• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2000.11a
• /
• pp.255-258
• /
• 2000

In this study, the structural, dielectric and piezoelectric properties of Pb[(Sb$\sub$1/2/Nb$\sub$1/2/)$\sub$x/- (Ni$\sub$1/3/Nb$\sub$2/3/)$\sub$0.15-x/- (Zr,Ti)$\sub$0.85/]O$_3$(x = 0, 0.01, 0.02, 0.03, 0.04, 0.05) ceramics is investigated as a function of Pb(Sb$\sub$1/2/Nb$\sub$1/2/)O$_3$ (abbreviated PSN) substitution. With the increase of PSN substitution, the crystal structure is transO$_3$formed from the tetragonal phase to the rhombohedral phase and the grain size is decreased abruptly. The curie temperature is decreased with the PSN substitution. The dielectric constant is increased with the PSN substitution and maximum value of 2290 is obtained at 4mol% PSN. With the PSN substitution, the coercive field is increased and the remnant polarization is decreased. The Electromechanical coupling factor(k$\sub$p/) Is showed the highest value of 0.622 at lmol% PSN and the mechanical quality factor(Q$\sub$m/) is decreased abruptly with the PSN substitution.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2005.07a
• /
• pp.66-67
• /
• 2005

In this study, in order to develop multilayer piezoelectric actuator, PMN-PNN-PZT ceramics were fabricated using $Li_2CO_3-Na_2CO_3$ as sintering aids and their piezoelectric and dielectric characteristics were investigated with the function of PNN substitution. With increasing PNN substitution, dielectric constant(${\varepsilon}r$), electromechanical coupling factor(kp), and piezoelectric d constant($d_{33}$) were increased at 10~12[mol%] PNN substitution and then decreased at all sintering temperature. With increasing PNN substitution, phase changed from tetragonal to rhombohedral at [10~12mol%] PNN substitution. At the 12[mol%] PNN substituted PMN-PZT composition ceramic sintered at 950[$^{\circ}C$], density, ${\varepsilon}r$, kp, $d_{33}$ and Qm showed the optimum value of 7.79[$g/cm^3$], 1160, 0.599, 419[pC/N) and 894, respectively for multilayer piezoelectric actuator application.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2001.11b
• /
• pp.434-437
• /
• 2001

In this study piezoelectric and dielectric properties of $Pb(Mn_{1/3}Nb_{2/3})O_{3}-Pb(Zr,Ti)O_{3}$ ceramics were investigated with $Pb(Ni_{1/3}Nb_{2/3})O_{3}$ substitution. As the $Pb(Ni_{1/3}Nb_{2/3})O_{3}$ substitution was increased, dielectric constant and electromechanical coupling factor (kp) were increased while mechanical quality factor decreased.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2005.11a
• /
• pp.178-180
• /
• 2005

In this study, in order to develop multilayer low temperature sintering piezoelectric transformer, $Pb_{0.97}Sr_{0.03}[(Mn_{1/3}Nb_{2/3})x(Zr_{0.48}Ti_{0.52})_{1-x}O_3]+$ 0.25wt% $CeO_2$+0.3 wt% $Nb_2O_5$ system ceramics were fabricated using $Li_2CO_3-CaCO_3$ and CuO as sintering aids and their piezoelectric and dielectric characteristics were investigated with the amount of PMN substitution. With increasing PMN substitution, electromechanical coupling factor kp and dielectric constant were increased.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2001.11a
• /
• pp.434-437
• /
• 2001

In this study piezoelectric and dielectric properties of Pb(Mn$\sub$1/3/Nb$\sub$2/3/)O$_3$-Pb(Zr,Ti)O$_3$ ceramics were investigated with Pb(Ni$\sub$1/3/Nb$\sub$2/3/)O$_3$ substitution. As the Pb(Ni$\sub$1/3/Nb$\sub$2/3/)O$_3$) substitution was increased, dielectric constant and electromechanical coupling factor (kp) were increased while mechanical quality factor decreased.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 1997.11a
• /
• pp.158-162
• /
• 1997

In this paper, the electrical and dielectrical properties were investigated in Pb(Zr,Ti)O$_3$-Pb(Mn,Nb)O$_3$ ceramics which are manufactured with the substitution of Ba in site Pb. In older to increase the del and Kp , Ba was substitued to site Pb from 0 to 0.1 by 0.02 mol%. As the Ba substitution is increased, dielectric constant is increased and electricmachanical coupling factor showed the maximum value at Ba 0.06mol% and the mechanical qualify factor is decreased and the tetragonality and the grain size are decreased as the Ba substitution.

• Journal of the Korean Society for Railway
• /
• v.9 no.6 s.37
• /
• pp.635-643
• /
• 2006

In this paper, a theorectical approach is studied to predict structural performances and weight-reduction rates of hybrid bodyshells in case that the materials of roof structures are substituted. To determine other light-weight materials to be substituted for the original roof materials, bending and twisting deformations are considered under constant stiffness and strength conditions, which derive some new weight-reduction indices from a structural performance point of view. The indices derived to estimate the weight-reduction can be utilized as a good criterion at the conceptual design for material substitution of the roofs.

• Proceedings of the KSR Conference
• /
• 2005.11a
• /
• pp.1071-1082
• /
• 2005

In this paper is studied a theoretical approach to predict structural performances and weight reduction rates of a carbody with shell type sections in case that its materials have to be substituted. For the material substitution design of a carbody, bending, axial and twisting deformations are considered under constant stiffness and strength conditions, which utilizes some new indices derived from a structural point of view. The developed indices to measure the weight reduction by the material substitution give good guidelines on conceptual design of carbodies.

• Proceedings of the KSR Conference
• /
• 2006.11b
• /
• pp.18-30
• /
• 2006

In this paper is studied a theoretical approach to predict structural performances and weight reduction rates of a car-body with shell type sections in case that its materials have to be substituted. For the material substitution design of a car-body, bending, axial and twisting deformations are considered under constant stiffness and strength conditions, which utilize some new indices derived from a structural performance point of view. The developed indices to measure the weight reduction by the material substitution give good guidelines on conceptual design of car-bodies.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.14 no.5
• /
• pp.87-92
• /
• 2010

This study set up 25, 35% for silica fume, SFFB's 2 level and water-combination material ratio, silica fume 10% for substitution ratio, and 4 level of SFFB 5, 10, 15(%) in order to compare and analyze the quality characteristic of ultra high strength concrete according to the substitution ratio of silica fume free binder (SFFB) that can be utilized as a substitute material for silica fume. As a result of an experimentation, the lower water-combination material ratio was, the higher addition ratio of high performance water-reducing agent for securing target liquidity increased, and it indicated the tendency that addition ratio of high performance water-reducing agent decreases because of material characteristic that SFFB has a lower absorptiveness than silica fume. The best strength was shown when SFFB substitution ratio is 10% at compressive strength and when substitution ratio is 15% at tensile strength, and it was indicated that at autogenous shrinkage contraction decreases compared to Plain(SF) regardless of substitution ratio of W/B and SFFB.