PZT压电蜂鸣片溅射金属化的研究

采用直流磁控溅射工艺实现了PZT压电蜂鸣片的金属化,分别研究了Cr/Cu/Ag、Ti/Cu/Ag、Cu/Ag 3种复合膜系电极薄膜的微观结构和电学性能差异,并与"丝网印刷银浆再高温烧结"(简称"丝印烧结")金属化工艺进行了比较。研究结果表明,用溅射金属化工艺制备的压电蜂鸣片,其电极膜层致密、均匀,一致性好,电学性能普遍优于丝印烧结工艺,其中又以Ti/Cu/Ag膜系为最佳,最大抗拉强度达到13.5 MPa、平均谐振电阻小于25Ω、机电耦合系数大于0.7,而金属化膜厚仅为丝印烧结工艺的1/4,另外电容量和谐振频率等指标均符合蜂鸣器的标准,各项性能全面优于丝印烧结金属化工艺,具有全过程无污染、生产成本低、可控性强,适合于产业化生产等优点,可以取代丝印烧结工艺。     

微波烧结微波介质陶瓷的研究进展

随着通信行业的发展,尤其是5G商用时代的来临,微波介质陶瓷的开发与探索成了近年来的研究热点.目前通常采用常压固相烧结的方式来制备微波介质陶瓷,但烧结温度较高、加热速度慢,且烧结时间过长,不仅会导致资源的损耗,还可能导致晶粒的异常长大.为了降低陶瓷材料的烧结温度,通常会添加烧结助剂,如B2 O3、CuO等,但加入烧结助剂会引入第二相从而影响微波介电性能.作为一种高效的烧结方法,微波烧结技术是在烧结过程中通过微波与材料粒子的相互作用或微波与基本微观结构耦合产生的热量进行加热,不仅能降低烧结温度、缩短烧结时间,还能改善材料的显微组织,因此,近年来微波烧结成为研究者关注的焦点.采用微波烧结制备的微波介质陶瓷在各个领域中都有应用,如Mg2 TiO4陶瓷用于多层电容器和微波谐振器,BaTiO3陶瓷用于多层陶瓷电容器(MLCC)和随机存取存储器(RAM),MgTiO3陶瓷用于微波滤波器、通信天线和微波频率全球定位系统,TiO2陶瓷用于电容器和低温共烧陶瓷基板等.不仅如此,采用微波烧结制备的微波介质陶瓷还表现出优异的化学稳定性和力学性能,如LiAlSiO4基陶瓷、MgO-B2 O3-SiO2基陶瓷等在多层陶瓷基板与微波集成电路中都有广泛的应用.微波烧结技术为制备优异的材料提供了可能,还可用于在各种粉末的制备,实现性能的进一步提升.本文综述了微波烧结制备微波介质陶瓷的研究进展,总结了常规烧结和微波烧结对材料性能的影响,并指出采用微波烧结制备的微波介质陶瓷目前存在的问题与发展趋势.     

Q235碳钢表面纳米TiO2复合膜的耐腐蚀性能

在低碳钢表面直接制备纳米TiO2薄膜,结合力不强,膜易脱落.为此,以Ni-P化学镀层作基体和膜之间的过渡层,然后采用溶胶凝胶-提拉法在Q235碳钢表面制备了均匀致密的纳米TiO2复合膜.研究了纳米TiO2复合膜的烧结温度、膜厚度对耐腐蚀性能的影响.结果表明:提拉3次,450℃烧结1 h的纳米TiO2复合膜在3%NaCl溶液中耐蚀性能较好;在紫外光照射下膜的腐蚀电位低于Q235碳钢基体,作为非牺牲性阳极对Q235碳钢具有优异的防腐蚀性能.     

95%氧化铝陶瓷烧结镍工艺探索北大核心CSCD

通过对不同Mo-Mn金属化配方体系的烧结镍工艺探索,发现烧结镍工艺适用于Mo含量高的Mo-Mn金属化配方体系。当Mo质量分数为70%时,镍粉粒度d0.5为1.872μm,镍层厚度为6~12μm时,封接件断面显示镍层连续、致密,陶瓷标准件的抗拉强度为116 MPa,陶瓷金属封接件的环境性能测试结果符合行业标准要求。     

4NiO-B2O3-V2O5低温烧结微波介质陶瓷的烧结特性、相结构和微波介电性能研究

以分析纯的B_2O_3、V_2O_5和NiO为原料,采用传统的固相反应法制备了4NiO-B_2O_3-V_2O_5微波介质陶瓷。利用SEM、XRD和微波网络分析仪分别对材料的烧结行为、微观结构、相变特性和微波介电性能进行了系统的研究。结果表明,4NiO-B_2O_3-V_2O_5陶瓷为复相结构。当烧结温度由575℃升高至675℃时,样品的体积密度、品质因素(Q×f)和谐振频率温度系数(τ_f)值呈现出先增大后减小的趋势,ε_r一直减小。当烧结温度为650℃时,陶瓷具有最佳的微波介电性能:Q×f=19 692 GHz,ε_r=4.9,τ_f=-20×10~(-6)/℃。低的烧结温度、优异的微波介电性能表明4NiO-B_2O_3-V_2O_5陶瓷可以作为滤波器、谐振器等微波器件的备选材料。     

