PTFE yog cov khoom siv tau zoo heev vim nws muaj cov khoom sib xyaw tshwj xeeb.PTFE yog chemically inert, weatherable, zoo heev hluav taws xob rwb thaiv tsev, kub tsis kam, tsis tshua muaj coefficient ntawm kev sib txhuam thiab tsis-nplaum zog.
Polymers feem ntau siv hauv kev tsim khoom thiab kev tsim vaj tsev, txawm li cas los xij, luam tawm kev tshawb fawb piav qhia txog lawv cov khoom siv tshuab zoo li tsis muaj npe vim lawv qhov tseem ceeb.Ntau ntawm cov ntaub ntawv uas tau nthuav tawm, tag nrho ib yam nkaus thiab feem ntau muab cov ntaub ntawv tsis txaus txog qhov tseeb pedigree ntawm cov polymer kuaj thiab nws cov keeb kwm ua tiav.Qhov no yog vim li cas thiaj li tsim kom muaj lub hauv paus-kab cov yam ntxwv ntawm cov khoom siv feem ntau nyuaj li ua qhov kev sim ntsuas qhov tseeb.Tsis tas li ntawd, kev ua qauv hauv computer kom raug ntawm cov khoom siv hluav taws xob polymer yog tseem nyob hauv nws cov me nyuam mos.Muaj ntau txoj hauv kev empirical feem ntau ua haujlwm, tab sis lawv zoo li tsis raug sab nraud ntawm qhov nqaim qhov ntau.Ib qho laj thawj rau qhov no, ib sab ntawm qhov nyuaj ntawm cov lus teb polymer, feem ntau cov ntaub ntawv tsis muaj nyob sab nraud ntawm qhov kev sim nqaim ntau yam los tawm tsam thiab nthuav tawm qhov muaj zog ntawm empirical lossis phenomenological raws li cov qauv tsim.Ntawm no, peb nthuav tawm thawj cov txiaj ntsig ntawm kev sib koom ua ke ntau txoj kev qhuab qhia txhawm rau nkag siab txog cov lus teb ntawm cov khoom siv polymer zoo los ntawm ob qho tib si kev sim pom thiab tom qab ntawd, nrog rau kev tsim cov qauv theoretical muaj peev xwm ua tau raws li cov lej hauv computer. .
Cov polymer uas tau piav qhia hauv txoj kev tshawb no yog poly (tetrafluoroethylene) (PTFE).Nws tau raug xaiv los ntawm ntau qhov laj thawj, suav nrog nws siv los ua cov khoom siv engineering rau cov khoom me me thiab nws muaj los ntawm ntau lub tuam txhab.Thaum kawm ntau dhau los, nws tau txais kev mloog me ntsis hauv cov ntaub ntawv qhib rau 25 xyoo dhau los.Peb tau xaiv los rov xyuas cov khoom siv no vim nws cov txheej txheem nyuaj thiab tsis muaj cov ntaub ntawv siv tshuab.PTFE yog cov khoom siv zoo heev hauv ntau txoj hauv kev.Nws nthuav tawm cov khoom muaj txiaj ntsig tshaj qhov kub tshaj plaws ntawm txhua lub polymer;PTFE khaws ib co kev ntsuas ntawm ductility ntawm 4 K thiab nyob rau hauv tej lub sij hawm yog siv nyob rau hauv daim ntaub ntawv ntawm 540 8C .Nws yog insoluble nyob rau hauv tag nrho cov hnyav hnyav thiab yog resistant rau yuav luag tag nrho cov acidic thiab caustic ntaub ntawv.PTFE muaj nyob rau hauv lub siab tshaj plaws resistivity ntawm tej yam khoom, ib tug heev dielectric zog thiab tsawg dielectric poob.Lub coefficient ntawm zawv zawg kev sib txhuam ntawm PTFE thiab ntau yam khoom siv engineering yog qhov tsawg heev thiab thaum sintered nrog hnav txo cov tebchaw, ib chav kawm tseem ceeb ntawm cov khoom siv bearing yog tsim.Ua ke nrog nws cov coefficient qis ntawm kev sib txhuam thiab tshuaj lom neeg ruaj khov, PTFE yuav luag tsis yooj yim rau lwm cov ntaub ntawv ua raws.Cov cuab yeej no feem ntau yog siv rau hauv kev lag luam ua tshuab uas yooj yim ntawm kev ntxuav yog qhov tseem ceeb.Ib qho ntawm PTFE uas tau tuav nws rov qab los ntawm kev lag luam thiab kev siv engineering ntau dua yog nws cov viscosity siab (1011 P ntawm 380 8C).Qhov no tiv thaiv kev txhaj tshuaj thiab tshuab moulding los ntawm kev ua tau thiab tsuas yog kim sintering thiab extrusion manufacturing txheej txheem muaj rau ib feem ntau lawm.
Daim ntawv no tsom mus rau lub hauv paus-kab cov yam ntxwv ntawm cov khoom siv thiab cov lus teb ntawm cov ntaub ntawv PTFE pedigreed ntawm qhov sib txawv-tus nqi thiab qhov kub thiab txias.Cov ntaub ntawv yav tom ntej yuav cuam tshuam nrog tensile thiab shear teb, cov ncauj lus kom ntxaws los ntawm polymer crystallinity, ballistic thiab poob siab tus cwj pwm thiab kev txhim kho ntawm cov qauv siv theoretical constitutive.
Kev tshawb fawb me me dhau los ntawm cov khoom compressive ntawm PTFE tau raug luam tawm.Qee qhov kev tshawb fawb ntawm cov khoom creep muaj tshwm sim, tab sis hais txog engineering deformation, tsuas yog rau tus neeg siv tau tuaj rau cov neeg sau ntawv.Xyoo 1963, Davies tau luam tawm ib daim ntawv qhia txog kev txhim kho ntawm Split-Hopkinson bar system.Raws li ib feem ntawm tsab ntawv ceeb toom no, ib chav tsev kub ntxhov siab / lim nkhaus rau PTFE tau nthuav tawm ntawm z1700 sK1 .Qhov siab tshaj plaws ntawm kev tswj hwm hauv qhov system no tsuas yog 3%.Ntxiv cov ntaub ntawv highstrain tus nqi ntawm polymer piv rau qhov kub thiab txias tau luam tawm los ntawm Grey thiab Walley .Koo luam tawm cov ntaub ntawv kev ntxhov siab / lim rau Imperial Chemical Industries PTFE cov khoom hu ua Halon G-80 hauv xyoo 1965.Cov teebmeem ntawm qhov kub thiab txias ntawm cov neeg kho tshuab teb kuj tau tham luv luv.
Post lub sij hawm: Aug-16-2016