference
• /
• 2000.10a
• /
• pp.235-237
• /
• 2000