Joint Strength with Soldering of Al2O3 Ceramics After Ni-P Chemical Plating

Ni-P alloy was chemically plated on Al2O3 ceramics to produce uniform alloy coatings at temperatures below 70~C. Cu metal was electroplated onto the Ni-P coating to facilitate the soldering and shorten the chemical plating time. Then, the electroplated ceramic specimens were soldered with 60 wt.% Sn-40 wt.% Pb solder in active colophony. The highest shear strength was acquired after the heat treatment at 170℃ for 15 min. The joint fractures mostly propagated along the interface between the ceramics and the Ni-P coating, with some fracture in both the ceramics and the Ni-P coating near the interface and some along the interface between the Cu and Ni-P coatings. The results show that ceramic surface roughness and the chemical plating parameters influence the coating quality, and that suitable heat treatment before the soldering also improves the adhesion between the ceramics and Ni-P coatings, thus strengthening the joints.     

试论综合材质在现代陶艺中的运用

陶瓷艺术已由传统的艺术程式进入了现代艺术表现阶段.在陶瓷艺术中,材质既是一种物质材料,又是重要的艺术表现手段.文章从传统陶瓷材质的单一性到现代陶瓷材质的丰富性为前导,探索综合材质与现代陶艺结合表现的诸多可能性,为现代陶艺表现形式的多样性起到一定的促进作用.     

Application of Reaction-Bonded Silicon Carbide in Manufacturing of Spacecraft Combustion Chamber

Silicon carbide (SiC) ceramics is a good structural ceramics material, which have a lot of excellent properties such as superior high-temperature strength up to a temperature of 1 350 ℃, chemical stability, good resistance to thermal shock and high abrasion resistance. The silicon carbide ceramics material has so far been used widely for manufacturing various components such as heat exchangers, rolls, rockets combustion chamber. Sintering of ceramics structural parts have many technological method, the reac...     

Abnormal dielectric characteristics of PMN-32%PT single crystal under dc bias

It has been reported that the single crystal of relaxor ferroelectrics (1-x)Pb(Mg1/3Nb2/3)O3-xPbTiO3 (PMN-xPT) with the compositions near the morphotropic phase boundary (MPB, 0.28相似文献   

用扩展电阻法研究陶瓷微区电导性能

本文把扩展电阻法应用于陶瓷微区电导性能研究.建立了微区的定位标识系统,可精确、方便地对选定的微区进行电导性能及组分的重复测定.该方法在研究Ba(Sn_(1-x)Sb_x)O_3、ZnO及BaTiO_3半导体瓷应用中得到有意义的结果.     

混合稀土Nd2O3和CeO2对氧化镁陶瓷硬度及抗热震性能的影响

采用轻质微米级（0.5 μm）MgO粉末为原料,Nd₂O₃、CeO₂为添加剂,聚乙烯醇为黏结剂,以242 MPa压强干压成型,常压1 550 ℃下烧结并保温2 h制得MgO陶瓷,对所得试样进行硬度、抗热震性能、显微结构及物相的测定。先探究不同添加量的单一稀土对MgO陶瓷的硬度及抗热震性能的影响,得到Nd₂O₃和CeO₂的最佳添加量ω分别为3%、8%。然后探究混合稀土Nd₂O₃和CeO₂对MgO陶瓷的性能影响,结果表明混合稀土添加总量ω为3%,Nd₂O₃与CeO₂的质量比为3∶7时,氧化镁陶瓷具有最好性能,硬度值为68 HRA,抗热震次数高达19次。     

基于掺铕钨酸盐荧光强度比的非接触温度传感

为了突破传统测温技术应用的局限性,利用NaY （WO₄）₂：Eu³⁺玻璃陶瓷（glass ceramics,GC）实现了具有非接触、实时响应、自校准等优势的双模荧光强度比（luminescence intensity ratio,LIR）测温。采用高温熔融淬灭法制备出含NaY （WO₄）₂：Eu³⁺纳米晶的透明GC样品,并进行系列光谱测量和热敏性能分析。结果表明,样品中Eu³⁺的激发态能级⁵D₁和⁵D₀和基态能级⁷F₂和⁷F₀为两对独立的热耦合能级,可分别基于这两对热耦合能级实现性能优异的双模LIR温度传感。该双模LIR测温技术数据可靠、测温范围广、灵敏度高,再结合GC材料优势,是可用于光纤温度传感器的核心技术材料。     

SrxBa1—xTiO3陶瓷的频域介电谱

用固相反应法制备ＳｒｘＢａ１－ｘＴｉＯ３系列陶瓷．当ｘ＝０．３０时呈现显著的驰豫相变特征．在５Ｈｚ至１ＭＨｚ范围,相对介电常数的实部ε′随频率ｆ的降低而增大．１／ε′与ｌｇｆ的关系曲线呈现折曲的２段直线．高频相对介电常数的实部ε′ｈ随ｘ的增加而增大是与顺电相的增加而对应．测量点（ε′,ε″）随频率ｆ的变化分布在复平面的一条直线上．     

用热处理方法降低PTC陶瓷发热体的电阻值

提出了一种利用隧道窑热处理方式降低ＰＴＣ陶瓷发热体电阻值的新方法．这种方法不仅能降低电阻值而且还能提高ＰＴＣ陶瓷的主要电性能;同时还讨论了热处理条件对电性能的影响．     

PIA法制备MMCs骨架工艺及进展

综述了有机前驱体浸渍烧蚀法(PIA)制备金属基复合材料(MMCs)用金属间化合物或陶瓷网络结构预制体的工艺过程及技术方法，分析了其制备工艺特点，指出。PIA法是目前制备MMCs最方便有效的方法。并论述了工艺进展的情况，展望了其发展前景，提出下一步需要解决的问题。