Kev npaj cov txheej txheem ntawm cov khoom siv carbon fiber composite

Kev Txheeb Xyuas Txog Cov Khoom Siv Carbon-Carbon Composite

Cov khoom sib xyaw ua ke Carbon/carbon (C/C)yog cov khoom siv carbon fiber reinforced composite nrog cov khoom zoo heev xws li lub zog siab thiab modulus, lub teeb tshwj xeeb gravity, me me thermal expansion coefficient, corrosion tsis kam, thermal shock tsis kam, kev sib txhuam zoo, thiab tshuaj lom neeg ruaj khov. Nws yog ib hom tshiab ntawm cov khoom siv kub ultra-high.

Cov khoom siv sib xyaw ua ke C/Cyog ib qho khoom siv engineering zoo heev uas muaj cov qauv thermal-functional. Ib yam li lwm cov khoom siv sib xyaw ua ke zoo, nws yog ib qho qauv sib xyaw ua ke uas muaj cov fiber-reinforced phase thiab cov theem yooj yim. Qhov txawv yog tias ob qho tib si cov theem reinforced thiab cov theem yooj yim yog tsim los ntawm cov pa roj carbon ntshiab nrog cov khoom tshwj xeeb.

Cov khoom siv sib xyaw ua ke ntawm cov pa roj carbon / carbonfeem ntau yog ua los ntawm cov pa roj carbon, cov ntaub carbon, cov fiber carbon ua cov khoom txhawb nqa, thiab cov pa roj carbon tso ua matrix, tab sis nws tsuas muaj ib qho khoom xwb, uas yog carbon. Yuav kom ua rau qhov ceev ntxiv, cov pa roj carbon uas tsim los ntawm carbonization yog impregnated nrog carbon lossis impregnated nrog resin (lossis asphalt), uas yog, cov ntaub ntawv carbon/carbon composite yog ua los ntawm peb cov ntaub ntawv carbon.

Cov txheej txheem tsim khoom ntawm cov khoom siv carbon-carbon composite

1) Kev xaiv cov carbon fiber

Kev xaiv cov pob khoom carbon fiber thiab kev tsim qauv ntawm cov ntaub fiber yog lub hauv paus rau kev tsim khoomC/C sib xyaw ua keCov khoom siv kho tshuab thiab cov khoom thermophysical ntawm C/C composites tuaj yeem txiav txim siab los ntawm kev xaiv cov hom fiber thiab cov yam ntxwv ntawm kev xaws ntaub, xws li kev teeb tsa pob xov paj, qhov sib nrug ntawm pob xov paj, cov ntsiab lus ntawm pob xov paj, thiab lwm yam.

2) Kev npaj cov carbon fiber preform

Cov roj carbon fiber preform yog hais txog ib daim ntaub dawb uas tau tsim rau hauv cov qauv tsim nyog ntawm cov fiber raws li cov khoom zoo thiab kev ua tau zoo uas yuav tsum tau ua kom tiav cov txheej txheem densification. Muaj peb txoj kev ua tiav tseem ceeb rau cov khoom ua ntej: cov ntaub mos mos, cov ntaub tawv thiab cov ntaub mos mos thiab tawv sib xyaw. Cov txheej txheem tseem ceeb ntawm cov ntaub yog: cov xov paj qhuav, kev npaj pawg pas nrig ua ntej impregnated, kev txiav cov ntaub zoo, cov xov paj fiber thiab peb-seem ntau-directional tag nrho cov ntaub. Tam sim no, cov txheej txheem tseem ceeb ntawm cov ntaub siv hauv C composite yog peb-seem ntau-directional tag nrho cov ntaub. Thaum lub sijhawm cov txheej txheem weaving, tag nrho cov ntaub woven tau teeb tsa rau hauv ib qho kev taw qhia. Txhua lub fiber yog offset ntawm ib qho kaum sab xis raws li nws tus kheej kev taw qhia thiab interwoven nrog ib leeg los tsim ib daim ntaub. Nws tus yam ntxwv yog tias nws tuaj yeem tsim ib daim ntaub peb-seem ntau-directional tag nrho, uas tuaj yeem tswj tau cov ntsiab lus ntawm cov fibers hauv txhua qhov kev taw qhia ntawm cov khoom siv C / C composite, yog li cov khoom siv C / C composite tuaj yeem ua rau muaj cov khoom siv kho tshuab tsim nyog hauv txhua qhov kev taw qhia.

3) Cov txheej txheem ua kom C/C ntom ntom

Qhov degree thiab kev ua haujlwm ntawm kev ua kom ntom ntom feem ntau cuam tshuam los ntawm cov qauv ntaub thiab cov txheej txheem ntawm cov khoom siv hauv paus. Cov txheej txheem txheej txheem tam sim no siv suav nrog impregnation carbonization, tshuaj lom neeg vapor deposition (CVD), tshuaj lom neeg vapor infiltration (CVI), tshuaj lom neeg kua deposition, pyrolysis thiab lwm yam. Muaj ob hom txheej txheem txheej txheem tseem ceeb: impregnation carbonization txheej txheem thiab tshuaj lom neeg vapor infiltration txheej txheem.

