Cov kev kho saum npoo dab tsi muaj rau corrosion-Resistant Heating Phaj?

Stainless hlau cua sov daim hlau tseem tuaj yeem corrode thaum raug qee cov kua qaub, ntsev lossis tshuaj ntxuav. Cov kev kho deg muab cov txheej txheem tiv thaiv rau lub phaj hauv qhov chaw hnyav, ncua kev pab cuam lub neej thiab tswj kev ua haujlwm thermal. Txhawm rau xaiv txoj cai corrosion resistant cua sov phaj saum npoo kev kho mob, koj yuav tsum paub txog cov tshuaj raug, kev khiav hauj lwm kub, mechanical hnav, thiab kev txwv nyiaj txiag. Kab lus no txheeb xyuas cov txheej txheem ntau tshaj plaws -PTFE, electroless npib tsib xee, tawv chrome thiab ceramic- thiab muaj cov txheej txheem xaiv rau cov khoom siv cua sov.

Yog vim li cas cua sov phaj nto kho
Cov phaj cua sov feem ntau yog ua los ntawm txhuas, hlau, lossis stainless hlau. Stainless hlau muaj kev tiv thaiv corrosion ntau heev, tab sis puas los ntawm chlorides (xws li, tshuaj tsuag ntsev, tshuaj dawb), muaj zog txo cov kua qaub, thiab qee cov tshuaj ntxuav. Aluminium tuaj yeem tawm tsam los ntawm alkalis thiab acids. Kev kho deg muaj ntau lub hom phiaj:

Chemical Barrier - Khaws lub hauv paus hlau kom deb ntawm cov txheej txheem corrosive, fumes lossis tshuaj ntxuav.

Tsis yog- cov yam ntxwv lo - Tiv thaiv kom tsis txhob kho cov resins, cov nplaum los yog cov khoom xyaw zaub mov los ntawm lo rau lub phaj.

Abrasion Resistance - Qhov saum npoo ntawm lub phaj yog tiv thaiv hnav los ntawm kev thauj khoom, tu lossis tiv tauj nrog cov khoom.

Dielectric rwb thaiv tsev - Tiv thaiv hluav taws xob conduction ntawm phaj thiab rhiab Cheebtsam (xws li semiconductor wafers).

Lub ntsiab hem thiab tej yam kev mob nyob rau hauv uas lub phaj yuav tsum tau siv dictate qhov kev xaiv ntawm txheej.

Common Surface Treatments Comparison
Cov lus hauv qab no qhia txog cov yam ntxwv tseem ceeb ntawm plaub qhov kev kho mob feem ntau siv rau corrosion-cov phaj cua sov.

Txheej Hom Max Nruam Temp (degree) Corrosion Resistance Hardness (HRC equiv) Tus nqi txheeb ze (ib m2) Qhov nruab nrab Thickness
PTFE (fluoropolymer) 260 Zoo heev (broad chemical range) Mos (~R 110 Shore D) Siab 0.3–0.8 mm
Electroless npib tsib xee (EN) 400 (diffusion) Nruab Nrab - Zoo (tiv taus feem ntau cov kua qaub, tab sis tsis muaj zog oxidizers) ~ 50 HRC Tsawg- Nruab Nrab 25-75 µm
Hard chrome 400 Nruab Nrab (porous, xav tau sealant) ~ 70 HRC Nruab Nrab 50-250 μm
Ceramic (Al₂O₃, plasma spray) 800+ Zoo heev (tshwj tsis yog muaj zog alkalis) ~ 60-70 HRC Siab 100-500 microns
1. PTFE (Polytetrafluoroethylene) Txheej
PTFE (muag feem ntau raws li lub npe lag luam Teflon®) yog fluoropolymer dav siv rau nws cov tshuaj lom neeg tsis zoo thiab tsis yog - nplaum nplaum. PTFE yog siv rau cov cua kub daim hlau nyob rau hauv daim ntawv ntawm ib tug kua dispersion los yog hmoov uas yog txau mus rau lub hlau nto thiab kho nyob rau hauv lub kub kub (feem ntau yog 370-400 degree).

Cov txiaj ntsig: •

Resistant yuav luag txhua yam tshuaj, suav nrog cov acids muaj zog (hydrochloric, sulfuric, nitric), bases, hnyav thiab oxidizers.

Tsis muaj nplaum nplaum tiv thaiv cov khoom txuas - zoo meej rau resin curing, ua zaub mov thiab tuav tuav.

Tsawg coefficient ntawm kev sib txhuam (0.05-0.10) txo qhov hnav ntawm zawv zawg qhov chaw.

