Evaporation hauv lub tshuab nqus tsev
May 11, 2022| Evaporation hauv lub tshuab nqus tsev
Thaum cov hlau yog rhuab hauv lub tshuab nqus tsev, dej hauv qhov cub thiab nitrogen, oxygen, thiab carbon monoxide nyob rau hauv cov huab cua, tshwj xeeb tshaj yog cov roj thiab lwm yam impurities coated ntawm lub workpiece, evaporate thiab khiav ntawm qhov kub thiab txias. Thaum qhov kub nce mus txog 800 degree, decomposition gases ntawm hydrogen, nitrogen, thiab oxide yuav raug tso tawm ntawm qhov chaw ntawm lub workpiece kom tiav cov degassing. Vim lub thermal decomposition thiab tsim cov phenomenon ntawm evaporation dissipation tshem tawm cov pa phem nyob rau saum npoo ntawm lub workpiece, thiab oxide emissions, ua rau cov hlau backlight, qhov no yog ib tug nam thiab qhov zoo ntawm lub tshuab nqus tsev kho cua sov, tshwj xeeb tshaj yog muaj teeb meem gases. ci kev kho cua sov, thiab lwm yam, los txhim kho qhov zoo ntawm workpiece, qhov no yog lwm txoj kev kho cua sov tsis tuaj yeem muaj ob qho tib si.
Tsis tas li ntawd, raws li lub hauv paus theoretical ntawm lub tshuab nqus tsev evaporation txheej txheem, evaporation ntawm hlau nyob rau hauv lub nqus tsev vacuum tau zoo siv. Txawm li cas los xij, nyob rau hauv cov txheej txheem ntawm kev kho cua sov, nws feem ntau pom tias qhov chaw yog glued rau ib leeg, los yog nruab nrab ntawm qhov chaw thiab thav ntawv. Nyob rau hauv kev kho mob ntawm high chromium txias ua hauj lwm tuag steel los yog chromium stainless hlau, qhov saum npoo yog txiv kab ntxwv tev, ntxhib heev, thiab corrosion kuj yog ho txo. Cov no yog qhov tsis zoo ntawm lub tshuab nqus tsev kho cua sov - cov khoom evaporative ntawm cov hlau.
According to the phase equilibrium theory, the equilibrium pressure (vapor pressure) of the vapor acting on the metal surface is different at different temperatures. High temperature, high vapor pressure, and solid metal evaporation capacity is large; If the temperature is low, the vapor pressure is low, and if the temperature is certain, the vapor pressure is going to be certain. When the external pressure is less than the vapor pressure at this temperature, the metal evaporates (sublimation >tshwm sim. Camphor nyob rau hauv cov huab cua los ntawm sublimation los ntawm ib tug khoom mus rau hauv roj kom evaporate. Qhov qis dua sab nraud, lub tshuab nqus tsev siab dua, thiab nws yooj yim dua rau evaporate. Ib yam li ntawd, cov hlau uas muaj vapor siab dua yuav evaporate yooj yim dua.
Yog li ntawd, kev saib xyuas yuav tsum tau them rau evaporation hauv kev kho cua sov. Nws tsis yog ib qho kev xav tias cov txiaj ntsig zoo tuaj yeem ua tiav los ntawm kev nce qib ntawm lub tshuab nqus tsev. Kev saib xyuas yuav tsum tau them rau evaporation, nyob ntawm seb hom kev ua haujlwm. Ntawd yog, raws li qhov vapor siab thiab cua sov kub ntawm cov ntsiab lus hlau hauv cov khoom siv hlau yuav tsum tau kho thaum lub sij hawm kho cua sov, lub tshuab nqus tsev tsim nyog raug xaiv los tiv thaiv cov hlau alloy los ntawm evaporating thiab khiav.
Xws li cov ntsiab lus alloy Mn, Ni, Co, thiab Cr hauv cov hlau thiab hlau, nrog rau cov khoom tseem ceeb ntawm cov hlau tsis muaj hlau xws li Zn, Pb, thiab Cu, cua sov hauv lub tshuab nqus tsev yog ib qho yooj yim los tsim lub tshuab nqus tsev. evaporation, thiaj li hais tias lub workpiece adhesion ntawm ib leeg, thiab los ntawm cov khoom thav duab ua rau obstacles. Tsis tas li ntawd, Cu thiab Ag-Mn alloys (raws li cov hlau muab tub lim) tau siv rau lub tshuab nqus tsev ntawm cov hlau tsis huv. Mn tau evaporated thaum rhuab hauv qab no 0.0133Pa, thiab nws muaj pes tsawg leeg tau hloov pauv, ua rau muaj qhov txo qis hauv lub zog ntawm qhov chaw brazing. Nyob rau hauv cov ntaub ntawv ntawm lub tshuab nqus tsev annealing ntawm 70 mus rau 30 tooj dag, Zn yog ho evaporated, ua rau dezincification, yog li nws yog ib qho nyuaj heev kom tau ib tug kaj nto.
