• The Korean Journal of Rheology
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• v.10 no.2
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• pp.113-120
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• 1998

사출성형공정은 대표적인 고분자 가공공정으로 그 복잡한 특성으로 인하여 공정변 수를 최적화하는 것을 주로 경험에 의존해 왔다. 본 연구에서는 사출성형공정의 보압과정 중에 보압의 이력을 최적화하여 제품각 부분의 부피수축율차이를 최소가 되게 하는 최적화 시스템을 개발하였다. 최적화 알고리즘으로는 GA방법을 사용하였으며 본 연구에서 제안한 최적화 시스템으로 보압과정의 최적화를 수행한 결과 부피수축율의 차이가 현저히 감소하는 것을 알수 있었다. 특히 SA방법을 사용하는 경우 초기의 최적화 속도가 GA를 사용하는 경 우에 비해서 뛰어남을 알수 있었다. 또한 충전과정과 보압과정을 함께 최적화하여 보압과정 만 최적화한 결과와 비교하여 보았다.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.04a
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• pp.630-634
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• 1997

In this paper,we will discuss in the forming process design of the making engine pulleys for automobiles. These pulleys are required to be made by precision deep drawing process because these are to be combined with bearings and engine timing belts. These pulleys are used of cold rolled steel plates starting with the initial blanking size of 115.2mm and the initial thickness of 1.2mm. Our deep drawing process is designed the continuous 5-steps process, that is, 1'st deep drawing, 2'nd reverse redrawing, 3'rd trimming, 4'th drawing-ironing and 5'yh piercing. This process need no in-process annealing.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1996.11a
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• pp.943-948
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• 1996

In this paper. we will discuss in making large size cylindrical shells with multithickness wall sections such as straight, stepped, tapered sides. These shells are constructed of type 6061 O temper aluminum starting with a blanking size of 877 mm plate. Its diameter to length ratio of 1 to 2.78 and a 36.7％ wall reduction is achieved by our continuous deep drawing process. This process required no in-process annealing. But after cold working, these shells is performed heat treatment to T6 condition. These shells are used for the making of seamless LPG pressure vessels after the spinning process. This process is composed of deep drawing, reverse redrawing, drawing-ironing and several ironing processes. In the verification of forming process design, we used DEFORM code.

• Applied Chemistry for Engineering
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• v.17 no.2
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• pp.194-200
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• 2006

Titanium oxide films were deposited by the nozzle type HCP RT-MOCVD for the application of metal-oxide films. In the case of TTNB, after depositing films, films must be annealed at a proper temperature, but in the case of titanium ethoxide, titanium oxide films could be directly deposited by titanium ethoxide without general annealing. We could confirm that ratio of O to Ti in the films was about 2 : 1 at RF-power of 240 watt, distance between cathode and substrate of 3 cm, deposition time of 20 min, and ratio of Ar to $O_2$ of 1 : 1. Therefore, we could obtain the titanium oxide film deposited by the nozzle type HCP RT-MOCVD without an annealing process and could apply in the metal-oxide deposition process at a low temperature.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.11a
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• pp.35-35
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• 2009

Capacitorless one transistor dynamic random access memory (1T-DRAM) cells were fabricated on the fully depleted strained-silicon-on-insulator (FD sSOI) and the effects of silicon back interface state on buried oxide (BOX) layer on the memory properties were evaluated. As a result, the fabricated 1T-DRAM cells showed superior electrical characteristics and a large sensing current margin (${\Delta}I_s$) between "1" state and "0" state. The back interface of SOI based capacitorless 1T-DRAM memory cell plays an important role on the memory performance. As the back interface properties were degraded by increase rapid thermal annealing (RTA) process, the performance of 1T-DRAM was also degraded. On the other hand, the properties of back interface and the performance of 1T-DRAM were considerably improved by post RTA annealing process at $450^{\circ}C$ for 30 min in a 2% $H_2/N_2$ ambient.

