Hluav taws xob tsheb PM Sintered Part

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1. Cov txheej txheem kub-programmed gas-solid cov tshuaj tiv thaiv: siv tungstic acid raws li tungsten precursor, methane ua cov pa roj carbon monoxide thiab txo cov roj, npaj ultra-fine tungsten carbide hmoov. Ntawm lawv, nyob rau hauv cov txheej txheem kub-programmed carbonization, cov cua kub qhov kev pab cuam yog nce qhov kub thiab txias mus rau 500 degree nyob rau hauv 30 feeb, lub cua sov tus nqi yog 18 degree ·min-1, thiab ces nce ntawm 500 degree mus rau 800 degree nyob rau hauv. 20 feeb, thiab cov cua kub yog 10 degree ·min-1, Reacted ntawm qhov kub thiab txias rau 12h, thiab ib txwm poob mus rau chav tsev kub nyob rau hauv kev tiv thaiv ntawm methane.

2. Txo carbonization ob-kauj ruam txoj kev: ua ntej npaj W hmoov los ntawm tungsten-muaj precursors, thiab ces carbonize nrog carbon-muaj tshuaj los tsim WC hmoov. Table 3 - Txoj kev npaj ultrafine WC hmoov los ntawm kev txo carbonization ob-kauj ruam txoj kev

3. Reductive carbonization ib-kauj ruam txoj kev: uas yog, lub precursor uas muaj tungsten (xws li WO3) yog ncaj qha txo thiab carbonized los tsim WC hmoov. Txoj kev no feem ntau xav tau kev npaj ntawm tungsten active precursor. Cov txheej txheem txuas ntxiv ntawm kev txo qis carbonization tuaj yeem txo cov txheej txheem ntws, txhim kho kev ua haujlwm ntawm ultrafine tungsten carbide hmoov tiam, thiab tib lub sijhawm, tau txais ultrafine tungsten carbide thiab nws cov hmoov hlau alloy muaj qhov zoo sib xws thiab cov khoom me me. Table 4 - Txoj kev npaj ultrafine WC hmoov los ntawm ib kauj ruam txo carbonization

4. Ntxiv 0.3g tungsten hmoov rau qhov sib xyaw ntawm 30 feem pua ​​H2O2, isopropanol thiab dej los ntawm kev sib tshuam microwave cua sov, thaum hmo ntuj, ntxiv 0.7gXC-72 carbon hmoov, kev kho ultrasonic tuaj yeem tau txais ib tug sib tov sib xyaw ua kua, qhuav, siv intermittent Methods Tungsten carbide nanocrystals yuav tau los ntawm cua sov nyob rau hauv lub qhov cub microwave rau ob peb feeb.

5. Gas theem txoj kev:

(1) Tshuaj vapor deposition method: Plasma enhanced chemical vapor deposition khoom siv, tungsten fluoride (WF6), methane (CH4) thiab hydrogen (H2) yog siv los ua raw khoom gases, thiab argon (Ar) yog siv los ua pa roj. Tus nqi ntws yog tswj los ntawm cais flowmeters. Lub substrate yog ua los ntawm hlau nickel ntawv. Cov substrates yog ultrasonically ntxuav nrog acetone, deionized dej, ethanol thiab deionized dej, thiab muab tso rau hauv cov tshuaj tiv thaiv chamber tom qab ziab. Ua ntej chemical vapor deposition, 100mL hydrogen gas tau dhau los ntawm 30min hauv qhov chaw kub kub kom tshem tawm cov oxides ntawm qhov chaw ntawm lub substrate. Cov qauv tom qab tshuaj vapor deposition tau annealed nyob rau hauv lub cub tawg nyob rau hauv nitrogen. Siv tungsten fluoride thiab methane ua precursors, ib spherical nano-tungsten carbide zaj duab xis nrog ib txoj kab uas hla ntawm 20-35nm tau npaj los ntawm plasma-enhanced tshuaj vapor deposition.