Zoo dielectric zog (ze li 20 kV / mm).

Kev txwv:

Qhov kub tsis tu ncua siab tshaj plaws kwv yees li . 260℃. Lub PTFE tawg saum toj no thiab tawm cov pa phem.

Soft Surface - yooj yim rau khawb lossis abrading los ntawm cov khoom ntse lossis cov khoom tawv.

Kev ua tsis zoo rau cov hlau, xav tau lub tsho tiv no (feem ntau yog PFA lossis FEP) thiab kev npaj txhij txhua.

Thicker coatings txo thermal conductivity me ntsis (tab sis negligibly rau feem ntau lub hom phiaj).

Cov ntsiab lus ntawm kev thov:
Lub thickness ntawm PTFE txheej ntawm cov khoom cua sov daim hlau yog feem ntau nyob rau hauv qhov ntau ntawm 0.3-0.8 hli. Ob peb txheej yog siv kom tau ib tug pinhole -dawb npog. Yuav tsum zam kev puas tsuaj. Ib qho khawb PTFE npog nthuav tawm lub hauv paus hlau thiab pab txhawb kev nthuav tawm ntawm undercutting corrosion.

2. Electroless nickel (EN) txheej
Electroless npib tsib xee deposits siv ib tug pib- cov tshuaj tiv thaiv catalytic, los tsim ib homogeneous txheej txawm nyob rau complex geometries nrog rau hauv lub qhov los yog qhov muag tsis pom voids. Cov txheej txheej muaj nickel-phosphorus alloy (feem ntau 6-12% P). Qhov zoo tshaj plaws corrosion kuj yog tau nrog siab phosphorus (10-12% P) EN rau cov cua sov phaj.

Pros:

Exceptional uniformity - qhov txawv nyob rau hauv thickness ntawm lub phaj loj feem ntau tsawg dua ± 10%.

Nruab nrab kom zoo tiv thaiv corrosion - resistant rau ntau yam acids (xws li dilute sulfuric, acetic), alkalis thiab ntsev tov. Tsis muaj zog rau oxidizers zoo li nitric acid lossis ferric chloride.

Raws li deposited hardness txog 50 HRC, tshav kub kho tau rau 65-70 HRC (corrosion kuj yog compromised).

Bonds zoo rau steel, aluminium thiab tooj liab alloys.

Tus nqi zoo rau cov phaj nruab nrab mus rau loj loj.

Kev txwv:

Tsis muaj tshuaj tiv thaiv zoo li PTFE lossis siab kawg ceramics. Yog tias siv tsis raug, EN tuaj yeem pinhole lossis tawg thaum caij tsheb kauj vab.

Qhov kub siab tshaj plaws yog li 400℃rau lub sijhawm luv luv. Yog tias qhov kub thiab txias tau khaws cia ntau dua 300℃rau lub sijhawm ntev, crystallization thiab embrittlement yuav tshwm sim.

Hluav taws xob conductivity - tsis yog dielectric (tej zaum yuav zoo rau hauv av, tsis zoo rau rwb thaiv tsev).

Cov ntsiab lus ntawm kev siv:
Electroless npib tsib xee feem ntau xav tau rau cov phaj cua sov siv hauv cov khoom siv hluav taws xob lossis cov khoom siv kho mob tsim khoom lag luam uas yuav tsum tau tswj kom nruj qhov ntev. Cov txheej yog nruab nrab ntawm 25 thiab 75 µm tuab. Kev kho cua sov tom qab plating (piv txwv li . 200℃rau 2 teev) nce adhesion thiab txo qis hydrogen embrittlement.

3. Hard Chrome Txheej
Hard chrome (qee zaum hu ua industrial chrome) yog txheej chromium siv los ntawm electrolytic deposition. Nws yog renowned rau nws zoo heev hardness thiab kuj rau hnav. Hard chrome yog siv rau cov hlau los yog stainless hlau substrates rau cua sov daim hlau.

Cov txiaj ntsig:

Hardness siab heev (65-70 HRC) - tiv thaiv khawb, khawb thiab khawb hnav.

Tsawg coefficient ntawm kev sib txhuam (0.15-0.20).

Cov khoom siv hluav taws xob zoo (chrome yog ~ 90 W / mK, tib yam li hlau).

tuaj yeem ua haujlwm ntawm qhov kub siab (txog 400℃yam tsis muaj kev puas tsuaj).

Kev txwv: 1.

