Titanium carbide: ntau lawm, muaj pes tsawg leeg, lub hom phiaj, khoom thiab kev siv

2024 Tus sau: Howard Calhoun | [email protected]. Kawg hloov kho: 2024-01-02 13:55

Titanium carbide yog ib qho ntawm cov lus cog tseg ntawm tungsten. Nws tsis yog qhov qis dua rau yav tom ntej ntawm lub cev thiab cov khoom siv kho tshuab, thiab kev tsim cov khoom siv no yog kev lag luam ntau dua. Nws yog feem ntau siv hauv kev tsim cov cuab yeej carbide, nrog rau hauv cov roj thiab kev lag luam, kev lag luam aviation thiab foob pob hluav taws.

Kev piav qhia thiab keeb kwm ntawm kev tshawb pom

Titanium carbide nyob hauv ib qho chaw tshwj xeeb ntawm kev hloov pauv hlau sib txuas ntawm Lub Sijhawm Table ntawm Cov Khoom Siv Tshuaj. Nws yog qhov txawv los ntawm nws qhov tshwj xeeb hardness, kub tsis kam thiab lub zog, uas txiav txim siab nws txoj kev siv dav siv los ua lub hauv paus rau cov alloys nyuaj uas tsis muaj tungsten. Cov tshuaj formula ntawm cov tshuaj no yog TiC. Outwardly, nws yog lub teeb grey hmoov.

Nws cov khoom lag luam tau pib hauv xyoo 1920, thaum cov tuam txhab tsim cov qij taws tau nrhiav lwm txoj hauv kev siv tshuab kim rau kev tsim cov tungsten filaments. Yog li ntawd, ib txoj kev tsim cov cemented carbide tau tsim. Cov tshuab no tsis tshua kim, txij li cov khoom siv raw -titanium dioxide yog pheej yig dua.

Xyoo 1970, kev siv titanium nitrite pib, uas ua rau nws muaj peev xwm ua kom cov viscosity ntawm cemented pob qij txha, thiab chromium thiab npib tsib xee additives ua rau nws muaj peev xwm ua kom cov corrosion kuj ntawm titanium carbide. Nyob rau hauv 1980, ib tug txheej txheem yog tsim los rau hmoov sintering nyob rau hauv lub zog ntawm uniform compression (nias). Qhov no txhim kho cov khoom zoo. Sintered carbide hmoov yog tam sim no siv nyob rau hauv daim ntaub ntawv uas kub, hnav thiab oxidation kuj yuav tsum tau.

tshuaj yam ntxwv

Cov khoom siv tshuaj ntawm titanium carbide txiav txim siab nws qhov tseem ceeb hauv kev siv tshuab. Cov tshuaj no muaj cov yam ntxwv hauv qab no:

• resistance to HCl, HSO₄, H₃PO_{4, alkali;}
• siab corrosion kuj hauv alkaline thiab acid daws;
• tsis muaj kev cuam tshuam nrog zinc melts, hom tseem ceeb ntawm metallurgical slag;
• nquag oxidation tsuas yog ntawm qhov kub siab tshaj 1100 ° C;
• melt wettability ntawm hlau, cam khwb cia hlau, npib tsib xee, cob alt, silicon;
• formation of TiCl_{4 in chlorine nruab nrab ntawm t>40 °C.}

Lub cev thiab cov cuab yeej cuab tam

Lub cev thiab cov yam ntxwv tseem ceeb ntawm cov khoom no yog:

1. Thermophysical: melting point - 3260 ± 150 ° C; boiling point - 4300 ° C; Thaum tshav kub kub muaj peev xwm - 50,57 J / (K∙mol); thermal conductivity ntawm 20 ° C (nyob ntawm cov ntsiab luscarbon) - 6.5-7.1 W / (m∙K).
2. Lub zog (ntawm 20 ° C): compressive zog - 1380 MPa; tensile zog (kub-pressed carbide) - 500 MPa; microhardness - 15,000-31,500 MPa; cuam tshuam lub zog - 9.5∙10⁴ kJ/m^{2; hardness ntawm Mohs nplai - 8-9 units.}
3. Tshuab: hnav tus nqi (nyob ntawm cov ntsiab lus carbon) - 0.2-2 µm / h; kev sib txhuam coefficient - 0.4-0.5; weldability tsis zoo.

