Kev sib xyaw ua ke ntawm cov khoom siv ceramic thiab cov hlau

1. Kev ua kom kub hnyiab

Nws nyuaj rau braze ceramic thiab ceramic, ceramic thiab cov khoom siv hlau. Feem ntau ntawm cov solder tsim ib lub pob ntawm qhov chaw ceramic, nrog me ntsis lossis tsis muaj ntub. Cov hlau brazing filler uas tuaj yeem ntub ceramics yog yooj yim los tsim ntau yam brittle compounds (xws li carbides, silicides thiab ternary lossis multivariate compounds) ntawm qhov sib koom ua ke thaum lub sijhawm brazing. Qhov muaj cov tshuaj no cuam tshuam rau cov khoom siv kho tshuab ntawm qhov sib koom ua ke. Tsis tas li ntawd, vim muaj qhov sib txawv loj ntawm cov coefficients thermal expansion ntawm ceramic, hlau thiab solder, yuav muaj kev ntxhov siab seem hauv qhov sib koom ua ke tom qab qhov kub brazing txias rau chav tsev kub, uas yuav ua rau sib koom ua ke tawg.

Qhov ntub dej ntawm cov solder ntawm qhov chaw ceramic tuaj yeem txhim kho los ntawm kev ntxiv cov hlau nquag rau cov solder; Qhov kub qis thiab lub sijhawm luv luv brazing tuaj yeem txo qhov cuam tshuam ntawm qhov sib cuam tshuam interface; Qhov kev ntxhov siab thermal ntawm qhov sib koom ua ke tuaj yeem txo tau los ntawm kev tsim cov qauv sib koom ua ke thiab siv ib txheej lossis ntau txheej hlau ua txheej nruab nrab.

2. Siv cov khoom siv vuam

Feem ntau cov khoom siv ceramic thiab hlau txuas nrog lub tshuab nqus tsev lossis lub tshuab hydrogen thiab argon. Ntxiv rau cov yam ntxwv dav dav, cov hlau nplaum rau cov khoom siv hluav taws xob nqus tsev kuj yuav tsum muaj qee qhov kev cai tshwj xeeb. Piv txwv li, cov hlau nplaum yuav tsum tsis txhob muaj cov khoom uas tsim cov pa siab, kom tsis txhob ua rau muaj kev xau dielectric thiab cathode lom ntawm cov khoom siv. Feem ntau nws tau teev tseg tias thaum lub cuab yeej ua haujlwm, lub siab ntawm cov hlau nplaum yuav tsum tsis pub tshaj 10-3pa, thiab cov pa siab ntawm cov pa tsis huv uas muaj yuav tsum tsis pub tshaj 0.002% ~ 0.005%; Cov w (o) ntawm cov hlau nplaum yuav tsum tsis pub tshaj 0.001%, kom tsis txhob muaj cov dej ua pa thaum lub sijhawm ua haujlwm hauv hydrogen, uas yuav ua rau cov hlau nplaum yaj; Tsis tas li ntawd, cov hlau nplaum yuav tsum huv thiab tsis muaj cov oxides saum npoo.

Thaum brazing tom qab ceramic metallization, tooj liab, lub hauv paus, nyiaj tooj liab, kub tooj liab thiab lwm yam alloy brazing filler hlau siv tau.

Rau kev sib xyaw ncaj qha ntawm cov khoom siv ceramics thiab cov hlau, yuav tsum xaiv cov hlau sib xyaw uas muaj cov khoom siv Ti thiab Zr. Cov hlau sib xyaw binary feem ntau yog Ti Cu thiab Ti Ni, uas siv tau ntawm 1100 ℃. Ntawm cov khoom sib xyaw ternary, Ag Cu Ti (W) (TI) yog cov khoom sib xyaw siv ntau tshaj plaws, uas siv tau rau kev sib xyaw ncaj qha ntawm ntau yam khoom siv ceramics thiab cov hlau. Cov hlau sib xyaw ternary siv tau los ntawm ntawv ci, hmoov lossis Ag Cu eutectic filler hlau nrog Ti hmoov. B-ti49be2 brazing filler hlau muaj kev tiv thaiv corrosion zoo ib yam li cov hlau tsis xeb thiab lub zog vapor qis. Nws tuaj yeem xaiv tau zoo hauv cov pob qij txha nqus tsev nrog kev tiv thaiv oxidation thiab to. Hauv ti-v-cr solder, qhov kub yaj yog qhov qis tshaj plaws (1620 ℃) ​​thaum w (V) yog 30%, thiab ntxiv Cr tuaj yeem txo qhov kub yaj. B-ti47.5ta5 solder tsis muaj Cr tau siv rau kev sib xyaw ncaj qha ntawm alumina thiab magnesium oxide, thiab nws qhov sib koom ua haujlwm tuaj yeem ua haujlwm ntawm qhov kub ambient ntawm 1000 ℃. Rooj 14 qhia cov dej ntws nquag rau kev sib txuas ncaj qha ntawm cov khoom siv ceramic thiab hlau.