Txawm li cas los xij, ntau yam tsis xws luag tuaj yeem zam tau yog tias cov kev xaiv tau ua tau zoo. Xws li Cr12MoV txias stamping tuag steel, nyob rau hauv lub tshuab nqus tsev kawm ntawv ntawm 1.33pa, 1050 degree kub tom qab 90min, nrog X-ray microanalyzer txiav txim siab ntawm chromium nyob rau hauv qhov kev ncua deb ntawm qhov chaw ntawm 150μm nyob rau hauv kev faib, cov txiaj ntsig tsis pom qhov tshwm sim ntawm chromium tshem tawm. Qhov no yog vim hais tias, ntawm 1.33Pa, theoretical evaporation kub ntawm chromium yog 1205 degree. Thaum nyob rau ntawm 1050 degree, qhov sib thooj vapor siab yog tsawg, txog 0.0133Pa, uas yog, lub vapor siab yog qis dua lub siab sab nraud, yog li tsis muaj evaporation. Cov piv txwv qhia tau hais tias cov evaporation ntawm alloying ntsiab tuaj yeem tiv thaiv ntev npaum li lub tshuab nqus tsev kawm ntawv tsim nyog.
Nws yuav tsum tau muab sau tseg tias ib co ntau dua vapor siab ntsiab lus nyob rau hauv lub alloy, xws li Mn, Cu, Al, thiab lwm yam, feem ntau yog yaj los yog nyob rau hauv daim ntawv ntawm ntau yam tebchaw nyob rau hauv ib tug khoom tov, nyob rau hauv lub nqus tsev vacuum, lub cua sov volatilization txoj kev yog tsis. tib yam, tab sis lawv txoj kev nyiam yog tib yam, qhov tsis hloov pauv thiab feem ntau hais lus, lub vapor siab yog qis dua li cov hlau ntshiab vapor siab.
Tsis tas li ntawd, thaum cua sov hauv lub tshuab nqus tsev, nws tseem tuaj yeem txiav txim siab raws li cov khoom siv hlau, los ntawm cov roj purity siab inert (xws li, thim rov qab inflation) los kho lub tshuab nqus tsev hauv qhov cub, nrog rau cov cua sov uas tsis muaj lub tshuab nqus tsev los tiv thaiv cov evaporation ntawm alloy ntsiab. Tshwj xeeb tshaj yog nyob rau ntawm 1200 degrees
Thaum qhov kub thiab txias saum toj no yog rhuab, Cr, Mn thiab lwm yam muaj siab vapor siab, yooj yim rau evaporate, thiab xav tau cua sov tsawg dua. Los ntawm lub siab purity, inert gas tsis tau tsuas yog kho lub nqus tsev kawm ntawv tab sis kuj vim lub hav zoov ntawm inert gas, tsim ntawm lub convection voj voog, yog ntau conducive rau uniform cua sov ntawm cov ntaub ntawv hlau.
Yog li ntawd, nyob rau hauv lub tshuab nqus tsev kho cua sov, lub vapor siab ntawm hlau yog ib qho teeb meem uas yuav tsis raug ignored. Rau cov hlau hlau dav dav, ua ntej, qhov kub ntawm cov cua sov ntawm kev kho cua sov yog tsawg dua thaum nws ncav cuag 1200 degree; Qhov thib ob, feem ntau, kev txiav nyiaj ntawm lub workpiece tom qab kev kho cua sov yog ntau dua li cov thickness ntawm lub caij evaporation txheej, yog li qhov zoo ntawm lub workpiece tsis cuam tshuam. Txawm li cas los xij, rau qib tseem ceeb thiab tshwj xeeb steel, yuav tsum tau them nyiaj rau lub siab vapor.
IKS PVD tuam txhab, kho kom zoo nkauj txheej tshuab, cuab yeej txheej tshuab, DLC txheej tshuab, kho qhov muag txheej tshuab, PVD nqus txheej kab, txoj haujlwm tig-key yog muaj. Hu rau peb tam sim no, E-mail:iks.pvd@foxmail.com