Dab tsi yog qhov tseem ceeb tsim qauv ntawm lub phaj cua sov rau lub tshuab nqus tsev kub xovxwm?

Cov xovxwm kub hauv lub tshuab nqus tsev vacuum nthuav tawm ob - teeb meem. Nws yuav tsum tau siv cov cua sov thiab lub siab los txuas cov ntaub ntawv, thaum tsis muaj paug lub tshuab nqus tsev vacuum nrog outgassing organics lossis cov pa roj. Cov cua kub cua kub ib txwm yuav tsis muaj sia nyob hauv qhov chaw zoo nkauj no, siab -stakes huab cua. Tsim cov cua sov phaj ntawm lub tshuab nqus tsev kub xovxwm los ntawm kos, nrog rau cov khoom purity, hermetic sealing thiab kub faib hauv siab. Hauv cov ntawv thov xws li kev sib txuas ntawm cov khoom siv hauv aerospace, semiconductor encapsulation lossis diffusion bonding ntawm cov hlau, platen nws tus kheej dhau los ua cov cuab yeej tseem ceeb.

Cov Kev Xav Tau Tshwj Xeeb ntawm Lub Nqus Ib puag ncig
Tsis muaj atmospheric convection nyob rau hauv lub tshuab nqus tsev chamber. Thaum tshav kub kub hloov ntawm lub platen mus rau lub workpiece tsuas yog tshwm sim los ntawm conduction (ntawm qhov chaw sib cuag) thiab los ntawm hluav taws xob. Qhov no ua rau qhov flatness thiab thermal uniformity ntawm qhov chaw ntawm lub platen tseem ceeb tshaj nyob rau hauv huab cua. Txhua qhov chaw ntawm platen thiab workpiece txwv kev sib cuag zoo thiab ua rau qhov kub thiab txias sib txawv.

Meanwhile, lub hoover ib puag ncig yog heev susceptible rau cov pa phem. Outgassing -cov pa tawm ntawm cov pa hauv qhov dej, cov dej noo, los yog cov khoom siv hluav taws xob tsis zoo los ntawm cov khoom siv - tuaj yeem ua rau lub tshuab nqus tsev tsis zoo, paug cov khoom ua haujlwm, lossis ua rau lub tshuab nqus tsev twj. Yog li, cov cua sov phaj tsim nyob rau hauv lub tshuab nqus tsev kub xovxwm yuav tsum muaj ultra- cov ntaub ntawv uas tsis muaj outgassing thiab leak- nruj.

Kev xaiv tseem ceeb ntawm cov khoom siv rau qis qis
Lub cev platen yuav tsum tau tsim los ntawm lub tshuab nqus tsev hlau. Cov kev xaiv nrov muaj xws li:

316L stainless hlau - Kev xaiv nrov tshaj plaws. Nws muaj tsawg outgassing, superior mechanical zog ntawm qhov kub thiab txias tsis kam rau oxidation nyob rau hauv lub tshuab nqus tsev vacuum bakeout. Feem ntau cov nto tiav yog polished los yog electropolished kom txo tau qhov chaw ntawm qhov chaw thiab ntxiv txwv outgassing.

Aluminium alloys (6061 lossis 7075) tshwj xeeb kho - Txhuas txhuas tsis yog hoover tus phooj ywg vim nws tuab, ntxeem tau oxide txheej uas khaws cov dej noo. Tab sis qhov tshwj xeeb tu thiab lub tshuab nqus tsev ci ntawm txhuas tuaj yeem siv rau cov ntawv thov kub nruab nrab (tsawg dua 250 degree). 316L yog qhov nyiam tshaj rau ultra- lub tshuab nqus tsev siab (UHV).

Inconel lossis lwm yam superalloys - Inconel lossis Haynes alloys tau teev tseg rau cov ntawv thov tshaj 500℃thaum stainless hlau poob lub zog. Cov no muaj tsawg vapor pressures ntawm qhov kub thiab txias.