Tau txais

Titanium carbide ntau lawm yog ua los ntawm ntau txoj hauv kev:

• Cov txheej txheem carbon-thermal los ntawm titanium dioxide thiab cov khoom siv carburizing (68 thiab 32% hauv qhov sib tov, feem). Raws li yav tas los, soot feem ntau yog siv. Cov khoom siv raw yog thawj zaug nias rau hauv briquettes, uas tom qab ntawd muab tso rau hauv lub crucible. Cov pa roj carbon saturation tshwm sim ntawm qhov kub ntawm 2000 ° C hauv qhov chaw tiv thaiv hydrogen.
• Direct carbidization ntawm titanium hmoov ntawm 1600 ° C.
• Pseudo-melting - cua sov ntawm cov hmoov hlau nrog soot briquettes hauv ob theem txheej txheem txog li 2050 ° C. Soot yaj nyob rau hauv titanium yaj, thiab cov zis yog carbide nplej mus txog 1 txhiab microns loj.
• Ignition hauv lub tshuab nqus tsev sib xyaw ntawm titanium hmoov thiab carbon dub (yav dhau los briquetted). Cov tshuaj tiv thaiv combustion kav ntev li ob peb vib nas this, ces cov muaj pes tsawg leeg yog txias.
• Plasma-chemical method los ntawm halides. Txoj kev no ua rau nws tuaj yeem tau txais tsis tau tsuas yog carbide hmoov, tab sis kuj coatings, fibers, ib leeg muaju. Qhov sib tov tshaj plaws yog titanium chloride, methane thiab hydrogen. Cov txheej txheem yog nqa tawm ntawm qhov kub thiab txias1200-1500 ° C. Lub plasma ntws yog tsim los ntawm kev tso tawm arc lossis hauv cov tshuab hluav taws xob ntau zaus.
• Los ntawm titanium alloy chips (hydrogenation, sib tsoo, dehydrogenation, carbonation lossis carbon dub carbidization).

Cov khoom tsim los ntawm ib qho ntawm cov txheej txheem no tau ua tiav hauv cov khoom sib tsoo. Sib tsoo rau hauv cov hmoov yog nqa mus rau qhov loj me ntawm 1-5 microns.

Fibers thiab crystals

Tau txais titanium carbide nyob rau hauv daim ntawv ntawm ib leeg muaju yog ua nyob rau hauv ntau txoj kev:

1. Txoj kev melting. Muaj ntau ntau yam ntawm cov tshuab no: cov txheej txheem Verneuil; kos los ntawm cov kua da dej tsim los ntawm melting sintered rods; Txoj kev electrothermal hauv arc furnaces. Cov tswv yim no tsis siv dav vim lawv xav tau cov nqi zog siab.
2. Txoj kev daws teeb meem. Kev sib xyaw ntawm titanium thiab carbon tebchaw, nrog rau cov hlau uas ua lub luag haujlwm ntawm cov kuab tshuaj (hlau, npib tsib xee, cob alt, aluminium lossis magnesium), yog rhuab hauv graphite crucible rau 2000 ° C hauv lub tshuab nqus tsev. Cov hlau yaj yog khaws cia rau ob peb teev, tom qab ntawd kho nrog hydrochloric acid daws thiab hydrogen fluoride, ntxuav thiab qhuav, ntab hauv qhov sib xyaw ntawm trichlorethylene thiab acetone kom tshem tawm graphite. Cov thev naus laus zis no tsim cov khoom siv lead ua siab purity.
3. Plasma-chemical synthesis nyob rau hauv lub reactor thaum lub sij hawm sib cuam tshuam ntawm lub plasma dav hlau nrog titanium halides TiCl₄, TiI_{4. Methane, ethylene, benzene, toluene thiab lwm yam yog siv los ua carbon.hydrocarbons. Lub ntsiab qhov tsis zoo ntawm txoj kev no yog kev siv technology complexity thiab toxicity ntawm raw cov ntaub ntawv.}

