Qhov tseem refractory hlau. Cov yam ntxwv ntawm cov hlau

Co - qhov no yog feem ntau cov ntaub ntawv uas (nrog rau yas thiab iav), uas yog siv los ntawm cov neeg txij ancient sij hawm. Txawm ces, cov txiv neej twb paub cov yam ntxwv ntawm cov hlau, nws siv los kom zoo dua nyob rau hauv tag nrho lawv lub zog los mus tsim yam zoo nkauj heev, khob iav, tsev neeg cov khoom, cov nroj tsuag.

Ib tug ntawm cov yam ntxwv tseem ceeb nyob rau hauv qhov kev xam ntawm cov tshuaj yog lawv hardness thiab siab melting point. Cov qualities cia koj txhais kom meej cov uas ntawm kev siv ntawm cov hlau. Yog li ntawd, peb xav txog tag nrho cov lub zog thiab tshwj xeeb mloog yog muab melting teeb meem.

Lub cev thaj chaw ntawm cov hlau

co yam ntxwv lub zog muaj peev xwm yuav qhia nyob rau hauv daim ntawv ntawm cov plaub ntsiab lus tseem ceeb.

1. Nws yog xim hlau sheen - tag nrho cov muaj hais txog tib yam nyiaj-dawb zoo nkauj yam ntxwv ci, nyob rau hauv tas li ntawd mus tooj liab thiab kub. Lawv muaj liab thiab daj tom tsim, ntsig txog. Calcium - nyiaj xiav.
2. Lub cev lub xeev - tag nrho cov khoom nyob rau hauv ib txwm tej yam kev mob, tshwj tsis yog rau mercury, uas yog nyob rau hauv daim ntawv ntawm ib tug kua.
3. Hluav taws xob thiab thermal conductivity - yog ntse txhua co, tab sis yog qhia nyob rau hauv cov zaubmov.
4. Malleability thiab ductility - kuj ntau rau tag nrho cov co parameter uas muaj peev xwm sawv rau txawv nyob ntawm seb cov neeg sawv cev.
5. Lub melting thiab kub point - txiav txim uas refractory hlau thiab ib tug uas tsis muaj melting point. Qhov no parameter yog txawv rau tag nrho cov khoom.

Tag nrho lub zog yog piav los ntawm tus tshwj xeeb tsa ntawm cov hlau ntxaij ntoo. Nws spatial arrangement, zoo thiab lub dag lub zog.

Fusible thiab refractory co

Qhov kev xaiv no yog qho tseem ceeb heev thaum nws tawm los rau cov cheeb tsam ntawm daim ntawv thov ntawm cov tshuaj. Refractory co thiab alloys - yog lub hauv paus ntawm mechanical engineering thiab shipbuilding, smelting thiab casting ntawm ntau yam tseem ceeb cov khoom, tau zoo ua hauj lwm cov cuab tam. Yog li ntawd, kev txawj ntse ntawm lub melting thiab kub kub plays ib tug yuav tsum muaj lub luag hauj lwm.

Piav txog lub co lub dag lub zog, muaj peev xwm faib lawv mus rau hauv ib qho nyuaj thiab nkig. Yog hais tias peb tham txog refractoriness, ntawm no qhov txawv ob lub ntsiab pawg:

1. Fusible - yog cov neeg uas yuav tau mus hloov lub cev lub xeev nyob kub hauv qab no 1000 ° ^C. Piv txwv li tin, hmoov txhuas, mercury, sodium, cesium, manganese, zinc, txhuas, thiab lwm tus neeg.
2. Refractory yog cov neeg uas nws melting kub yog siab tshaj cov hoob nqi. Muaj tsis muaj ntau, tab sis nyob rau hauv kev xyaum no yog siv txawm tsawg.

Rooj co muaj ib tug melting point saum toj no 1000 ^{° C,} yog hais hauv qab no. Nws yeej nyob ntawd thiab cov txheej txheem ntawm cov feem ntau refractory cov neeg sawv cev.