Ntuj ntxeem tau. Cov txheej chromium yog micro- tawg rau cov khoom corrosive kom ncav cuag lub hauv paus hlau. Yuav tsum muaj lub sealant los tiv thaiv corrosion, xws li roj los yog lwm yam polymeric sealer.

nruab nrab corrosion kuj - ua hauj lwm zoo nyob rau hauv me me tab sis tsis muaj zog acids los yog chlorides.

Kev txhawj xeeb ib puag ncig - hexavalent chromium yog qhov txaus ntshai. Plating yuav tsum tau tso cai tshwj xeeb thiab kho cov khib nyiab.

Tsis zoo li qub; yuav tsum tau ncej- sib tsoo vim tsim- ntawm ntug (dog- pob txha).

Daim ntawv thov:
Hard chrome yog tsim los rau kev kub siab lamination daim hlau lossis txhua daim ntawv thov uas muaj kev phom sij loj yog kev siv tshuab thiab qhov kev hem thawj thib ob yog corrosion. Cov tuab tuab yog 50-250 µm. Qhov saum npoo yog feem ntau hauv av tiaj tus tom qab plating thiaj li ua tau raws li qhov kev cia siab rau kev ua siab ntev. Lub phaj yog muab tso rau hauv kev pabcuam tom qab kev kho sealing (xws li dipping hauv cov roj uas tsis muaj corrosion).

4. Plasma Sprayed Aluminium Oxide Ceramic Txheej
Thermal spray method, xws li plasma lossis HVOF, yog siv los siv cov txheej txheem ceramic. Cov khoom siv hmoov ceramic, feem ntau yog txhuas oxide (Al2O3) lossis chromium oxide (Cr2O3) yog rhuab thiab tom qab ntawd txav mus rau saum npoo ntawm lub phaj, tsim kom muaj txheej txheej tuab.

Pros:

Muaj peev xwm kub heev, mus txog 800C thiab siab dua.

Cov tshuaj tiv thaiv zoo heev - Al₂O₃ yog resistant rau feem ntau cov kua qaub, alkalis thiab cov kuab tshuaj (tsis suav nrog muaj zog hydrofluoric acid thiab kub concentrated alkalis).

High dielectric zog - muaj hluav taws xob rwb thaiv tsev ntawm lub phaj thiab ib feem.

Sib npaug hardness Zoo 60-70 HRC Zoo hnav tsis kam.

Kev txwv:

Brittle - nquag tawg thaum raug cuam tshuam los yog thermal raug mob. Cov kab nrib pleb hauv cov xim uas qhia cov hlau yooj yim.

Yuav tsum tau npaj qhov ntxhib (grit blasting) rau kev sib txuas. Tsis haum rau cov ntawv thov tiav.

Cov tuab tuab (100-500um) tuaj yeem cuam tshuam qhov ntev ntev.

Tus nqi ntau dua li electroless nickel lossis nyuaj chrome.

Daim ntawv thov:
Ceramic coatings yog siv rau cov cua kub daim hlau rau kub kub molding, semiconductor wafer ua (qhov twg hluav taws xob cais yuav tsum tau), thiab nyob rau hauv hnyav tshuaj tej yam kev mob siab tshaj 260℃(dhau ntawm PTFE txwv). Ib txheej txheej ceramic (piv txwv li, impregnated nrog ib lub polymer) tuaj yeem txo qhov porosity thiab nce corrosion kuj.

Cov txheej txheem xaiv: Sib piv txheej rau daim ntawv thov
Kev xaiv ntawm corrosion resistant nto kho cov cua sov phaj yog cuam tshuam los ntawm plaub yam tseem ceeb.

Tshuaj Tiv Thaiv
Chemical Ib puag ncig: Pom zoo: Tsis pom zoo:
Muaj zog acids (HCl, H₂SO₄, HNO₃) PTFE, Ceramic Hard chrome, Electroless nickel
Muaj zog alkalis (NaOH, KOH) PTFE, Hard chrome (sealed) Ceramic (tshem los ntawm kub alkalis), EN ntsev tsuag (NaCl, marine ib puag ncig) PTFE, Electroless NiHard chrome (tsis kaw)
Organic kuab tshuaj (acetone, cawv) Txhua yam tsim nyog txaus. - Oxidising agents (bleach, peroxide) PTFE, Ceramic Electroless nickel (pitting)
Ua haujlwm kub
Txog li 260℃- PTFE yog unsurpassed nyob rau hauv chemical resistance thiab non-stick yam ntxwv.

260-400℃- Electroless npib tsib xee lossis tawv chrome (nrog cov sealants tsim nyog). Ceramic kuj ua haujlwm tab sis nws kim dua.

