Tshawb xyuas cov khoom ntawm cov ntxeem tau silicon carbide ceramics

Cov khoom tshwj xeeb ntawm ntxeem tau silicon carbide ceramicsfeem ntau yog vim nws qhov tshwj xeeb ntxeem tau qauv, uas muaj porosity, pore loj thiab tis, thiab cov duab ntawm qhov. Yog li ntawd, nws yog ib qho tsim nyog los tswj nws qhov porosity, qhov pore loj thiab kev faib tawm, thiab cov pore zoo los ntawm kev npaj kom tau txais cov qauv uas xav tau. Yog li nws txoj kev npaj tau yog lub hom phiaj ntawm kev tshawb fawb.

Cov khoom ntawm ntxeem tau SiC ceramics

1.Pore ​​khoom

①Porosity

Porosity yog qhov feem pua ​​​​ntawm cov ntim uas nyob hauv lub qhov hws hauv cov khoom ntxeem tau mus rau tag nrho cov ntim ntawm cov khoom ntxeem tau (xws li qhib qhov hws, ib nrab qhib qhov hws thiab kaw qhov pores ntawm 3 hom). Kev tshawb fawb qhia tau hais tias kev ua tau zoo ntawm cov khoom ntxeem tau tsuas yog nyob ntawm qhov porosity.

② Pore morphology

Pore ​​morphology yog hais txog lub morphology ntawm pores nyob rau hauv porous ceramics. Thaum lub pores yog equiaxed pores, tag nrho cov kev ua tau zoo ntawm cov khoom yog isotropic; tab sis thaum lub pores yog striped los yog tiaj tus, xws li los ntawm carbonization ntawm ntoo npaj los ntawm silicon cov tshuaj tiv thaiv sintering ntxeem tau SiC ceramics, lub pore qauv yog ib tug tej yam kev taw qhia.

③Pore ​​txoj kab uas hla thiab faib

Pore ​​txoj kab uas hla tsawg dua 2nm rau cov ntaub ntawv microporous, qhov pore loj ntawm 2 ~ 50nm rau cov ntaub ntawv mesoporous, loj dua 20nm rau cov ntaub ntawv macroporous. Los ntawm qhov pore loj thiab kev faib tawm ntawm qhov cuam tshuam ntau dua ntawm kev ua tau zoo, suav nrog permeability, permeability tus nqi thiab kev ua haujlwm pom.

2.Mechanical zog

Porous SiC ceramicCov ntaub ntawv yog nkig thiab lawv cov khoom siv kho tshuab feem ntau yog qhov txawv txav los yog lub zog compression. Porosity thiab kev npaj muaj kev cuam tshuam loj rau cov khoom siv hluav taws xob ntawm porous SiC ceramics.

3.Thermal conductivity

Porosity thiab pore morphology muaj kev cuam tshuam loj rau cov thermal conductivity ntawm ntxeem tau ceramics. Rau cov porous ceramics nrog cov pore faib, cov thermal conductivity txo qis thaum lub pore tus nqi nce. Txawm li cas los xij, vim qhov pore morphology ntawm cov khoom siv porous ceramic npaj los ntawm cov txheej txheem sib txawv, muaj qhov sib txawv loj, yog li cov txheej txheem hloov hluav taws xob yog sib txawv thiab nyuaj.

Porous SiC ceramicsmuaj lub cev zoo heev ntawm SiC nws tus kheej, xws li cov khoom loj loj, siab tshwj xeeb thaj chaw, siab hardness, corrosion kuj, kub tsis kam, siab thermal conductivity, tsis tshua muaj coefficient ntawm thermal expansion, thiab tsis kam rau thermal shock, nyob rau sab saum toj. txaus siab ntawm qhov ntxeem tau ntawm cov ceramics.