(2) Kho cov tshuaj vapor theem txheej txheem: Ntsuas qhov tsim nyog ntawm nano-WO3 hmoov, muab nws sib npaug hauv lub nkoj quartz tshuaj tiv thaiv, thiab tso lub nkoj quartz rau hauv qhov kub-kub stainless hlau tubular reactor (ψ90cm), thiab tom qab ntawd react lub stainless hlau muab tso rau hauv lub tubular tsis kam rauv. Qhov kub nce ntawm 540 degree mus rau 660 degree, thiab qhov no yog theem ntawm H2 txo nano-WO3. Thaum qhov kub thiab txias maj mam nce mus rau 660 degree nyob rau hauv lub tshav kub preservation theem, H2 txaus tus nqi yuav tsum tau kho kom nce. Kev nce tus nqi ntawm H2 yog qhov zoo rau tshem tawm cov dej vapor thiab ua rau cov txheej txheem tshuaj tiv thaiv mus zoo. Tom qab cov tshuaj tiv thaiv tau tuav ntawm 660 degree rau 1.5 teev, nano-WO3 hmoov nyob rau hauv lub nkoj quartz tshuaj tiv thaiv tau tag nrho txo ​​mus rau nano{18}}W hmoov. Lub sijhawm no, H2 ntws txo qis, acetylene gas valve qhib, acetylene ntws tswj, thiab cov tshuaj tiv thaiv nkag mus rau theem carbonization. Tshav kub rau 800 degree thiab khaws cia ntawm 800 degree rau 4h. Tom qab cov txheej txheem carbonization dhau lawm, nano- -W hmoov nyob rau hauv lub nkoj quartz tshuaj tiv thaiv yog pib hloov mus rau nano-WC hmoov. Lub sijhawm no, acetylene valve raug kaw thiab H2 txaus tus nqi txo. Tsis tu ncua pub ib tus lej ntawm high-purity H2 kom txog thaum lub stainless hlau reactor txias rau chav tsev kub.

(3) Cov txheej txheem tshuaj vapor condensation: dhau lub siab-purity CO cab cab roj los ntawm cov evaporator uas muaj W(CO) 6 precursor, cov cab kuj roj ntws tus nqi yog 1200mL / min, evaporator kub yog tswj ntawm 120 degree, thiab ces tus Carrier gas nqa lub precursor vapor nyob rau hauv qhov kub ntawm 600 ~ 800 degree nyob rau hauv lub tubular reactor, CO roj yog decomposed rau hauv CO2 thiab C, thiab W thiab C yog ua ke ntawm txog 1000 degree los ua nano-tungsten carbide, thiab thaum kawg. WC tuaj yeem tau txais hauv chav sau khoom.

(4) Gas-theem carbonization txoj kev: siv WO3 ua raw khoom thiab methanol ua carbon. Raws li qhov kev txiav txim ntawm Co/Fe catalyst, nanoscale WC tuaj yeem tau txais los ntawm kev ua haujlwm ntawm qhov kub ntawm 450-950 degree rau 1.5-4 teev. Tsawg-kub catalytic cracking ntawm methanol yog saws, thiab methanol nkag mus rau hauv lub preheating yeeb nkab los ntawm cov kua twj tso kua mis flowmeter, thiab qhov kub ntawm lub preheating yeeb nkab yog tswj ntawm 300-420 degree . Tom qab methanol yog preheated thiab vaporized, nws raug xa mus rau catalytic cracker, thiab cov roj methanol tuaj yeem tawg ntawm 420-550 degree kom tau txais qhov xav tau cov tshuaj tiv thaiv cua CO thiab H2; CO thiab H2 react nrog nano WO3 hmoov rau 1.

