資源描述：
《本科畢業(yè)設(shè)計(jì)---sic陶瓷的高壓燒結(jié)工藝及性能.doc》由會(huì)員上傳分享，免費(fèi)在線閱讀，更多相關(guān)內(nèi)容在學(xué)術(shù)論文-天天文庫(kù)。
1、SiC陶瓷的高壓燒結(jié)工藝及性能材料專業(yè)本科畢業(yè)論文河摘要碳化硅陶瓷具有高溫強(qiáng)度高、抗氧化性強(qiáng)、耐磨損性好、熱膨脹系數(shù)小、硬度高、抗熱震和耐化學(xué)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(jià)鍵性很強(qiáng)的化合物,其自擴(kuò)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(dāng)?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(shí)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(jī)對(duì)SiC陶瓷的高壓燒結(jié)，對(duì)SiC陶瓷的高壓燒結(jié)工藝及性能進(jìn)行了初步的研究，并進(jìn)行了理論分析，探索
2、了其顯微結(jié)構(gòu)與性能之間的關(guān)系。通過(guò)對(duì)SiC復(fù)相陶瓷的相對(duì)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(shí)間和燒結(jié)制度，增進(jìn)致密化，進(jìn)而達(dá)到改進(jìn)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(shí)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(wú)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(duì)陶瓷的性能有明顯的影響，實(shí)驗(yàn)結(jié)果表明：Al2O3是SiC燒結(jié)
3、的有效燒結(jié)助劑,在低添加量下(約2wt%)即可實(shí)現(xiàn)陶瓷的全致密燒結(jié)。燒結(jié)工藝對(duì)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)IIISiC陶瓷的高壓燒結(jié)工藝及性能材料專業(yè)本科畢業(yè)論文河ABSTRACTSiCceramicsisagoodmaterialwithhightemperaturestrength,oxidationresistance,wearresistance,thermalexpansioncoefficient,highhardness,the
4、rmalshockandchemicalresistanceandotherexcellentproperties,therefore,hasbeenwidelyusedinmanyfields.However,SiCisacovalentbondstrongcompound,theself-diffusioncoefficientisextremelysmall,thesinterabilityispoor.SiCsinteredintheconventionalpowdermetallurgyprocessconditions,withoutth
5、einclusionofsuitableadditives,pureSiCdensificationisdifficult.Usingultra-highpressuresinteringmethodcanlowerthetemperature,theshorterthetime,thelowsinteringadditivesaddedamountobtainedbyahigh-densityandhigh-performanceceramic.Inthispaper,basedonsixsideshigh-pressurejackingmachi
6、neofSiCceramicshighpressuresintering,highpressuresinteringprocessandtheperformanceofSiCceramicshascarriedonthepreliminaryresearch,andhascarriedonthetheoreticalanalysis,toexploretherelationshipbetweenitsmicrostructureandproperties.ThroughtherelativedensityofSiCceramiccompoundpha
7、sespectrumandXRDanalysis,foundthathighpressuresinteringSiCceramicmaterialwithexcellentperformance,mainlyreflectedintheperformanceofthermalconductivityandtoughnessin,hasthegoodapplicationprospect.Comparedwithnormalpressure,highpressuresinteringcaneffectivelyreducemetalsinteringt
8、imeandsinteringtheceramicsystem,promotedensification,a
