首页 | 官方网站   微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 62 毫秒
1.
论述了SiCp/Ni-P复合镀层与钢基体的结合强度及其影响因素。复合镀层中离界面5μm厚度以内区域的组成及应力状态对镀层/基体的界面结合有决定性作用,在该区域以外SiC粒径变化不影响镀层的结合强度。适当的热处理可提高界面结合力。  相似文献   

2.
纤维涂层对复合材料力学性能的影响   总被引:8,自引:0,他引:8  
对于SiC纤维/MAS微晶玻璃复合系统,发现在烧结温度下,纤维和基体之间有较严重的化学反应发生,界面结合强,力学性能较差.通过对NicalonSiC纤维加涂层,发现Nb2O5和c涂层对复合材料的界面结合改善不大,而LCAS晶玻璃涂层能使纤维和基体间的界面结合明显减弱,力学性能大幅度提高,室温抗折强度和断裂韧性分别达327MPa和13.9MPa·m1/2.  相似文献   

3.
采用真空热压扩散结合工艺制备出SiCf/Ti-15-3复合板材,研究制备工艺,SiCf,基体合金特性,复合材料的显微组织及界面特征,结果表明,合适条件下国产射频加热CVD法制备的SiCf与Ti-15-3基体具有较好的相容性,界面结合良好,在拉伸条件下SiCf有从基体拔出的倾向,纤维具有脆性解理断口特 ,Ti-15-3基体具有塑性断口特征。  相似文献   

4.
SiC纤维补强微晶玻璃基复合材料的界面结合   总被引:5,自引:0,他引:5  
本文通过SiC纤维对LCAS(Li2O-CaO-Al2O3-SiO2)和MAS(MgO-Al2O3-SiO2)微晶玻璃的补强,观察和分析了在不同复合系统中纤维与基体的界面结合。在SiC纤维/LCAS微晶玻璃复合系统中,发现纤维与基体之间有一中间界面层,它主要是在复合材料的烧结过程中通过扩散形成,并且于1200℃时在界面上形成富C层。SiC纤维/MAS微晶玻璃基复合材料由于在烧结过程中有化学反应发生  相似文献   

5.
多向细编碳/碳复合材料界面力学性能测试与表征   总被引:4,自引:3,他引:1       下载免费PDF全文
本文用自制装置研究了多向细编C/C复合材料纤维束性能,分析了工艺过程的影响。同时用界面微脱粘实验技术研究了C/C复合材料界面性能,给出了相应的理论模型和界面应力分布,提出了由界面脱粘力,纤维、基体和复合材料性能表征界面剪切强度的方法,为C/C复合材料优化设计提供了定量参数。结果表明:织物结构、织物编织工艺以及织物/基体复合对纤维的强度影响很大,降为原始纤维的20%左右,对模量影响小。不同界面层次,纤维/基体的界面结合情况和界面剪切强度不同,Z向纤维束中纤维/基体结合好,具有最高的结合强度,SEM观察证实有大量基体碳在纤维上枝联。  相似文献   

6.
SiCp/Al-Si复合材料中SiC/Al界面处亚晶铝带的研究   总被引:1,自引:0,他引:1  
通过利用TEM研究SiCp/Al-Si昨合材料发现,SiC/Al界面结合紧密,在靠近SiC界面的Ala基体中,有一层厚度小于1μm的“亚晶铝带”,它紧靠SiC表面形成,与远离SiC的Al基体有几度的位向差,这种“亚晶铝带”在SiC/Al界面上普遍存在,其内有大量位错。  相似文献   

7.
SiC纤维/LCMAS微晶玻璃基复合材料的界面结合和力学性能   总被引:2,自引:1,他引:1  
本工作通过在母体玻璃中引入MgO后进行热处理得到一系列具有不同热膨胀系数的微晶玻璃.SiC纤维/LCMAS微晶玻璃基复合材料在烧结条件下,在纤维和基体间形成一厚度约为2μm的界面层.纤维、基体间的界面剪切应力通过单根纤维压出法测试,发现纤维、基体间的界面剪切强度对复合材料的力学性能有严重的影响,并且SiC纤维/LCMAS系微晶玻璃基复合材料具有较高的界面剪切强度,通过降低基体的热膨胀系数减弱界面剪切强度,可使复合材料的强度和断裂韧性都得到明显的改善.  相似文献   

