Cov txheej txheem tsim khoom ntawm polyether ether ketone (PEEK) yas thiab nws daim ntawv thov hauv kev lag luam aerospace
Polyether ether ketone (PEEK) yog ib hom yas engineering uas muaj kev ua tau zoo heev uas siv dav thaum cov khoom siv yuav tsum muaj zog, ruaj khov, thiab tiv taus cua sov hauv qab qhov xwm txheej hnyav. Hauv kev lag luam aerospace, PEEK tau nyiam kev saib xyuas vim nws tuaj yeem hloov pauv hlau hauv qee yam khoom, thaum muab cov txiaj ntsig xws li qhov hnyav sib dua, tiv taus tshuaj lom neeg siab, thiab tiv taus kev qaug zog thiab hnav. Tsab xov xwm no tham txog cov txheej txheem tsim khoom PEEK los ntawm kev xav txog tshuaj lom neeg-polymer, nws cov theem kev lag luam, thiab yuav siv cov khoom no li cas hauv ntiaj teb aerospace.
Kev piav qhia ntawm PEEK thiab nws cov yam ntxwv
PEEK yog ib yam khoom siv semicrystalline aromatic polymers. Nws cov qauv saw hlau muaj cov ether (-O-) thiab ketone (-CO-) pawg uas teeb tsa rau ntawm cov nplhaib aromatic. Qhov kev sib xyaw ua ke no ua rau muaj cov khoom siv kho tshuab muaj zog thiab kev ruaj khov thermal siab. Feem ntau, PEEK paub txog nws qhov chaw yaj siab (kwv yees li 343 ° C), tiv taus cua sov ntev zoo heev, thiab tiv taus ntau cov kuab tshuaj thiab cov tshuaj lom neeg. Ntxiv mus, PEEK tiv taus hluav taws xob thiab tuaj yeem tsim los ua kom tau raws li qhov yuav tsum tau ua kom muaj kev nyab xeeb xws li hluav taws, pa luam yeeb, thiab kev lom (FST), uas yog qhov tseem ceeb hauv cov dav hlau.
Cov khoom zoo no ua rau PEEK ua "thermoplastic ua tau zoo heev." Tsis zoo li cov thermosets, uas thaum khov lawm nyuaj rau rov ua dua tshiab, PEEK, ua ib qho thermoplastic, tuaj yeem rov ua dua los ntawm cua sov, muab kev ywj pheej ntawm kev tsim khoom (piv txwv li, kev txhaj tshuaj, extrusion, compression, lossis qee yam kev siv 3D printing), txawm hais tias nws xav tau cov khoom siv uas muaj peev xwm tswj tau qhov kub siab.
Cov ntaub ntawv raw thiab cov ntsiab cai ntawm kev ua tshuaj rau kev tsim PEEK
Hauv kev lag luam, PEEK yog tsim los ntawm kev ua polymerization uas muaj cov monomers aromatic activated. Ib txoj kev tsim khoom uas paub dav dav suav nrog kev sib xyaw ntawm aromatic dihalides nrog bisphenolate ntsev hauv cov kuab tshuaj polar aprotic ntawm qhov kub siab. Lub tswv yim, kev tsim ether bond tshwm sim los ntawm nucleophilic aromatic substitution (SNAr), uas ua haujlwm zoo rau cov nplhaib aromatic nrog cov pab pawg electron-withdrawal thiab tawm hauv.
Hauv kev xyaum ua lag luam, kev xaiv monomer, hom puag, kev xaiv cov kuab tshuaj, thiab kev tswj kev ntshiab muaj feem cuam tshuam rau qhov hnyav molecular ntawm polymer, kev faib tawm ntawm qhov hnyav molecular, xim, thiab kev ua tau zoo kawg. Vim tias PEEK yog rau cov ntawv thov tseem ceeb (suav nrog aerospace), cov khoom tsis huv ntawm ionic, dej noo, thiab cov kuab tshuaj seem yuav tsum tau tswj hwm nruj me ntsis.
Cov theem ntawm cov txheej txheem tsim khoom PEEK hauv kev lag luam
Txawm hais tias txhua tus neeg tsim khoom yuav muaj kev hloov pauv hauv lawv cov txheej txheem tiv thaiv thiab cov zaub mov txawv, cov txheej txheem tsim khoom PEEK dav dav tuaj yeem muab faib ua cov kauj ruam hauv qab no.
