碳化硅致密陶瓷材料研究进展

碳化硅材料以其优异的性能得到了越来越广泛的应用,通过简要介绍碳化硅致密陶瓷的制备方法及其性能和总结近年来国内外的研究进展,来展望碳化硅致密陶瓷材料的研究发展趋势。     

碳化硅质陶瓷膜材料评价方法的选择及材料评价

国内评价高温下碳化硅质陶瓷膜材料的标准和方法较少,本文基于碳化硅陶瓷膜材料具体实际应用工况条件,就材料的强度,耐高温、高压性能,孔结构及透气性能等方面,提出了系列测试标准和方法,并进行了测试。实验测得山东工陶院生产的碳化硅质陶瓷膜材料的抗弯曲强度能够达到18MPa,支撑体气孔率和孔径分别为34%和60μm,分离膜平均孔径为17μm,材料的线胀系数在5×10-6/k,热震性能能够满足1000℃下10次不裂,在1m/min风速下材料的初始压降为750Pa。碳化硅陶瓷膜材料具有良好强度、高温热性能和较好的孔梯度结构。     

重结晶碳化硅材料的制备与应用研究进展

从原料纯度及颗粒形状、成型方法、烧结温度及烧结气氛等方面阐述了重结晶碳化硅材料的制备工艺及其特点,并与其他组成或性能相近的碳化硅材料做了对比;介绍了重结晶碳化硅材料的组成、结构与性能特点,重点介绍了重结晶碳化硅材料在高温强度、抗氧化性等方面的研究,并概述了重结晶碳化硅材料在高温窑具、柴油车尾气净化器等领域的应用情况。     

碳化硅纤维及其复合材料

碳化硅纤维及其复合材料是目前使用温度最高的增强材料和先进复合材料，本文简要介绍先驱体转换法和化学气相沉积法制备碳化硅纤维的工艺，不同工艺方法制备的碳化硅纤维的性能比较，碳化硅纤维及其复合材料的现状与应用。     

自结合碳化硅与重结晶碳化硅辩析

本文对自结合碳化硅及重结晶碳化硅进行了较详细的分析,澄清了人们的一些模糊认识。叙述了β—SiC结合碳化硅及重结晶碳化硅的生产工艺及基本性能。初步推测了提高重结晶碳化硅材料性能的途径。     

碳化硅/环氧树脂复合材料的制备及性能研究

分别采用固化剂D230、9035、acamine2636与环氧树脂E51混合,然后分别与用硅烷偶联剂(KH550、KH560、A171)处理的碳化硅颗粒混合,采用浇注法制备了碳化硅/环氧树脂复合材料。以材料的弯曲强度为评价方法,研究了3种不同固化剂构成的环氧树脂体系以及3种硅烷偶联剂对碳化硅/环氧树脂复合材料性能的影响,以及复合材料弯曲强度与材料中环氧树脂含量的关系。结果表明,3种固化剂中以D230、9035制备的材料性能为好;采用KH550、KH560处理碳化硅颗粒后的材料性能比不处理或采用A171处理碳化硅颗粒后的材料性能为好。随着复合材料中环氧树脂相含量的增加复合材料的弯曲强度下降。     

多孔SiC陶瓷制备工艺研究进展

多孔碳化硅(SiC)陶瓷由于具有优异的高温强度、化学稳定性、良好的抗热震和抗氧化性能等,已经得到了广泛应用。研究表明:材料的显微结构、气孔大小、形貌、气孔率等对多孔碳化硅陶瓷的性能有很大影响。本文详细综述了各种多孔碳化硅陶瓷的制备方法及其应用,并结合目前的研究成果、兴趣和关注点给出了一些意见和建议。     

反应烧结碳化硅高温性能的研究进展

反应烧结碳化硅具有优良的力学性能、抗侵蚀性能和抗氧化性能等优点,是一种高致密度、低成本和净尺寸成型的材料.但由于反应烧结法的特殊工艺,反应烧结碳化硅中常含有较多游离硅,严重损害了材料的高温性能.主要阐述了反应烧结碳化硅高温力学性能、抗氧化性能、导热性能和抗热震性能的研究现状,并总结了近年来降低游离硅含量、提高反应烧结碳...     

熔铝炉用碳化硅纤维-碳化硅复合材料

碳化硅具有许多优良性能,但是碳化硅的断裂韧性不算太高。纤维增韧是改善材料韧性的最常用的一种方法。为此,有人研究了碳化硅短纤维增强碳化硅耐火材料的制备及其断裂性能。将碳化硅纤维切成长度为20mm的短纤维,按加入量(质量分数,下同)分别为0、0.1%、0.5%和1.0%加入到碳化硅     

国内简讯

国内已制得碳化硅纤维 碳化硅纤维是一种新型增强材料。其高温稳定性和抗氧化性能特别突出。碳化硅纤维能与树脂。陶瓷、金属等基体复合,是制造耐高温结构复合材料很有希望的增强材料。     

反应烧结碳化硅材料的抗热震性能研究

通过对比不同温差热震后材料的残余强度 ,对反应烧结碳化硅材料的抗热震性能进行了研究。结果表明 :反应烧结碳化硅材料的抗热震性能与显微组织密切相关 ,低游离硅含量与小粒径的反应烧结碳化硅材料具有较好的抗热震断裂性能 ,而高游离硅含量或大碳化硅粒径的材料具有相对优异的抗热震损伤性。对反应烧结碳化硅材料的抗热震性与显微组织的关系进行了探讨。     