• Proceedings of the KIEE Conference
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• 1991.11a
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• pp.286-289
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• 1991

We simulated ion implantation and annealing condition of 1 ${\mu}m$ CMOS device using process simulator, SUPREM-II. In this simulation, optimal condition of ion implantation for symmetric threshold voltage determination of PMOS and NMOS region, junction depth and sheet resistance of source/drain region, impurity profile of each region are investigated. Ion implantation dose for 3 ${\mu}m$ N-well junction depth and symmetric threshold voltage of $|0.6|{\pm}0.1$ V were $1.9E12Cm^{-2}$(for phosphorus), $1.7E122Cm^{-2}$(for boron) respectively. Also annealing condition for dopant activation are examined about $900^{\circ}C$, 30 minutes. After final process step, N-well junction, P+ S/D junction and N+ S/D junction depth are calculated 3.16 ${\mu}m$, 0.45 ${\mu}m$ and 0.25 ${\mu}m$ respectively.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.15 no.1
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• pp.136-144
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• 2016

The air-conditioning industry is closely related to types of lifestyles, climate, and products. With the improvement of national income, the pursuit of pleasant living and working environments, and South Korea's four seasons and distinct climatic conditions, demand for air conditioning has increased. In addition, the industry is becoming increasingly precise and cooperative, and the increase in the domestic production of sophisticated air conditioning and continued growth of future industrial cooperation are expected to rapidly rise. Accordingly, the study of air piping systems can improve the productivity and quality of products and cost savings and can achieve vibration reduction. Additionally, using a heat treatment furnace for copper tube annealing treatment reduces the risk of using an oxy-acetylene torch.

• Journal of the Korean Society for Heat Treatment
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• v.27 no.2
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• pp.72-78
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• 2014

Isothermal transformation behavior of a 10% Cr heat resistant steel fabricated by centrifugal casting process was investigated. Normalized specimen at $1100^{\circ}C$ for 1 hour was isothermally annealed at temperature range between $600^{\circ}C$ and $700^{\circ}C$ with various time. The annealed specimen had eutectoid structure which was generated along austenitic grain boundary during isothermal annealing. Areal fraction of eutectoid structure increased up to 25% after holding at $700^{\circ}C$ for 20 hours. It was observed that austenitic matrix was transformed to ferrite structure and fine $M_{23}C_6$ carbides with increase of annealing time. Time-temperature-transformation diagram of the centrifugally cast 10% Cr steel with 0.18 wt% C was plotted based on the results of isothermal transformation behavior.

• Progress in Superconductivity
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• v.4 no.2
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• pp.153-156
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• 2003

We have studied fabrication of $MgB_2$ thin film on $SrTiO_3$ (001) and r-cut $A1_2$$O_3$ substrates by rf magnetron sputtering method using and $ MgB_2$ single target and two targets of Mg and B, respectively. Based on P -T phase diagram of $MgB_2$ and vapor pressure curves of Mg and B, a three-step process was employed. B layer was deposited at the bottom to enhance the film adhesion to the substrate. Secondly, co-sputtering of Mg and B was done. Finally, Mg was sputtered on top to compensate fur the loss of Mg during annealing. Subsequently, $MgB_2$ films were in-situ annealed in various conditions. The sample fabricated using the three-step process showed $T_{c}$ of 24 K and formation of superconducting $MgB_2$ phase was confirmed by XRD spectra. In case of co-sputtering deposition, $T_{c}$ depended on annealing time and argon pressure. However, those made by single-target sputtering showed non-superconducting behavior or low transition temperature, at best.est.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.9 no.6
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• pp.1-6
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• 2010

Patterned optical components are widely used for optical products such as LCD and lighting. Since CCFL was used as a light source in the products, prism films having linear continuous optical patterns were widely used. However, LED which is a dot light source is popular recently, therefore, the optical products need new optical components having non-continuous optical patterns. Indentation machining method is a powerful method for machining of non-continuous pattern. When a copper mold and a brass mold were machined by this method, severe plastic deformation called pile-up was observed around the patterns. Since pile-up has negative relationship to ductility, this deformation can be eliminated by annealing treatment which makes the materials ductile. No plastic deformation occurred when machined after annealing at $600{^{\circ}C}$ and $575{^{\circ}C}$ for copper and brass, respectively. Finally, non-continuous optical patterns with high quality were machined on a copper mold and a brass mold successively.