外场下PbLa（Zr,Sn，Ti）O3陶瓷相变及介电性能行为研究

研究了温度、等静压力对PbLa（Zr，Sn，Ti）O3陶瓷相变、介电常数（εr）及损耗（tanδ）的影响。结果表明：在温度场下，随着温度的升高，PbLa（Zr,Sn，Ti）O3陶瓷从四方反铁电相（AFET）转变为立方顺电相（PEc），在低温段出现频率弥散现象；在压力场下，随着等静压力的增加极化过的AFE陶瓷发生FE／AFE相变，同时伴随突然的释放电荷过程；在一定的等静压力下，经极化后变为铁电体的PbLa（Zr,Sn，Ti）O3陶瓷在温度的诱导下会转变为反铁电相，最后转变为顺电相；随着等静压力的增加，铁电／反铁电转变温度降低，反铁电／顺电转变温度上升。     

Zr掺杂对反铁电陶瓷[(Bi_(1/2)Na_(1/2))_(0.94)Ba_(0.06)]_(1-x)Zr_xTiO_3介电及储能性能的影响

采用传统固相反应制备无铅反铁电陶瓷材料[(Bi1/2Na1/2)0.94Ba0.06](1-x)ZrxTiO3(x=0,0.03,0.06,0.09),研究材料的相结构、介电特性及储能性能。结果表明:此陶瓷的极化强度Ps、介电常数εr,随着Zr含量的增加而减小,能量储存性能也随之改变。P-E电滞回线显示,当x=0.03时,此材料的储能性能最好。     

(Bi_(0.46)Na_(0.46)Ba_(0.06)La_(0.02))Zr_xTi_((1-x))O_3反铁电陶瓷介电性能及储能性能的研究

采用传统固相反应法制备无铅反铁电陶瓷材料(Bi0.46Na0.46Ba0.06La0.02)ZrxTi(1-x)O3(x=0,0.02,0.04,0.06),研究了材料的相结构、介电及储能性能。结果表明,随着Zr含量增加,晶粒尺寸逐渐减少,介电常数逐渐减少,储能密度先增加后减少。少量的Zr掺杂(x=0.02)可以大幅度提高陶瓷的储能密度。在60kV/cm的电场下,其储能密度由x=0的0.43 J/cm3提高到x=0.02的0.77 J/cm3,提高了近80%。     

(Bi0.5Na0.5)TiO3-Ba(Ti,Zr)O3固溶体无铅压电陶瓷

改善烧结制度制备(Bi0.5Na0.5)TiO3-Ba(Ti,Zr)O3(简称BNT-BZT)系无铅压电陶瓷,能得到较高的致密度.该压电陶瓷具有良好的电学性能.电学性能的最佳成分点位于准同型相界附近四方相的区域,组成为(Bi0.5Na0.5)TiO3-xBa(TiyZr)O3x=0.09～0.12的范围内,此时具有最大的压电常数(d33=147pC/N)和室温介电常数(ε33T/ε0=881.4).BNT-BZT陶瓷体系的机电耦合系数Kp受BZT含量的影响较小,而BZT含量对机械品质因数Qm的影响较大.     

空心阴极离子镀(Ti,Zr)N膜层制备及应用研究

用空心阴极离子镀(HCD)技术制备了(Ti,Zr)N膜层,研究了氮分压对膜层硬度的影响.以结合强度为判据,采用基体温度、轰击气压、负偏压及中间层沉积时间作为试验的变化因素,用正交试验法优化了制备(Ti,Zr)N膜层的最佳工艺规范.应用优化的工艺参数对印制板(PCB)刀具进行了镀膜强化应用,结果表明,镀层性能良好,能够延长刀具的使用寿命.     

Pb(Zr0.95Ti0.05)O3纳米粉的制备及其钙钛矿结构的稳定性

论文采用溶胶-凝胶技术合成了Pb（Zr0.95Ti0.05）O3纳米粉,并探讨了煅烧温度对PZT(95/5)钙钛矿相结构稳定性的影响。据TGA-DSC的实验结果,确定了干凝胶粉的煅烧温度范围为550℃-750℃。XRD实验结果表明,随着煅烧温度的升高,粉体主晶相的强度逐渐升高,杂质相的峰高逐渐减弱直至消失。当在750℃煅烧时,粉体结构为单一的钙钛矿相。利用SEM观察发现,随着煅烧温度的升高,所合成的粉体的尺寸逐渐变小、均匀。当在750℃煅烧时,单一钙钛矿结构的粉体的平均粒径尺寸为100 nm。     

近β型钛合金Ti4Zr1Sn3Mo25Nb(TLM)热处理与材料强化研究

利用光学显微镜、X射线衍射仪、透射电镜和力学试验机、摩擦试验机研究了不同热处理条件对新型近β型钛合金Ti4Zr1Sn3Mo25Nb(TLM)的显微组织、相变以及力学性能和耐磨性的影响。结果表明:TLM合金在β相区固溶处理后主要形成亚稳的等轴β相(βms),在低温时效时βms开始分解,在晶粒内部形成大量密集次生α相(αs),并呈现点状和细针状分布,从而使合金产生弥散强化和细晶强化。680℃,1h空冷+510℃,6h空冷TLM钛合金的耐磨性最好,其耐磨性优于退火态Ti6Al4V和时效态Ti-13Nb-13Zr钛合金。     