Cov lus no hlau muaj xws li tag nrho cov neeg sawv cev, uas nws melting kub yog siab tshaj ^{1000 °} C. Txawm li cas los, nyob rau hauv kev xyaum, muaj ntau yam ntawm lawv tsis siv rau ntau yam yog vim li cas. Piv txwv li, vim hais tias ntawm nyiaj txiag cov kev pab cuam vim radioactivity los yog siab dhau heev lawm degree ntawm fragility, raug corrosive nres.

Tsis tas li ntawd los ntawm lub rooj nws yog cuab kev tias lub feem ntau refractory hlau nyob rau hauv lub ntiaj teb no - yog tungsten. Lub qis tshaj tus nqi rau kub. Thaum ua hauj lwm nrog co yog ib qho tseem ceeb softness. Yog li ntawd, muaj ntau yam ntawm cov zoo hais saum toj no yog siv rau cov kev cov hom phiaj.

Feem ntau cov refractory hlau - tungsten

Nyob rau hauv lub periodic rooj nws yog nyob rau hauv lub ordinal tooj 74. Lub npe yog muab tau los ntawm lub npe lub npe nrov physicist Stephen Wolfram. Nyob rau hauv tej yam kev mob yog ib tug khoom refractory hlau silvery-dawb xim. Nws muaj ib tug qhia tau nws yog xim hlau sheen. Sib suab inert nyob rau hauv cov tshuaj tiv thaiv nkag reluctantly.

Nyob rau hauv cov xwm, nyob rau hauv daim ntawv ntawm cov zaub mov muaj:

• wolframite;
• scheelite;
• Gyubnera;
• ferberite.

Zaum tau muaj pov thawj hais tias tus tungsten - lub feem ntau refractory hlau ntawm tag nrho cov. Txawm li cas los, muaj tswv yim uas seaborgium raws tau tuav cov ntaub ntawv ntawm no hlau. Tab sis nws yog ib tug neeg caij nrog ib tug heev luv luv lub sij hawm ntawm cov hav zoov. Yog li ntawd, los ua pov thawj nws tseem tsis tau tau.

Thaum ib tug kub (saum toj no 1500 ^C) tungsten yuav zas thiab malleable. Yog li ntawd, tau los tsim ib tug nyias hlau rau lub hauv paus ntawd. Qhov no tej khoom vaj tse yog siv rau qhov siv thiab ua filaments rau hauv cov tsev neeg lub teeb qhov muag teev.

Raws li feem ntau cov refractory hlau uas yuav mas kub ^ntawm ntau tshaj 3400 C, tungsten yog thov nyob rau hauv cov nram no teb cov technology:

• raws li ib tug Vuam electrode nyob rau hauv argon;
• rau acid-ceev, hnav-resistant thiab thaum tshav kub kub-resistant alloys;
• raws li ib tug caij cua kub;
• nyob rau hauv lub tshuab nqus tsev hlab li cov filament thiab thiaj li nyob.

Sib nrug los ntawm tungsten hlau, dav siv nyob rau hauv lub kos duab, science thiab electronics nws tebchaw. Raws li cov refractory hlau nyob rau hauv lub ntiaj teb no thiab nws cov ntaub ntawv ib tug compound nrog ib tug heev zoo cov yam ntxwv: check, resistant rau txhua hom tshuaj txiav txim, yog tsis raug xeb, tiv tsawg tsawg thiab siab kub (yeej, tungsten sulphide, nws ib muaju thiab lwm yam).

Niobium thiab alloys

Nb, los yog niobium, - nyob rau hauv ib txwm tej yam kev mob ntawm nyiaj-dawb lustrous hlau. Nws tseem yog refractory, raws li cov kev hloov kub mus rau ib tug kua hauv lub xeev rau nws yog 2477 ° ^C. Nws yog ib qhov zoo, raws li zoo raws li lub ua ke ntawm tsawg reactivity thiab superconductivity tso cai niobium yog ua ntau nrov nyob rau hauv cov tswv yim kev ua pej xeem txhua txhua xyoo. Niaj hnub no, qhov no hlau yog siv nyob rau hauv lag luam xws li:

• foob pob ua ntxaij science;
• Aerospace kev lag luam;
• nuclear zog;
• tshuaj apparatus siv;
• xov tooj cua engineering.

