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1、摘要碳化硅陶瓷具有高溫強度高、抗氧化性強、耐磨損性好、熱膨脹系數(shù)小、硬度高、抗熱震和耐化學腐蝕等優(yōu)良特性,因此,在很多領(lǐng)域得到廣泛應(yīng)用。然而,SiC是一種共價鍵性很強的化合物,其自擴散系數(shù)極小,可燒結(jié)性很差。在傳統(tǒng)的粉末冶金SiC燒結(jié)工藝條件下,如果不加入適當?shù)奶砑觿?純SiC是很難燒結(jié)致密化。采用超高壓燒結(jié)方法可以在較低溫度、較短時間、低燒結(jié)助劑添加量下獲得高致密度、高性能的陶瓷。本文利用高壓六面頂壓機對SiC陶瓷的高壓燒結(jié)，對SiC陶瓷的高壓燒結(jié)工藝及性能進行了初步的研究，并進行了理論分析，探索了
2、其顯微結(jié)構(gòu)與性能之間的關(guān)系。通過對SiC復(fù)相陶瓷的相對密度和XRD譜的研究分析，發(fā)現(xiàn)高壓燒結(jié)的SiC陶瓷材料具有優(yōu)良的性能，主要體現(xiàn)在導(dǎo)熱性能和韌性在，有良好的應(yīng)用前景。與常壓相比，高壓燒結(jié)可以有效的降低金屬陶瓷的燒結(jié)時間和燒結(jié)制度，增進致密化，進而達到改進性能的目的。六面頂高壓燒結(jié)技術(shù)是一種快速、高效的燒結(jié)技術(shù)，大大降低了燒結(jié)溫度和縮短了燒結(jié)時間，并且可制備出接近理論密度的復(fù)相陶瓷材料。采用超高壓燒結(jié)工藝可以燒結(jié)獲得無燒結(jié)助劑添加的高致密度SiC陶瓷(致密度92%~100%)。燒結(jié)工藝對陶瓷的性能有
3、明顯的影響，實驗結(jié)果表明：Al2O3是SiC燒結(jié)的有效燒結(jié)助劑,在低添加量下(約2wt%)即可實現(xiàn)陶瓷的全致密燒結(jié)。燒結(jié)工藝對添加了燒結(jié)助劑陶瓷性能的影響與純SiC的燒結(jié)類似,但獲得的陶瓷的致密度普遍較高。關(guān)鍵詞：SiC陶瓷高溫高壓技術(shù)燒結(jié)性能物相分析（XRD譜)ABSTRACTSiCceramicsisagoodmaterialwithhightemperaturestrength,oxidationresistance,wearresistance,thermalexpansioncoeffici
4、ent,highhardness,thermalshockandchemicalresistanceandotherexcellentproperties,therefore,hasbeenwidelyusedinmanyfields.However,SiCisacovalentbondstrongcompound,theself-diffusioncoefficientisextremelysmall,thesinterabilityispoor.SiCsinteredintheconvention
5、alpowdermetallurgyprocessconditions,withouttheinclusionofsuitableadditives,pureSiCdensificationisdifficult.Usingultra-highpressuresinteringmethodcanlowerthetemperature,theshorterthetime,thelowsinteringadditivesaddedamountobtainedbyahigh-densityandhigh-p
6、erformanceceramic.Inthispaper,basedonsixsideshigh-pressurejackingmachineofSiCceramicshighpressuresintering,highpressuresinteringprocessandtheperformanceofSiCceramicshascarriedonthepreliminaryresearch,andhascarriedonthetheoreticalanalysis,toexploretherel
7、ationshipbetweenitsmicrostructureandproperties.ThroughtherelativedensityofSiCceramiccompoundphasespectrumandXRDanalysis,foundthathighpressuresinteringSiCceramicmaterialwithexcellentperformance,mainlyreflectedintheperformanceofthermalconductivityandtough
8、nessin,hasthegoodapplicationprospect.Comparedwithnormalpressure,highpressuresinteringcaneffectivelyreducemetalsinteringtimeandsinteringtheceramicsystem,promotedensification,andthusachievethepurposeofimprovingperformance.Cubichigh
