Considerations for BaTiO3Ceramics with High Piezoelectric Properties Fabricated by Microwave Sintering Method

A microwave sintering method was used to prepare C3S from Ca(OH)2, SiO2 and MexOy. f-CaO assay, X-ray diffraction and SEM were used to characterize the sintered samples.The results indicated that ion oxides played a very important role in C3S formation in conventional sintering, the use of MexOy as an additive was so effective in promoting C3S formation. The experimental results showed that samples were heated at an electric heating temperature(1500°C) and then further sintered with microwave for 30~60 min, tricalcium silicate could be formed with kilogram step. The new burning technique can greatly increase the forming speed of tricalcium silicate, MnO2, CuO and Ni2O3 could enhance the microwave sintering.

Download Full-text

High Piezoelectric Properties and High TC in KNN-Based Lead-Free Ceramics Sintered in Reducing Atmosphere

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.281.628 ◽

2018 ◽

Vol 281 ◽

pp. 628-633

Author(s):

Yi Chao Zhen ◽

Zhen Yong Cen ◽

Wei Feng ◽

Xiao Hui Wang ◽

Long Tu Li

Keyword(s):

Piezoelectric Properties ◽

Rhombohedral Phase ◽

Lead Free ◽

Reducing Atmosphere ◽

Lead Free Ceramics ◽

Commercial Applications ◽

T Phase ◽

Sintering Method ◽

Mn Doped ◽

Piezoelectric Constants

Lead-free MnO doped 0.955K0.5Na0.5NbO3-0.045Bi0.5Na0.5ZrO3(abbreviate as KNN-0.045BNZ) ceramics have been prepared by a conventional solid-state sintering method in a reducing atmosphere. The addition of MnO suppresses grain growth and eliminates the liquid phase. MnO dopant changes the crystalline structures of KNN-0.045BNZ ceramics from the classical Morphotropic Phase Boundary (MPB) with rhombohedral phase (R) and tetragonal phase (T) to the suppressed MPB with R/T phase. The 0.4% MnO doped KNN-0.045BNZ ceramics show an excellent electrical properties with quasi static piezoelectric constantd33=300 pC/N, Curie temperatureTC= 350 °C, insulation resistivity ρ=4.83 × 1011(Ω・cm), and high field piezoelectric constants =438 pm/V (atEmax= 25 kV/cm). The results indicate that the 0.4%Mn doped KNN-0.045BNZ ceramic is a promising lead-free piezoelectric candidate material for commercial applications.

Download Full-text

EFFECT OF Pr DOPING ON FERROELECTRIC BEHAVIORS OF Pb(Zr0.65Ti0.35)O3

International Journal of Modern Physics B ◽

10.1142/s0217979208039332 ◽

2008 ◽

Vol 22 (13) ◽

pp. 2071-2082

Author(s):

F. YUAN ◽

F. GAO ◽

K. F. WANG ◽

S. DONG ◽

Y. WANG ◽

...

Keyword(s):

Piezoelectric Properties ◽

Ferroelectric Properties ◽

Crystallographic Structure ◽

Dielectric Measurements ◽

Ceramic Samples ◽

Solid State Sintering ◽

Sintering Method ◽

Rhombohedral Symmetry ◽

Ferroelectric And Piezoelectric Properties ◽

Dielectric Relaxor

Pr -doped Pb ( Zr 0.65 Ti 0.35) O 3 ( Pb 1-x Pr x( Zr 0.65 Ti 0.35)1-x/4 O 3, PPZT) ceramic samples are prepared using conventional solid-state sintering method, and their structural, dielectric, ferroelectric, and piezoelectric properties are investigated, focusing on the effects of Pr -doping. Upon increasing Pr doping level x, a transition of the crystallographic structure from rhombohedral symmetry to tetrahedral and finally to pseudocubic symmetry is observed at x ~ 0.08. The detailed dielectric measurements present a clear indication of relaxor-like behaviors at x = 0.08, while the samples at x < 0.08 offer slightly improved ferroelectric properties compared with pure Pb ( Zr 0.65 Ti 0.35) O 3. In spite of the dielectric relaxor behaviors induced by Pr -doping, both the ferroelectric and piezoelectric properties of PPZT are degraded at x = 0.08. The physics underlying the Pr -doping induced relaxor behaviors is then discussed.

