钛酸铋钠基压电材料制备技术研究进展

钛酸铋钠(BNT)基压电材料因具有较好的电学性能以及高居里温度等优点,成为了压电材料领域的研究热点之一。如何制备出性能优异的钛酸铋钠基压电材料,是满足各个领域应用要求的重要环节。重点综述了近年来钛酸铋钠基压电材料制备技术的研究进展,从固相烧结、放电等离子烧结以及微波烧结等角度对其烧结技术进行论述;从溶胶-凝胶、脉冲激光沉积和射频磁控溅射等角度对其薄膜制备技术进行综述;对热喷涂制备压电涂层的机理和工艺进行总结。结果表明,烧结温度是影响块体材料结构和性能的关键因素,其中放电等离子烧结与微波烧结相较于传统的固相烧结能够有效控制材料的烧结温度;在钛酸铋钠薄膜的制备中对沉积温度、氧气压力以及退火温度的控制可以有效提高薄膜电学性能;热喷涂制备的钛酸铋钠涂层通过热处理工艺能够改善涂层的电学性能,并且热喷涂能够在复杂零件表面实现压电涂层的可控制备,其中钛酸铋钠压电陶瓷薄膜和涂层的制备扩展了其应用范围。最后,展望了压电陶瓷材料技术的未来发展趋势,为压电材料制备技术的研究提供了一定的参考。     

PYN对BS-PT压电陶瓷变温压电性能的影响

用前驱体法制备出了BS-x PT-y PYN(y=0.1,0.15,0.2,0.3)压电陶瓷。对压电陶瓷MPB处进行变温铁电、介温、变温应变等变温测试,重点分析其温度稳定性和弛豫性能。结果表明,各MPB组分都有良好的温度稳定性,在0.32BS-0.58PT-0.1PYN中,铁电性能随着温度升高而逐渐增强,其余3个组分基本保持不变;而随着PYN含量的增加,PT的减少,体系弛豫性逐渐增强。     

碱性溶液环境中CrSi(Ni,Al)电阻薄膜的电学稳定性及劣化机理

研究磁控溅射法制备的Cr-Si-Ni和Cr-Si-Ni-Al电阻薄膜在模拟的碱性环境（NaOH溶液）中,介质溶液浓度和温度对薄膜电学稳定性的影响及其机理。结果表明：经热处理后呈纳米晶结构的2种薄膜在低温低浓度的碱性溶液中具有较好的电学稳定性和耐腐蚀性能,但是,随着溶液浓度和温度的增大其电学稳定性和耐腐蚀性能急剧下降,特别是在高温高浓度的碱性溶液中薄膜在很短时间内就出现性能劣化现象;2种薄膜在低温低浓度的碱性溶液中能够迅速地在膜层表面形成稳定的钝化保护层,从而有效地抑制溶液离子对薄膜内层的进一步腐蚀;而在高温或高浓度的碱性溶液中薄膜表面难以形成稳定的钝化保护层。     

掺锑SnO2薄膜电学性能及热应力的研究

采用热喷涂法制备掺锑SnO2电热膜，研究退火对不同衬底膜电学性能和热应力状态的影响。结果表明，600℃退火可使硼硅玻璃衬底膜的电学性能稳定性增强，退火温度对石英衬底膜的电学稳定性影响不大，但可使热应力降低。     

压电换能器在谐振频率附近的等效电路仿真及实验研究

针对压电换能器的串并联谐振频率附近难以确定其最优匹配阻抗参数等问题,采用saber软件对阻抗匹配过程中匹配电感的参数进行仿真分析,以研究匹配电感参数对串并联谐振频率区电流大小及高频变压器次级电流电压相位差的影响。同时,对空载、加载等工况下串并联谐振区进行实验研究与验证。研究结果表明:将匹配电感调至最佳值时,压电换能器的输出电流最大,高频变压器次级电流电压相位差为零;压电换能器在空载工况下,其工作于串联谐振状态时的性能较好;而在加载工况下,其工作于并联谐振状态时的性能较好。     

