간행물
한국재료학회지 KCI 등재 SCOPUS Korean Journal of Materials Research
- 발행기관 한국재료학회
- 자료유형 학술지
- 간기 월간
- ISSN 2799-8525 (Print)2799-8681 (Online)
- 수록기간 1991 ~ 2024
- 주제분류 공학 > 재료공학 공학 분류의 다른 간행물
- 십진분류KDC 530DDC 620
권호리스트/논문검색
제32권 제9호 (2022년 9월) 6건
1.
2022.09
구독 인증기관 무료, 개인회원 유료
The overall process, from the pre-treatment of aluminum substrates to the eco-friendly neutral electroless Ni-P plating process, was observed, compared, and analysed. To remove the surface oxide layer on the aluminum substrate and aid Ni-P plating, a zincation process was carried out. After the second zincation treatment, it was confirmed that a mostly uniform Zn layer was formed and the surface oxide of aluminum was also removed. The Ni-P electroless plating films were formed on the secondary zincated aluminum substrate using electroless plating solutions of pH 4.5 and neutral pH 7.0, respectively, while changing the plating bath temperature. When a neutral pH7.0 electroless solution was used, the Ni-P plating layer was uniformly formed even at the plating bath temperature of 50 oC, and the plating speed was remarkably increased as the bath temperature was increased. On the other hand, when a pH 4.5 Ni-P electroless solution was used, a Ni-P plating film was not formed at a plating bath temperature of 50 oC, and the plating speed was very slow compared to pH 7.0, although plating speed increased with increasing bath temperature. In the P contents, the P concentration of the neutral pH 7.0 Ni-P electroless plating layer was reduced by ~ 42.3 % compared to pH 4.5. Structurally, all of the Ni-P electroless plating layers formed in the pH 4.5 solution and the neutral (pH 7.0) solution had an amorphous crystal structure, as a Ni-P compound, regardless of the plating bath temperature.
4,000원
2.
2022.09
구독 인증기관 무료, 개인회원 유료
The recycling of solid waste materials to fabricate carbon-based electrode materials is of great interest for low-cost green supercapacitors. In this study, porous carbon foam (PCF) was prepared from waste floral foam (WFF) as an electrode material for supercapacitors. WFF was directly carbonized at various temperatures of 600, 800, and 1,000 oC under an inert atmosphere. The WFF-derived PCF (C-WFF) was found to have a specific surface area of 458.99 m2/g with multi-modal pore structures. The supercapacitive behavior of the prepared C-WFF was evaluated using a three-electrode system in a 6 M KOH aqueous electrolyte. As a result, the prepared C-WFF as an active material showed a high specific capacitance of 206 F/g at 1 A/g, a rate capability of 36.4 % at 20 A/g, a specific power density of 2,500 W/kg at an energy density of 2.68 Wh/kg, and a cycle stability of 99.96 % at 20 A/g after 10,000 cycles. These results indicate that the C-WFF prepared from WFF could be a promising candidate as an electrode material for high-performance green supercapacitors.
4,000원
3.
2022.09
구독 인증기관 무료, 개인회원 유료
In this study, Barium Germanium glasses were prepared with a composition of xBaO-(72-x)GeO2-8La2O3-20ZnO where x = 16.0, 18.0, 20.0, 22.0 and 24.0 mol% respectively. Their physical and optical properties, such as refractiveness index, glass transition temperature (Tg), softening temperature (Ts), transmittance and Knoop hardness were studied. The results showed that refractive index, Tg, Ts and coefficient of thermal expansion (CTE) increased with increasing BaO concentration. The refractive index of all the prepared samples was observed between 1.7811 to 1.7881. The Abbe number was calculated by formula using nd (589.3 nm), nf (656.3 nm) and nc (486.1 nm) and observed to be between 38 to 40. The Abbe number of the prepared sample was similar to that of BaO and GeO2. The transmittance of the prepared glasses was observed to be between 80 ~ 82 % throughout the range from 200 nm to 800 nm. Knoop hardness divided into seven steps were measured 5 class (≥ 450 ~ < 550) of all prepared samples.
4,000원
4.
2022.09
구독 인증기관 무료, 개인회원 유료
A spin coating process for RRAM, which is a TiN/TiO2/FTO structure based on a PTC sol solution, was developed in this laboratory, a method which enables low-temperature and eco-friendly manufacturing. The RRAM corresponds to an OxRAM that operates through the formation and extinction of conductive filaments. Heat treatment was selected as a method of controlling oxygen vacancy (VO), a major factor of the conductive filament. It was carried out at 100 oC under moisture removal conditions and at 300 oC and 500 oC for excellent phase stability. XRD analysis confirmed the anatase phase in the thin film increased as the heat treatment increased, and the Ti3+ and OH- groups were observed to decrease in the XPS analysis. In the I-V analysis, the device at 100 oC showed a low primary SET voltage of 5.1 V and a high ON/OFF ratio of 104. The double-logarithmic plot of the I-V curve confirmed the device at 100 oC required a low operating voltage. As a result, the 100 oC heat treatment conditions were suitable for the low voltage driving and high ON/OFF ratio of TiN/TiO2/FTO RRAM devices and these results suggest that the operating voltage and ON/OFF ratio required for OxRAM devices used in various fields under specific heat treatment conditions can be compromised.
4,000원
5.
2022.09
구독 인증기관 무료, 개인회원 유료
Research is being actively conducted on the continuous thin plate casting method, which is used to manufacture magnesium alloy plate for plastic processing. This study applied a heat transfer solidification analysis method to the melt drag process. The heat transfer coefficient between the molten magnesium alloy metal and the roll in the thin plate manufacturing process using the melt drag method has not been clearly established until now, and the results were used to determine the temperature change. The estimated heat transfer coefficient for a roll speed of 30 m/min was 1.33 × 105 W/m2·K, which was very large compared to the heat transfer coefficient used in the solidification analysis of general aluminum castings. The heat transfer coefficient between the molten metal and the roll estimated in the range of the roll speed of 5 to 90 m/min was 1.42 × 105 to 8.95 × 104 W/m2·K. The cooling rate was calculated using a method based on the results of deriving the temperature change of the molten metal and the roll, using the estimated heat transfer coefficient. The DAS was estimated from the relationship between the cooling rate and DAS, and compared with the experimental value. When the magnesium alloy is manufactured by the melt drag method, the cooling rate of the thin plate is in the range of about 1.4 × 103 to 1.0 × 104 K/s.
4,000원
6.
2022.09
구독 인증기관 무료, 개인회원 유료
In this study, surface roughness and interfacial defect characteristics were analyzed after forming a high-k oxide film on the surface of a prime wafer and a test wafer, to study the possibility of improving the quality of the test wafer. As a result of checking the roughness, the deviation in the test after raising the oxide film was 0.1 nm, which was twice as large as that of the Prime. As a result of current-voltage analysis, Prime after PMA was 1.07 × 10 A/cm2 and Test was 5.61 × 10 A/cm2, which was about 5 times lower than Prime. As a result of analyzing the defects inside the oxide film using the capacitancevoltage characteristic, before PMA Prime showed a higher electrical defect of 0.85 × 1012 cm2 in slow state density and 0.41 × 1013 cm2 in fixed oxide charge. However, after PMA, it was confirmed that Prime had a lower defect of 4.79 × 1011 cm2 in slow state density and 1.33 × 1012 cm2 in fixed oxide charge. The above results confirm the difference in surface roughness and defects between the Test and Prime wafer.
4,000원