Download Full-text

EFFECT OF YTTRIUM ON DIELECTRIC, PYROELECTRIC AND PIEZOELECTRIC PROPERTIES OF PBN FERROELECTRICS

International Journal of Modern Physics B ◽

10.1142/s0217979206035345 ◽

2006 ◽

Vol 20 (21) ◽

pp. 3081-3091 ◽

Cited By ~ 2

Author(s):

K. SAMBASIVA RAO ◽

N. VALLIS NATH ◽

P. MURALI KRISHNA ◽

D. MADHAVA PRASAD ◽

JOON HYUNG LEE

Keyword(s):

Transition Temperature ◽

Spontaneous Polarization ◽

Room Temperature ◽

Piezoelectric Properties ◽

Pyroelectric Coefficient ◽

Tetragonal Symmetry ◽

Maximum Volume ◽

Stiffness Constant ◽

Method Substitution ◽

Sintering Method

Materials with batch formula Pb (1-x-3y/2) R y Ba x Nb 2 O 6, where R=Y, (1-x)=0.73, 0.63, 0.53 and y=0.00, 0.02 have been prepared by the double sintering method. Substitution of yttrium (Y) restored tetragonal symmetry of PBN but reduced lattice parameters, cell volume and enhanced the density. Transition temperature of PBN has decreased due to the substitution of Y3+. Enhanced room temperature spontaneous polarization (Ps)=149.97 μ C/sq. cm has been observed in PBN53, which is above MPB, whereas enhanced value of Ps=112.74 μ C/sq. cm is found in Y: PBN63 at MPB region. The room temperature Pyroelectric coefficient (PRT=1.07) has been observed in the composition where maximum volume of Ps is obtained. Similarly, enhanced values of piezoelectric coefficients Kp=0.244, Kt=0.353, K31=0.131, d31=60, d33=159 and g31=3.65 have also been found in the same material PBN53. Substitution of Yttrium enhanced the stiffness constant 13.59 in PBN 73 to 14.27 of Y: PBN73.

Download Full-text

Structure and Piezoelectric Properties of (1-X)K0.49Na0.51NbO3-XLiTaO3 Lead-Free Piezoceramics

Materials Science Forum ◽

10.4028/www.scientific.net/msf.663-665.1310 ◽

2010 ◽

Vol 663-665 ◽

pp. 1310-1313 ◽

Cited By ~ 1

Author(s):

Yue Ming Li ◽

Liang Jiang ◽

Zhong Yang Shen ◽

Run Hua Liao ◽

Zhu Mei Wang

Keyword(s):

Phase Transition ◽

Room Temperature ◽

Electromechanical Coupling ◽

Piezoelectric Properties ◽

Lead Free ◽

Electromechanical Coupling Coefficient ◽

Orthorhombic Symmetry ◽

Coexistence Region ◽

Solid State Sintering ◽

Sintering Method

Lead-free (1-x)K0.49Na0.51NbO3-xLiTaO3 (x=0.00-0.07) piezoceramics were fabricated by the conventional solid-state sintering method, the effects of LiTaO3 content on the phase structure and piezoelectric properties of the ceramics were investigated. All the ceramics show single perovskite structure with a phase transition from an orthorhombic symmetry to a tetragonal one across an orthorhombic-tetragonal coexistence region with 0.04<x<0.06. For the ceramic sample with x=0.05, due to the coexistence of orthorhombic and tetragonal phases near room temperature, enhanced piezoelectric constant d33=236 pC/N and planar electromechanical coupling coefficient kp=40.9% are observed. In addition to other good electrical properties such as εr=969, tgδ=0.015 and Qm=41, this ceramic is a promising lead-free piezoelectric material.

Download Full-text

Preparation and Characterization of (1-x)BiScO3-xPbTiO3 Ceramics by Two-Step Sintering

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.368-372.8 ◽

2008 ◽

Vol 368-372 ◽

pp. 8-10 ◽

Cited By ~ 1

Author(s):

Ting Ting Zou ◽

Xiao Hui Wang ◽

Long Tu Li

Keyword(s):

Grain Size ◽

Low Temperature ◽

High Performance ◽

Piezoelectric Properties ◽

Sintering Temperature ◽

Sintering Aid ◽

Potential Approach ◽

Fine Grain ◽

Sintering Method

High-performance fine-grain (1-x)BiScO3-xPbTiO3 ceramics were prepared by two-step sintering method. Influences of sintering temperature, holding time, and composition on the microstructure and properties were discussed. The BSPT ceramics obtained via two-step sintering reaches density higher than 95% at a low temperature of 800°C without any sintering aid, and the grain size of the ceramics is also effectively controlled. Excellent piezoelectric properties between the composition of x=0.63 and x=0.64 reveals a probable MPB in this range, suggesting a potential approach to pursue high performance BSPT ceramics.

