Thin films of silicon carbide nitride （SiCN） were prepared on （111） oriented silicon substrates by pulsed high-energy density plasma （PHEDP）. The evolution of the chemical bonding states between silicon, nitroge...Thin films of silicon carbide nitride （SiCN） were prepared on （111） oriented silicon substrates by pulsed high-energy density plasma （PHEDP）. The evolution of the chemical bonding states between silicon, nitrogen and carbon was investigated as a function of discharge voltage using X-ray photoelectron spectroscopy. With an increase in discharge voltage both the C 1s and N 1s spectra shift to lower binding energy due to the formation of C--Si and N--Si bonds. The Si--C--N bonds were observed in the deconvolved C ls and N ls spectra. The X-ray diffractometer （XRD） results show that there were no crystals in the films. The thickness of the films was approximately 1-2 μm with scanning electron microscopy （SEM）.展开更多
Steam oxidation resistance of Si3N4 and Si2N2O as well as SiAlON bonded SiC refractories at 900℃was tested according to ASTM-C863.Phase composition and microstructure before and after oxidation were analyzed by XRD a...Steam oxidation resistance of Si3N4 and Si2N2O as well as SiAlON bonded SiC refractories at 900℃was tested according to ASTM-C863.Phase composition and microstructure before and after oxidation were analyzed by XRD and SEM.The results show that Si3N4 and Si2N2O bonded SiC refractory presents better steam oxidation resistance than SiAlON bonded SiC.For Si3N4 and Si2N2O bonded SiC,the oxidation speed is higher with more pronounced volume expansion in the early 100 h;afterwards,the volume expansion slows down gradually and starts to level off after 300 h.It is considered that the high silica glass phase formed during the oxidation covers Si3N4 and Si2N2O,and SiC as a protective layer and fills the open pores.But for SiAlON bonded SiC,the volume expands gradually and constantly with the increasing oxidation duration even after 500 h,due to the continuous formation of mullite transformed from oxidation products and Al2O3 in SiAlON.展开更多
1 Scope This standard specifies the definition, classifica- tion, technical requirements, test methods, quality appraisal procedures, packing, marking, transportation, storage, and quality certificate of silicon nitri...1 Scope This standard specifies the definition, classifica- tion, technical requirements, test methods, quality appraisal procedures, packing, marking, transportation, storage, and quality certificate of silicon nitride bonded silicon carbide bricks.展开更多
By the method of TG-DSC(thermo gravimetric analysis -differential scanning calorimeter) , the chemical reactions of Fe-Si3 N4 bonded SiC during the sintering process in nitriding furnace have been studied. Analyses ha...By the method of TG-DSC(thermo gravimetric analysis -differential scanning calorimeter) , the chemical reactions of Fe-Si3 N4 bonded SiC during the sintering process in nitriding furnace have been studied. Analyses have been conducted on the reason of disintegration of specimens when ferro-silicon was added greater than 15% and on the method to reduce damage. The result indicated that there are mainly three important reactions occurred during the nitriding process of samples, they are: the oxidation of carbon, the melting of ferro-silicon and the nitriding of ferro -silicon. Controlling the balance of partial pressure of N2 and slowing down the rate of temperature rising can reduce the disintegration of samples .展开更多
文摘Thin films of silicon carbide nitride （SiCN） were prepared on （111） oriented silicon substrates by pulsed high-energy density plasma （PHEDP）. The evolution of the chemical bonding states between silicon, nitrogen and carbon was investigated as a function of discharge voltage using X-ray photoelectron spectroscopy. With an increase in discharge voltage both the C 1s and N 1s spectra shift to lower binding energy due to the formation of C--Si and N--Si bonds. The Si--C--N bonds were observed in the deconvolved C ls and N ls spectra. The X-ray diffractometer （XRD） results show that there were no crystals in the films. The thickness of the films was approximately 1-2 μm with scanning electron microscopy （SEM）.
文摘Steam oxidation resistance of Si3N4 and Si2N2O as well as SiAlON bonded SiC refractories at 900℃was tested according to ASTM-C863.Phase composition and microstructure before and after oxidation were analyzed by XRD and SEM.The results show that Si3N4 and Si2N2O bonded SiC refractory presents better steam oxidation resistance than SiAlON bonded SiC.For Si3N4 and Si2N2O bonded SiC,the oxidation speed is higher with more pronounced volume expansion in the early 100 h;afterwards,the volume expansion slows down gradually and starts to level off after 300 h.It is considered that the high silica glass phase formed during the oxidation covers Si3N4 and Si2N2O,and SiC as a protective layer and fills the open pores.But for SiAlON bonded SiC,the volume expands gradually and constantly with the increasing oxidation duration even after 500 h,due to the continuous formation of mullite transformed from oxidation products and Al2O3 in SiAlON.
文摘1 Scope This standard specifies the definition, classifica- tion, technical requirements, test methods, quality appraisal procedures, packing, marking, transportation, storage, and quality certificate of silicon nitride bonded silicon carbide bricks.
文摘By the method of TG-DSC(thermo gravimetric analysis -differential scanning calorimeter) , the chemical reactions of Fe-Si3 N4 bonded SiC during the sintering process in nitriding furnace have been studied. Analyses have been conducted on the reason of disintegration of specimens when ferro-silicon was added greater than 15% and on the method to reduce damage. The result indicated that there are mainly three important reactions occurred during the nitriding process of samples, they are: the oxidation of carbon, the melting of ferro-silicon and the nitriding of ferro -silicon. Controlling the balance of partial pressure of N2 and slowing down the rate of temperature rising can reduce the disintegration of samples .
