共查询到16条相似文献,搜索用时 62 毫秒
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铝基碳化硅增强材料(Al/SiC)和低温共烧陶瓷(LTCC)的钎焊 总被引:1,自引:1,他引:0
铝基碳化硅增强材料 (Al/SiC)和低温共烧陶瓷 (LTCC)适合高性能微波电路的高密度组装 .对这两种材料进行焊接时 ,温度和气氛对基材的焊接性能影响很大 .铝基碳化硅增强材料的镀层在焊接温度时容易发生氧化 ,低温共烧陶瓷的厚膜导体在真空加热和高温还原性气体的条件下焊接性劣化 .采用金基钎料中温钎焊时 ,优质的焊料和合理的焊接工艺是获得优质焊缝的关键 . 相似文献
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提出了一种新型宽频带双频差分天线.该天线基于低温共烧陶瓷(Low Temperature Co-Fired Ceramies,简称LTCC)技术,采用矩形环状贴片,并使用两条叉形微带馈线进行差分馈电,是一种具有平衡结构的宽缝隙天线,该结构使得天线拥有很宽的频带宽度.天线两频段的中心频率为2.63 GHz和5.13 GH... 相似文献
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Theories and applications associated with sintering of ceramics and reducing of sintering temperature are reviewed. The whole sintering process is divided into three sub-processes as powder preparation, compaction and sintering, and each sub-process is discussed in terms of its possible contribution to the reducing of sintering temperature. New approach for practical optimization of sintering process is investigated. The application of above in the Low Temperature Co-fired Ceramics (LTCC) is discussed. Meanwhile, many successful applications in reducing the sintering temperatures are presented. 相似文献
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研究了准同型相界(morphotropic phase boundary 简称MPB)附近不同组分的锆钛酸铅(PZT)压电陶瓷在交流电场下的电致疲劳特性.发现电场频率对材料的电致疲劳性能有较大影响.高频电场下不同组分PZT材料的疲劳现象均不明显;低频电场下,不同组分的PZT材料疲劳特性差异较大.分析认为氧空位及其缔合缺陷偶极子在不同频率交变电场下的响应差异是其主要原因.拉曼光谱分析表明,低频疲劳后准同型相界区材料中部分菱方相转变为四方相,使其抗疲劳性能下降. 相似文献
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铁电陶瓷的电疲劳机理研究 总被引:3,自引:0,他引:3
研究了PMN-PNN-PZ-PT和PLT铁电陶瓷的电疲劳特性及其疲劳机理。研究结果表明,疲劳与所加的疲劳电压大小有很大关系。当电压较小时,疲劳不明显;当电压较大时,疲劳加剧。 相似文献
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《材料科学技术学报》2019,35(12):2883-2891
Porous ultrahigh temperature ceramics(UHTCs) are potential candidates as reusable thermal protection materials of transpiration cooling system in scramjet engine. However, low strength and low porosity are the main limitations of porous UHTCs. To overcome these problems, herein, a new and simple in-situ reaction/partial sintering process has been developed for preparing high strength and high porosity porous YB_2C_2. In this process, a simple gas-releasing in-situ reaction has been designed, and the formation and escape of gases can block the shrinkage during sintering process, which is favorable to increase the porosity of porous YB_2C_2. In order to demonstrate the advantages of the new method, porous YB_2C_2 ceramics have been fabricated from Y_2O_3, BN and graphite powders for the first time. The as-prepared porous YB_2C_2 ceramics possess high porosity of 57.17%–75.26% and high compressive strength of 9.32–34.78 MPa.The porosity, sintered density, radical shrinkage and compressive strength of porous YB_2C_2 ceramics can be controlled simply by changing the green density. Due to utilization of graphite as the carbon source, the porous YB_2C_2 ceramics show anisotropy in microstructure and mechanical behavior. These features render the porous YB_2C_2 ceramics promising as a thermal-insulating light-weight component for transpiration cooling system. 相似文献