Download Full-text

Double Inhibitory Actions on WC Grains of Microwave Sintered WC-12wt%Co-VC Alloy

Materials Science Forum ◽

10.4028/www.scientific.net/msf.816.715 ◽

2015 ◽

Vol 816 ◽

pp. 715-721 ◽

Cited By ~ 1

Author(s):

Rui Bao ◽

Jian Hong Yi ◽

Jia Min Zhang ◽

Yi Chun Liu ◽

Feng Xian Li ◽

...

Keyword(s):

Mechanical Properties ◽

Positive Impact ◽

Rupture Strength ◽

Microwave Sintering ◽

Inhibitory Effects ◽

Microwave Exposure ◽

Microstructure Observation ◽

Average Grain Size ◽

Bulk Alloys ◽

Sintering Method

It is well known that grain-refinement has a positive impact on the mechanical properties of WC-Co cemented carbide. The effect of VC inhibitor and microwave on density, microstructure and mechanical properties of the sintered WC–12wt%Co alloy was investigated in the present study. The ball milled WC-12wt%Co-xVC composites were compressed and fabricated by using microwave sintering method. The experimental results indicate that the microwave sintering cycle was significantly shorter to that of vacuum processing, and the density of bulk alloys increased with VC inhibitor contents and microwave sintering temperatures. Moreover, the microstructure observation of the sintered samples suggests that VC inhibitor had prominent inhibitory action on WC grains in microwave exposure, and the WC average grain size of alloy with 0.7wt%VC inhibitor was 0.43μm when the sintering temperature reached 1420°C. It is also evident that WC-12wt% alloys with an appropriate proportion of VC inhibitor exhibited higher hardness (92.1HRA) and better transverse rupture strength (2380MPa). And finally the mechanism of inhibitory effects on WC grains under microwave irradiation was discussed.

Download Full-text

Structural, magnetic and electrical properties of NiCuZn ferrites prepared by microwave sintering method suitable for MLCI applications

Journal of Physics and Chemistry of Solids ◽

10.1016/j.jpcs.2010.06.007 ◽

2010 ◽

Vol 71 (9) ◽

pp. 1373-1380 ◽

Cited By ~ 50

Author(s):

M. Penchal Reddy ◽

G. Balakrishnaiah ◽

W. Madhuri ◽

M. Venkata Ramana ◽

N. Ramamanohar Reddy ◽

...

Keyword(s):

Electrical Properties ◽

Microwave Sintering ◽

Sintering Method ◽

Magnetic And Electrical Properties

Download Full-text

Synthesis of Ultra-Fine Zirconium Diboride Powders by Polymer Template Method Following by Microwave Sintering

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.697.49 ◽

2016 ◽

Vol 697 ◽

pp. 49-53

Author(s):

Qi Huang Deng ◽

Zhi Hui Ding ◽

Xiang Feng Shen ◽

Shi Yu Du ◽

Qing Huang

Keyword(s):

Phase Composition ◽

Optimum Parameter ◽

Microwave Sintering ◽

Zirconium Diboride ◽

Synthesis Temperature ◽

Molar Ratio ◽

Template Method ◽

Particle Sizes ◽

Polymer Template ◽

Sintering Method

Zirconium diboride (ZrB2) nanoparticles were synthesized by polymer template method using zirconyl (ZrOCl2∙8H2O), boric acid (H3BO3), Chitosan and Mannitol (C6H14O6) with microwave sintering method. SEM and other analytic methods were used to study the phase composition and the microstructure of the nanoparticles.The influence of the ratio of zirconium to boron and carbon on the purity of ZrB2 powders, as well as the synthesis temperature and the holding time were studied. Pure ZrB2 at the molar ratio of C/Zr/B=10/5.2/1 can be obtained. The optimum parameter for microwave sintering is 1320 °C for 1h, which is about 300°C lower than conventional carbonization reduction to obtain ZrB2 powders. The synthesized powders have small particle sizes (50nm) with nearly spherical morphology.

Download Full-text