微波介质陶瓷谐振器磁控溅射金属化

微波介质陶瓷谐振器在无线通信基站中有广泛的应用,其品质因数(Q值)主要由材料的介质损耗和金属膜的电导损耗所决定的,传统丝印烧结的金属化膜损耗较大,已成为限制谐振器Q值的主要因素。本文采用直流磁控溅射对相对介电常数为45的微波介质陶瓷进行金属化处理,研究了不同的清洗工艺和复合膜系对介质谐振器性能的影响。实验结果表明,1表面精细打磨和等离子清洗工艺有利于提高膜层结合力,其中Cr/Cu/Ag复合膜系性能最佳,溅射金属化膜层结合力可达6.4MPa,优于丝印工艺的1.8MPa;250~100nm厚度的过渡层金属Cr对Q值几乎无影响,因此可用Cr层提高结合力,且不会牺牲器件Q值;3溅射后器件的Q值最大可达到2673,明显优于丝印烧结工艺的2268。     

压电陶瓷蜂鸣片测试仪的校准方法

正0引言压电陶瓷蜂鸣片测试仪是针对压电陶瓷蜂鸣片分选而专门设计配套的智能型测试仪器,能直接显示压电陶瓷蜂鸣片的谐振频率和等效电阻数值,用于蜂鸣片生产过程中的质量检测,属于"半导体材料工艺参数测量仪"计量器具。目前没有检定或校准压电陶瓷蜂鸣片测试仪的技术依据。为确保压电陶瓷蜂鸣片测试仪测量结果的准确可靠,保障压电陶瓷蜂鸣片的生产质量,研究并确定压电陶瓷蜂鸣片测试仪主要参数的校准方法具有重要意义。     

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(Zr0.48Ti0.52)O3-0.05Pb(Mn1/3Sb2/3)O3-0.05Pb(Zn1/3Nb2/3)O3四元体系为研究对象,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850℃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306 pC/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。     

烧结温度对0.55Pb(Ni_(1/3)Nb_(2/3))O_3-0.45Pb(Zr_(0.3)Ti_(0.7))O_3压电陶瓷性能的影响

0.55Pb(Ni1/3Nb2/3)3-0.45Pb(Zr0.3Ti0.7)O3(0.55PNN-0.45PZT)组分的弛豫型压电陶瓷因具有较高的压电性能,已被作为制备含金属芯压电陶瓷纤维的材料等使用。为了进一步提高压电陶瓷纤维的电学性能,采用传统固相烧结法制备了0.55PNN-0.45PZT压电陶瓷,研究了烧结温度对材料结构、表面形貌和电学性能的影响。结果表明,在烧结温度为1200℃时,材料的各方面性能较佳:密度为8.12g/cm3,d33=850pC/N,kp=0.62,εr=7317,tanδ=0.033,Qm=41.66。     

铁氧体磁芯的磁控溅射金属化工艺的研究

铁氧体贴片电感要求金属化薄膜具有高的抗拉强度和高温焊接性,传统金属化工艺不能满足要求.本文采用磁控溅射技术对铁氧体电感磁芯进行金属化,研究了不同金属膜系以及不同工艺对薄膜抗拉强度和高温焊接性能的影响,结果表明磁控溅射金属化在抗拉强度及耐焊性方面明显优于电镀和蒸发,结合强度高达70N以上.推荐膜层结构是Cr/NiCu/Ag,其中NiCu厚度150～200 nm较宜.金属化膜焊接情况较符合凝固模型,金属间化合物会降低焊接性和抗拉强度,但是可以起到阻挡作用.更好的相结构是形成固溶体组织,并设计膜层结构来防止反浸蚀.该技术已经成功应用于国内最大铁氧体贴片电感厂的规模化生产中.     

RTGG法制备(Na_(0.84)K_(0.16))_(0.5)Bi_(0.5)TiO_3无铅压电织构陶瓷的研究

以NaCl-KCl熔盐法制备出了片状的Bi4Ti3O12微晶模板,选用此模板分别采用干法和湿法流延工艺结合RTGG技术制备了(Na0.84K0.16)0.5Bi0.5TiO3无铅压电织构陶瓷。研究了不同工艺条件下获得的织构陶瓷烧结行为、织构度、显微组织结构和电性能的变化规律。结果表明,(Na0.84K0.16)0.5Bi0.5TiO3织构陶瓷的烧成温度范围只有10~20℃,其介电性能、压电性能呈现明显的各向异性,沿垂直于流延方向织构陶瓷的各种电学性能均明显优于平行于流延方向的电学性能,两种流延方法在1150℃烧结所得的(Na0.84K0.16)0.5Bi0.5TiO3织构陶瓷在显微组织结构和电性能方面均表现出最强的各向异性,该织构陶瓷的压电常数d33=134pC/N。     