Cov hlau khaws nws lub zog txawm nyob rau hauv heev tsawg kub. Raws li cov khoom yus muaj los ntawm xeb kuj, Thaum tshav kub kub kuj, durability, yav tom ntej conductivity.

Qhov no hlau yog ntxiv rau lub txhuas ntaub ntawv los mus txhim kho cov tshuaj kuj. Los ntawm nws tsim cathodes thiab anodes, nws yog doped nrog non-ferrous alloys. Txawm npib nyob rau hauv tej lub teb chaws ua li cas nrog cov ntsiab lus ntawm niobium.

tantalum

Hlau, nyob rau hauv free daim ntawv nyob rau hauv zoo tib yam tej yam kev mob thiab them nrog ib tug oxide zaj duab xis. Nws muaj ib tug txheej ntawm lub cev thaj chaw uas tso cai rau nws mus yuav ntau thiab tseem ceeb heev rau cov neeg. Nws lub ntsiab yam ntxwv raws li nram no:

1. Thaum kub saum toj no ^txog 1000 C yuav superconducting.
2. Qhov no yog lub feem ntau tom qab lub refractory hlau ntawm tungsten thiab rhenium. Lub melting kub yog 3017 ° ^C.
3. Zoo kawg nkaus absorbs gases.
4. Vim nws yog ib qho yooj yim mus ua hauj lwm raws li nws yog dov nyob rau hauv khaubncaws sab nraud povtseg, ntawv ci thiab hlau yooj yim.
5. Muaj zoo hardness thiab nkig, khaws ductility.
6. Nws yog ib heev resistant rau tshuaj cov neeg ua hauj (tsis yaj txawm nyob rau hauv aqua regia).

Vim xws yam ntxwv muaj peev xwm mus nce tej chaw raws li ib lub hauv paus rau ntau high-kub thiab acid resistant, corrosion-resistant alloys. Nws heev heev tebchaw nrhiav ntaub ntawv sau npe nyob rau hauv nuclear physics, electronics, xam pab kiag li lawm txoj kev npaj. Lawv yog siv raws li superconductors. Yav tas los, tantalum yog siv raws li ib tug keeb nyob rau hauv lub filament. Tam sim no nws qhov chaw tau coj los ntawm tungsten.

Chromium thiab nws alloys

Ib tug ntawm cov yam hlau nyob rau hauv nws daim ntawv uas ntuj yog xiavlus-dawb xim. Nws melting point yog qis dua hais tias pom tau hais tias kom txog rau thaum tam sim no lub ntsiab thiab yog ^{hais txog} 1907 C. Txawm li cas los, nws yog tseem siv nyob rau hauv lub kos duab thiab kev lag luam thoob plaws, raws li zoo amenable mus txhua yam influences, ua thiab molded.

Tshwj xeeb tshaj yog tseem ceeb cov chromium li napylitelya. Nws yog thov rau cov khoom mus muab lawv zoo nkauj ci, kev tiv thaiv tiv thaiv corrosion thiab txhim kho kev coj kuj. Cov no yog hu ua chrome plating.

chromium alloys yog heev nrov. Vim tias txawm me me ntawm no hlau nyob rau hauv lub hlau tshuam tsub kom lub hardness thiab kuj rau cov teebmeem ntawm lub yav tas.

zirconium

Ib tug ntawm feem ntau kim hlau, li ntawd, nws siv nyob rau hauv kev daim ntaub ntawv yog ib qhov nyuaj. Txawm li cas los, yam ntxwv lub cev ua nws tsuas irreplaceable nyob rau hauv ntau ntau lwm yam industries.

Nyob rau hauv tej yam kev mob, ib tug zoo nkauj nyiaj-dawb hlau. Nws muaj ib tug txaus siab melting ntsiab lus - 1855 ^C. Nws muaj zoo hardness, corrosion kuj, txij thaum lub sib kom nquag plias. Tsis tas li ntawd exhibits zoo heev biocompatibility nrog daim tawv nqaij thiab tag nrho cov kab mob. Qhov no ua rau nws ib tug tseem ceeb hlau rau siv nyob rau hauv cov tshuaj (seev, dag nqua, thiab thiaj li nyob).