Rooj 14 cov hlau nplaum uas siv rau kev sib txuas ua los ntawm cov av nplaum thiab cov hlau

2. Kev siv tshuab txhuam

Cov khoom siv ua los ntawm cov khoom siv ua los ntawm cov hlau uas tau ua tiav lawm tuaj yeem raug txhuam rau hauv cov roj inert uas muaj cov pa roj ntshiab, hydrogen lossis qhov chaw nqus tsev. Feem ntau, kev txhuam los ntawm cov hlau nqus tsev yog siv rau kev txhuam ncaj qha rau cov khoom siv ua los ntawm cov hlau uas tsis muaj hlau.

(1) Cov txheej txheem brazing thoob ntiaj teb Cov txheej txheem brazing thoob ntiaj teb ntawm ceramic thiab hlau tuaj yeem muab faib ua xya txheej txheem: kev ntxuav qhov chaw, txheej nplaum, ceramic nto metallization, nickel plating, brazing thiab post weld tshuaj xyuas.

Lub hom phiaj ntawm kev ntxuav qhov chaw yog kom tshem tawm cov roj av, cov hws tawm thiab cov zaj duab xis oxide ntawm qhov chaw ntawm cov hlau puag. Cov khoom hlau thiab cov khoom siv solder yuav tsum tau degreased ua ntej, tom qab ntawd cov zaj duab xis oxide yuav tsum tau tshem tawm los ntawm kev ntxuav acid lossis alkali, ntxuav nrog dej ntws thiab ziab. Cov khoom uas muaj kev xav tau siab yuav tsum tau kho cua sov hauv lub tshuab nqus tsev lossis lub tshuab hydrogen (txoj kev ion bombardment kuj tseem siv tau) ntawm qhov kub thiab lub sijhawm kom huv si ntawm qhov chaw. Cov khoom ntxuav yuav tsum tsis txhob kov cov khoom roj lossis tes liab qab. Lawv yuav tsum tau muab tso rau hauv cov txheej txheem tom ntej lossis rau hauv lub tshuab ziab khaub ncaws. Lawv yuav tsum tsis txhob raug cua ntev. Cov khoom ceramic yuav tsum tau ntxuav nrog acetone thiab ultrasonic, ntxuav nrog dej ntws, thiab thaum kawg rhaub ob zaug nrog dej deionized rau 15 feeb txhua zaus.

Kev txheej nplaum yog ib qho txheej txheem tseem ceeb ntawm kev ua kom cov khoom siv ceramic metallization. Thaum lub sijhawm txheej, nws raug siv rau ntawm qhov chaw ceramic uas yuav tsum tau ua kom cov khoom siv ceramic metallization nrog txhuam lossis tshuab txheej nplaum. Lub thickness ntawm txheej feem ntau yog 30 ~ 60 hli. Cov nplaum feem ntau yog npaj los ntawm cov hmoov hlau ntshiab (qee zaum ntxiv cov hlau oxide tsim nyog) nrog qhov loj me ntawm kwv yees li 1 ~ 5um thiab cov nplaum organic.

Cov khoom siv ceramic uas tau muab tshuaj txhuam lawm raug xa mus rau lub cub tawg hydrogen thiab sintered nrog hydrogen ntub lossis ammonia tawg ntawm 1300 ~ 1500 ℃ rau 30 ~ 60 feeb. Rau cov khoom siv ceramic coated nrog hydrides, lawv yuav tsum tau cua sov txog li 900 ℃ kom decompose cov hydrides thiab react nrog hlau ntshiab lossis titanium (lossis zirconium) seem ntawm qhov chaw ceramic kom tau txais cov hlau txheej ntawm qhov chaw ceramic.

Rau Mo-Mn txheej hlau, txhawm rau ua kom nws ntub nrog cov hlau nplaum, ib txheej nickel ntawm 1.4 ~ 5um yuav tsum tau electroplated lossis coated nrog ib txheej ntawm nickel hmoov. Yog tias qhov kub brazing qis dua 1000 ℃, txheej nickel yuav tsum tau ua ntej sintered hauv lub cub tawg hydrogen. Qhov kub sintering thiab lub sijhawm yog 1000 ℃ / 15 ~ 20 feeb.

Cov khoom siv ua los ntawm cov av nplaum uas tau kho yog cov khoom ua los ntawm hlau, uas yuav tsum tau muab sib dhos ua ke nrog cov pwm hlau tsis xeb lossis graphite thiab cov pwm av nplaum. Yuav tsum tau muab cov khoom siv solder tso rau ntawm cov pob qij txha, thiab cov khoom ua haujlwm yuav tsum tau khaws cia kom huv si thoob plaws hauv kev ua haujlwm, thiab yuav tsum tsis txhob kov los ntawm tes liab qab.

Yuav tsum tau siv lub tshuab argon, hydrogen lossis lub tshuab nqus tsev kom sov. Qhov kub ntawm lub tshuab nyob ntawm seb lub hlau twg siv lub tshuab no. Yuav kom tiv thaiv tau qhov tawg ntawm cov khoom siv ceramic, qhov txias yuav tsum tsis txhob ceev dhau. Tsis tas li ntawd, lub tshuab no kuj siv tau qee qhov siab (kwv yees li 0.49 ~ 0.98mpa).