Tshaj 400℃- Tsuas yog cov coatings ceramic (los yog liab qab stainless hlau nrog cov alloys tshwj xeeb) yuav tiv taus cov cua sov.

Mechanical Hnav thiab Erosion
High hnav (sliding qhov chaw, abrasive tu) - Hard chrome lossis ceramic.

Tsawg hnav (plate zoo li qub, mos so) - PTFE lossis electroless npib tsib xee.

Thermal Cycling thiab Mechanical Load
Kev caij tsheb kauj vab nruab nrab (20℃txog 200℃thiab rov qab) yog ua haujlwm zoo los ntawm PTFE thiab electroless npib tsib xee. Hard chrome tuaj yeem tawg yog tias lub substrate nthuav dav heev. (piv txwv li txhuas nyob rau hauv chrome - tsis tau qhia.) ceramics yog qhov tsawg kawg nkaus ntawm thermal shock tshwj tsis yog muab thickly rau ntawm ib tug matched -expansion substrate (xws li ceramic ntawm Invar).

Cov teeb meem raug nqi
Rau kev tiv thaiv me ntsis corrosion, electroless npib tsib xee yog qhov pheej yig tshaj plaws. PTFE yog siab dua vim ntau txheej txheej thiab primer yuav tsum tau. Hard chrome nqi sib txawv nrog tuab thiab ncej- sib tsoo. Ceramic spray feem ntau yog kim tshaj plaws vim yog cov cuab yeej tshwj xeeb thiab cov nqi tso nyiaj tsawg.

Cov Tswv Yim Qhia Txog Kev Qhia Txog Txheej Txheej
Thaum tsim ib qho kev qhia tshwj xeeb rau corrosion- tiv taus cua sov phaj, cov ntaub ntawv hauv qab no yuav tsum suav nrog:

Cov khoom siv substrate - Aluminium, hlau, lossis stainless hlau. Aluminium yuav tsum tau tshwj xeeb pretreatment (zincate los yog anodize) ua ntej electroless nickel los yog PTFE.

Txheej hom thiab thickness - piv txwv li, "PTFE txheej, 0.5 hli nominal thickness, pinhole -dawb ib ASTM D714."

Corrosion test yuav tsum tau - piv txwv li, "48 teev ntsev tsuag ib ASTM B117 tsis muaj xeb liab."

Kev ntsuas kub - "Kev ua haujlwm tsis tu ncua ntawm 200 degree, cuam tshuam rau 250 degree."

Flatness tom qab txheej - "Coated nto flatness yuav tsum tsis pub tshaj 0.05 hli tshaj 300 hli."

Ntug thiab qhov kev pab them nqi - "Tag nrho cov npoo thiab dhau los ntawm- qhov yuav tsum tau coated tsis muaj substrate raug."

Nyob rau hauv ib puag ncig corrosive, nws yog ib qho tseem ceeb kom sib npaug tshuaj tiv thaiv nrog cov neeg kho tshuab durability. Lub PTFE-coated phaj uas niaj zaus txhuam nrog lub ncoo abrasive yuav sai sai. Hloov pauv, lub phaj nyuaj chrome hauv lub da dej muaj zog acid yuav ua rau nws cov micro- tawg hauv lub lis piam.

Xaus
Cov kev kho deg ua rau nthuav dav lub hnab ntawv ua haujlwm ntawm cov hlau hlau cua sov. PTFE coatings muab cov tshuaj tsis sib haum xeeb thiab tsis yog - nplaum ua haujlwm txog 260℃. Electroless npib tsib xee muab cov khoom sib xws, tus nqi - tiv thaiv zoo rau qhov nruab nrab corrosion ib puag ncig. Hard chrome plating muab qhov hnyav hnyav tab sis yuav tsum tau muab khi rau kev tiv thaiv corrosion. Ceramic coatings ua rau siab -kub thiab siab - dielectric daim ntaub ntawv. Kev xaiv ntawm corrosion resistant cua sov phaj saum npoo kev kho mob yuav tsum xav txog tej yam tshuaj raug, qhov kub thiab txias, mechanical hnav, thiab thermal cycling tej yam kev mob. Cov khoom siv tiv thaiv yog ib feem tseem ceeb ntawm kev tsim lub tshuab cua sov; txoj kev kho saum npoo kom raug ncua kev pab cuam lub neej, txo kev sib kis, thiab ua kom zoo thermal ua haujlwm zoo hauv kev ua haujlwm hnyav.