• 열처리공학회지
• /
• 제18권4호
• /
• pp.223-228
• /
• 2005

Tube hydroforming provides a number of advantages over conventional stamping process, including fewer secondary operation, weight reduction, assembly simplification, adaptability to forming of complex structural components and improved structural strength and stiffness. It can produce wide range of products such as subframe, engine cradle, and exhaust manifold. In this study, the effect of the heat treatment conditions such as post seam annealing (PSA) and bright annealing (BA) on the ovality and hydro-formability of steel tubes has been investigated. Hydroformabilities have been estimated by the bulging heights obtained at various processing parameters such as internal pressure, axial feeding and heat treatment conditions. The ovality and forming height are strongly influenced by material properties after heat treatments.

• 한국자기학회지
• /
• 제5권5호
• /
• pp.507-510
• /
• 1995

A heat-treatment method of pre-annealing and then flash annealing(FA) has been used to improve the soft magnetic properties of nanocrystalline $Fe_{76}CuSi_{13}B_{10}$ and $Fe_{74}CuNb_{3}Si_{12}B_{10}$ alloys. Outstanding magnetic properties of nanocrystalline $Fe_{74}CuNb_{3}Si_{12}B_{10}$ alloy were attained by flash-annealing in air after annealed at $500^{\circ}C$ for 0.5hr below the crystallization temperature. The same results were obtained for $Fe_{74}CuSi_{13}B_{10}$ alloy. The measurment of relief of stress and X-ray diffraction were used to analyze the effect of flashannealing.

• 열처리공학회지
• /
• 제35권6호
• /
• pp.314-318
• /
• 2022

Transparent conducting ZnO/Ti/ZnO tri-layer films deposited on glass substrate with DC and RF magnetron sputtering were rapid thermal annealed at 150, 300 and 450℃ for 5 minutes and then effect of annealing temperature on the structural and optoelectronics properties of the films were investigated. The structural properties are strongly related to annealing temperature and the largest grain size is observed in the films annealed at 450℃. The electrical resistivity also decreases as low as 7.7 × 10^-4 Ωcm. The visible transmittance also depends on the annealing temperature. The films annealed at 450℃ show a higher transmittance of 80.6% in this study.

• Journal of Information Processing Systems
• /
• 제18권4호
• /
• pp.562-574
• /
• 2022

As traditional ways of evaluation prove to be ineffective in evaluating the effect of interactive multimedia physical education (PE) teaching, this study develops a new evaluation model based on the simulated annealing algorithm. After the evaluation subjects and the principle of the evaluation system are determined, different subjects are well chosen to constitute the evaluation system and given the weight. The backpropagation neural network has been improved through the simulated annealing algorithm, whose improvement indicates the completion of the evaluation model. Simulation results show that the evaluation model is highly efficient. Compared with traditional evaluation models, the proposed one enhances students' performance in PE classes by 50%.

• 한국주조공학회지
• /
• 제35권5호
• /
• pp.109-113
• /
• 2015

In this study, the measurement of FN (ferrite volume fraction) and the solution annealing ratio at a temperature of $1130^{\circ}C$ were determined with 15A elbow fittings of shell cast SSC13, and the corrosion resistance with and without austenitizing solution annealing were investigated in comparison with AISI304. The delta ferrite phase was observed in the material due to the slow cooling effect of the shell mold casting. However, the delta ferrite phase decreased gradually with the solution annealing at a temperature of $1130^{\circ}C$. The hardness generally decreased with a heat treatment; however, its corrosion resistance was improved with the heat treatment. In addition, when a passivation treatment was applied, its corrosion ratio showed the lowest value. The pattern of general corrosion decreased due to the decrease in the delta ferrite phase with the solution annealing treatment. Consequently, it is suggested that the corrosion resistance of SSC13 elbow fittings can be improved by increasing the ratio of any solution annealing treatment used and by decreasing the ferrite phase. The relationship between the ratio of solution annealing and delta ferrite is expressed as follows: SA (solution annealing ratio,%) = 98 - FN (ferrite volume fraction, %).

