刘伟星
,
赵哲
,
涂宝峰
,
崔大安
,
区定容
,
程谟杰
催化学报
doi:10.1016/S1872-2067(14)60235-7
纳米TiO2修饰的La0.6Sr0.4Co0.2Fe0.8O3-δ(LSCF)阴极被直接应用于YSZ电解质电池上. TiO2可阻止LSCF和YSZ间的化学反应,抑制SrZrO3的形成. LSCF-0.25 wt% TiO2阴极电池在0.7 V和600°C下的电流密度是LSCF阴极电池的1.6倍.电化学阻抗谱结果表明, TiO2修饰显著加快了氧离子注入电解质的过程,这可能与TiO2抑制了阴极/电解质界面处高电阻SrZrO3层的形成有关.本文为在ZrO2基电解质上使用高性能的(La,Sr)(Co,Fe)O3阴极材料提供了一种简单有效的方法.
关键词:
中温固体氧化物燃料电池
,
阴极
,
二氧化钛
,
界面反应
,
氧化锆基电解质
Yanhua LI
材料科学技术（英文）
SiCf/Ti-6Al-4V composites were fabricated by the powder-coated fiber method. The precursor fiber was prepared under the optimized parameter, and the composites were made using the vacuum hot pressure method. The influence of heat exposure time on products of the interfacial reaction was investigated using scanning electron microscope (SEM) and analytical transmission electron microscope (TEM) with energy dispersive spectrometer (EDS). The main products are TiC and Ti5Si3 after vacuum exposing the samples at 700℃ for 50 h. The growth dynamics of interfacial reaction products was analyzed quantitatively, which fitted the parabola rule. The activity energy of the reaction was 252 kJ•mol-1.
关键词:
Powder coated fiber
,
null
,
null
,
null
,
null
Haitao MA
,
Haiping XIE
,
Lai WANG
,
null
,
null
材料科学技术（英文）
The microstructure and melting behavior of Sn-9Zn-2Cu (SZC) lead-free solder with 3 wt pct Bi and various amount of Ni additions were studied. The wetting properties and the interfacial reaction of Sn-Zn-Cu with Cu substrate were also examined. The results indicated that the addition of 3 wt pct Bi could decrease the melting point of the solder and Ni would refine the microstructure and the rod-shape Cu5Zn8 phase changed into square-shape (Cu, Ni)5Zn8 phase. The addition of Bi, Ni greatly improved the wettability of SZC solder. In addition, the interfacial phase of the solders/Cu joint was typical planar Cu5Zn8 in SZC-3Bi-1Ni alloy.
关键词:
Lead-free solder
,
null
,
null
,
null
,
null
Guoxing ZHANG
,
Qiang KANG
,
Nanlin SHI
,
Geping LI
,
Dong LI
材料科学技术（英文）
In order to evaluate the interfacial reaction, a SiCf/Ti (TA1) composite was fabricated by a vacuum hot pressing method and then heat-treated in vacuum at 800℃ for up to 100 h. The elemental distributions of C, Si and Ti at the interfacial reaction zone were investigated. It was found that the reaction zone occurs during the fabrication process and continuously grows at high temperature because the Si and C atoms diffuse from SiC fibers to the matrix and Ti atoms diffuse in the opposite direction. The growth of the reaction zone is diffusion controlled and the mechanism of the reaction can be described by a reactive diffusion model of solid-state growth of an AmBn layer between two elementary substances A and B.
关键词:
SiCf/Ti (TA1) composite
,
null
,
null