1) Kev npaj thiab kev ntxuav cov khoom siv raw
Cov kauj ruam pib suav nrog kev ziab cov monomer thiab cov kuab tshuaj, nrog rau kev ntxuav kom tshem tawm cov pa phem xws li dej, cov hlau ions, lossis cov tshuaj uas tuaj yeem tiv thaiv kev loj hlob ntawm cov saw hlau (cov khoom siv xaus saw hlau). Dej yog tus yeeb ncuab tseem ceeb hauv ntau cov txheej txheem polymerization vim tias nws tuaj yeem hloov pauv qhov kev ua haujlwm thiab cuam tshuam rau qhov hnyav molecular ntawm cov khoom. Yog li ntawd, lub kaw lus feem ntau yuav tsum qhuav heev, suav nrog kev siv cov roj inert rau kev npog.
2) Kev tsim cov ntsev bisphenolate (kev ua kom nucleophile ua haujlwm)
Feem ntau cov phenolic monomers raug hloov mus ua lawv cov ntsev siv lub hauv paus (piv txwv li, carbonate). Lub hom phiaj yog los tsim cov nucleophile muaj zog (phenolate) uas yooj yim tawm tsam cov halogenated aromatic monomer. Cov kauj ruam no kuj xav tau kev tswj hwm stoichiometric kom raug, vim tias qhov tsis sib npaug ntawm qhov sib piv ua haujlwm tuaj yeem txo qhov degree ntawm polymerization thiab cuam tshuam rau cov khoom siv kho tshuab.
3) Cov tshuaj tiv thaiv polymerization ntawm qhov kub siab
Qhov kev tshuaj tiv thaiv tseem ceeb tshwm sim ntawm qhov kub siab hauv lub tshuab ua kom tsis txhob xeb uas muaj peev xwm ua kom muaj viscosity siab. Cov kuab tshuaj polar aprotic pab yaj cov tshuaj tiv thaiv thaum ntxov, ua rau kev tshuaj tiv thaiv mus zoo. Thaum cov saw polymer loj hlob, viscosity nce ntxiv dramatically, thiab kev tswj thermal ua qhov tseem ceeb ntxiv los tiv thaiv cov kub lossis thermal degradation.
Hauv theem no, cov txheej txheem xws li kub, lub sijhawm nyob, thiab qhov nrawm ntawm kev nplawm cuam tshuam rau qhov hnyav molecular. Cov chaw tsim khoom feem ntau tsom mus rau qhov ntau yam viscosity yaj vim nws cuam tshuam nrog kev yooj yim ntawm kev ua tiav tom qab (piv txwv li, extrusion) thiab kev ua tau zoo kawg.
4) Kev xaus, kev txias, thiab kev tso dej tawm (kev rho tawm)
Tom qab mus txog qib polymerization uas xav tau, qhov kev ua tshuaj tiv thaiv raug nres thiab qhov sib tov raug txias. Tom qab ntawd cov polymer raug cais tawm, feem ntau los ntawm kev nchuav rau hauv cov khoom tsis muaj kuab tshuaj lossis los ntawm cov kauj ruam sib cais tshwj xeeb. Lub hom phiaj yog cais PEEK ntawm cov kuab tshuaj, cov ntsev inorganic, thiab cov seem ntawm kev ua tshuaj tiv thaiv.
5) Ntxuav thiab ziab
Cov polymer uas raug cais tawm raug ntxuav ntau zaus kom txo cov ionic content thiab cov solvent residue. Theem ziab yog ua tiav nyob rau hauv cov xwm txheej uas ua kom muaj qhov av noo tsawg heev. Rau cov ntawv thov aerospace, kev tswj cov volatile thiab cov pa phem yog qhov tseem ceeb vim tias lawv tuaj yeem cuam tshuam rau outgassing, qhov zoo ntawm qhov chaw, thiab kev ruaj khov mus sij hawm ntev.