6. Txoj kev ua kua theem:

Siv cov pa roj carbon monoxide ntshiab uas muaj qhov qhib (nruab nrab sab hauv txoj kab uas hla 50nm, sab nraud txoj kab uas hla 100nm, ntev li 200μm), raus rau hauv 20mL ammonium paratungstate pentahydrate tov [(NH4Chemicalbook) 10W12O41•5H2O5 (pH ≈ 5) ntawm vigorous degree. Tom qab 20 feeb, cov tshuaj evaporated lawm nyob rau hauv chav tsev kub. Tom qab ntawd nws tau tso tseg thaum hmo ntuj, qhov ntsuas kub tau tswj ntawm 120 degree kom qhuav ntxiv, thiab thaum kawg nws tau calcined ntawm 350 degree rau 2 teev los tsim cov tungsten carbide precursor. Nyob rau hauv lub tshuab nqus tsev, qhov kub thiab txias yog tswj ntawm 1000 ~ 1300 degree los ua cov txheej txheem ua ntej kom tau txais ib qho khoom siv tungsten carbide nanostructure.

7. Khoom theem txheej txheem

(1) Supercritical CO2 heat treatment method: Put 1.0g tungsten powder (purity 99%, average diameter 2μm), 2.3g metallic sodium (purity 98%), and 10.0g dry ice (purity>99 feem pua) rau hauv autoclave feem. Tom qab ntawd muab cov autoclave kaw rau hauv lub qhov cub cua sov, nce qhov kub ntawm 6 00 degree ntawm tus nqi ntawm 10 degree / min, thiab tom qab ntawd ua kom qhov kub thiab txias rau 20h, tom qab ntawd txias lub autoclave mus rau chav tsev kub kom tau txais qhov kub thiab txias. Cov khoom siv dub, thiab kho cov khoom siv dub nrog dilute hydrochloric acid Sodium carbonate, thiab tom qab ntawd kho cua sov kom tau txais cov tshuaj NaOH, thiab thaum kawg cov qauv raug ntxuav nrog dej distilled thiab qhuav ntawm 80 degree rau 2 teev kom tau 0.2 g ntawm cov khoom. khoom.

(2) combustion method: Sib tov cov khoom siv xiav tungsten, sodium azide thiab carbon dub. Cov reactants tau hauv av uniformly nyob rau hauv ib tug ceramic mortar thiab ces nias rau hauv lub tog raj kheej stainless hlau. Txoj kab uas hla ntawm lub tog raj kheej steel phaj yog 50 hli, phab ntsa thickness yog 1 hli, thiab qhov siab yog 60 hli. Cov tshuaj tiv thaiv pob hnyav txog 150 ~ 170g. Lub chaw soj nstuam combustion feem ntau yog ua raws li qhov siab ntawm 2.5MPa argon. Muab cov tshuaj tiv thaiv pob rau hauv cov reactant, thiab tom qab ntawd ignite Ni-Cr hlau hlau rau saum lub hau ntawm lub pob kom ua tiav cov tshuaj tiv thaiv combustion.

