【摘 要】
:
Silicon nitride based composites with different addition (0,2 or 5 wt%) of short carbon fibers (Cf) were prepared by hot-press sintering method,using rod-like Si3N4 powders as raw materials and Y2O3 a
【机 构】
:
State Key Laboratory of High Performance Ceramics and Superfine Microstructure,Shanghai Institute of
论文部分内容阅读
Silicon nitride based composites with different addition (0,2 or 5 wt%) of short carbon fibers (Cf) were prepared by hot-press sintering method,using rod-like Si3N4 powders as raw materials and Y2O3 as sintering additives.The morphological,structural,and compositional analysis and observation of the Cf/Si3N4 composites were carried out by XRD,SEM,and TEM.And also the thermal conductivity and mechanical measurements were performed.The results show that part of the Cf can react with Si3N4 or SiO2 on top of Si3N4 grains during sintering process,forming a intermedium layer of SiC.The highest value of thermal conductivity (k),45.8 Wm-1K-1,belongs to the sample of 2 wt% Cf/Si3N4,while the thermal conductivity of Si3N4 without Cf addition is only 37.1 Wm-1K-1.The addition of Cf can improve the thermal conductivity of the composites,while the degradation of Cf into transition layers of nano-sized SiC grains deteriorates k.The fracture toughness has a slight increase with Cf addition.And the measured hardness values for all samples are within a range of 16.6~16.8 GPa.
其他文献
Introduction Cancer drug resistance is referring to the tolerance of cancer cells when treated withchemotherapy.Once the drug resistance occurs,therapeutic effect of anticancer drugwould decrease sign
Purpose: The aim of this study was to better understand the underlying drug release characteristics from matrix tablets based on the combination of chitosan (CS) and different types of carrageenans (κ
The repair processing of out-of-autoclave is becoming an important way of repairing composite structures.In order to study the non-autoclave repair processing and to improve the repair quality,even in
由于碳纤维复合材料(CFRP)的各向异性,其纤维铺层方向是影响加工性能的重要因素.本文以单向碳纤维复合材料(UD-CFRP)为研究对象,选用四种不同的纤维方向角度铺层的碳纤维复合材料结构进行铣削试验研究.通过从切削力、切口质量和刀具磨损等方面的分析,得出了纤维方向角0小于900时,碳纤维复合材料结构铣削力较大,对刀具磨损较严重,但己加工表面切口质量较好的结论.
本文介绍了基于瑞利背向散射的高密度分布式光纤传感技术.该技术可以评价整条光纤长度上的应变,分辨率达到毫米级.使用该技术测量碳纤维增强复合材料层合板静态弯曲下的应变.分辨率设为2mm时,每个层合板可以得到300多个有效数据.同时在层合板上粘贴光纤布拉格光栅(FBG)传感器与分布式光纤传感器进行对比.二者测试结果非常吻合,说明分布式光纤传感技术可以监测整个结构的应变,并且可以对结构关键区域进行定位.
The use of liquid resin manufacturing processes such as resin transfer molding (RTM) and vacuum assisted RTM (VARTM) has developed rapidly for aerospace applications in recent years.These processes wi
含二氮杂萘酮联苯结构聚芳醚是一类综合性能优异的耐高温热塑性树脂,可采用多种方式加工成型.与传统聚芳醚相比,具有低成本、优异的高温力学性能和良好的溶解性等优势,可作为基体树脂应用于制备复合材料.本文主要介绍了近几年在含二氮杂萘酮联苯结构热塑性聚芳醚树脂基复合材料方面的研究进展,包括玻璃纤维增强复合材料、碳纤维增强复合材料、粉末增强复合材料、耐磨复合材料和功能复合材料等,同时也包括基体树脂的化学和物理
In this study,obtaining acoustic emission signals by monitoring of acoustic emission experiment process for FRP composites containers hydraulic and blasting.Parameter analysis is used for analyzing ac
Silicon infiltrated silicon carbide (Si-SiC) ceramics,as a high hardness material,are difficult to machine,especially drilling micro-holes.In this study,interaction of intense picosecond laser pulses
Inorganic coating was fabricated on the surface of the porous Si3N4 ceramic by polymer derived (PD) and spraying technology.The phase of the coating was characterized by X-ray diffraction (XRD).The su