铌酸钾钠无铅压电陶瓷掺杂及制备技术现状

铌酸钾钠无铅压电陶瓷因具有环境友好型、良好的电学性能、较好的居里温度等成为当前压电铁电材料的研究热点之一,广泛应用于科技、工业等方面。综述近年来铌酸钾钠压电陶瓷材料的研究进展,主要从金属离子及其氧化物掺杂、稀土离子,以及其他化合物掺杂等方面对铌酸钾钠的掺杂制备进行总结,从热压烧结、微波烧结及放电等离子烧结等方面对其烧结技术进行论述,从激光脉冲沉积技术、射频磁控溅射法等方面对其成形工艺进行综述。结果表明,对铌酸钾钠压电陶瓷进行掺杂制备及采取先进的烧结技术可以明显提升其电学性能,铌酸钾钠压电陶瓷薄膜和涂层的制备拓展了铌酸钾钠的应用范围,使其可以应用于国防、航空航天及通信等方面。最后对铌酸钾钠的发展趋势进行总结。主要从铌酸钾钠陶瓷的掺杂制备、烧结工艺及成形工艺等方面进行综述,对铌酸钾钠压电陶瓷在各领域的研究有一定理论与参考意义。     

KxNa1-xNbO3无铅压电陶瓷的常压烧结及其性能研究

以固相法合成了铌酸钾钠(KxNa1-xNbO3)粉体,采用常压烧结制备了铌酸钾钠无铅压电陶瓷,研究了粉体相组成,烧结温度,极化电压与陶瓷致密度、电学性能的关系。结果表明:当x=0.5,烧结温度为1050℃,极化电压为3kV/mm时,可制备出具有较好压电性能的铌酸钾钠压电陶瓷(相对密度为94%,压电常数d33=105pC/N,平面机电耦合系数kp=0.39,介质损耗tanδ=0.29,机械品质因数Qm=45,介电常数εr=720)。随着极化电场的增加,陶瓷压电性能提高,当极化电场E=3kV/mm时,极化基本达到饱和。     

(K_xNa_(1-x))NbO_3基陶瓷的热稳定性研究（英文）

采用传统固溶反应法制备了(K_xNa_(1-x))_(1-y)Li_yNb_(0.80)Ta_(0.20)O_3(x=0.40~0.60;y=0.03,0.035,0.04)系列无铅压电陶瓷,研究了其压电性能的温度稳定性。实验得出在研究的组分范围内,陶瓷的压电常数d_(33)可达到250 pC/N,k_p到达50%。在高达约325℃的老化试验中发现,尽管在室温下存在多型相变的影响,但陶瓷的d_(33)和k_p值几乎一直保持不变。而且,陶瓷的k_p值在-50℃到120℃的宽温度范围内几乎不受温度影响,显示了很好的温度稳定性。另外还从两相共存的温度范围对陶瓷的热稳定性能进行了讨论。     

烧结温度对0.9PbZr0.52Ti0.48O3-0.1NaNbO3压电陶瓷结构及电学性能的影响

采用传统固相烧结法制备了钠过量的0.9PbZr0.52Ti0.48O3-0.1NaNbO3(PZT-NN)压电陶瓷,研究了烧结温度对PZT-NN陶瓷晶体结构及其电学性能的影响。XRD结果表明,不同温度烧结的PZT-NN陶瓷均为单一钙钛矿结构,在1125~1150℃温区烧结时,陶瓷发生了由四方相向正交相的相变。随烧结温度进一步升高,压电常数d33、介电常数εr以及剩余极化强度Pr均呈递减趋势,烧结温度为1125℃的PZT-NN陶瓷具有较好的电学性能:d33=218pC/N,εr=851,tanδ=0.02。PZT-NN陶瓷的相对密度随烧结温度的升高而增大,在1150℃时达到95%,钠过量的NaNbO3加入使PZT陶瓷的致密化烧结温度降低了50~150℃。     

多铁性陶瓷BiFeO_3-PbTiO_3-BaTiO_3的介电、压电及其老化性能研究

采用高温固相法制备了钙钛矿结构的0.7BiFeO_3-0.2PbTiO_3-0.1BaTiO_3陶瓷,研究了该陶瓷的介电性能、压电性能及其老化性能。结果表明,该陶瓷是一种非常有潜力的高温压电陶瓷,其介电常数和介电损耗分别为390和0.015,铁电居里温度TC约为600℃,压电常数d_(33)约为100 pC/N,压电常数的时间稳定性和热稳定性好,热退极化温度Td约为500℃。压电常数热退极化机理主要为内在的剩余极化老化,辅以低浓度氧空位等外在缺陷对畴壁的钉扎作用。     

