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 ~ 2025
- 주제분류 공학 > 재료공학 공학 분류의 다른 간행물
- 십진분류KDC 530DDC 620
권호리스트/논문검색
제35권 제9호 (2025년 9월) 8건
1.
2025.09
구독 인증기관 무료, 개인회원 유료
This study investigated how adding nanoparticles to cocklebur biodiesel affected a 4-stroke compression ignition (CI) engine. The biodiesel was mixed with titanium oxide nanoparticles at concentrations of 4 ppm in each blend. Engine performance characteristics were examined including consumed gas heat, brake thermal efficiency (BTE), and brake specific fuel consumption (BSFC). The tests were conducted under a variety of loads and speeds, and the outcomes were compared to those from tests using only pure diesel and only pure biodiesel. According to the findings, adding nanoparticles to the biodiesel enhanced engine performance, with the highest gains being shown at B36F4 content. At 75 % and 100 % load, the BSFC was reduced by 6.8 % and 7.6 %, respectively. When compared to pure biodiesel, the brake thermal efficiency increased by 6.7 % and 8.8 %. The temperature of the exhaust gas decreased as the concentration of nanoparticles increased. The performance of the 4-stroke CI engine was improved when nanoparticles were added to cocklebur biodiesel making it a competitive alternative to traditional diesel fuel.
29,000원
2.
2025.09
구독 인증기관 무료, 개인회원 유료
Polymeric materials are extensively utilized in various industrial applications, including as gas barriers, fuel cells, sensors, and in semiconductor processes, and are particularly critical to ensure sealing performance in high-pressure gas systems. The diffusivity and solubility of gases within polymers significantly influences their sealing efficacy and is closely related not only to polymer–gas interactions but also to the thermodynamic properties of the gases. Notably, gas solubility exhibits a quantitative correlation with critical temperature, attributed to the condensability of the gas molecules. In this study, the solubility of five pure gases (H2, He, N2, O2, Ar) with varying critical temperatures was quantitatively measured and analyzed under high-pressure conditions (1-10 MPa) in four polymers differing in structure and density. The experiments employed both volumetric and manometric methods to measure gas desorption concentration, with meticulous corrections for minor temperature and atmospheric pressure variations to ensure data accuracy. The results demonstrated that the logarithmic solubility of gases in polymers increases linearly with the gas critical temperature, consistent across all polymer samples. This finding aligns with predictions from the Non-Equilibrium Lattice Fluid (NE-LF) model, which has been shown to accurately describe gas solubility behavior in glassy polymers.
4,000원
3.
2025.09
구독 인증기관 무료, 개인회원 유료
In situations where materials are rare difficult to obtain, the ability to test small specimens is becoming increasingly important, particularly for aerospace. In the nuclear power generation field, tensile and small punch testing of small specimens is being utilized to evaluate integrity. In this study, we designed and validated small specimens suitable for aircraft engine components. A fixture for small plate specimens was optimized using finite element analysis to ensure uniform stress distribution, and the specimens were manufactured through precision machining. Tensile tests and creep rupture tests were conducted, and the results were analyzed and compared with those from round specimens made from the same alloy. The yield strength and tensile strength of the small plate specimens were within 5 % of the round specimens, but there was less elongation compared to the round specimens. The difference in the decrease in elongation of the round specimens and small plate specimens was analyzed using the Voce equation to identify the cause. The approach used in this study enables the evaluation of the mechanical properties of engine components with limited material options or those in operation, and is expected to be utilized for monitoring the condition of critical components.
4,000원
4.
2025.09
구독 인증기관 무료, 개인회원 유료
Interest in high-permittivity dielectric materials suitable for classical systems has been increasing, and competition for commercial applications continues. However, despite the development of such dielectric materials, additional compositional improvements are still required to achieve low-temperature sintering that would allow co-firing with Cu internal electrodes in multilayer structures, and research in this area remains insufficient. In this study, we aimed to optimize a low-temperature sintering composition based on Pb0.94La0.06(Zr0.83Ti0.17)O3, which, in preliminary experiments, exhibited a dielectric constant above 1,300 at sintering temperatures exceeding 1300 °C. As the amount of Na ion addition increased, low-temperature sintering was effectively promoted. However, the dielectric constant simultaneously decreased. When K ions were further added to the Lead Lanthanum Zirconate Titanate (PLZT)+Na composition, the low-temperature sintering properties were maintained or improved, and the dielectric constant increased compared with Na-only addition. To precisely readjust the MPB region under the influence of large additive content, the Zr ion fraction was varied from 0.84 to 0.92. Within this range, the MPB composition was found to shift slightly as the Zr content increased. As a result, the optimal composition among the PLZT ceramics sintered at 950 °C was determined to be Zr 0.86, which exhibited a dielectric constant of approximately 900 and an energy storage density of about 2 J/cm3. These findings suggest that such a composition could be applicable for low-temperature co-firing with Cu electrodes in Multi-Layer Ceramic Capacitors (MLCCs) for classical systems.
4,000원
5.