• 한국자기학회지
• /
• 제25권2호
• /
• pp.47-51
• /
• 2015

이 연구에서는 DC스퍼터링(DC Magnetron Sputtering)방식으로 제작 된 MgO 터널 장벽층을 갖는 자기터널접합을 급속 열처리 방식(Rapid Thermal Annealing)을 이용하여 열처리 공정 중의 구조적, 조성적 변화 및 스핀 수송 특성의 변화를 연구하였다. 본 연구를 통하여 급속 열처리 방식이 기존 일반적인 열처리 방식에 비하여 높은 터널링자기저항비를 얻을 수 있다는 것을 발견하였다. 또한, 열처리 시간의 단축을 통하여 Mn, Ta, Ru 등의 내부물질의 인접한 층으로의 확산을 억제할 수 있다는 것을 알 수 있었다. 유의미한 데이터를 수집하기 위하여 다양한 열처리 온도 조건과 시간조건에서 급속 열처리를 실시 한 후 자기 터널 접합의 전, 자기적 특성을 관찰하였다. 이러한 특성 변화는 향후 보다 우수하고 안정적인 자기적 특성과 열적 안정성을 갖는 자기터널접합 제작을 위해 다양하게 응용될 수 있다고 생각된다.

• 소성∙가공
• /
• 제31권5호
• /
• pp.273-280
• /
• 2022

Although the mechanical properties of high-entropy alloys depend on the annealing conditions, limited works were established to investigate the annealing effect on the mechanical properties of Mo-added high-entropy alloys. Therefore, in the present work, the annealing effects on the microstructural evolution and mechanical properties of Mo-added high-entropy alloy were investigated. As a result, incomplete recrystallization from the limited annealing time not only suppresses deformation-induced phase transformation during cryogenic tensile test but also induces a deformation instability that results into the ductility reduction compare with the fully recrystallized sample. This result represents adjustment of annealing time is useful to control both transformation-induce plasticity and deformation instability of high-entropy alloys, and this can be applied to control the mechanical properties of metallic alloys by combining pre-straining and subsequent annealing.

• 한국결정성장학회지
• /
• 제17권1호
• /
• pp.11-17
• /
• 2007

The spherical NiZn ferrite particles were prepared by ultrasonic spray pyrolysis with mixed solution of aqueous metal nitrates. The NiZn ferrite particle was observed with nano-sized primary particles of about 10 nm or less before annealing which represented as paramagnetic behavior measured at 77 K and room temperature. The typical abnormal growth of primary particles like polyhedral primary particles was observed by annealing at 1273 K with Zn-concentration dependency. The XRD patterns showed good crystallinity of NiZn ferrite powder after annealing. In annealing process, the intra-particle sintering phenomenon was observed and the spherical particle morphology was collapsed at 1673 K. The saturation magnetization of NiZn ferrite powder for each annealing temperature was decreased with measuring temperature of $77{\sim}$300K.

• Journal of Information Display
• /
• 제11권1호
• /
• pp.12-16
• /
• 2010

The effect of the crystallization and activated annealing of Si films using an excimer laser and the new CW blue laser are described and compared with furnace annealing for application in advanced TFTs and for future applications. Pulsed excimer laser annealing (ELA) is currently being used extensively as a low-temperature poly-silicon (LTPS) process on glass substrates as its efficiency is high in the ultra-violet (UV) region for thin Si films with thickness of 40-60 nm. ELA enables extremely low resistivity relating to high crystallinity for both the n- and p-type Si films. On the other hand, CW blue laser diode annealing (BLDA) enables the smooth Si surface to have arbitral crystal grains from micro-grains to an anisotropic huge grain structure only by controlling its power density. Both annealing techniques are expected to be applied in the future advanced TFT systems.

• 한국세라믹학회지
• /
• 제43권3호
• /
• pp.185-192
• /
• 2006

The effects of annealing on structural and electrical properties of ITO/PES (Indium Tin Oxide/Polyethersulfone) films was investigated. Amorphous ITO thin films were grown on plastic substrates, PES using low temperature DC magnetron sputtering. Various post annealing techniques were attempted to research variations of microstructure and electrical properties: i) conventional thermal annealing, ii) excimer laser annealing, iii) UV irradiation. The electrical properties were obtained using Hall effect measurements and DC 4-point resistance measurement. The microstructural features were characterized by FESEM, XRD, Raman spectroscopy in terms of morphology and crystallinity. Optimized UV treatment exhibits the enhanced conductivity and crystallinity, compared to those of conventional thermal annealing.