(3) Txau cov txheej txheem hloov hluav taws xob: siv qhov kub thiab txias 250-350 degree, siab siab 2.5-3.5MPa ultra-speed air spray heat conversion method, ua ntej ua nano-scale WO3 oxide hmoov, thiab txo nws mus rau WO2.9 xiav tungsten nrog hydrogen ntawm 420-500 degree hmoov, thiab tom qab ntawd siv ultra-high-speed interlayer shearing crusher kom ntxiv crusher xiav tungsten hais, thiab ua raws li qhov loj me me los ntawm kev ua kom muaj zog hydrocyclone classifier. , thiab cais cov nano-xiav tungsten particle slurry nrog ib tug nruam centrifuge los khom thiab cais loj hais ntawm xiav tungsten Cov hmoov rov qab mus rau lub ultra-high-speed interlayer shearing tshuab mus txuas ntxiv shearing thiab crushing; Thaum lub sij hawm xiav tungsten shearing thiab crushing txheej txheem, ib tug phenolic resin tso tus neeg sawv cev yog ntxiv los npog cov nano-xiav tungsten hais, thiab H2 yog pub rau ob hnub, thiab txo qhov cub yog pumped thiab drained nyob rau hauv nruab nrab Restore tungsten hmoov nrog ib tug nruab nrab. Qhov luaj li cas tsawg dua los yog sib npaug ntawm 80nm ntawm 700-740 degree, ces sib tov nano-scale tungsten hmoov nrog nano-carbon dub hmoov, ntxiv phenolic resin tso tus neeg sawv cev, thiab sib tov nyob rau hauv ib tug ultra-high-speed interlayer shearing tshuab rau ua cov khoom siv carbonized Slurry, tom qab raug centrifugally qhuav, carbonized ntawm qhov kub ntawm 980-1000 degree, tom qab raug tso tawm ntawm lub cub tawg, lub bridging aggregates yog tawg los ntawm high-speed interlayer shearing tshuab, thiab ces cov hydrocyclone yog cais. , nruam centrifugal sedimentation, centrifugal sib cais ntawm cawv, ziab, thiab lub zog zaus airflow vibration Sieve, los ntawm 15μm sieve, tuaj yeem ua rau hauv WC hmoov nrog qhov nruab nrab particle loj ntawm tsawg dua los yog sib npaug rau 90nm, thiab cov duab particle yog ze li ntawm spherical. .

(4) Catalytic method: Thaum tshav kub kub zeolite-HX, -NaX, qauv KX thiab WO3 qauv nyob rau hauv ib tug He (99.99 feem pua) cua ntawm 200 degree rau 2h, ces siv CO (99.99 feem pua) ntawm 100mL/min thiab Nws (99.99 feem pua) 20mL / Min ntawm 300 ~ 750 degree rau reductive carbonization cov tshuaj tiv thaiv nrog cov qauv. Ua li no, CO thiab WO3 tuaj yeem tsim WC ntawm qhov kub thiab txias.

(5) Txoj kev txo qis carbonization ncaj qha: siv WO3 hmoov thiab cov hmoov carbon los ncaj qha txo cov pa roj carbonization hauv qhov chaw txo qis. Cov tshuaj tiv thaiv tau nqa tawm hauv ib qho khoom siv alumina embedding.

8. Thermal decomposition method:

Nws yog ib qho yooj yim txoj kev uas tsis tas yuav tsum tau ib tug template los npaj ib tug precursor nyob rau hauv ib tug tej yam surfactant, thiab ces ci lub precursor ntawm ib tug tsim nyog kub kom decompose nws kom tau ib tug ib-seem nanomaterial. Piv txwv li: sib tov PW (H3PW12O40) aqueous tov thiab CTAB (C13H33N (CH3) 3Br) aqueous tov kom tau dawb precipitate [C21.95H41.19N1.33] 3PW12O40. Lub precipitate tau ncaj qha thermally decomposed ntawm 1000 degree rau 10 h kom tau WC nanorods thiab WC nanosheets.

9. Magnetron sputtering txoj kev:

Ib txoj hauv kev uas cov neeg nqa khoom muaj roj zoo siab zoo li lub plasma bombarding lub hom phiaj kom loj hlob ib qho tshwj xeeb nanostructure ntawm lub substrate. Piv txwv li, WCX zaj duab xis tso los ntawm magnetron sputtering ntawm Si(110) substrate yog raug rau kev kho cua sov kom tau W2C nanowires.

Explosive heating method: ib txoj hauv kev tshwj xeeb kom tau txais nanostructures los ntawm kev tswj cov cua kub kom nce cov reactants los ntawm qhov kub thiab txias mus rau qhov kub siab hauv lub sijhawm luv luv. Piv txwv li: tswj cov hmoov sib xyaw ntawm graphite thiab tungsten hmoov kom sov rau hauv hluav taws xob hluav taws xob ntawm qhov cua kub ceev heev (los ntawm chav tsev kub txog 1900 degree hauv ib thib ob) thiab khaws cia rau 30 feeb, thiab thaum kawg txias rau chav sov.

Hlau Txhaj Moulding txheej txheem

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