氮化物结合碳化硅耐火材料的研究进展

对氮化物结合碳化硅结合耐火材料的研究现状进行了综合评述，认为氮化硅或赛隆结合的碳化硅在性能上更适宜于高炉内应用；氧化法烧成的含氮化物结合产品性能还需要进一步改进。     

碳化硅中氮化物结合剂的形成

ＳｉＣ有极好的热机械和化学性能，通常用来制备ＳｉＣ材料的结合剂是：粘土－莫来石、非氧化物和利用ＳｉＣ的再结晶，ＳｉＣ与莫来石的反应是整个粘土碳氮共渗反应的最后阶段。通过这个反应产生了Ｓｉ－Ａｌ－Ｏ－Ｎ系统中的β－赛隆和氧氮化合物。本文使用天然矿物如粘土和滑石，研究ＳｉＣ材料中β－赛隆和Ｓｉ３Ｎ４结合剂的形成。试验先将ＳｉＣ－粘土混合物在１０００ｋｇ／ｃｍ＾２压力下成型，试样在流动的Ｎ２气中，于１４     

赛隆结合碳化硅耐火材料

赛隆和无氧化合物近年来在耐火材料生产中得到广泛应用,用这些材料制成的制品成功地在黑色冶金热工设备和其它工业部门中使用。在碳化硅耐火材料烧成过程中及赛隆结合剂形成时,起着很大作用的不仅是含氧化铝添加剂的数量,而且还有得到此添加剂的过程。在这方面,本文介绍了不同含量氧化铝添加剂对含赛隆的碳化硅耐火材料性能的影响之有关研究。     

氮化硅结合碳化硅耐火材料的氧化

氮化硅结合碳化硅耐火材料高温氧化后，其抗折强度有所提高，但经扫描电镜观察，材料断面结构已发生了明显的变化。该材料长时间在氧化气氛中使用，可靠性将下降。     

氧氮化硅结合碳化硅窑具材料研究

利用热力学分析了氧氮化硅结合相的生成机理。探讨了硅粉加入量对氧氮化硅生成量、材料的各项理化性能以及抗氧化性能的影响。结果表明：氧氮化硅的含量随Ｓｉ含量的增加而增加,制品的常温耐压强度和荷重软化温度相应提高     

氮化物结合碳化硅窑具材料抗氧化性能研究

在不同氧化温度下(115 0～14 5 0℃)对氮化物(Si2 N2 O)结合碳化硅(SiC)与氮化硅(Si3N4 )结合碳化硅(SiC)两种氮化物结合SiC窑具材料的抗氧化性进行了对比研究。结果表明:在显气孔率与氧化面积相近的情况下,Si2 N2 O结合SiC材料低温下(<12 5 0℃)具有较好的抗氧化性,而Si3N4 结合SiC材料高温下(≥12 5 0℃)具有较好的抗氧化性。     

赛隆结合碳化硅耐火材料的微观结构与性能分析

在对赛隆结合碳化硅粉分别进行了氧化与侵蚀试验的基础上,用岩相与电子探针的方法分析了赛隆结合碳化硅砖的微观结构与性能关系。     

赛隆结合碳化硅耐火材料的微观结构与性能分析

在对赛隆结合碳化硅粉分别进行了氧化与侵蚀试验的基础上,用岩相与电子探针的方法分析了赛隆结合碳化硅砖的微观结构与性能关系。     

氮化硅结合碳化硅树料的抗渣侵蚀性

借助光学显微镜、扫描电子显微镜和Ｘ射线衍射分析等手段，研究了矿渣侵蚀后的氮化硅结合碳化硅材料的显微结构和物相组成．探讨了氮化硅结合碳化硅材料的损坏机理。     

氧氮化硅结合碳化硅制品的生产与使用

以工业用黑色碳化硅砂、硅粉为主要原料，研制出了导热性能优良、抗热震性好、耐高温、耐侵蚀及耐磨损，且生产工艺较简单、成本较低的氧氮化硅结合的碳化硅制品．该产品已广泛应用于冶金炉、化工设备及发电用锅炉的内衬，并取得了较满意的效果。     

Corrosion behavior of silicon nitride bonded silicon carbide refractory material by molten copper and copper slag

Silicon Carbide refractories may be used in contact with copper and copper slags. The object for the investigation of corrosion by the melt of copper and the copper slag was SiC siphon block of the slag collector in the runner of the cathode shaft furnace. It is exposed to the permanent flow of copper with small amount of slag. Slag on the surface of the melt is stopped by siphon block and it suffers the most extensive corrosion wear, but the same time it is a good object for investigation, because different parts of this plate are exposed to intensive corrosion by different corrosive agents.General observations show, that the corrosion of Si₃N₄-SiC by slag is sufficiently more extensive and the wear is about 3 mm per month, while the wear by the flowing copper is below 1 mm per month.The observation of the cross section of the exposed Si₃N₄-SiC plate on macro level shows 4–5 zones of different color. Microstructural observations show almost no changes of the material in direct contact with molten copper without exposure of air, that suggests slow dissolution of Silicon Carbide and Silicon Nitride in the flowing melt of copper (physical dissolution in case of permanent removal of reactants). The most severe wear of Si₃N₄-SiC refractory is by slag, because the chemical erosion takes place.     