利用FCVA法和CO2、N2制备Ti(C,O,N)纳米复合薄膜的研究

使用CO2和N2利用磁过滤阴极弧法（FCVA）在Si（100）和304不锈钢上沉积Ti(C,N,O)薄膜。采用XPS, XRD, Raman, SEM, 摩擦磨损试验机,电化学实验站检测得出气体流速对薄膜成分、相结构和薄膜性能的作用。当混合气体流量从10sccm升高的50sccm时,薄膜中的C和N含量有明显增加,而O和Ti含量有小幅下降;当混合气体流量从50sccm升高到80sccm时,薄膜中的C和N含量下降,而Ti含量有小幅上升,O含量急剧上升。薄膜由nc-Ti(C,N,O)纳米晶结构,转变为nc-Ti(C,N,O)/a-CNx,a-TiO2/a-CNx,N-doped a-TiO2/a-C纳米复合结构。N-doped a-TiO2/a-C纳米复合结构薄膜具有最低的摩擦系数（0.34）,nc-Ti(C,N,O)/a-CNx,N-doped a-TiO2/a-C纳米复合结构薄膜在Hanks溶液中均表现出良好的抗腐蚀能力。     

ACu3Ti4O12(A=Ca, Sr, Ba)的介电性能

利用传统固相反应法制备理想摩尔配比的CaCu3Ti4O12(CCTO)、SrCu3Ti4O12(SCTO)和BaCu3Ti4O12(BCTO)陶瓷样品,测量它们在不同频率下的介电常数和介电损耗随温度的变化关系.结果发现,CaCu3Ti4O12的介电性能基本上属于德拜弛豫,而造成SCTO和BCTO与CCTO介电性能差异巨大的原因是结构的畸变和杂相的出现.     

Zr/Cu/Zr部分瞬间液相焊扩散连接Ti(C,N)-Al_2O_3陶瓷基复合材料

采用Zr箔/Cu箔/Zr箔中间层对Ti(C,N)-Al2O3陶瓷基复合材料进行部分瞬间液相扩散连接实验,研究保温时间对元素扩散及界面反应产物的影响,探讨了制约接头室温强度的因素,对比分析了在部分瞬间液相扩散连接过程中,辅助脉冲电流对元素扩散及接头强度的作用机制.结果表明,预置Zr箔/Cu箔/Zr箔中间层通过部分瞬间液相扩散连接,在加热温度950℃,保温时间15~30 min条件下接头强度达到最大值.保温时间过短,活性元素Zr削弱基体强度,保温时间过长,Zr与Cu在界面生成金属间化合物降低了接头的强度.扩散焊过程中施加辅助脉冲电流能够有效缓解接头的残余应力,防止裂纹在脆性基体材料中扩展;但是同时促进了界面处的反应进程,显著提高了界面处Cu-Zr金属间化合物的形成速度,使得界面易成为接头的薄弱环节.     

Imprint characteristics of Pt/Pb(Zr,Ti)O3/Ir capacitors

The dynamic and static imprint characteristics of PZT thin film capacitors prepared by a two step reactive sputtering method were studied. The imprint is caused by an internal field generated by the trapping of electronic charges at interfacial layers that are injected, from the electrode. When unipolar pulse stressing is applied to the PZT capacitor, the cumulative time rather than the pulse cycles accounts more for the dynamic imprint characteristics. The amount of voltage shift in the polarization(P)-voltage(V) curve is reduced when the unipolar pulses are applied at elevated temperatures or a high amplitude pulse is applied. For static imprint stressing, the voltage shift increases with the temperature and is readily removed by application of bipolar pulses to the imprinted PZT capacitor at elevated temperatures. A method to estimate the lifetime limitation as a result of imprint failure in 1T/1C FRAMs is proposed.     

BNT-BZT压电陶瓷准同相界处材料性能的研究

研究(1-x)(Bi0.5Na0.5)TiO3-xBa(Ti0.95Zr0.05)O3(BNT-BZT)体系陶瓷的准同型相界,以及陶瓷材料的微观结构和性能之间的关系.BNT-BZT陶瓷体系在富BNT和Zr含量低的区域存在准同型相界,在相界附近可能得到性能优良的无铅压电陶瓷,相界点在x≈0.1这个区域内.将BNT陶瓷和BZT陶瓷固溶后能够得到d33大于150 pC/N,居里温度在240℃左右,介电常数在900左右的性能良好的无铅压电陶瓷.     