6) Kev sib xyaw ua ke: ntxiv cov khoom siv ntxiv thiab cov khoom txhawb nqa
PEEK ntshiab twb muaj zog heev lawm, tab sis hauv ntau daim ntawv thov nws tau txhim kho nrog cov khoom sau / cov khoom txhawb nqa xws li carbon fiber, fiberglass, lossis PTFE kom txo qis qhov coefficient ntawm kev sib txhuam thiab ua rau muaj kev tiv thaiv hnav. Kev sib xyaw ua ke yog ua tiav los ntawm kev siv lub tshuab extruder kub siab. Cov khoom siv txhawb nqa yuav tsum sib xws, qhov sib xyaw ua ke, thiab qhov ntev ntawm cov fiber tswj kom ua tiav cov khoom siv kho tshuab xav tau.
7) Pelletizing thiab kev tswj xyuas zoo
Cov khoom kawg feem ntau yog ua los ntawm cov pellet kom yooj yim rau kev ua ntxiv. Kev tswj xyuas zoo suav nrog kev ntsuas viscosity, kev tshuaj xyuas cov ntsiab lus tshauv (rau cov khoom sau), DSC rau crystallinity thiab melting point, TGA rau thermal stability, kev sim tshuab (tensile, flexural, impact), thiab kev sim FST yog tias npaj rau sab hauv dav hlau.
Kev ua cov PEEK ua cov khoom
Hauv kev tsim khoom, PEEK tuaj yeem ua tiav los ntawm:
- Kev txhaj tshuaj molding rau cov khoom sib xyaw ua ke xav tau cov pwm thiab cov tshuab uas muaj peev xwm ua tau kub heev.
- Extrusion los tsim cov profiles, kav dej, zaj duab xis, lossis cov duab tiav ib nrab.
- Kev txhaj tshuaj molding rau cov ntawv lossis qee yam duab.
- Kev siv tshuab ntawm cov pas nrig / phaj PEEK semi-finished kom raug rau qhov kev kam rau siab.
– Qee yam kev tsim khoom ntxiv (piv txwv li qib kev lag luam FFF/FGF) uas xav tau kev tswj qhov kub siab hauv chav luam ntawv kom txo qhov warpage thiab delamination.
Vim tias PEEK yog semicrystalline, qhov txias ntawm qhov cuam tshuam rau crystallinity, uas thaum kawg cuam tshuam rau qhov tawv, tshuaj lom neeg tsis kam, thiab qhov ruaj khov ntawm qhov ntev. Kev tswj qhov kub ntawm pwm thiab kev kho tom qab annealing feem ntau yog siv los ua kom tau cov khoom zoo tshaj plaws.
Cov ntawv thov PEEK hauv kev lag luam aerospace
Hauv kev siv tshuab aerospace, cov ntaub ntawv raug xaiv raws li lawv qhov sib piv ntawm lub zog thiab qhov hnyav, kev tiv taus cua sov, kev tiv taus hluav taws, kev tiv taus kua, thiab kev ntseeg tau mus sij hawm ntev. PEEK ua tau raws li ntau yam ntawm cov qauv no, tshwj xeeb tshaj yog hauv cov qib sib xyaw lossis qib tshwj xeeb.
1) Cov khoom sib txuas thiab cov brackets sib dhos
PEEK (tshwj xeeb tshaj yog carbon fiber-reinforced) yog siv rau cov brackets, clamps, thiab cov khoom txhawb nqa uas yav dhau los ua los ntawm txhuas lossis hlau hauv qee qhov chaw. Nws cov txiaj ntsig tseem ceeb yog txo qhov hnyav, tiv taus corrosion, thiab ruaj khov thaum lub sijhawm kub.
2) Lub kaw lus cable, cov khoom sib txuas thiab cov khoom rwb thaiv tsev
PEEK siv dav hauv cov insulators, connectors, thiab cable sheathing vim nws qhov dielectric stability thiab kub tsis kam. Hauv cov dav hlau niaj hnub no, uas siv hluav taws xob ntau zuj zus, qhov xav tau cov ntaub ntawv rwb thaiv tsev ua haujlwm zoo tseem niaj hnub loj hlob tuaj.
3) Cov kabmob, cov bushings, thiab cov khoom sib xyaw ua ke
Cov qib PEEK uas hloov kho nrog PTFE/carbon fiber feem ntau siv rau hauv cov bushings, washers, thiab lwm yam khoom sib txhuam. Cov ntaub ntawv no muaj kev tiv thaiv kev hnav zoo, kev sib txhuam qis, thiab kev ua haujlwm ruaj khov hauv qee qhov chaw tshuaj lom neeg.