氮化硅结合碳化硅耐火材料在钢水中的腐蚀行为

运用扫描电镜（ＳＥＭ）技术，研究了氮化硅结合碳化硅耐火材料在钢水中的腐蚀行为。结果表明，金属与氮化硅结合碳化硅材料之间的界面清晰，基体内部无任何金属渗入，但氧化的材料表面有氧化物粘附。     

激光闪射法测试氮化硅结合碳化硅材料导热系数的研究

激光闪射法在材料导热系数的测量方面已得到广泛研究和应用。利用激光闪射法测试了氮化硅结合碳化硅材料的导热系数,分析了影响结果准确性的因素,并提出了相应措施。     

Effect of self-developed graphene lubricant on tribological behaviour of silicon carbide/silicon nitride interface

The research presented in this paper aims to investigate the effectiveness of different surface roughness and lubrication conditions on the interfacial tribological properties between silicon carbide (SiC) and silicon nitride (Si₃N₄) ceramics, particularly for providing insight into the mechanisms of how graphene reduces the friction and wear rate. The worn groove topography and surface composition were characterised in detail with 3D laser measuring microscopy and X-ray photoelectron spectroscopy. The tribological test results on the UMT-TriboLab show that a smooth initial surface is more likely to obtain a low friction coefficient and wear rate under water lubrication. The proper initial surface roughness for SiC and Si₃N₄ ceramics is approximately Ra 10?nm, and it will be lower in an alcohol or graphene aqueous solution. A large load does not worsen the tribological behaviour of a Si₃N₄ ball sliding against a SiC disk, and it reduces the friction coefficient and wear rate. Among the five lubrication states of dry friction, dry graphene lubrication, water lubrication, graphene solution lubrication, and self-developed graphene lubrication, the self-developed graphene lubricant can exhibit an ultra-low friction coefficient of 0.009 and ultra-low wear rate of 1.69?×?10^?7?mm³/N·m. The excellent tribological property of the graphene-coated ceramic surface helps the prepared lubricant to decrease the friction coefficient effectively. Furthermore, the graphene film can protect the SiC from being oxidised by water under the tribo-activated action, and therefore, lead to ultra-low wear rate under low friction condition. Alcohol improves the tribological property of the self-developed graphene lubricant, mainly because of the good wettability between graphene and ethanol. The self-developed graphene lubricant can be applied in water-lubricated ceramic bearings and motorised precision spindles.     

A comparative study of silicon nitride and SiAlON ceramics against E. coli

In recent decades, due to some limitations from alumina (Al₂O₃) and zirconia (ZrO₂), silicon nitride (Si₃N₄) has been investigated as a novel bioceramic material, mainly in situations where a bone replacement is required. Si₃N₄ ceramics and its derivative form, SiAlON, possess advantages in orthopedics due to their mechanical properties and biologically acceptable chemistry, which accelerates bone repair. However, biological applications require additional properties, enabling stronger chemical bonding to the surrounding tissue for better fixation and the prevention of bacteria biofilm formation. Therefore, two commercial Si₃N₄ and SiAlON ceramics were investigated in this study and compared to each other according to their material properties (like wetting angles and surface chemistry) and their antibacterial behaviors using E. coli. Results provided evidence of a 15% reduction in E. coli colonization after just 24 h on Si₃N₄ compared to SiAlON which is impressive considering no antibiotics were used. Further, a mechanism of action is provided. In this manner, this study provides evidence that Si₃N₄ should be further studied for a wide range of antibacterial orthopedic, or other suitable biomaterial applications.     

Wet-chemical coating of silicon carbide fibers with hexagonal boron nitride layers

Hexagonal BN fiber coatings and BN powders were prepared by pyrolysis of the raw materials boric acid and urea in an atmosphere consisting of hydrogen and nitrogen. The powders were used to determine the appropriate mixing ratio of the raw materials to produce BN with the desired composition and crystal structure. The pyrolysis of boric acid and urea in a molar mixing ratio of 1:2 resulted in a BN that was hexagonal and had a near-stoichiometric composition.To prepare a solution for the coating of fibers, boric acid and urea were dissolved in an ethanol-water mixture. The coating was then applied to SiC filaments using a continuous roll-to-roll dip-coating process. It could be shown by SEM/EDS that BN layers were applied to the fibers. No significant bridging in the fiber bundle was found. Furthermore, it could be demonstrated by grazing incidence x-ray diffraction that the layers were crystalline.     

Bipolar resistive switching characteristics of silicon carbide nitride (SiCN)-based devices for nonvolatile memory applications

The present study reports silicon carbide nitride (SiCN) as a new material for resistive switching-based nonvolatile memory device applications. The Cu/SiCN/Pt device exhibit uniform and stable bipolar resistive switching behavior. A thorough current-voltage (I-V) analysis suggests an Ohmic conduction mechanism within the low resistance state (LRS), whereas within the high resistance state (HRS) trap-controlled modified space charge limited conduction (SCLC) mechanism was found to be dominated. The resistance vs. temperature measurement (R-T curve) within LRS and HRS along with a model analysis indicates an interesting result that the formation of conduction path during LRS is not due to Cu filament but may be formed by trap-to-trap hopping of electrons via nitride-related traps between the top and bottom electrodes. The resistive switching in Cu/SiCN/Pt device was operated via electron transport path formation/rupture by electron trapping/de-trapping. The reliability of device was measured in terms of endurance and retention, which exhibits good endurance over 10⁵ cycles and long retention time of 10⁴ s at room-temperature as well as at 200 °C. The above result suggests the feasibility of Cu/SiCN/Pt devices for futuristic nonvolatile memory application at high temperature and harsh environment.