8.
钎焊工艺对WC—Co/NiCrBSi复合涂层性能的影响   总被引:2,自引:0,他引:2  
采用真空钎焊技术,在45^#钢基体表面焊一层(WC-Co/NiCrBSi)复合涂层,研究了不同钎焊工艺对涂层自身结合强度、涂层与基体间连接强度以及涂层抗磨料磨损性能的影响。钎焊工艺为1080℃×10min时,涂层自身结合强度为146MPa;涂层与基体间的最高连接强度为367MPa。涂层的抗磨料磨损性能比Co-Cr-W堆焊涂层和(WC-Co/NirBSi)火焰堆焊层的高。  相似文献   

9.
本文研究了SiC晶须增韧氧化物陶瓷基复合材料中的晶须/基体界面结构性质及其在补强增韧作用中的作用机制。TEM观察结果表明:复合材料中的SiCw/Al2O3、SiC2/ZrO2(2Y)和SiCw/ZrO2(6Y)界面结合致密,在分析电镜下未发现明显的界面过滤层或界面相,由于膨胀失配而受拉应力作用的界面基体一侧往往成为微裂纹形核的有利部位,ZrO2中t-m相变的体积膨胀效应可以抵消这种热应力,调整基体  相似文献   

10.
Si3N4/SiC纳米复合陶瓷的微观结构   总被引:5,自引:0,他引:5  
利用JEM2000EXⅡ高分辨电镜和HF2000冷场发射枪透射电镜对Si3N4SiC纳米笔合陶瓷材料的微观组织,结构和成分进行了研究。结果表明,SiC颗粒弥散分布基体相β-Si3N4晶内和晶界,晶内SiC颗粒与基体相的界面结构有三种类型;1)直接结合的的界面;2)完全非晶态的界面;3)混合型的界面,晶间SiC颗粒与基体相的界面大部分是直接结合的。  相似文献   

11.
凝固科学技术与材料   总被引:8,自引:0,他引:8  
从凝固科学与实践发展的角度介绍了当前凝固材料体系的基本框架和凝固科学主要发展阶段的基本理论。作为材料科学与工程的基本组成,凝固科学技术正在现代科学理论的基础上针对传统材料的改性提高和新材料的发展需求,以控形、控构、控性为目标开展优质铸件的定向、晶体生长、快凝、深过冷及各种新型和超常领域凝固过程的研究,并介绍了其中某些方面和展望了可能的发展趋势。  相似文献   

12.
Production planning and scheduling are becoming the core of production management, which support the decision of a petrochemical company. The optimization of production planning and scheduling is attempted by every refinery because it gains additional profit and stabilizes the daily production. The optimization problem considered in industry and academic research is of different levels of realism and complexity, thus increasing the gap. Operation research with mathematical programming is a conventional approach used to address the planning and scheduling problem. Additionally, modeling the processes, objectives, and constraints and developing the optimization algorithms are significant for industry and research. This paper introduces the perspective of production planning and scheduling from the development viewpoint.  相似文献   

13.
The national measurement system for photometric and radiometric quantities is presently based upon techniques that make these quantities traceable to a high-accuracy cryogenic radiometer. The redefinition of the candela in 1979 provided the opportunity for national measurement laboratories to base their photometric measurements on optical detector technology rather than on the emission from high-temperature blackbody optical sources. The ensuing technical developments of the past 20 years, including the significant improvements in cryogenic radiometer performance, have provided the opportunity to place the fundamental maintenance of photometric quantities upon absolute detector based technology as was allowed by the 1979 redefinition. Additionally, the development of improved photodetectors has had a significant impact on the methodology in most of the radiometric measurement areas. This paper will review the status of the NIST implementation of the technical changes mandated by the 1979 redefinition of the candela and its effect upon the maintenance and dissemination of optical radiation measurements.  相似文献   