2025.09
구독 인증기관 무료, 개인회원 유료
High-temperature sintering is required to obtain pure and dense alumina, but it results in excessive grain growth, which eventually deteriorates the performance of the material. Technologies have been developed to lower the sintering temperature, such as the addition of a sintering aid, but these methods may cause secondary phases and still deteriorate physical properties. In this study, pure high-density alumina sintered bodies were prepared by applying an aerodynamic levitation (ADL) process without using sintering additives. Alumina that was sintered using a furnace showed a relative sintering density of 98.3 %, while alumina produced by the ADL process showed a relative density of 99.75 %. Compared to alumina prepared with the general sintering method, ADL alumina showed about a 37 % increase in hardness. ADL alumina showed a dense microstructure, attributed to instantaneous sintering at a high temperature of 2,000 °C or higher, and crystal grain growth was suppressed by rapid cooling to room temperature, resulting in ultra-high density. The ADL method is a promising manufacturing method that can improve the mechanical properties of ceramics that need to be sintered at high temperatures, and can be used to manufacture special high-performance ceramics for application in high-temperature environments.
4,000원
6.
2025.09
구독 인증기관 무료, 개인회원 유료
Graphene, mechanically exfoliated as a single-atom-thick two-dimensional (2D) material, is renowned for its exceptional carrier mobility and mechanical strength, making it a highly promising material for a wide range of applications; however, following the synthesis of large-area, high-quality graphene, quality degradation, such as tearing, frequently occurs during the transfer process. Currently, chemical vapor deposition (CVD) enables reliable synthesis of large-area graphene, and both wet and dry transfer methods are widely employed to transfer graphene onto various substrates. This study focuses on the wet transfer method to improve transfer efficiency by optimizing the interfacial adhesion among graphene, the polymethyl methacrylate (PMMA) support layer, and the target substrate. To enhance the efficiency of the wet transfer process, the PMMA concentration and ultraviolet ozone (UVO) treatment time were systematically optimized. As a result, a transfer yield of up to 97.16 % was achieved under optimized conditions consisting of 6 % PMMA concentration and 15 min of UVO exposure. This research contributes to the development of highly efficient graphene transfer techniques, which are crucial for reducing production costs and processing time in a wide range of advanced applications such as electronics, energy storage, biomedical devices, environmental monitoring, and materials science.
4,000원
7.
2025.09
구독 인증기관 무료, 개인회원 유료
In this study, carbon nanotube (CNT) purification results were compared between the conventional wet process using strong acids and the dry process using chlorine gas at high temperatures. To evaluate the effect of catalyst support in both methods, purification experiments were conducted using Tuball SWCNT from OCSiAl (without support) and CVD CNT synthesized with supported catalysts (Fe-Mo/MgO). Before and after treatment, the CNT samples were analyzed using scanning electron microscopy (SEM), Raman spectroscopy, and thermogravimetric analysis (TGA) to compare the morphology of CNT bundles, the distribution and content of impurities, and crystallinity. The results confirm that the dry process exhibited superior characteristics for both Tuball SWCNT and CVD CNT. In particular, changes in the IG/ID ratio observed in Raman spectroscopy and the reduction of residue in TGA clearly demonstrate high crystallinity and high-purity purification without damaging the CNTs. TGA reveals a reduction in ash content from 20.2 % to 3.2 % for Tuball SWCNT and from 63.1 % to 5.4 % for CVD CNT, while Raman spectroscopy confirms the preservation of the IG/ID ratio (~50) in Tuball SWCNT and its increase from 6.86 to 9.05 in CVD CNT. The purification method proposed in this study is expected to be effectively applied in fields requiring high-purity SWCNTs, such as electronics, sensors, and energy storage devices.
4,000원
8.
2025.09
구독 인증기관 무료, 개인회원 유료
Transparent and conducting SnO2 and SnO2/Ag/SnO2 (SAS) films were deposited on glass substrates by magnetron sputtering at room temperature. The effect of the SnO2 target power and Ag interlayer on the visible transmittance and electrical properties of the film was considered. Although all the SnO2 films had an amorphous structure under all sputtering power conditions, SnO2 films deposited at a target power of 60 W showed a lower resistivity of 2.25 Ω cm and a lower surface roughness of 1.4 nm. The average visible transmittance also varied with target power conditions. The average visible transmittance increased from 73.7 % (40 W) to 76.3 % (60 W) and then decreased to 73.2 % (80 W). When all films were compared, it was found that the SnO2 films deposited at 60 W had a higher figure of merit of 2.98 × 10-7 Ω-1. In addition, the SnO2 films with a Ag 10 nm interlayer showed a lower resistivity of 4.28 × 10-5 Ω cm and a visible transmittance of 70.58 %. The Ag interlayer in the SnO2 films increased the figure of merit to 7.88 × 10-3 without substrate heating or post-deposition annealing. The observed results confirm that the optical and electrical properties of SnO2 films can be enhanced by optimizing the sputtering target power condition and the thickness of the Ag interlayer, respectively.
4,000원