Tag nrho cov khoom siv sab hauv, suav nrog cov khoom siv cua sov, rwb thaiv tsev, cov xov hlau thermocouple, thiab cov ntaub ntawv foob, yuav tsum ua raws li cov kev txwv tsis pub dhau los ntawm cov qauv xws li ASTM E595 (rau qhov chaw thiab lub tshuab nqus tsev) nrog rau tag nrho cov khoom poob (TML) 1.0% thiab khaws cov khoom tsis zoo (CVCM) 0.1%.

Cov ntaub ntawv uas yuav tsum zam:

Aluminium txheem (siab outgassing, ntxeem tau oxide).

Plastics los yog polymers (txuag rau ob peb lub siab -kub, qis outgassing qib zoo li Vespel los yog Kapton siv sparingly).

Viton lossis cov pa elastomers (silicone lossis fluorosilicone tuaj yeem siv tau hauv cov chaw txwv; feem ntau txhua yam -cov ntsaws ruaj ruaj yog qhov zoo dua).

Cua sov Elements Vacuum{0}}Compatible, Hermetically Enclosed
Lub platen yog embedded nrog cua sov ntsiab lus uas yuav tsum tau hermetically kaw kom tsis txhob outgassing los yog hais los ntawm sab hauv. Txais kev tsim qauv yog:

Mineral-insulated (MI) cua sov cables - Resistance hlau (NiCr los yog sib npaug) encased nyob rau hauv compacted magnesium oxide (MgO) hmoov, nyob rau hauv ib tug seamless hlau sheath (Inconel, 316SS los yog Alloy 600). Hauv kev tsim khoom, MgO yog qhuav thiab nqus tau degassed Qhov kawg ntawm lub sheath yog welded kaw.

Standard cartridge rhaub feem ntau muaj cov organic kawg seals uas outgas. Cartridge rhaub nrog Welded Kaw Rau hoover kev pab cuam, tsuas yog variants nrog tag nrho welded kawg kaus mom thiab MgO sau yuav siv tau.

Encapsulated Resistive Elements - Rau cov platens nyias, etched foil heaters tuaj yeem ua hermetically encapsulated ntawm ob daim hlau hlau los ntawm laser vuam nyob ib ncig ntawm lub periphery.

Internal xov txuas cov cua kub ntsiab lus rau feedthroughs yuav tsum tau insulated siv cov khoom uas tsis muaj outgassing. Tag nrho cov khiav yog zoo dua mineral insulated cable. Yog tias xav tau cov xaim hloov tau yooj yim, PTFE lossis Kapton (polyimide) rwb thaiv tsev yog qhov tsim nyog tab sis nws yuav tsum tau nqus kom huv. Tsis muaj PVC lossis nylon hlau ntawm tus qauv.

Hluav taws xob Feedthroughs & Thermocouple (Hermetic)
Txhua lub zog hluav taws xob lossis cov kab hluav taws xob uas mus los ntawm cov cua sab nraud ntawm lub tshuab nqus tsev thiab mus rau hauv lub phaj yuav tsum hla lub tshuab nqus tsev. Qhov no yog ua los ntawm ceramic- mus rau - hlau feedthroughs. Tus txheej txheem kub xovxwm platen nyob rau hauv lub tshuab nqus tsev xovxwm nta:

Fais fab feedthroughs - Ob los yog ntau dua conductors (nyob ntawm ib qho - los yog peb-theem cua sov, raws li qhov tsim nyog) brazed rau hauv ib tug hlau flange los yog ncaj nraim rau hauv lub platen lub cev Cov ceramic insulator feem ntau yog 95% lossis 99% alumina thiab raug muab khi rau cov hlau hermetically.

Thermocouple feedthroughs - Finewire thermocouple extensions (Hom K los yog J) khiav los ntawm lub tshuab nqus tsev haum, feem ntau nrog me me ceramic-rau- hlau foob.

Cov feedthroughs no yuav tsum tau ntsuas rau qhov ua haujlwm kub ntawm lub platen (feem ntau yog 300-500C rau lub tshuab nqus tsev kub xovxwm daim ntawv thov) thiab qhov sib txawv siab (1 atm sab nraum, nqus tsev). Lawv raug kuaj nrog lub helium huab hwm coj spectrometer kom cov pa xau tsawg dua 10⁻⁹ mbar·L / s.

