PreparationofZrW2O8-Cf/E51low/negativeCTE compositesandeffectofultrasonictimeonits thermaland mechanicalproperty

In Order to prepare low expansion,highstrengthandlightweightcomposites,ZrW2O8-Cf/ E51compositeswerepreparedbycompression moldingmethod,andtheeffectsofultrasonictimeon itsmicrostructure,thermalexpansionbehaviorandultimatetensilestrengthwerestudied.Theresults showthattheagglomeratedparticleswillbeblockedbythefibersandgatheronthesurfaceoffiber bundlesduringthepreparation. Within20 minutes,theagglomeration ofZrW2O8 particlescan be reducedbyprolongingtheultrasonictime.Withthedecreaseofparticleagglomeration,thefracture surfaceofthecompositeswillbechangedfromplanewithoutfiberpull-outtouneven withfiberpull-out.Duringthethermalexpansion process,the dL/L0of ZrW2O8-Cf/E51 composites show three stages:increase,decreaseandslowincreaseunderthecombinedactionofcarbonfiberand ZrW2O8 particles.When ultrasonictimeincreasesfrom 5 min to 20 min,the averagethermalexpansion coefficientofZrW2O8-Cf/E51compositesdecreasesbyabout130%,andtheultimatetensilestrength increasesbyabout8%.