AlN陶瓷的Ti-Ag-Cu活性封接工艺

在AlN陶瓷的Ti Ag Cu活性封接工艺中 ,研究Ti的引入方式对其与金属封接抗拉强度的影响。其中Ti以四种不同方式引入 :涂Ti粉、夹Ti箔、直接使用Ti Ag Cu合金焊料以及溅射Ti膜     

锆钛酸铅压电陶瓷元件高温老化行为及其微观机制

长时高温作用会显著加速压电陶瓷元件电学性能的退化，极大地影响压电元件使用寿命。本工作在85、125和150℃下对PZT压电陶瓷元件进行长时老化处理，研究并分析了高温老化过程中PZT陶瓷元件电学性能退化规律及其微观机制。压电常数与介电常数随老化周期延长均退化明显，初期退化速率较慢，后期退化加快并逐渐趋于稳定，介电常数和压电常数退化均符合Boltzmann变化规律。85℃和125℃下老化49 d时，元件介电常数退化率达到最大，分别为31.01%和36.48%;压电常数退化率达到最大，分别为11.57%和19.02%。PZT压电元件介电性能退化主要由表面Ag电极内结构退化、Ag/PZT界面弱化及PZT陶瓷退极化三方面所贡献，其中界面弱化和陶瓷退极化占主导。长时高温作用促使Ag电极逐渐缓慢氧化生成Ag₂S,晶粒收缩产生大量孔洞，导致Ag电极致密度下降和Ag/PZT界面分层，降低了Ag/PZT的电容率；此外，长时高温作用加速了PZT陶瓷电畴转向无序状态，促进氧空位位移钉扎电畴壁，导致了PZT压电元件介电性能退化。     

化学改性对气体压力膨化孔洞聚丙烯膜的压电热稳定性和机电性能的影响

通过压电d33系数等温衰减测量、热刺激放电（TSD）技术及介电谐振谱分析，研究了孔洞PP原膜及其化学改性膜在经历相同的压力膨化和热处理工艺后的压电热稳定性和机电性能。对比性地研究了90℃膨化和RT膨化对孔洞PP膜压电热稳定性和机电性能的影响。结果表明：化学改性及热膨化工艺改善了孔洞PP膜的压电热稳定性和机电性能，且90℃膨化改性膜比RT膨化改性膜具有更好的压电热稳定性和机电性能。     

Cu粉和Ni粉添加剂对V20Ti30Cr50贮氢合金电化学性能的影响

采取手工混合和混合加烧结的方法,研究了Cu粉和Ni粉添加剂对V20Ti30Cr50贮氢合金电化学性能的影响.结果表明:烧结前,添加铜粉的V20Ti30Cr50合金的电极具有较高的放电容量,其最大放电容量为342.7mAh/g,但放电平台电压较低,仅为-0.4V(相对于Hg/HgO电极),而添加镍粉的合金电极的最大放电容量仅为73.4mAh/g,没有明显的放电平台;烧结后,添加铜粉的电极由于表面Cu4Ti3化合物的生成,电极的放电容量降低到30mAh/g,放电平台电压仍仅为-0.4V,而烧结的添加镍粉的电极合金与镍粉表面结合紧密,同时有TiNi第二相的生成,增加了合金电极表面的电催化活性,合金的放电平台电压提高到-0.8V,并且最大放电容量显著增加到209mAh/g.     

Insertion of triangulated surfaces into a meccano tetrahedral discretization by means of mesh refinement and optimization procedures

In this paper, we present a new method for inserting several triangulated surfaces into an existing tetrahedral mesh generated by the meccano method. The result is a conformal mesh where each inserted surface is approximated by a set of faces of the final tetrahedral mesh. First, the tetrahedral mesh is refined around the inserted surfaces to capture their geometric features. Second, each immersed surface is approximated by a set of faces from the tetrahedral mesh. Third, following a novel approach, the nodes of the approximated surfaces are mapped to the corresponding immersed surface. Fourth, we untangle and smooth the mesh by optimizing a regularized shape distortion measure for tetrahedral elements in which we move all the nodes of the mesh, restricting the movement of the edge and surface nodes along the corresponding entity they belong to. The refining process allows approximating the immersed surface for any initial meccano tetrahedral mesh. Moreover, the proposed projection method avoids computational expensive geometric projections. Finally, the applied simultaneous untangling and smoothing process delivers a high‐quality mesh and ensures that the immersed surfaces are interpolated. Several examples are presented to assess the properties of the proposed method.     

