纳米碳化硅半导体材料光致发光特性的研究进展

概述了纳米碳化硅半导体材料,如采用各种成膜技术在硅衬底上制备的纳米碳化硅(nc-SiC:H)膜,镶嵌在各种介质如(α-SiC:H、SiO2或ZSM-5中的纳米晶碳化硅的光致发光特性及其最近研究进展     

非晶碳化硅薄膜光学特性的热退火效应

通过Raman光谱、紫外-可见透射光谱技术及原子力显微镜对非晶碳化硅薄膜结构和光学特性的热退火效应进行了研究。结果表明,碳化硅拉曼谱带随退火温度的增加而逐渐红移和尖锐化,显示了薄膜中晶化有序度的提高。退火后薄膜包含大量紧凑的纳米团簇,膜面相对于未退火样品较为粗糙。根据紫外-可见透射光谱导出的光学带隙从原始样品的1．86eV连续增加到经1050℃退火样品的2．23eV。碳化硅薄膜中纳米团簇的形成及其晶化程度的增加导致了薄膜光学带隙的蓝移效应。     

Sintering and microstructure of silicon carbide ceramic with Y3Al5O12 added by sol-gel method

Silicon carbide (SIC) ceramic with YAG (Y3Al5O12) additive added by sol-gel method was liquid-phase sintered at different sintering temperatures, and the sintering mechanism and microstructural characteristics of resulting silicon carbide ceramics were analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM) and elemental distribution of surface (EDS). YAG (yttrium aluminum garnet) phase formed before the sintering and its uniform distribution in the SiC/YAG composite powder decreased the sintering temperature and improved the densification of SiC ceramic. The suitable sintering temperature was 1860 ℃ with the specimen sintered at this temperature having superior sintering and mechanical properties, smaller crystal size and fewer microstructure defects. Three characteristics of improved toughness of SiC ceramic with YAG added by sol-gel method were microstructural densification, main-crack deflection and crystal ‘bridging‘.     

SiC-Al2O3-Y2O3体系陶瓷料浆的制备与性能研究

采用超声波分散法制备了SiC-Al2O3-Y2O3体系陶瓷料浆,利用Zeta电位分析仪、粘度计、pH测试仪等设备对料浆的物理性能进行了测试,讨论分析了Zeta电位、pH值、粘度、固含量、素坯强度、沉降速率对陶瓷料浆性能的影响规律,结果表明:pH值为9.5,固含量为58%,加入0.8%阿拉伯树胶作为分散剂时SiC-Al2O3-Y2O3体系陶瓷料浆流动性好、固含量高、不易沉降。     

用泥土和石头做燃料?

有一位科学家曾发现了一种高效新能源,它的放热量是同样质量石油的4倍～100倍,这个数字也许不算什么,令人震惊的是,这种新能源竟然是地球上最常见的、组成石头和土壤的主要物质——硅酸盐!这怎么可能呢!硅酸盐可是非常耐热的,砖瓦、陶瓷、耐火材料等就是硅酸盐煅烧出来的。谁也没有发     

SiC/mullite复相孔陶瓷的常压烧结与性能研究

常压烧结以活性碳为造孔剂的SiC/mullite复相多孔陶瓷。测定了试样的显气孔率、孔径分布和热震性能,通过XRD及SEM等研究了SiC/mullite复相多孔陶瓷的晶相组成和显微结构。在配料中加入7%的CaCO3降低了烧结温度。     

超细粉制造工艺

结合我公司多年碳化硅粉砂制造及设备改造经验,对碳化硅超细粉制造工艺及装备进行分析并提出改进措施。     

MB型同步发电机ZnO快速灭磁及转子过电压保护装置

随着电力事业的飞速发展，发电机容量不断增大，原先采用的DM2型灭磁开关或线性电阻灭磁，放电间隙或线性电阻过压保护都不能满足要求。现在国外已普遍用碳化硅(SIC)压敏电阻作灭磁和过电压保护，国内从1986年开始，也在大中型同步发电机上逐步采用高能氧     

Microstructure and mechanical properties of liquid phase sintered silicon carbide composites

Silicon carbide (SiC) composites were prepared by hot-press sintering from α-SiC starting powders with BaAl2Si2O8 (BAS). The effects of additives on densification, microstructure, flexural strength, and fracture behavior of the liquid phase sintered (LPS) SiC composites were investigated. The results show that the served BAS effectively promotes the densification of SiC composites. The flexural strength and fracture toughness of the SiC composites can reach a maximum value of 454 MPa and 5.1 MPa·m1/2, respectively, for 40% (w/w) BAS/SiC composites. SiC grain pullout, crack deflection, and crack bridging were main toughening mechanisms for the sintered composites.