Graphite nrog TaC txheej

I. Kev tshawb nrhiav cov txheej txheem

1. Lub cev TaCl5-C3H6-H2-Ar

2. Qhov kub ntawm qhov tso tawm:

Raws li cov qauv thermodynamic, nws tau suav tias thaum qhov kub siab dua 1273K, lub zog Gibbs dawb ntawm cov tshuaj tiv thaiv qis heev thiab cov tshuaj tiv thaiv tiav lawm. Cov tshuaj tiv thaiv tas mus li KP loj heev ntawm 1273K thiab nce sai nrog qhov kub, thiab qhov kev loj hlob maj mam qeeb ntawm 1773K.

Kev cuam tshuam rau qhov morphology ntawm qhov txheej: Thaum qhov kub tsis haum (siab dhau lossis qis dhau), qhov chaw nthuav tawm cov pa roj carbon dawb lossis cov qhov xoob.

(1) Thaum kub siab, qhov ceev ntawm cov tshuaj reactant atoms lossis pawg neeg ua haujlwm ceev dhau, uas yuav ua rau muaj kev faib tawm tsis sib xws thaum lub sijhawm sib sau ua ke ntawm cov ntaub ntawv, thiab thaj chaw nplua nuj thiab pluag tsis tuaj yeem hloov pauv tau yooj yim, ua rau muaj qhov hws.

(2) Muaj qhov sib txawv ntawm qhov pyrolysis reaction rate ntawm alkanes thiab qhov txo qis reaction rate ntawm tantalum pentachloride. Cov pyrolysis carbon yog ntau dhau thiab tsis tuaj yeem ua ke nrog tantalum hauv lub sijhawm, ua rau qhov chaw raug qhwv los ntawm carbon.

Thaum qhov kub thiab txias tsim nyog, qhov chaw ntawm lubKev txheej txheem TaCyog ntom.

TaCcov khoom me me yaj thiab sib sau ua ke, cov duab siv lead ua tiav, thiab ciam teb ntawm cov noob hloov pauv mus zoo.

3. Piv ntawm Hydrogen:

Tsis tas li ntawd xwb, muaj ntau yam uas cuam tshuam rau qhov zoo ntawm cov txheej:

-Qhov zoo ntawm qhov chaw

-Qhov chaw tso roj av

-Qhov degree ntawm uniformity ntawm reactant roj sib tov

II. Cov teeb meem ib txwm muaj ntawmtantalum carbide txheej

1. Txheej tawg thiab tev tawv

Cov coefficient ntawm kev nthuav dav thermal linear CTE:

2. Kev tshuaj xyuas qhov tsis zoo:

(1) Ua rau:

(2) Txoj kev piav qhia tus cwj pwm

① Siv cov thev naus laus zis X-ray diffraction los ntsuas qhov seem seem.

② Siv txoj cai Hu Ke los kwv yees qhov kev ntxhov siab seem.

(3) Cov qauv sib xws

3. Txhim kho qhov sib xws ntawm cov txheej txheem thiab cov substrate

(1) Txheej txheej loj hlob ntawm qhov chaw

Kev siv tshuab thermal reaction deposition thiab diffusion TRD

Cov txheej txheem ntsev molten

Ua kom yooj yim rau cov txheej txheem tsim khoom

Txo qhov kub ntawm cov tshuaj tiv thaiv

Tus nqi qis dua

Zoo dua rau ib puag ncig

Haum rau kev tsim khoom lag luam loj

(2) Txheej txheej sib xyaw ua ke

Kev sib koom ua ke

CVDtxheej txheem

Txheej ntau yam khoom

Kev sib xyaw ua ke ntawm cov txiaj ntsig ntawm txhua yam khoom

Kho kom yooj yim kho cov khoom sib xyaw thiab qhov sib piv ntawm cov txheej

4. Kev siv tshuab thermal reaction deposition thiab diffusion TRD

(1) Lub Tswv Yim Ua Rau Muaj Kev Tshwm Sim

TRD thev naus laus zis kuj hu ua embedding process, uas siv boric acid-tantalum pentoxide-sodium fluoride-boron oxide-boron carbide system los npajtantalum carbide txheej.

① Molten boric acid yaj tantalum pentoxide;

② Tantalum pentoxide raug txo kom ua cov tantalum atoms nquag thiab diffuses rau ntawm qhov chaw graphite;

③ Cov tantalum atoms nquag raug adsorbed rau ntawm qhov chaw graphite thiab ua rau muaj kev cuam tshuam nrog cov carbon atoms los tsimtantalum carbide txheej.

(2) Tus yuam sij teb

Hom txheej carbide yuav tsum ua kom tau raws li qhov yuav tsum tau ua kom lub zog oxidation dawb ntawm cov khoom tsim cov carbide siab dua li ntawm boron oxide.

Lub zog Gibbs dawb ntawm cov carbide qis txaus (txwv tsis pub, boron lossis boride yuav raug tsim).

Tantalum pentoxide yog ib qho oxide nruab nrab. Hauv cov borax uas kub heev, nws tuaj yeem cuam tshuam nrog cov alkaline oxide sodium oxide uas muaj zog los tsim sodium tantalate, yog li txo qhov kub ntawm cov tshuaj tiv thaiv thawj zaug.