sitionare℃,ahydrogentoMTSratioof,andapressureofafewkPa.Argonwasusedasdilutegastoslowdownthechemicalreactionrateofdeposition.Afterthedensificationofthecompositeswasfinished,theC/SiCcompositeswerecoatedwithsilicon-molybdenumalloy(Si-Mo)meltattemperatureof~℃invacuumfor.h...OxidationtestsTheoxidationtestswereconductedat~℃inair.Thethermalshockexperimentswereconductedasfollows:thesampleswereplacedintothefinthedevelopmentofasuccessfuloxidationprotectionsystemforcarbon-basedcompositematerials[,].Thecriticalfactorsforoxidationprotectionsystemofcarbon-basedcompositematerialsare:(i)oxygendiffusionthroughthecoatingmicro-cracks;(ii)volatilityofcoatingmaterialsathightemperature;(iii)oxidationofcoatingbydiffusionofoxygenthroughthecoatinglayer,and;(iv)thechemicalandmechanicalcompatibilitybetweencoatingandsubstrate.Theoxidationprotectioncoatingforcompositesisusuallypreparedbychemicalvapordeposition(CVD)methodwhichhasbeendescribedelsewhere[].Thecoatinghasasandwichstructurewhichcouldbedi