K改性的BNT-BZT压电陶瓷制备与性能研究

无铅压电陶瓷是压电材料中一个重要的研究方向，为了能够取代目前广泛应用的含铅材料，需要进一步提高无铅陶瓷材料的各项性能，尤其是压电性能。BNT-BZT系陶瓷是钛酸铋钠（BNT）和锆钛酸钡（BZT）两相形成的固溶体，在BNT-BZT陶瓷体系中，富BNT和低Zr含量的区域存在准同型相界，在相界附近可以得到性能优良的无铅压电陶瓷，其性能以3大约150pC/N，居里温度在240℃左右，介电常数大约900。在BNT-BZT相界点处掺杂K离子，研究了K改性的BNT-BZT体系陶瓷的微观结构与性能。实验结果表明，以3达到165pC／N；居里温度达到270℃；烧结中出现了玻璃相，预烧温度和烧结温度相对于原体系都有适当降低。     

Fabrication of niobium doped Pb（Zr, Ti）O3 fibers by viscous polymer processing

A technique based on viscous polymer processing （VPP） was described, which can produce high ceramic content green fibers. PZT-5 ceramic powders were ball milled to get high dispersibility. The slurry prepared for VPP was a composition of PZT-5 powder, PVA binder and glycerin. High ceramic content PZT-5 fibers were extruded with the slurry. The results show that the ceramic powders have fine mean particle size of 0.54 pan, high specific surface area of 3.55 m^2/g and zeta potential of 8.81 mV after 16 h milling. The fibers sintered at 1 280 ℃ for 4 h have pure perovskite structure and grains of 2-5 μm in size, with little pores or cracks. The ultimate tensile strength of sintered fibers is up to 13.84 MPa compared with 2.88 MPa of green fibers. The remnant polarization （Pr） and coercive field （Ec） of the fibers are 50.65 μC/cm^2 and 2.45 kV/mm, respectively. This fiber can withstand an electric field of 9 kV/mm higher than the ceramic （5 kV/mm）, which shows high directional and compact qualities.     

Effect of annealing temperature on ferroelectric properties of （Bi, Nd）4（Ti, V）3O12 thin films

Thin films of Nd^3＋/V^5＋-cosubstituted bismuth titanate, （Bi3.sNd0.5）（ Ti2.96V0.04）O12 （BNTV）, were fabricated on the Pt（111）/Ti/SiO2/Si（100） substrates by a chemical solution deposition technique and annealed at different temperatures of 650, 700, 750 and 800 ℃. The surface morphology and ferroelectric properties of the samples were studied in detail. The result shows that the film annealed at 800 ℃ indicates excellent ferroelectricity with a remanent polarization of 2Pr=40.9 i.tC/cm^2, a coercive field （Ec） of 114 kV/cm at an applied electrical field of 375 kV/cm. The substitution of Ti-site ion by V^5＋ ions could improve the upper limit of the optimal annealing temperature by decreasing the space charge density in BNT thin film. Additionally, the mechanism concerning the dependence of ferroelectric properties of BNTV thin films on the annealing temperature was discussed.     

溶剂热法制备纳米Pb（Zr0．52Ti0．48）O3粉体

以硝酸铅、氧氯化锆、四氯化钛、氢氧化钾和氨水为原料，以乙醇和水的混合液为溶剂，采用溶剂热法合成了纳米Pb（Zr0．52Ti0．48）O3粉体。通过XRD和TEM对粉体进行了表征，并研究了醇水比（Vethanol/Vwater）和温度对粉体物相和粒径的影响。研究结果表明：在180℃、醇水比1：1以及KOH为2mol／L的条件下，可以制备粒径约为10nm的PZT粉体；适量乙醇的加入有利于合成纳米PZT粉体并降低生成PZT所需的温度。     

Ba（Sn0．1Ti0．9）O3粉体的熔盐法制备与性质

采用熔盐法研究了Ba（Sn0．1Ti0．9）O3铁电体粉体的制备工艺和粉体性质。探讨了在熔盐催化下，合成温度对Ba（Sn0．1Ti0．9）O3反应完全程度及粉体形态的影响。结果表明，当反应温度达到900℃时，在熔盐环境下即可合成单相固体Ba（Sn0．1Ti0．9）O3，随着反应温度提高，粉体尺寸变化不大，但当温度超过950℃时出现晶粒异常长大趋势。烧结陶瓷的形貌和介电性质显示陶瓷粉体烧结活性好且介电性质优良。     

Properties of Pb(Zr, Ti)O3 fibres with a radial gradient structure

One difficulty during the fabrication of lead zirconate titanate (PZT) materials is the high partial pressure and the accompanied evaporation of lead oxide (PbO) during sintering. To overcome this problem, atmospheric powders are used in the sintering step, whereby a composition and microstructure gradient across the fibre radius can be expected. In this study, therefore, the microstructure (porosity, grain size), the chemical and the phase composition as well as the ferroelectric properties were analysed across the fibre diameter. For these investigations, extruded PZT fibres with a green diameter of 300 μm and 70 μm were sintered at 1200 °C for 2 h in a PbO-enriched atmosphere. The measurements revealed that the chemical and thus the phase composition vary across the radius of the fibres for both fibre diameters, but the observed gradients are much more pronounced for 70 μm fibres. By removing the affected surface layer of a 300 μm diameter fibre, the maximum free strain could be increased by 20%.