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。     

碳化硅陶瓷固相烧结的烧结机理及研究进展简

碳化硅陶瓷材料具有高硬度、高强度、抗氧化、耐高温、高热导率、低线胀系数等优良性能,同时具有优良的化学稳定性且能够耐大多数种类的酸碱溶液腐蚀,在石油、化工、建材、航空、机械等诸多领域得到了广泛应用。本文主要阐述了碳化硅陶瓷固相烧结的烧结机理,并对目前国内外关于碳化硅陶瓷固相烧结的研究进展进行了阐述。     

高炉出铁沟喷补料实验室研制

以一级矾土熟料和碳化硅为主要原料 ,配以适量的碳质材料、复合添加剂等 ,研制出适用于中小型高炉出铁沟的快速修补用喷补料。试验结果表明 ,该料具有附着率高、粘接强度大、耐侵蚀、耐冲刷、热震稳定性好等特点     

SiC质耐火材料的氧化机理

SiC材料是一种性能优良的耐火材料，具有高导热性，高抗热震性，良好的高温强度等优点，但是由于碳化硅在氧化性气体，如O2，CO2，水蒸汽中发生膨胀劣化，严重影响SiC耐火材料的使用湿度和应用范围，本文主要讨论不同结合剂类型的SiC耐火材料的氧化特征，并提出抗氧化的可能途径。     

Directionally Solidified Boride and Carbide Eutectic Ceramics

Borides and carbides generally have outstanding hardness, excellent wear resistance, and high melting points due to their covalent bonding. Directionally solidified eutectic (DSE) composites of boride and carbide constituent phases have been investigated since the 1970s as an approach to produce dense composite microstructures with added control over the microstructure. A variety of DSE ceramic composites have been developed and evaluated as potential materials for structural and functional applications due to their unique thermo‐electro‐mechanical properties. Renewed interest over the past few decades has been motivated, in part, by the needs for ultrahigh‐temperature composites for aerospace applications along with low‐density composites for armor applications. Some directionally solidified boride and carbide DSEs exhibit advantages in material properties over monolithic materials. This study reviews historical and recent research on processing methods, microstructure, crystallography, and material properties (mechanical, electrical, thermal properties, and oxidation resistance) of directionally solidified boride and carbide eutectic ceramic composites. Opportunities along with current limitations and needs for future developments are also reviewed and discussed.     

Some Physical Properties of Eight Refractory Oxides and Carbides

An investigation of eight hot-pressed refractory oxides and carbides for possible gas-turbine application was undertaken. The properties, short-time tensile strength at elevated temperatures, thermal-shock resistance, coefficient of linear expansion, and density, were determined. The compositions of the ceramics included beryllium oxide, magnesium oxide, stabilized zirconia, zircon, boron carbide, 85% silicon carbide plus 15% boron carbide, titanium carbide, and zirconium carbide. The short-time tensile strengths of these ceramics were determined at 1800° and 2200°F. Resistance to thermal shock was determined by rapid cooling in air to room temperature from 1800°, 2000°, 2200°, and 2400°F. The thermal-expansion characteristics of these materials were studied from room temperature to 1100°F.
Zirconium carbide was the strongest material at 2200°F. with a maximum short-time tensile strength of 15,850 lb. per sq. in.; however, it exhibited extremely poor resistance to oxidation. Boron carbide had a short-time tensile strength of 22,550 lb. per sq. in. at 1800°F., and was the strongest material at this temperature. Boron carbide also had very poor resistance to oxidation and was among the worst compositions investigated in its ability to resist fracture by thermal shock. The evaluation of strength of boron carbide at 2200°F. was unsuccessful because it fluxed with the grips. Titanium carbide had the best resistance to thermal shock, and had strengths of 15,850 lb. per sq. in. at 1800°F. and 9400 lb. per sq. in. at 2200°F. It was the most promising of the eight compositions investigated. Hot-pressing of these eight highly refractory bodies indicated that a density of at least 93% of theoretical density could be obtained by this fabrication method.     

等离子喷涂工艺参数对B4C涂层性能的影响

本文研究了喷涂距离对大气等离子喷涂Ｂ４Ｃ涂层的沉积效率、气孔率、显微硬度和抗热震性能的影响,发现喷涂距离会严重影响Ｂ４Ｃ粉末在等离子体射流中的熔融状态,从而对这些性能产生显著影响。实验结果表明,通过优化工艺参数,尤其是选择适当的喷涂距离,可以在大气呀涂条件下制得同高压等离子喷涂相近所孔率和显微硬度的Ｂ４Ｃ涂层。     

高炉用新型自结合碳化硅砖性能研究

借助XRD、SEM等技术,对新型自结合碳化硅砖的抗碱性、抗渣性和抗热震性等高炉耐火材料的关键使用性能进行了研究,并与Si3N4结合碳化硅高炉砖进行了对比。结果表明:这种新型自结合碳化硅砖热导率高,力学性能好,抗碱性、抗渣性和抗热震性优良,预计用作高炉内衬具有良好的应用前景。     

SiC whiskers-reinforced polyimide aerogel composites with robust compressive properties and efficient thermal insulation performance

Polyimide (PI) aerogels enable promising application in many fields but are always inhibited by their weak resistance to high temperature and low mechanical properties. Herein, novel PI aerogel composites with efficient heat insulation and high compressive performance are prepared by introducing Silicon carbide whiskers (SiCw) as reinforcement. The SiCw in aerogel function as shrinkage inhibitor and high temperature stabilizer. The addition of SiCw exhibits obvious enhancement and toughening effect, the compressive strength of the PI aerogel composites increases from 1.09 to 1.96 MPa. These PI aerogel composites also show enhanced high temperature stability. The as-prepared PI aerogel composites possess integrated properties of high-temperature resistance, low thermal conductivity, and high compressive strength, which can be the candidate for the application in aerospace.