多层压电陶瓷变压器的振动与疲劳

低温共烧多层压电陶瓷变压器具有体积小、转换效率高、升压比高、无电磁辐射等优点,是传统电磁变压器在小功率仪器设备上理想的替代品.采用Pb(Mg_(1/3)Nb_(2/3))O_3-Pb(Ni_(1/3)Nb_(2/3))O_3-Pb(ZrTi)O_3低烧瓷料,通过干法流延多层叠印技术制备出高性能多层压电陶瓷变压器样品,内电极银钯浆配比7:3.利用Polytec300-F扫描激光测振仪测试了多层压电陶瓷变压器沿长度伸缩振动的位移和模态.通过对压电变压器振动性能和升压比的测试,研究了器件性能衰减及疲劳特性.     

一种低温共烧压电陶瓷的制备

压电陶瓷多层膜的低温共烧特性及压电性能密切依赖于其成分。采用调节压电材料成分,以0．90Pb（zr048Ti0.52）03—0．05Pb（Mnl／3Sb2／3）03-0．05Pb（Zn1/3Nb2／3）03四元体系为研究对象,同时添加烧结助剂CuO来实现多层膜的低温烧结。对多层膜的流延、排胶、烧结、极化等工艺进行探索以优化工艺参数,最终获得850oC烧结温度下的高致密度多层压电陶瓷。压电性能的测试表明三层结构的压电多层膜陶瓷表观d33达873pC／N,远高于同成分单层陶瓷306pC／N的d33值。采用多普勒激光测振仪进行扫频实验,测定了多层陶瓷纵向振动速度的频谱,确定了基于该多层膜压电振子的最优谐振频率。     

Optical and electrical properties of TiO2/Au/TiO2 multilayer coatings in large area deposition at room temperature

TiO2/Au/TiO2 multilayer thin films were deposited at polymer substrate at room temperature using dc (direct current) magnetron sputtering method.By varying the thickness of each layer,the optical and electrical properties of the TiO2/Au/TiO2 multilayer films can be tailored to suit different applications.The thickness and optical properties of the Au layer and the quality of the Au-dielectric interfaces are critical for the electrical and optical performance of the Au-dielectric multilayer thin films.At the thickness of 8 nm,the Au layer forms a continuous structure having the lowest resistivity and it must be thin for high transmittance.The multilayer stack can be optimized to have a sheet resistance of 6 Ω/sq.at a transmittance over 80% at 680 nm in wavelength.The peak transmittance shifts towards the long wavelength region when the thickness of the two TiO2 (upper and lower) layers increases.When the film thickness of the two TiO2 film is 45 nm,a high transmittance value is obtained for the entire visible light wavelength region.     

Achieving remarkable piezoelectric activity in Sb–Mn co-modified CaBi4Ti4O15 piezoelectric ceramics

CaBi₄Ti₄O₁₅ (CBT)-based Aurivillius high-temperature piezoceramics with different Sb–Mn co-doping amounts were synthesized via the conventional sintering technique. The influences of doping amount on the product were studied via their crystal structure, microstructure, and piezoelectric performance. It is found that an appropriate Sb–Mn co-doping amount can effectively optimize the crystal structure and decrease the oxygen vacancy concentration in CBT ceramics, leading to enhanced electrical properties. Optimized electrical performance with a high Curie temperature (T_C) of 792 °C and a remarkable piezoelectric coefficient (d₃₃) of 25 pC/N were achieved at a doping amount (x) of 0.05. Furthermore, this ceramic is found to exhibit an excellent thermal stability, with d₃₃ retaining 88% of its original value after annealing at 600 °C for 2 h. Moreover, this ceramic shows a high electrical resistivity (ρ) of 1.35×10⁸ Ω·cm with a small dielectric loss (tan δ) of 1.7% at 400 °C. Because of such outstanding piezoelectric performance, it is believed that these Sb–Mn co-doped CBT ceramics could be potential candidates for high-temperature piezoelectric applications.     

