Cov txheej txheem tsim khoom ntawm cov tshuaj sintering silicon carbide

Cov tshuaj tiv thaiv-sintered silicon carbide yog ib qho khoom siv kub kub tseem ceeb, nrog lub zog siab, siab hardness, siab hnav tsis kam, siab corrosion tsis kam thiab siab oxidation tsis kam thiab lwm yam khoom zoo heev, yog dav siv hauv tshuab, aerospace, tshuaj lom neeg kev lag luam, lub zog thiab lwm yam teb.

 

1. Kev npaj cov khoom siv raw

Cov khoom siv raw ntawm silicon carbide reactive sintering feem ntau yog carbon thiab silicon hmoov, uas carbon tuaj yeem siv ntau yam khoom muaj carbon, xws li thee coke, graphite, charcoal, thiab lwm yam. Feem ntau, silicon hmoov yog xaiv nrog qhov loj me ntawm 1-5μm siab purity silicon hmoov. Ua ntej, carbon thiab silicon hmoov sib xyaw ua ke hauv ib qho kev faib ua feem, ntxiv cov binder thiab cov neeg sawv cev ntws kom tsim nyog, thiab do kom sib npaug. Tom qab ntawd, cov khoom sib xyaw no muab tso rau hauv lub tshuab sib tsoo pob rau kev sib tsoo pob kom sib xyaw thiab sib tsoo kom txog thaum qhov loj me tsawg dua 1μm.

2. Cov txheej txheem molding

Cov txheej txheem molding yog ib qho ntawm cov kauj ruam tseem ceeb hauv kev tsim silicon carbide. Cov txheej txheem molding feem ntau yog nias molding, grouting molding thiab static molding. Kev nias molding txhais tau tias cov khoom sib tov raug muab tso rau hauv pwm thiab tsim los ntawm kev siv tshuab siab. Grouting molding txhais tau tias kev sib tov cov khoom sib tov nrog dej lossis cov kuab tshuaj organic, txhaj rau hauv pwm los ntawm lub koob txhaj tshuaj hauv qab lub tshuab nqus tsev, thiab tsim cov khoom tiav tom qab sawv. Static pressure molding txhais tau tias cov khoom sib tov rau hauv pwm, nyob rau hauv kev tiv thaiv ntawm lub tshuab nqus tsev lossis huab cua rau static pressure molding, feem ntau ntawm lub siab ntawm 20-30MPa.

3. Cov txheej txheem sintering

Kev sintering yog ib kauj ruam tseem ceeb hauv cov txheej txheem tsim khoom ntawm cov tshuaj tiv thaiv-sintered silicon carbide. Qhov kub thiab txias sintering, lub sijhawm sintering, huab cua sintering thiab lwm yam yuav cuam tshuam rau kev ua haujlwm ntawm cov tshuaj tiv thaiv-sintered silicon carbide. Feem ntau, qhov kub thiab txias sintering ntawm cov tshuaj tiv thaiv sintering silicon carbide yog nruab nrab ntawm 2000-2400 ℃, lub sijhawm sintering feem ntau yog 1-3 teev, thiab huab cua sintering feem ntau yog inert, xws li argon, nitrogen, thiab lwm yam. Thaum lub sijhawm sintering, cov khoom sib xyaw yuav dhau los ua tshuaj lom neeg los ua cov siv lead ua silicon carbide. Tib lub sijhawm, carbon kuj tseem yuav tshuaj lom neeg nrog cov pa roj hauv huab cua los tsim cov pa roj xws li CO thiab CO2, uas yuav cuam tshuam rau qhov ceev thiab cov khoom ntawm silicon carbide. Yog li ntawd, kev tswj hwm huab cua sintering thiab lub sijhawm sintering tsim nyog yog qhov tseem ceeb heev rau kev tsim cov tshuaj tiv thaiv-sintered silicon carbide.

4. Cov txheej txheem tom qab kho mob

Cov silicon carbide uas raug sintered yuav tsum tau muaj cov txheej txheem kho tom qab tsim khoom. Cov txheej txheem kho tom qab feem ntau yog kev siv tshuab, kev sib tsoo, kev txhuam, kev oxidation thiab lwm yam. Cov txheej txheem no yog tsim los txhim kho qhov tseeb thiab qhov zoo ntawm cov silicon carbide uas raug sintered. Ntawm lawv, cov txheej txheem sib tsoo thiab kev txhuam yog ib txoj kev ua tiav, uas tuaj yeem txhim kho qhov tiav thiab qhov tiaj tus ntawm cov silicon carbide nto. Cov txheej txheem oxidation tuaj yeem tsim ib txheej oxide los txhim kho qhov tsis kam oxidation thiab kev ruaj khov tshuaj ntawm cov silicon carbide uas raug sintered.

Hauv ntej, kev tsim cov silicon carbide reactive sintering yog ib qho txheej txheem nyuaj, yuav tsum paub ntau yam thev naus laus zis thiab cov txheej txheem, suav nrog kev npaj cov khoom siv raw, cov txheej txheem molding, cov txheej txheem sintering thiab cov txheej txheem tom qab kho. Tsuas yog los ntawm kev paub txog cov thev naus laus zis thiab cov txheej txheem no kom meej meej thiaj li tsim tau cov khoom siv silicon carbide reaction-sintered zoo kom tau raws li qhov xav tau ntawm ntau qhov chaw siv.