95%氧化铝陶瓷烧结镍工艺探索

通过对不同Mo-Mn金属化配方体系的烧结镍工艺探索,发现烧结镍工艺适用于Mo含量高的Mo-Mn金属化配方体系。当Mo质量分数为70%时,镍粉粒度d0.5为1.872μm,镍层厚度为6～12μm时,封接件断面显示镍层连续、致密,陶瓷标准件的抗拉强度为116 MPa,陶瓷金属封接件的环境性能测试结果符合行业标准要求。     

塑料表面溅射电磁屏蔽膜的研究

电磁干扰(EMI)日益严重,在产品表面镀覆电磁屏蔽膜成为抗EMI主要措施之一.本文采用磁控溅射技术在聚酯塑料(PET)上制备出附着力大于5 MPa、2 GHz～4 GHz频率范围内屏蔽效能大于60 dB的复合结构的电磁屏蔽膜,并研究了导电膜、导磁膜及其复合膜层的电磁屏蔽特性.有关数据表明:镀覆500 nm Cu+300 nm 1Cr18Ni9Ti的复合屏蔽膜可以获得屏蔽效果、成膜速率和结合力的综合好效果.溅射功率、膜层厚度对电磁屏蔽特性和结合力有一定影响.     

BaTi4O9微波介质陶瓷制备及低温烧结研究进展

微波介质陶瓷作为现代移动通讯中的关键基础材料,以其优异的介电性能已成为现代微波通讯技术的研究重点之一,而BaO-TiO2体系中的BaTi4O9微波介质陶瓷由于具有微波介电性能优异、制备工艺简单以及成本低等优点,已经成为微波介质陶瓷研究领域的热点.从BaTi4O9微波介质陶瓷的结构与性能入手,介绍了BaTi4O9陶瓷的制备工艺、方法及其在器件方面的应用,概述了BaTi4O9微波介质陶瓷在低温烧结方面的研究进展.     

铝合金微弧电泳复合膜层的工艺制备

采用微弧氧化的方法先在铝合金表面制备一层致密多孔的陶瓷层,然后再通过电泳处理在铝合金表面制备出微弧电泳复合膜层.采用扫描电镜对复合膜层的表面形貌和截面线进行扫描分析,通过电化学分析和划格法测结合力试验对微弧电泳膜层性能进行了检测分析,并进一步探讨了不同的微弧氧化参数对后续电泳成膜的影响.结果表明,微弧电泳复合膜层的耐碱性及与基体间结合力均优于传统电泳膜层,且微弧氧化膜层的厚度影响后续电泳能否成膜,氧化层的致密性影响后续电泳膜层的光洁度.     

电真空器件用陶瓷二次金属化镀镍层起泡现象的研究

陶瓷二次金属化镍层烧结后起泡是影响产品质量和合格率的一个主要因素,本文针对陶瓷的一次金属化和二次金属化工艺,经XPS、XRF、SEM等方法分析,得出:陶瓷的二次金属化起泡与其沉积层的基材和沉积层的厚度有关,陶瓷一次金属化烧结后钼的特殊形貌--钼颗粒较大、颗粒之间结合疏松和钼的电化学特性,决定钼上的沉积层厚度必须在合适范围内--4～9μm,才能减小沉积层中的应力,保证烧结后镍层与钼有良好的结合力.     

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.……     

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.     

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     

Win-Win Cooperation

正The Chinese Premier Li Keqiang's recent trip to the UK has reinforced the China-UK comprehensive strategic partnership;just as the British Prime Minister David Cameron put it,"the relationship is gaining in strength,depth and understanding"after a bucket of business deals being inked worth more than 30 billion US dollars.From the first agreement signing in 2004 to the new agreement of mutual standards recognition and adoption in     

Systematic Approach for Emerging Industry

正A national directory of standards complexes for strategic emerging sectors was recently developed and released jointly by 12governmental departments,namely,SAC,NDRC,MOST,MIIT,MEP,MOA,AQSIQ,State Forest Administration,State Administration of Science and Technology for National Defense,State Oceanic Administration and National Railway Administration.     

Strictest Pollutants Emission Standards

正Four new national standards on air pollutant emission control offi cially issued by the Ministry of Environment Protection(MEP)together with AQSIQ and SAC has been brought into force from July 1,2014.The Emission standard for air pollutants of coal-burning,oil-burning and gasfi red boilers,which is the strictest emission standard historically,will tackle the stubborn pollution problem of boilers and waste incineration in most of China’s regions.     

Instructions to Authors

New Carbon Materials is a bimonthly journal published with the permission of the Ministry of Science and Technology and of the State News and Publication Agency.The journal is sponsored by the Institute of Coal Chemistry,Chinese Academy of Sciences,and is published by Science Press.Aims and Scope     

Progress on Standards Copyright Protection

正Recently,National Copyright Administration of China(NCAC)has rewarded 215 organizations and 179 individuals for their outstanding efforts on investigating standards copyright infringement and piracy in 2013.Hua Jianhua,the Deputy-Director of National Standards Copyright Protection Workgroup Office won a third prize of the national individual award.In 2012,SAC set up the national standards copyright protection working group,and developed policies to crack down standards infringement and piracy behaviors and to strengthen standards copyright protection.