14.
15.
单贺飞 《包装工程》2022,43(18):341-349
目的 探索江门世遗文化的传承、发展和转化的新思路,践行国家在《粤港澳大湾区发展规划》纲要中要求江门承担与港澳地区文化创意合作与开发任务的分工。方法 与澳门高校紧密合作,开展专业培训课程,以开平碉楼为例,从人文视角开展设计研究,梳理开平碉楼的文化脉络,把世遗文化的元素和其背后的文化融入文创产品中,提升文创产品的附加值,推动当地文创产业结构的变革。结果 两地高校构建了稳定的科研团队,开设长期有效的设计培训课程,与景区建立了研究协作关系,帮助景区构建了一套产销研的商业模式。结论 以跨区域高校合作为平台,以文创产品为抓手,依托江澳两地的资源优势,可以构建江门世遗文化全新的品牌形象,最终推动开平世遗文化的活化。  相似文献   

16.
17.
PSD和PWELCH函数的分析改进及应用   总被引:1,自引:0,他引:1  
针对MATLAB中两个内建功率谱密度计算函数psd()和pwelch()计算结果迥异的现象,在功率谱密度估计理论的基础上,根据经典的周期图理论和Welch平均周期图方法,通过详细分析源程序,解析计算方法,发现psd()计算的并不是工程单边功率谱密度,而是采样信号双边谱,故与pwelch()结果迥异,另外pwelch()不能对分段信号数据进行预处理。就上述不足提出了相应的改进措施,比较验证表明改进措施行之有效。  相似文献   

18.
By making a step on one surface ( ) of a rectangular small paralellepiped copper crystal, dislocations could be created by the molecular dynamic method. The dislocation created was not a complete edge dislocation but a pair of Heidenreich-Shockley partial dislocations. Each time a dislocation was created, the stress on the surface was released. Small copper crystals having a notch were pulled (until fracture), compressed and buckled by use of the molecular dynamic method. An embedded atom potential was used to represent the interaction between atoms. Dislocations were created near the tip of the notch. A very sharp yield stress was observed. The results of high speed deformations of pure silicon small crystals using the molecular dynamics are presented. The results suggest that plastic deformation may be possible for the silicon with a high speed deformation even at room temperature. Another small size single crystal, the same size and the same surfaces, was compressed using molecular dynamic method. The surfaces are {110}, {112} and {111}. The compressed direction was [111]. It was found that silicon crystals are possible to be compressed with a high speed deformation. This may suggest that silicon may be plastically deformed with high speed deformation.  相似文献   

19.
Miniature and MEMS-type vacuum sensors and pumps   总被引:1,自引:0,他引:1  
Anna Grecka-Drzazga 《Vacuum》2009,83(12):1419-1426
In the paper, the observable trends of the actual research and development of selected types of miniature and MEMS-type vacuum sensors are presented. Some information about the new types of active vacuum gauges, which are offered by the leading manufacturers of the vacuum measurement instruments, is given. Next, the list of MEMS devices that need vacuum for proper operation is presented. Some aspects of vacuum-encapsulation of MEMS devices, on wafer level and package level are shown. The new conceptions of obtaining and maintenance of high and ultra-high vacuum in MEMS devices are described. They concern the conception of integration of a miniature orbitron pump on-chip with MEMS-type device or with vacuum part of the portable advanced instruments such as electron microscope, ion mass spectrometer, and free electron laser.  相似文献   

20.
New measurements are reported for the density and viscosity of tetralin and trans-decalin. The density was determined from room temperature to 60°C for tetralin and to 95°C for trans-decalin. The kinematic viscosity was measured up to temperatures slightly above 100°C. Our results improve upon the values recommended by the American Petroleum Institute for these liquids.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司    京ICP备09084417号-23

京公网安备 11010802026262号