温度稳定型Li_2(Zn_(1–x)Co_x)_2Mo_3O_(12)陶瓷的微波介电性能研究

采用固相反应法制备了Li_2(Zn_(1–x)Co_x)_2Mo_3O_(12)陶瓷,研究了Co~(2+)取代对其相结构和微波介电性能的影响,并通过添加Ti O_2调节了该陶瓷的τ_f值。结果表明:不同Co~(2+)取代的Li_2(Zn_(1–x)Co_x)_2Mo_3O_(12)陶瓷均显示出单相钒铁铜矿结构。随着Co~(2+)取代量的增加,陶瓷的致密化温度显著降低,相对密度和Q·f值均呈现先增大后减小的趋势。当x=0.1时,陶瓷具有相对较好的微波介电性能:ε_r=10.85,Q·f=65 031 GHz,τ_f=–73×10~(–6)/℃。添加Ti O_2能够有效调节Li_2Zn_2Mo_3O_(12)陶瓷的τ_f值向正值方向移动,0.4Li_2(Zn_(0.9)Co_(0.1))_2Mo_3O_(12)-0.6Ti O_2陶瓷的介电性能较佳:ε_r=15.80,Q·f=22 991 GHz,τ_f=–4.5×10~(–6)/℃。     

液相法制备炭／炭复合材料的显微结构

采用光学显微镜和扫描电子显微镜对用液相法制备的3种单向纤维增强炭／炭复合材料的显微结构进行了观察和分析，这3种炭／炭复合材料分别采用纯沥青作基体和沥青加焦炭粉、树脂加焦炭粉作预浸初基体制得，在热压成形初坯体内，收缩的微裂纹沿纤维轴向与外界相通，可被再浸渍填充，而孔洞则大多与外界隔绝，不能被再浸渍填充，实验结果表明：集炭填充料的添加改变了复合材料的显微结构，可调整炭／炭复合材料的纤料的纤维体积分数，减少气孔的形成，有利于再浸渍致密化；它还扰乱基体状结构组织，导致其焦炭粉颗粒呈紊乱状态。     

CaB2O4掺量对烧结后hBN结构及摩擦性能的影响

为了促进hBN的结晶生长,降低其摩擦系数,研究了CaB2 O4掺量对烧结后hBN结构和摩擦性能的影响.在hBN中加入CaB2 O4作为烧结助剂,在N2气氛下于2000℃保温5 h对不同CaB2 O4掺量的hBN进行了烧结,采用XRD、SEM和摩擦磨损试验机对烧结后hBN的物相组成、显微结构和摩擦性能进行了表征,并探讨了烧结后hBN的摩擦磨损机理.结果表明:烧结后,hBN晶体呈片状.随着CaB2 O4掺量由0％增加到15％,hBN晶体直径由0.5～2μm逐渐增大到2～4.5μm;晶体厚度由100 nm增加到200 nm,说明在N2气氛下,2000℃,保温5 h时,CaB2 O4的加入可以促进hBN的结晶生长.hBN块体的摩擦系数随着CaB2 O4掺量的增加有下降的趋势.随着温度从室温增加到800℃,烧结后hBN的摩擦系数先增大后减小.     

浅谈陶瓷脆性与改善脆性的途径

主要分析了陶瓷材料的脆性特征及显微结构与脆性的关系，提出了改善脆性的途径。     

高温合金熔液泡沫陶瓷过滤网的研制

研制的过滤高温合金熔液的泡沫陶瓷是刚玉一莫来石质陶瓷，具有较高的物理机械性能。能在1600t以下工作。在真空炉和其它熔模铸造上作了多次过滤浇注试验，结果表明：铸件的夹杂报废率降低30％～50％。     

电沉积Co-Cr_3C_2纳米复合涂层的热稳定性（英文）

研究了电沉积Co-Cr3C2纳米复合涂层的热稳定性。析出相Cr3C2颗粒均匀弥散地分布在涂层中,质量分数大约为30%。600℃以上退火导致涂层当中形成孔隙。400℃以下和600℃以上退火分别有利于Co纳米晶粒沿[002]和[220]方向生长。低于400℃退火可以同时获得优异的耐磨性和高硬度。经低于400℃退火,涂层的摩擦系数达到0.12,而经200℃退火后的涂层的摩擦系数低至0.04。     

陕西汉中细晶岩理化性能的研究

借助于DTA、XRD、OM、SEM等手段，系统研究了陕西汉中细晶岩的理化性能、显微结构和矿物组成。结果表明：细晶岩具有良好的理化性能，可能独成瓷，可单独成瓷，是制作炻质墙地砖的理想原料。     

Properties and microstructure of NiO/SDC materials for SOFC anode applications

NiO/SDC composites and Ni/SDC cermets for solid oxide fuel cell （SOFC） anode applications were prepared from nickel oxide （NiO） and samada doped ceria （SDC） powders by the powder metallurgy process. The physical and mechanical properties, as well as the microstructure of the NiO/SDC composites and the Ni/SDC cermets were investigated. It is shown that the sintedng temperature of the NiO/SDC composites and NiO content plays an important role in determining the microstructure and properties of the NiO/SDC composites, which, in turn, influences the microstructure, electrical conductivity, and mechanical properties of the Ni/SDC cermets. The present study demonstrated that composition and tprocess parameters must be appropriately selected to optimize the microstructure and the properties of NiO/SDC materials for solid oxide fuel cell applications.     

Effects of Ce and Ti on the microstructures and mechanical properties of an Al-Cu-Mg-Ag ahoy

The effects of Ce and Ti additions on the microstructures and mechanical properties of an Al-Cu-Mg-Ag alloy have been studied, It has been shown that either Ce or Ti can decrease the as-cast grain size of the Al-Cu-Mg-Ag alloy, increase the nucleation ratio for Ω phase as heterogeneous nucleation centers, inhibit the growth of Ω phase during aging, and thus increase the volume fraction and decrease the spacing of Ω phase. These microstructures increase the yield strength and tensile strength. However, if both Ce and Ti are added to the alloy, they form （Ce,Ti）-contained compounds and increase the grain size during casting, but have no effects on the nucleation and the growth of Ω phase during aging. The alloy containing both Ce and Ti has a relatively lower Vicks hardness and strength compared to the alloy containing either Ce or Ti.     

焊后热处理工艺对TD3合金钨极氩弧焊接头显微结构与力学性能影响

用高Nb的Ti-Al-Nb基合金作填充金属钨极氩弧焊TD3合金,探讨了焊后时效处理和焊后固溶 时效处理状态下母材及其接头显微结构和力学性能特点.结果表明:接头进行焊后固溶 时效处理相对较合理,热影响区、焊缝区分别为其室温、高温力学性能的薄弱区域;与焊后时效处理相比,焊后固溶 时效处理状态下母材力学性能较低,这主要归因于热处理过程中片状相粗化.