Piezoelectric and dielectric properties of Lix（K0.46Na0.54） 1-xNb0.86Ta0.1 Sb0.04O3 lead-free ceramics

Lead-free piezoelectric ceramics Lix（K0.46Na0.54）1-xNb0.86Ta0.1Sb0.0403 （with x ranging from 0 to 0.1） were synthesized by conventional solid state sintering method. The effect of cationic substitution of Li for K and Na in the A sites of perovskite lattice on the structure, phase transition behavior and electrical properties were investigated. Morphotropic phase boundaries（MPB） between orthorhombic and tetragonal phase are found in the composition range of 0.06≤x≤0.08. Analogous to Pb（Zr, Ti）O3, the dielectric and piezoelectric properties are enhanced for the composition near the morphotropic phase boundary. The Li0.06（K0.46Na0.54）0.94- Nb0.86Ta0.1Sb0.04O3 ceramics show excellent electrical properties, that is, piezoelectric constant d33=215 pC/N, planar electromechanical coupling factor kp=41%, dielectric constant ε33^T /ε0=1 303, and dielectric loss tan δ=2.45%. The results indicate that Lix（K0.46Na0.54）1 -xNb0.86Ta0.1Sb0.0403 ceramic is a promising lead-free piezoelectric material.     

Effect of sintering temperature and composition on microstructure and properties of PMS-PZT ceramics

The piezoelectric ceramics xPb（Mn1/3Sb2/3）O3-（1-x）Pb（Zr1/2Ti1/2）O3 （abbreviated as PMS-PZT） were synthesized by traditional ceramics process. The effect of sintering temperature and the amount of Pb（Mn1/3Sb2/3）O3 （abbreviated as PMS） on phase structure, microstructure, piezoelectric and dielectric properties of PMS-PZT ceramics was investigated. The results show that the pure perovskite phase is in all ceramics specimens, the phase structure of PMS-PZT ceramics changes from tetragonal phase to single rhombohedral phase with the increasing amount of PMS. The dielectric constant εr, Curie temperature Tc, electromechanical coupling factor kp and piezoelectric constant d33 decrease, whereas the mechanical quality factor Qm and dielectric loss tanδ increase with the increasing amount of PMS in system. The optimum sintering temperature is 1 200-1 250 ℃. It is concluded that the PMS-PZT （x=0.07） ceramics sintered at 1 250 ℃ is suitable for high-power piezoelectric transformer. These properties include εr=674.8, tanδ =0.005 25, kp=0.658, Qm= 1 520, d33=230 pC/N, Tc=275 ℃.     

Mechanical properties and friction−wear characteristics of VN/Ag multilayer coatings with heterogeneous and transition interfaces

The heterogeneous multilayer interface of VN/Ag coatings and transition multilayer interface of VN/Ag coatings were prepared on Inconel 781 and Si(100), and the microstructures, mechanical and tribological properties were investigated from 25 to 700 °C. The results showed that the surface roughness and average grain size of VN/Ag coatings with transition multilayer interface are obviously larger than those of VN/Ag coatings with heterogeneous multilayer interface. The coatings with transition multilayer interface have higher adhesion force and hardness than the coatings with heterogeneous multilayer interface, and both coatings can effectively restrict the initiation and propagation of microcracks. Both coatings have excellent self-adaptive lubricating properties with a decrease of friction coefficient as the temperature increases, but their wear rates reveal a drastic increase. The phase composition of the worn area of both coatings was investigated, which indicates that a smooth Ag, Magnéli phase (V₂O₅) and bimetallic oxides (Ag₃VO₄ and AgVO₃) can be responsible to the excellent lubricity of both coatings. To sum up, the coatings with transition multilayer interface have excellent adaptive lubricating properties and can properly control the diffusion rate and release rate of the lubricating phase, indicating that they have great potential in solving the problem of friction and wear of mechanical parts.     

Numerical simulation of temperature field in multilayer heterogeneity lamination laser soldering

A temperature field numerical simulation is carried out using the finite dement method for laser soldering on PECT (piezoelectric ceramics transformer). A three-dimensional model of laser soldering temperature field of multilayer materials is established. Then, the model was simplified in order to perform an efficient finite dement analysis. Moreover, the temperature distribution characteristic in the laser soldering is investigated and verified by experiments. In all cases, the numerical results are in good agreement with the experimental measurements.