Main daim ntaub ntawv ntawm zirconium thiab nws cov tebchaw, xws li alloys, raws li nram no:

• nuclear fais fab;
• pyrotechnics;
• alloying co;
• tshuaj;
• bioposudy siv;
• yam ntxwv cov ntaub ntawv uas ;
• zoo li ib tug superconductor.

Zirconium thiab alloys txawm decorations no yog ua los rau lub hauv paus ntawd, muaj peev xwm ntawm influencing kev txhim kho ntawm tib neeg noj qab haus huv.

molybdenum

Yog hais tias koj nrhiav tau tawm yog dab tsi feem ntau refractory hlau, nyob rau hauv tas li ntawd mus rau lub xws tungsten thiab molybdenum tej zaum yuav hu ua. Nws melting kub yog 2623 ° ^C. Yog li ntawd nws yog heev nyuaj, zas thiab workable.

Nws yog siv mas tsis nyob hauv cov ntshiab daim ntawv tiam sis raws li ib feem ntawm cov alloys. Lawv, ua tsaug rau lub xub ntiag ntawm molybdenum heev strengthened nyob rau hauv coj kuj, Thaum tshav kub kub kuj thiab anticorrosion.

Ib txhia molybdenum tebchaw yog siv raws li kev lubrication. Tsis tas li ntawd, qhov no yog qhov doping hlau cov ntaub ntawv uas ib txhij muaj feem xyuam rau lub dag lub zog thiab anticorrosion, uas yog tsis tshua muaj heev.

vanadium

Grey hlau nrog ib tug silvery ci. Nws muaj ib tug ncaj high nqi ntawm melting (1920 ° ^C). Nws yog tsuas yog siv raws li ib lub hauv paus nyob rau hauv ntau dab vim nws inertia. Zog yog siv nyob rau hauv ob qho tib si rau hauv lub tshuaj tam sim no qhov chaw nyob rau hauv qhov siv thiab ua inorganic acids. Lub ntsiab tseem ceeb yog tsis ntshiab hlau, namely ib co ntawm nws cov tebchaw.

Rhenium thiab nws alloys

Yuav ua li cas yog cov feem ntau refractory hlau tungsten tom qab? Nws rhenium. Nws melting tus nqi yog ^{hais txog} 3186 C. Rau superior zog thiab tungsten, thiab molybdenum. Plasticity nws tsis yog siab dhau heev lawm. Kev thov rau rhenium yog heev loj, tiam sis cov ntau lawm yog complexity. Vim hais tias ntawm no, nws yog ib lub kim tshaj plaws hlau nyob rau hauv hav zoov niaj hnub no.

Nws yog siv rau qhov siv thiab ua:

• dav hlau xyaw;
• thermocouples;
• filament xov rau spectrometers thiab lwm yam pab kiag li lawm;
• raws li ib lub hauv paus nyob rau hauv cov roj refining.

Tag nrho cov ntaub ntawv sau npe yog kim, li ntawd nws yog tsuas yog siv nyob rau hauv cov ntaub ntawv ntawm huab yuav tsum, thaum los hloov ib yam dab tsi lwm tus neeg yog tsis tau.

titanium alloys

Titan - ib tug heev sib hlau nyiaj-dawb xim, uas yog dav siv nyob rau hauv lub metallurgical kev lag luam thiab cov hlau. Nws yuav tawg thaum nyob rau hauv ib tug finely faib lub xeev, thiaj li yog ib tug hluav taws teeb meem.

Nws yog siv nyob rau hauv aircraft thiab foob pob ua ntxaij ntau lawm, zus tau tej cov ships. Lug siv nyob rau hauv cov tshuaj vim hais tias ntawm biocompatibility nrog rau lub cev (artificial nqua, piercings, kev cog hniav, thiab lwm yam).