Defect control for enhanced piezoelectric properties in SnO 2 and ZrO 2 co-modified KNN ceramics fired under reducing atmosphere

2017 ◽  
Vol 37 (5) ◽  
pp. 2057-2065 ◽  
Author(s):  
Yu Huan ◽  
Xiaohui Wang ◽  
Tao Wei ◽  
Peiyao Zhao ◽  
Jing Xie ◽  
...  
2018 ◽  
Vol 281 ◽  
pp. 628-633
Author(s):  
Yi Chao Zhen ◽  
Zhen Yong Cen ◽  
Wei Feng ◽  
Xiao Hui Wang ◽  
Long Tu Li

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.


Author(s):  
Zhenyong Cen ◽  
Shuaishuai Bian ◽  
Ze Xu ◽  
Ke Wang ◽  
Limin Guo ◽  
...  

AbstractIt is a very difficult work to sinter K0.5Na0.5NbO3 (KNN)-based materials with good reduction resistance in strong reducing atmosphere. 0.945K0.48Na0.52Nb0.96Ta0.04O3−0.055BaZrO3 + 0.03ZrO2 + y mol%MnO (KNNT−0.055BZ + 0.03Zr + yMn) ceramics sintered in reducing atmosphere were prepared successfully by conventional solid-state reaction methods. MnO dopant increases grain size at y = 5–8 due to strong lattice distortion and then decreases grain size at y = 9 due to much Mn4Nb2O9 accumulated at the grain boundary. MnO dopant as an excellent sintering aid can effectively reduce volatilization of alkali metal by decreasing the sintering temperature (Tsinter). Reducing alkali metal volatilization can greatly reduce oxygen vacancies and improve piezoelectric properties. MnO dopant can improve the anti-reduction properties. The KNNT−0.055BZ + 0.03Zr + yMn ceramics at y = 6–9 show outstanding anti-fatigue of unipolar piezoelectric strain under the synergistic effect of reduced oxygen vacancies due to reduced volatilization and increased grain size. Piezoelectric properties and temperature stability of KNNT−0.055BZ + 0.03Zr ceramics sintered in reducing atmosphere are improved simultaneously by MnO dopant. Optimum inverse piezoelectric coefficient (d 33 * ) of ceramics at y = 8 reaches up to 480 pm/V under low driving electric field E = 20 kV/cm at room temperature, and its temperature stability of d 33 * reaches 158 °C. It will be an excellent lead-free material candidate for the preparation of multilayer piezoelectric actuators co-fired with nickel electrode.


2018 ◽  
Vol 101 (9) ◽  
pp. 4108-4117 ◽  
Author(s):  
Zhenyong Cen ◽  
Yichao Zhen ◽  
Wei Feng ◽  
Peiyao Zhao ◽  
Lingling Chen ◽  
...  

2019 ◽  
Vol 10 (10) ◽  
Author(s):  
Anton Bonartsev ◽  
Vera Voinova ◽  
Elizaveta Akoulina ◽  
Andrey Dudun ◽  
Irina Zharkova ◽  
...  

Alloy Digest ◽  
1976 ◽  
Vol 25 (9) ◽  

Abstract ANACONDA Alloy 1870 is a free-cutting high-conductivity copper. It is a deoxidized copper with lead added to impart free-cutting properties. The various and unusual properties of Alloy 1870 make it suitable for many applications in the manufacture of parts machined from rods and for current-carrying studs, nuts and bolts designed for use at normal temperatures. Because it is deoxidized, it is not susceptible to hydrogen embrittlement if heated in a reducing atmosphere. This datasheet provides information on composition, physical properties, hardness, elasticity, tensile properties, and shear strength. It also includes information on corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: Cu-318. Producer or source: Anaconda American Brass Company.


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