Fibers tau txais los ntawm kev tso tawm ntawm titanium chloride hauv qhov nruab nrab gaseous (propane, carbon tetrachloride tov nrog hydrogen) ntawm qhov kub ntawm 1250-1350 ° C.

Daim ntawv thov ntawm titanium carbide

Cov khoom sib xyaw no yog siv los ua cov khoom siv hauv kev tsim cov cua sov-resistant, kub-resistant thiab nyuaj tungsten-dawb alloys, hnav-resistant coatings, cov ntaub ntawv abrasive.

Titanium carbide carbide tshuab yog siv rau cov khoom hauv qab no:

• cuab yeej rau kev txiav hlau;
• ntu ntawm cov tshuab dov;
• tshav kub-resistant crucibles, thermocouple qhov chaw;
• furnace lining;
• dav hlau qhov chaw;
• tsis siv cov vuam electrodes;
• cov khoom siv tsim los rau kev siv cov khoom hnyav;
• abrasive pastes rau polishing thiab tiav qhov chaw.

Qhov yog ua los ntawm hmoov metallurgy:

• by sintering thiab kub nias;
• by plam casting hauv plaster pwm thiab sintering hauv graphite furnaces;
• pab nias thiab sintering.

Titanium carbide coatings tso cai rau koj kom ua tau zoo ntawm cov khoom thiab tib lub sijhawm txuag ntawm cov khoom kim. Lawv muaj cov yam ntxwv hauv qab no:

• siab hnav tsis kam thiab hardness;
• tshuaj lom neeg ruaj khov;
• qis coefficient ntawm kev sib txhuam;
• tsis tshua muaj siab rau qhov txias vuam;
• scale resistance.

Ib txheej ntawm titanium carbide yog siv rau cov khoom siv hauv ob peb txoj hauv kev:

• Vapor deposition.
• Plasma lossis detonation txau.
• YLaser cladding.
• Ion-plasma txau.
• Electro-spark alloying.
• Diffusion saturation.

Cermet kuj yog tsim los ntawm titanium carbide thiab npib tsib xee tshav kub-tiv taus alloys - cov khoom sib xyaw uas tso cai rau ua rau kom hnav tsis kam ntawm cov khoom hauv cov kua tawm los ntawm 10 npaug. Kev siv cov khoom sib xyaw no tau cog lus tias yuav ua rau muaj kev pab cuam lub neej ntawm cov cuab yeej siv twj thiab lwm yam khoom siv, uas suav nrog kev txhaj tshuaj nozzles rau kev tswj cov dej hauv dej, hluav taws kub hnyiab, cov khoom siv tho, li qub.

YCarbidesteel

Tungsten thiab titanium carbides yog siv rau kev tsim cov carbide steels, uas nyob rau hauv lawv cov khoom nyob nruab nrab ntawm ib qho nyuaj alloys thiab high-ceev steels. Cov hlau refractory muab lawv nrog siab hardness, lub zog thiab hnav tsis kam, thiab cov hlau matrix - toughness thiab ductility. Qhov loj feem ntawm titanium thiab tungsten carbide tuaj yeem yog 20-70%. Cov ntaub ntawv zoo li no tau txais los ntawm cov txheej txheem ntawm cov hmoov metallurgy qhia saum toj no.

Carbide steels yog siv los tsim cov cuab yeej txiav, nrog rau cov khoom siv tshuab,ua hauj lwm nyob rau hauv tej yam kev mob ntawm cov neeg kho tshuab muaj zog thiab corrosive hnav (bearings, gears, bushings, shafts thiab lwm yam).