资源描述：
《sic-tin陶瓷的影响》由会员上传分享，免费在线阅读，更多相关内容在教育资源-天天文库。
1、SiC-TiN陶瓷的影响第34卷第6期2006年6月硅酸盐JoURNALoFT衄CHESECERAMICSoCⅢTY,,bl_34.NO.6June,2006稀释剂含量对自蔓延高温合成Si3N4-SiC—TiN陶瓷的影响张学军,郑永挺,韩杰才,周立娟(哈尔滨工业大学,复合材料与结构研究所,哈尔滨150001)摘要:以TiSi2和SiC为原料,利用自蔓延高温合成(sel~propagafionhigh—temperaturesynthesis,SHS)方法合成直径为24mm的Si:aN4-SiC-TLN陶瓷.通过理论计算和实验研究了不同孔隙率压坯中稀释剂SiC含量对反应物TiSi2
2、转化率的影响.结果表明:SiC在一定范围内增加有利于TiSi2的氮化,且含40%(质量分数,下同)SiC和50%SiC的压坯在燃烧合成过程中发生了SiC的氮化反应.压坯孔隙率为50%(体积分数,下同)时,反应物TiSi2氮化充分,最终产物为Si3N4_Sic—nN.孔隙率为45%,含量为30%SiC和40%SIC压坯的合成产物中残留游离Si,50%SIC压坯的合成产物中未发现游离si.在稀释剂含量为35SiC,氮气压力为150MPa条件下,所得的Si3N4-SiC-TiN复相陶瓷抗弯强度达430MPa,断裂韧性为3.6MPa.m¨2.关键词:稀释剂:氮化硅一碳化硅一氮化钛陶瓷:自
3、蔓延高温合成:氮化中图分类号:TQ174文献标识码:A文章编号:0454-5648(2006)06-0708~05EFFECToFDILUENTCoNTENToNSi~I4--SiC-TiNCERAMICSPREPAREDBYSELF.PRoPAGATIoNmGH.TEM口E.ERATURESYNTHESISZHANGXuejun,ZHENGYongting,HANJiecai,ZHOULijuan(CentreforCompositeMaterials,HarbinInstituteofTechnology,Harbin150001,China)Abstract:SiN4—Si
4、C—TiNmultiphaseceramicsampleswimadiameterof24mmwerepreparedwimTiSi,andSiCpowdersastherawmaterialsbytheself-propagationhigh—temperaturesynthesisrSHS)memod.TheeffectofdifferentcontentsofdiluentSiCinmesamplesonconversionpercentageofreactantTiSi,wascalculatedinmeoryandanSHStestWascarriedout.There
5、sultsshowmatacertaindegreeofincreaseofSiCcontentWashelpfulfornitrificationofTiSi,,andSiCparticleswerenitrifiedduringmeSHSprocessinthesamplesofgreencompactswith40%(inmass,mesalnebelow)SiCand50%SiCdiluent.TheTiSi,reactantsinmegreencompactswith50%(involume,thesalnebelow)porositywerefullymtrified
6、andthefinalproductswerecomposedofSign4,SiCandTiN.Freesiliconwasdetectedinthe30%and40%SiC—dilutedsam['leswim45%pomsity.whilenofreesiliconWasfoundinme50%porositygreenparts.SiN4—SiC—TiNceramicwithabendingstrengmof430MPaandafracturetoughnessof3.6MPa.mwasobtainedaftertheSHSunderanitrogenpressureof
7、l50MPaandUSingagreencompactwim35%SiCdiluent.Keywords:diluent;siliconmtride-siliconcarbide-titaniumnitrideceramics;self-propagationhigh—temperaturesynthesis;mtrification氮化硅(Si3N4)陶瓷是高温结构制品最理想的材料之一.然而,SiN陶瓷的脆性很大程度上限制了它的应用.因此,进一步提高Si3N4陶瓷的强度,尤其是
