Densification behaviors and piezoelectric properties of MnO2, SiO2-doped Pb(Ni1/3Nb2/3)O3–PbTiO3–PbZrO3 ceramics

1993 ◽  
Vol 8 (12) ◽  
pp. 3184-3191 ◽  
Author(s):  
Jong H. Moon ◽  
Hyun M. Jang ◽  
Beoung D. You
Keyword(s):  
Grain Growth ◽  
Oxygen Vacancies ◽  
Piezoelectric Properties ◽  
Mechanical Quality Factor ◽  
Growth Behavior ◽  
Microstructural Development ◽  
Relative Dielectric Permittivity ◽  
Diffusion Controlled ◽  
Mechanical Quality ◽  
Grain Growth Behavior

The roles of additives (MnO2, SiO2, and CdO) in controlling microstructural development and piezoelectric properties of Pb(Ni1/3Nb2/3)O3– PbTiO3–PbZrO3(PNN–PT–PZ) ceramics were systematically examined. The addition of SiO2 (<1 wt. %) to the pseudoternary PNN–PT-PZ system enhances densification, but suppresses grain growth significantly. On the other hand, the presence of MnO2 expedites the rate of grain growth without increasing the rate of densification appreciably. The observed difference in the grain-growth behavior was discussed in terms of the viscosity of liquid phase formed during sintering and the diffusion-controlled process for the solute-atoms transport. The rapid increase in the mechanical quality factor (Qm) and the decrease in the relative dielectric permittivity (∊r) and d33 for the MnO2-doped specimens indicate the formation of oxygen vacancies by the dissolution of Mn-atoms into the B-sites of perovskite structure. On the contrary, the presence of CdO (2 mol %) remarkably increases ∊r and d33 of PNN–PT–PZ ceramics.

Effects of Mn-Doping on the Piezoelectric and Ferroelectric Properties of (Na0.8K0.2)0.5Bi0.5TiO3 Ceramics

2008 ◽  
Vol 368-372 ◽  
pp. 69-71 ◽  
Author(s):  
Xiang Ping Jiang ◽  
Long Zhu Li ◽  
Fu Lan Jiang ◽  
Yan Yan Zheng ◽  
Li Hua Liu
Keyword(s):  
Solid State ◽  
Dielectric Loss ◽  
Grain Growth ◽  
Remnant Polarization ◽  
Piezoelectric Properties ◽  
Ferroelectric Properties ◽  
Mechanical Quality Factor ◽  
Lead Free ◽  
Mn Doping ◽  
Mechanical Quality

Lead-free piezoelectric ceramics of (Na0.8K0.2)0.5Bi0.5TiO3+x wt.% Mn (abbreviated as NBKT-x% Mn, x=0~0.5) were synthesized by solid-state reaction. The grain growth of the ceramics was restrained by Mn-doping at a certain extent. The mechanical quality factor Qm increases and the dielectric loss tanδ decreases with the increase of Mn-doping. Best piezoelectric properties were obtained for the composition of NKBT-0.2%Mn: d33=158 pC·N-1, tanδ=2.9% at 1 kHz, Qm=110 and kp=30%. The P-E loops show that remnant polarization Pr and coercive field Ec decrease slightly with the amount of the Mn2+ increasing up to 0.2wt.% and then increase as the content of Mn2+ increases further. NKBT-0.5wt. % Mn exhibits strong ferroelectricity with remnant polarization Pr = 38μC/cm2.

Step Free Energy Change and Microstructural Development in BaTiO3-SiO2

2007 ◽  
Vol 352 ◽  
pp. 25-30 ◽  
Author(s):  
Jaem Yung Chang ◽  
Suk Joong L. Kang
Keyword(s):  
Free Energy ◽  
Grain Growth ◽  
Driving Force ◽  
Growth Behavior ◽  
Abnormal Grain Growth ◽  
Free Energy Change ◽  
Energy Change ◽  
Microstructural Development ◽  
Two Phase ◽  
Grain Growth Behavior

The effect of step free energy on the grain growth behavior in a liquid matrix is studied in a model system BaTiO3-SiO2. BaTiO3-10SiO2 (mole %) powder compacts were sintered at 1280°C under various oxygen partial pressures (PO2), 0.2, ~ 10-17 and ~ 10-24 atm. As the step free energy decreases with the reduction of PO2, it was possible to observe the change in growth behavior with the reduction of the step free energy. At PO2 = 0.2 atm, essentially no grain growth (stagnant grain growth) occurred during sintering up to 50 h. At PO2 ≈ 10-17 atm, abnormal grain growth followed stagnant grain growth during extended sintering (incubation of abnormal grain growth). At PO2 ≈ 10-24 atm, normal grain growth occurred. These changes in growth behavior with PO2 and the step free energy reduction are explained in terms of the change in the critical driving force for appreciable growth relative to the maximum driving force for grain growth. The present experimental results provide an example of microstructure control in solid-liquid two- phase systems via step free energy change.

scholarly journals Effect of Cold-Deformation on Austenite Grain Growth Behavior in Solution-Treated Low Alloy Steel

Metals ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 1004 ◽  
Author(s):  
Xianguang Zhang ◽  
Kiyotaka Matsuura ◽  
Munekazu Ohno
Keyword(s):  
Mechanical Properties ◽  
Low Temperature ◽  
Grain Growth ◽  
Cold Deformation ◽  
Growth Behavior ◽  
Low Alloy Steel ◽  
Solution Treated ◽  
Austenite Grain ◽  
Grain Growth Behavior ◽  
Austenite Grain Growth

The occurrence of abnormal grain growth (AGG) of austenite during annealing is a serious problem in steels with carbide and/or nitride particles, which should be avoided from a viewpoint of mechanical properties. The effects of cold deformation prior to annealing on the occurrence of AGG have been investigated. It was found that the temperature range of the occurrence of AGG is shifted toward a low temperature region by cold deformation, and that the shift increases with the increase of the reduction ratio. The lowered AGG occurrence temperature is attributed to the fine and near-equilibrium AlN particles that are precipitated in the cold-deformed steel, which is readily dissolved during annealing. In contrast, coarse and non-equilibrium AlN particles precipitated in the undeformed steel, which is resistant to dissolution during annealing.

Piezoelectric Properties of PZT-5 Fiber/Epoxy Resin 1-3 Composites

2011 ◽  
Vol 239-242 ◽  
pp. 486-489
Author(s):  
Ling Fang Xu ◽  
Wen Chen ◽  
Jing Zhou ◽  
Chang Ping Yang
Keyword(s):  
Epoxy Resin ◽  
Coupling Coefficient ◽  
Piezoelectric Properties ◽  
Volume Fraction ◽  
Mechanical Quality Factor ◽  
Casting Method ◽  
Anisotropic Property ◽  
Niobium Doped ◽  
Mechanical Quality ◽  
Method Effects

Niobium doped Pb(Zr,Ti)O3fiber/epoxy resin 1-3 composites with different ceramic volume fraction of 10-85% were fabricated by filling-casting method. Effects of ceramic volume fraction on electric properties were investigated. For a typical 30% ceramic content composite, the thickness coupling coefficientkt, mechanical quality factorQm, acoustic impedanceZmand anisotropic propertykt/kpwere 0.67, 0.55, 11.03 MRayl and 2.23, respectively.

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