Certification Institutions Expected to Update and Transfer Information on Present Standards

Standards are the basis for production enterprises to organize production, ex-factory inspection, trade (delivery) and technical exchanges, product certification, quality arbitration and supervision.……     

Flow calorimeter for enthalpy increment measurements on condensed gases

A flow calorimeter for enthalpy increment measurements on condensed gases is presented. A better knowledge of the properties of the liquefied natural gas is needed, and therefore a liquid loop has been designed for our flow calorimeter. The fluid loop in the calorimeter is designed in order to avoid the two-phase region, since two phases would give compositional disturbances in the measurements. The avoidance of the two-phase region is made possible by increasing the pressure of the test fluid after the measurement section, then heating the fluid at super-critical pressure past the critical point. Finally, the fluid is throttled to the low-pressure gas state at the inlet condition of the compressor that circulates the fluid. To perform the pressure increase, a new cryogenic pump has been designed. To evaluate the new equipment, measurements were taken on liquid ethane over the temperature range 146–256 K at pressure between 0.9 and 5.1 MPa.     

Refrigerators Enter a New Era of Health Preservation Frestech initiates the establishment of China's first standard for household sterilization refrigerators

On November 30, 2007, the China Association for Standardization (CAS) held a press conference at Beijing Diaoyutai State Guest House. Leaders from the China Household Electric Appliance Research Institute, the China Household Electric Appliance Association, and the China Consumers' Association attended and made speeches.……     

Optimum-Simulation von Ernteprozessen

Zusammenfassung Bei der Gestaltung von Ernteprozessen — beispielsweise des Prozesses Mähdrusch, Körnertransport und -abnahme — als transportverbundene Fließarbeitsverfahren mit mindestens zwei verschiedenen Arbeitsmitteln gibt es einen großen Optimierungsspielraum. Solche Prozesse sind mehrstufige Bedienungsprozesse mit gemischter Anordnung der Bedienungseinrichtungen. Außerdem besitzen sie stark ausgeprägte räumliche Aspekte. Es wird vor allem gezeigt, welche Merkmale solcher Prozesse in Simulationsmodellen abgebildet sein müssen, welche Zielgrößen in Abhängigkeit von welchen Einflußgrößen unter Berücksichtigung welcher Prozeßbedingungen ermittelt werden sollten und wie der Bewertungsprozeß zur Ermittlung der gewünschten Informationen gestaltet werden muß.     

A study of centrifugal cast high boron high speed steel

In the present study a high‐boron high speed steel (HSS) roll material was designed. Many expensive alloy elements have been substituted by cheap boron alloy, and high‐boron high speed steel roll has been manufactured by centrifugal casting method. The microstructures, mechanical properties and wear resistance of centrifugal casting high‐boron high speed steel roll have been investigated by optical microscopy (OM), scanning electron microscopy (SEM), and X‐ray diffraction (XRD) analysis, hardness test, impact test and wear test. The results indicated that the solidification microstructures of high‐boron high speed steel roll consisted of M₂(B,C), (W,Mo)₂(B,C), M₃(B,C), M₂₃(B,C)₆ type borocarbides and martensite, a small amount of retained austenite. Borocarbides were continuously distributed over the grain boundary. After quenching from 1050 °C, local broken network appeared in partial borocarbides, and fine secondary borocarbide precipitated from the matrix. After tempering from 525 °C, the amount of precipitated borocarbide increased significantly. After heat treatment, the hardness of high‐boron high speed steel roll excelled 60 HRC, and its impact toughness excelled 8.0 J/cm². The single groove steel rolling amount of high‐boron high speed steel rolls increases by 500% than that of bainite cast iron roll, when the rolls are used in K₁ mill housing of bar mill.     

Brainstorming for ISO Strategy 2016-2020

正Responding to ISO’s appeal for survey for the to-be-developed ISO Strategy Plan for 2016-2020,SAC hosted a special workshop over the needs and comments of various fi elds on June 8 in Beijing.The workshop was attended by ISO President-elect and Ansteel General Manager Zhang Xiaogang,SAC Vice-Administrator Yu Xinli,and 30 experts from     

CNAS Passes APLAC's PTP Review

正The review group of Asia Pacific Laboratory Accreditation Cooperation(APLAC)carried out a 4-day peer review of the proficiency testing provider(PTP)for China National Accreditation Service for Conformity Assessment(CNAS)from July 28 to 31,2014.CNAS passed the PTP review with excellent performance.Two senior peer reviewers of APLAC made a comprehensive,rigorous and detailed review of CNAS’s PTP accreditation activities,and made the on-spot inspection of the review groups in Shanghai and Shenzhen respectively.     

新闻(英文)

正China and Greece Sign the Standardization Cooperation Agreement Witnessed by Chinese Premier Li Keqiang and Greek Prime Minister Antonis Samaras,AQSIQ Minister Zhi Shuping and ELOT Chairman and Executive Director Angelos Tolkas signed the SAC-ELOT Standardization Cooperation Agreement.The Agreement is one of the critical cooperation documents signed during Li Keqiang’s visit in Greece,encouraging China and Greece to