• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 2005.10a
• /
• pp.134-135
• /
• 2005

The responses of nanocrystalline aluminum powder of different grain sizes, prepared by ball milling and consolidated into bulk specimens by hot pressing, were determined under quasi-static and dynamic compression. The experiments demonstrated that the reduction in grain size resulted in several-fold increase in hardness and strength; the responses of nanocrystalline aluminum was found to be strain-rate dependent.

• Proceedings of the Korean Powder Metallurgy Institute Conference
• /
• 2006.09b
• /
• pp.894-895
• /
• 2006

WC-$10C_o$-0.8VC nanocrystalline powders were sintered by spark plasma sintering (SPS) and hot press sintering (HPS), and the microstructure and properties were compared. Results show that dense WC-$10C_o$-0.8VC can be obtained by SPS in several minutes when the sintering temperature is $>1200^{\circ}C$. Sintered at a temperature of $1300^{\circ}C$ the sample prepared by SPS for 3 minutes has higher density, finer grains and better properties than that prepared by HPS for 60 minutes. SPS can be used to prepare nanocrystalline WC-$10C_o$-0.8VC with improved properties when suitable sintering parametesr are chosen.

• Proceedings of the Korean Powder Metallurgy Institute Conference
• /
• 2006.09b
• /
• pp.786-787
• /
• 2006

The magnetic inductance of nanocrystalline $Fe_{73}Si_{16}B_7Nb_3Cu_1$ and an amorphous FeSiB powder sheet has been investigated to identify RFID performance. The powder was mixed with binder and solvent and tape-casted to form films. Results show annealing significantly influenced on the inductance of the material. The surface oxidation of the particles was the main reason for the reduced inductance. The maximum inductance of $Fe_{73}Si_{16}B_7Nb_3Cu_1$ alloy was about $88{\mu}H$ at 17.4 MHz, about 65% greater compared to the FeSiB alloy. The higher inductance in the nanocrystalline alloy indicates it may be used as a potential replacement of current RFID materials.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• 2018.05a
• /
• pp.154-154
• /
• 2018

Conventional inductive powerline communications typically use ferrite cores. However, since the recent nanocrystalline cores are expected to perform better, this paper aims to measure the performance of inductive couplers using nanocrystalline cores. To do this, we used inductive powerline communications to observe the communication range when increasing the number of cores from one to five. This experiment shows that we have the best communication performance when we connect 5 cores.

• Proceedings of the Korean Powder Metallurgy Institute Conference
• /
• 1996.11a
• /
• pp.20-20
• /
• 1996

• Proceedings of the Materials Research Society of Korea Conference
• /
• 2000.11a
• /
• pp.126-126
• /
• 2000

• Proceedings of the Materials Research Society of Korea Conference
• /
• 1998.11a
• /
• pp.134-134
• /
• 1998

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• v.32 no.3
• /
• pp.262-266
• /
• 2006

The silver nanocrystalline is widely used for biological field because of its biocompatibility and anti-microbial effect. The objective of this study was to evaluate the therapeutic efficacy of the silver nanocrystalline ointment on the temporomandibular joint (TMJ) capsulitis. Total 39 patients were included in this study and all patients were received single topical application of the silver nanocrystalline ointment (group A, n=30) or placebo ointment (group B, n=19). Measured variables were maximum mouth opening (MMO), visual analog scale (VAS) for pain, and VAS for function. In results, we could not assess any therapeutic efficacy of single application in the chronic TMJ capsulitis (p>0.05). However, the single application of silver nanocrystalline ointment showed significant improvement in MMO and VAS for pain compared to placebo effect in the acute TMJ capsulitis (p<0.05). We could not find any complications related to ointment application in both groups. In conclusion, the single application of silver nanocrystalline ointment was effective in improving patient's symptom in acute TMJ capsulitis without any noticing complications.

• Journal of Powder Materials
• /
• v.28 no.4
• /
• pp.293-300
• /
• 2021

We investigate the effect of phosphorous content on the microstructure and magnetic properties of Fe_83.2Si_5.33-0.33xB_10.67-0.67xP_xCu_0.8 (x = 1-4 at.%) nanocrystalline soft magnetic alloys. The simultaneous addition of Cu and P to nanocrystalline alloys reportedly decreases the nanocrystalline size significantly, to 10-20 nm. In the P-containing nanocrystalline alloy, P atoms are distributed in an amorphous residual matrix, which suppresses grain growth, increases permeability, and decreases coercivity. In this study, nanocrystalline ribbons with a composition of Fe_83.2Si_5.33-0.33xB_10.67-0.67xP_xCu_0.8 (x = 1-4 at.%) are fabricated by rapid quenching melt-spinning and thermal annealing. It is demonstrated that the addition of a small amount of P to the alloy improves the glass-forming ability and increases the resistance to undesirable Fe_x(B,P) crystallization. Among the alloys investigated in this work, an Fe_83.2Si₅B₁₀P₁Cu_0.8 nanocrystalline ribbon annealed at 460℃ exhibits excellent soft-magnetic properties including low coercivity, low core loss, and high saturation magnetization. The uniform nanocrystallization of the Fe_83.2Si₅B₁₀P₁Cu_0.8 alloy is confirmed by high-resolution transmission electron microscopy analysis.

• Proceedings of the Korean Powder Metallurgy Institute Conference
• /
• 1997.10a
• /
• pp.39-39
• /
• 1997