Txhua qhov kab noj hniav hauv platen --xws li lub qhov muag tsis pom kev rau lub thermocouple lossis lub hnab tsho threaded rau lub fastener-- tuaj yeem yog "txog li virtual." Ib qho tseem ceeb: Cov roj uas nyob hauv cov kab noj hniav yuav maj mam tawm mus rau hauv lub tshuab nqus tsev, ua kom lub twj tso kua mis-down lub sij hawm thiab deteriorating lub hauv paus siab. Lub tsev tsim qauv yuav tsum tso cai rau qhov tso pa tawm mus rau cov kab noj hniav kom txuas lawv mus rau qhov chaw sab nraud lossis lawv yuav tsum tau muab tshem tawm tag nrho. Piv txwv li, lub qhov dej thermocouple feem ntau yog vented los ntawm ib lub qhov me me (0.5-1.0 mm txoj kab uas hla) dhuav dhau mus rau saum npoo ntawm platen, tso cai rau kev khiav tawm ntawm huab cua.

Thermal Uniformity Raws li lub tshuab nqus tsev
Nyob rau hauv qhov tsis muaj convective cua ntws los pab rau hauv kev faib tawm ntawm tshav kub, lub platen yuav tsum nyob ntawm tsuas yog raws li conduction thiab sab hauv hluav taws xob kom tau ib tug uniform deg kub. Cov yam ntxwv tseem ceeb tsim rau uniformity:

Optimized heater arrangement - Cov khoom cua sov tau muab tso rau raws li kev txheeb xyuas qhov tseeb (FEA) xws li qhov sib txawv ntawm qhov chaw ua haujlwm kub nyob hauv ± 2-5℃. Feem ntau muaj ob peb tus kheej tswj cov cua sov thiab cov thermocouples rau cheeb tsam tswj.

Thick platen lub cev nrog siab conductivity - Ib tug tuab platen (piv txwv li, 25–40 mm) yuav txhim kho lateral tshav kub. Tab sis muaj kev sib pauv ntawm thickness thiab hnyav thiab thermal teb.

Flatness thiab polishing nto - Sab saum toj tiv toj yog av tiaj tus mus rau hauv 0.025-0.05 hli (0.001-0.002 ntiv tes) hla thaj tsam platen. Qhov zoo ntawm qhov chaw tiav (Ra < 0.8 μm) muab kev tiv thaiv thermal zoo rau cov khoom ua haujlwm thiab txo qhov chaw ntawm qhov chaw tawm.

Rwb thaiv tsev tom qab lub platenQhov tsis yog - ua hauj lwm ntawm lub platen feem ntau yog insulated nrog qis - outgassing ceramic fiber boards (xws li, silica los yog alumina fiber) kom steer cua sov rau pem hauv ntej. Cov boards no yuav tsum tau ci tawm kom tshem tawm cov binders thiab volatiles.

Qhov tseeb, cov platens feem ntau ci tawm hauv lub tshuab nqus tsev ua ntej siv, feem ntau ntawm 150-300℃hauv lub tshuab nqus tsev rau ntau teev, kom tshem tawm cov dej noo thiab cov khoom seem. Tom qab ua noj ua haus, lub platen tau mus txog nws qhov ruaj khov qis outgassing xeev.

Lub tshuab nqus tsev kub xovxwm cua sov phaj tsim daim ntawv txheeb xyuas
Lub tshuab nqus tsev kub xovxwm cua sov phaj tsim cov ntawv txheeb xyuas meej yog raws li hauv qab no:

Qeb qhov tseem ceeb feature pov thawj txoj kev
Body material 316L stainless steel (or Inconel for >500 degree) Cov ntaub ntawv pov thawj kev kho deg (electropolish)
Hermetically sealed ntxhia-insulated (MI) cable Heating elementNo organic kawg seals, welded sheath
Internal rwb thaiv tsev Compacted MgO (qhuav, nqus tsev degassed) Chaw tsim tshuaj paus outgassing cov ntaub ntawv los ntawm hoover
FeedthroughsCeramic-rau-hlau, tus nqi xau<10-9 mbar·L/sHelium leak test