Cov kua theem impregnation-carbonization

Txoj kev ua kua theem impregnation yog qhov yooj yim hauv cov khoom siv thiab muaj kev siv dav, yog li cov kua theem impregnation txoj kev yog ib txoj hauv kev tseem ceeb rau kev npaj cov ntaub ntawv C / C composite. Nws yog kom immerse lub preform ua los ntawm carbon fiber rau hauv cov kua impregnant, thiab ua rau lub impregnant nkag mus rau hauv qhov voids ntawm preform los ntawm pressurization, thiab tom qab ntawd los ntawm ntau cov txheej txheem xws li kho, carbonization, thiab graphitization, thaum kawg tau txaisCov ntaub ntawv sib xyaw ua ke C/C. Nws qhov tsis zoo yog tias nws siv sijhawm rov ua dua impregnation thiab carbonization cycles kom ua tiav qhov yuav tsum tau ua kom ceev. Cov khoom sib xyaw thiab cov qauv ntawm impregnant hauv cov kua theem impregnation txoj kev yog qhov tseem ceeb heev. Nws tsis tsuas yog cuam tshuam rau qhov ua haujlwm ntawm densification, tab sis kuj cuam tshuam rau cov khoom siv kho tshuab thiab lub cev ntawm cov khoom. Kev txhim kho cov pa roj carbonization ntawm impregnant thiab txo cov viscosity ntawm impregnant yeej ib txwm yog ib qho ntawm cov teeb meem tseem ceeb uas yuav tsum tau daws hauv kev npaj cov khoom siv C/C composite los ntawm cov kua theem impregnation txoj kev. Cov viscosity siab thiab cov pa roj carbonization qis ntawm impregnant yog ib qho ntawm cov laj thawj tseem ceeb rau tus nqi siab ntawm cov khoom siv C/C composite. Kev txhim kho kev ua tau zoo ntawm impregnant tsis tsuas yog txhim kho kev ua haujlwm ntawm cov khoom siv C/C composite thiab txo lawv cov nqi, tab sis kuj txhim kho ntau yam khoom ntawm cov khoom siv C/C composite. Kev kho mob tiv thaiv oxidation ntawm C/C composite cov ntaub ntawv Carbon fiber pib oxidize ntawm 360 ° C hauv huab cua. Graphite fiber zoo dua li carbon fiber me ntsis, thiab nws qhov kub oxidation pib oxidize ntawm 420 ° C. Qhov kub ntawm oxidation ntawm C/C composite cov ntaub ntawv yog li 450 ° C. C/C composite cov ntaub ntawv yooj yim heev rau oxidize hauv huab cua oxidative kub siab, thiab qhov oxidation tus nqi nce sai nrog rau qhov nce ntawm qhov kub. Yog tias tsis muaj kev ntsuas tiv thaiv oxidation, kev siv C/C composite cov ntaub ntawv mus sij hawm ntev hauv qhov chaw oxidative kub siab yuav ua rau muaj kev puas tsuaj loj heev. Yog li ntawd, kev kho mob tiv thaiv oxidation ntawm C/C composite cov ntaub ntawv tau dhau los ua ib feem tseem ceeb ntawm nws cov txheej txheem npaj. Los ntawm qhov kev xav ntawm cov thev naus laus zis tiv thaiv oxidation, nws tuaj yeem faib ua cov thev naus laus zis tiv thaiv oxidation sab hauv thiab cov thev naus laus zis tiv thaiv oxidation txheej txheem.

Theem Tshuaj Vapor

Kev tso pa tshuaj lom neeg (CVD lossis CVI) yog tso cov pa roj carbon ncaj qha rau hauv cov qhov ntawm cov khoom seem kom ua tiav lub hom phiaj ntawm kev sau cov qhov thiab ua kom qhov ceev. Cov pa roj carbon uas tso rau hauv cov khoom seem yooj yim rau graphitize, thiab muaj kev sib raug zoo nrog cov fiber. Nws yuav tsis ntsws thaum lub sijhawm rov ua carbonization zoo li txoj kev impregnation, thiab cov khoom siv lub cev thiab cov khoom siv kho tshuab ntawm txoj kev no zoo dua. Txawm li cas los xij, thaum lub sijhawm CVD, yog tias cov pa roj carbon raug tso rau ntawm qhov chaw ntawm cov khoom seem, nws yuav tiv thaiv cov roj kom tsis txhob nkag mus rau hauv cov qhov sab hauv. Cov pa roj carbon uas tso rau ntawm qhov chaw yuav tsum tau tshem tawm cov tshuab thiab tom qab ntawd yuav tsum tau ua ib qho kev tso pa tshiab. Rau cov khoom tuab, txoj kev CVD kuj muaj qee qhov teeb meem, thiab lub voj voog ntawm txoj kev no kuj ntev heev.