Abstract:Rigidthermalinsulatingmaterials(RTIM)werepreparedfromceramicfibersthroughsintering.Theeffectsof density,fiberorientation,testtemperatureandcompositionwithaerogelonthemechanicalpropertiesoftheRTIMwereinvestigated.TheresultsindicatethatthemechanicalpropertiesoftheRTIMincreasewiththeincreasingofthedensity.Tensile andcompressivepropertiesoftheRTIMinplanedirectionarefourtimeslargerthanthatinthicknessdirection.ThecompressivepropertiesoftheRTIMat800℃ and1000℃are90%and50%ofthoseatroomtemperaturerespectively.The compressivepropertiesofcompositesincreasedby35%aftercompositionwithaerogel,whilethetensilepropertiesofcompositeskeepunchanged.