Cov pa roj carbon ntawm txhua qhov tawg ntawm cov qauv sintered yog txawv, nrog rau cov pa roj carbon ntawm A-2.5 awt.% hauv qhov ntau no, tsim cov khoom siv ntom ntom uas yuav luag tsis muaj qhov hws, uas yog tsim los ntawm cov khoom sib xyaw silicon carbide thiab silicon dawb. Nrog rau kev nce ntxiv ntawm cov pa roj carbon, cov ntsiab lus ntawm cov tshuaj tiv thaiv-sintered silicon carbide nce maj mam, qhov loj me ntawm cov khoom me me ntawm silicon carbide nce, thiab silicon carbide txuas nrog ib leeg hauv cov duab pob txha. Txawm li cas los xij, cov pa roj carbon ntau dhau tuaj yeem ua rau cov pa roj carbon seem hauv lub cev sintered. Thaum cov pa roj carbon dub raug nce ntxiv mus rau 3a, qhov sintering ntawm cov qauv tsis tiav, thiab cov "interlayers" dub tshwm sim sab hauv.
Thaum cov pa roj carbon reacts nrog molten silicon, nws qhov ntim nthuav dav yog 234%, uas ua rau cov qauv me me ntawm cov tshuaj tiv thaiv-sintered silicon carbide muaj feem cuam tshuam nrog cov pa roj carbon hauv billet. Thaum cov pa roj carbon hauv billet me me, cov silicon carbide tsim los ntawm cov tshuaj tiv thaiv silicon-carbon tsis txaus los sau cov qhov hws nyob ib puag ncig cov hmoov carbon, ua rau muaj ntau cov silicon dawb hauv cov qauv. Nrog rau kev nce ntawm cov pa roj carbon hauv billet, cov tshuaj tiv thaiv-sintered silicon carbide tuaj yeem sau cov qhov hws nyob ib puag ncig cov hmoov carbon thiab txuas cov silicon carbide qub ua ke. Lub sijhawm no, cov ntsiab lus ntawm cov silicon dawb hauv cov qauv txo qis thiab qhov ceev ntawm lub cev sintered nce ntxiv. Txawm li cas los xij, thaum muaj ntau cov pa roj carbon hauv billet, cov silicon carbide thib ob tsim los ntawm cov tshuaj tiv thaiv ntawm carbon thiab silicon sai sai nyob ib puag ncig lub toner, ua rau nws nyuaj rau cov silicon molten tiv tauj lub toner, ua rau cov pa roj carbon seem nyob hauv lub cev sintered.
Raws li cov txiaj ntsig XRD, cov khoom sib xyaw ua ke ntawm cov tshuaj tiv thaiv-sintered sic yog α-SiC, β-SiC thiab silicon dawb.
Hauv cov txheej txheem ntawm kev kub siab sintering, cov pa roj carbon atoms tsiv mus rau lub xeev pib ntawm SiC nto β-SiC los ntawm molten silicon α-theem ob. Txij li thaum silicon-carbon reaction yog ib qho exothermic reaction nrog ntau ntawm cov cua sov reaction, txias sai tom qab lub sijhawm luv luv ntawm spontaneous kub reaction ua rau susaturation ntawm carbon yaj hauv kua silicon, yog li ntawd cov β-SiC particles precipitated nyob rau hauv daim ntawv ntawm carbon, yog li txhim kho cov khoom siv kho tshuab ntawm cov khoom. Yog li ntawd, theem ob β-SiC noob refinement yog qhov zoo rau kev txhim kho ntawm lub zog khoov. Hauv Si-SiC composite system, cov ntsiab lus ntawm cov silicon dawb hauv cov khoom txo qis nrog kev nce ntawm cov ntsiab lus carbon hauv cov khoom siv raw.
Xaus lus:
(1) Qhov viscosity ntawm cov tshuaj reactive sintering slurry nce nrog rau qhov nce ntawm cov pa roj carbon dub; Tus nqi pH yog alkaline thiab maj mam nce.
(2) Nrog rau kev nce ntxiv ntawm cov pa roj carbon hauv lub cev, qhov ceev thiab lub zog khoov ntawm cov khoom siv ua los ntawm cov tshuaj tiv thaiv-sintered uas npaj los ntawm txoj kev nias ua ntej nce thiab tom qab ntawd txo qis. Thaum cov pa roj carbon dub yog 2.5 npaug ntawm qhov pib, peb-taw tes khoov lub zog thiab qhov ceev ntawm cov billet ntsuab tom qab cov tshuaj tiv thaiv sintering siab heev, uas yog 227.5mpa thiab 3.093g / cm3, feem.
(3) Thaum lub cev uas muaj cov pa roj carbon ntau dhau raug sintered, cov kab nrib pleb thiab cov cheeb tsam dub "sandwich" yuav tshwm sim hauv lub cev ntawm lub cev. Qhov laj thawj rau qhov tawg yog tias cov roj silicon oxide tsim tawm hauv cov txheej txheem ntawm kev sib xyaw ua ke tsis yooj yim rau kev tso tawm, maj mam sib sau ua ke, lub siab nce siab, thiab nws cov nyhuv jacking ua rau muaj kev tawg ntawm billet. Hauv thaj chaw dub "sandwich" hauv lub sinter, muaj ntau cov pa roj carbon uas tsis koom nrog hauv kev sib xyaw ua ke.
Lub sijhawm tshaj tawm: Lub Xya Hli-10-2023