Ntxiv rau qhov kev tshuaj xyuas qhov zoo ntawm qhov chaw, cov vuam vuam kuj tseem yuav tsum raug kev tshuaj xyuas thermal shock thiab kev tshuaj xyuas cov khoom siv kho tshuab. Cov khoom sib khi rau cov khoom siv nqus tsev kuj yuav tsum raug kuaj xyuas qhov xau raws li cov cai tswjfwm cuam tshuam.

(2) Thaum brazing ncaj qha (txoj kev ua hlau nquag), ua ntej ntxuav qhov chaw ntawm cov khoom siv ceramic thiab hlau weldments, thiab tom qab ntawd sib sau ua ke. Txhawm rau kom tsis txhob muaj kab nrib pleb los ntawm cov coefficients thermal expansion sib txawv ntawm cov khoom siv tivthaiv, cov txheej buffer (ib lossis ntau txheej ntawm cov ntawv hlau) tuaj yeem tig ntawm cov weldments. Cov hlau brazing filler yuav tsum tau clamped ntawm ob lub weldments lossis muab tso rau ntawm qhov chaw uas qhov sib txawv puv nrog cov hlau brazing filler kom deb li deb tau, thiab tom qab ntawd brazing yuav tsum tau ua zoo li lub tshuab nqus tsev brazing.

Yog tias Ag Cu Ti solder siv rau kev sib txhuam ncaj qha, yuav tsum siv txoj kev sib txhuam nqus tsev. Thaum qhov degree nqus tsev hauv lub cub tawg ncav cuag 2.7 × Pib cua sov ntawm 10-3pa, thiab qhov kub tuaj yeem nce sai sai lub sijhawm no; Thaum qhov kub nyob ze rau qhov chaw yaj ntawm cov solder, qhov kub yuav tsum tau tsa qeeb qeeb kom qhov kub ntawm txhua qhov ntawm qhov vuam zoo ib yam; Thaum cov solder yaj, qhov kub yuav tsum tau tsa sai sai mus rau qhov kub brazing, thiab lub sijhawm tuav yuav tsum yog 3 ~ 5 feeb; Thaum lub sijhawm txias, nws yuav tsum tau txias qeeb qeeb ua ntej 700 ℃, thiab nws tuaj yeem txias ntuj nrog lub cub tawg tom qab 700 ℃.

Thaum Ti Cu cov khoom siv solder raug brazed ncaj qha, daim ntawv ntawm solder tuaj yeem yog Cu ntawv ci ntxiv rau Ti hmoov lossis Cu qhov chaw ntxiv rau Ti ntawv ci, lossis qhov chaw ceramic tuaj yeem coated nrog Ti hmoov ntxiv rau Cu ntawv ci. Ua ntej brazing, tag nrho cov hlau yuav tsum tau degassed los ntawm lub tshuab nqus tsev. Qhov kub degassing ntawm oxygen-free tooj liab yuav tsum yog 750 ~ 800 ℃, thiab Ti, Nb, Ta, thiab lwm yam yuav tsum tau degassed ntawm 900 ℃ rau 15 feeb. Lub sijhawm no, qhov degree nqus tsev yuav tsum tsis pub tsawg dua 6.7 × 10-3Pa. Thaum lub sijhawm brazing, sib sau ua ke cov khoom yuav tsum tau welded hauv lub fixture, cua sov lawv hauv lub tshuab nqus tsev rau 900 ~ 1120 ℃, thiab lub sijhawm tuav yog 2 ~ 5 feeb. Thaum lub sijhawm brazing tag nrho, qhov degree nqus tsev yuav tsum tsis pub tsawg dua 6.7 × 10-3Pa.

Cov txheej txheem brazing ntawm Ti Ni txoj kev zoo ib yam li Ti Cu txoj kev, thiab lub brazing kub yog 900 ± 10 ℃.

(3) Txoj kev siv oxide brazing Txoj kev siv oxide brazing yog ib txoj kev los ua kom muaj kev sib txuas zoo los ntawm kev siv cov iav theem tsim los ntawm kev yaj ntawm oxide solder los nkag mus rau hauv cov khoom siv ceramics thiab ua kom cov hlau ntub. Nws tuaj yeem txuas cov khoom siv ceramics nrog cov khoom siv ceramics thiab cov khoom siv ceramics nrog cov hlau. Cov hlau oxide brazing filler feem ntau yog tsim los ntawm Al2O3, Cao, Bao thiab MgO. Los ntawm kev ntxiv B2O3, Y2O3 thiab ta2o3, brazing filler hlau nrog ntau yam melting point thiab linear expansion coefficients tuaj yeem tau txais. Tsis tas li ntawd, fluoride brazing filler hlau nrog CaF2 thiab NaF ua cov khoom tseem ceeb kuj tseem siv tau los txuas cov khoom siv ceramics thiab cov hlau kom tau txais cov pob qij txha nrog lub zog siab thiab tiv taus kub siab.