4) Cov kev cai sab hauv dav hlau thiab FST
Rau sab hauv tsev, FST (hluav taws, pa luam yeeb, lom) cov qauv yog nruj heev. PEEK tuaj yeem tsim los ua kom tau raws li cov kev xav tau no, ua rau nws haum rau ntau yam kev siv sab hauv tsev, suav nrog cov khoom uas xav tau kev tiv taus cua sov thiab lub zog kho tshuab yam tsis ntxiv qhov hnyav ntau dhau.
5) Cov khoom sib xyaw thermoplastic rau cov qauv
Ib qho kev hloov pauv loj yog kev siv cov khoom sib xyaw ua ke carbon fiber matrix nrog PEEK (Carbon Fiber Reinforced PEEK/CFR-PEEK). Piv rau cov thermosets, cov thermoplastic composites muaj peev xwm rau kev vuam thermal, kev tsim khoom sai dua, thiab kev tiv thaiv kev cuam tshuam zoo. Hauv cov ntsiab lus aerospace, qhov no yog qhov zoo rau cov vaj huam sib luag, cov khoom ruaj khov, thiab qee qhov chaw uas xav tau kev sib xyaw ua ke ntawm kev tawv thiab kev muaj peev xwm tsim khoom zoo dua.
Cov teeb meem thiab kev xav txog kev siv PEEK hauv kev tsav dav hlau
Txawm hais tias nws muaj qhov zoo, PEEK ntsib ntau yam teeb meem. Ua ntej, cov khoom siv thiab cov nqi ua tiav siab dua vim yog qhov kub thiab txias ntawm kev ua tiav thiab cov kev cai tswj hwm zoo. Qhov thib ob, kev tsim cov khoom yuav tsum xav txog kev sib xyaw ua ke anisotropy thiab kev hloov pauv ntawm cov khoom vim yog kev taw qhia ntawm cov fiber lossis cov xwm txheej txias. Qhov thib peb, rau cov ntawv thov tau ntawv pov thawj, cov khoom siv thiab cov txheej txheem yuav tsum dhau ntau qhov kev sim thiab cov ntaub ntawv pov thawj.
Kev kaw
PEEK yog ib hom yas engineering zoo heev uas muaj kev sib xyaw ua ke ntawm lub zog, kev tiv taus cua sov, kev tiv taus tshuaj lom neeg, thiab lub peev xwm los ua cov thermoplastic. Nws cov txheej txheem tsim khoom suav nrog kev sib xyaw ua ke ntawm qhov kub siab nrog kev tswj hwm nruj ntawm qhov huv, stoichiometry, thiab kev rwb thaiv tsev ntawm cov khoom. Thaum pelleted thiab / lossis compounded, PEEK tuaj yeem tsim ua cov khoom los ntawm kev txhaj tshuaj molding, extrusion, machining, lossis ua cov carbon fiber matrix composite. Hauv kev lag luam aerospace, PEEK yog siv los txo qhov hnyav, txhim kho kev tiv taus corrosion, thiab ua tau raws li kev ua tau zoo thiab kev nyab xeeb, xws li brackets thiab insulators rau bearings thiab cov thermoplastic composites siab-ruaj khov. Nrog rau qhov sib txawv ntawm kev ua haujlwm zoo dua thiab kev siv hluav taws xob ntau ntxiv, lub luag haujlwm ntawm PEEK thiab nws tsev neeg ntawm cov thermoplastics ua tau zoo yuav txuas ntxiv mus loj hlob.
Yog tias koj xav tau, kuv tuaj yeem hloov kho tsab xov xwm no rau hauv cov qauv ntawv tshawb fawb (nrog rau cov lus hais thiab cov ntaub ntawv sau), lossis ntxiv cov ntu tshwj xeeb xws li cov txheej txheem txheej txheem (qhov kub thiab txias, kev tswj hwm crystallinity), cov ntaub ntawv kawm txog CFR-PEEK cov ntawv thov sib xyaw, lossis kev sib piv ntawm PEEK nrog PEI, PPS, thiab PTFE rau cov ntawv thov aerospace.
