Kev Ua Tau Zoo ntawm Dawb Fused Alumina hauv Kev Nqis Peev Casting
1. Cov Khoom Siv Peev Txheej Casting Plhaub
Dawb fused aluminayog tsim los ntawm kev sib xyaw cov alumina zoo hauv kev lag luam ntawm qhov kub siab tshaj 2000°C. Nws muaj kev ntshiab tshwj xeeb (α-Al₂O₃cov ntsiab lus > 99–99.6%) thiab qhov siab refractoriness ntawm 2050°C–2100°C, nrog rau qhov coefficient ntawm thermal expansion qis (kwv yees li 8×10⁻⁶/°C). Cov khoom no ua rau nws yog ib qho kev xaiv zoo heev rau cov xuab zeb zircon ib txwm muaj ua cov khoom siv plhaub tseem ceeb rau kev nqis peev casting. Nws cov khoom sib xws siab (qhov loj me ntawm cov noob faib > 95%) thiab kev sib kis zoo pab tsim cov pwm denser, ruaj khov dua, txhim kho qhov chaw casting tiav thiab qhov tseeb ntawm qhov ntev thaum txo cov nqi tsis zoo.
2. Kev Txhawb Nqa Pwm
Nrog rau Mohs hardness ntawm 9.0 thiab kev khaws cia lub zog kub zoo heev (tswj kev ncaj ncees saum 1900°C),dawb fused aluminantev lub neej ua haujlwm pwm los ntawm 30–50%. Thaum siv rau hauv pwm lossis cores rau hlau cam khwb cia, hlau cam khwb cia, lossis cov hlau tsis yog ferrous, nws zoo tiv taus kev yaig ntawm cov hlau ntws thiab txo qhov zaus ntawm kev kho thiab kev saib xyuas.
Cov txiaj ntsig ntawm Dawb Fused Alumina
(1) Kev Ruaj Ntseg Kub Siab
Dawb fused aluminamuaj kev ruaj khov zoo heev thaum lub sijhawm ua haujlwm casting. Nws cov coefficient thermal expansion yog li ib feem peb ntawm cov ntaub ntawv ib txwm muaj, pab tiv thaiv pwm tawg lossis casting deformation vim muaj kev hloov pauv kub sai. Nws cov pa roj tsawg (kev tso pa roj <3 ml/g) txo cov porosity thiab blowhole defects.
(2) Qhov Zoo ntawm Kev Ua Tiav Nto
Thaum siv ua hmoov txhuam zoo (qhov loj me ntawm 0.5–45μm),dawb fused aluminamuab kev sib xws, txawm tias kev txhuam uas tuaj yeem ua tiav qhov roughness ntawm casting ntawm Ra <0.8μm. Nws qhov xwm txheej uas ua rau nws tus kheej ntse (qhov tawg < 5%) ua kom muaj kev txiav zoo thiab ruaj khov.
(3) Kev Hloov Kho Tau Raws Li Txheej Txheem
Peb muaj cov noob hloov kho tau qhov loj me ntawm F12 txog F10000 kom haum rau ntau yam txheej txheem casting:
Cov qib ntxhib (F12–F100): Rau kev tso pwm tawm hauv cov qauv nyuaj, ua rau kom muaj kev vam meej ntawm kev rhuav pwm ntau dua 25%.
Cov qib zoo (F220–F1000): Rau kev tsim cov khoom siv ceramic uas muaj qhov tseeb siab nrog kev ua kom nruj li±0.1 hli.
3. Tus Nqi Txhim Kho Cov Txheej Txheem
(1) Kev Siv Nyiaj Tau Zoo
Hloov cov xuab zeb zircon nrogdawb fused alumina tuaj yeem txo cov nqi khoom siv los ntawm 30–40%. Nws kuj tseem ua rau lub plhaub tuab kom raug txo los ntawm 15–20% (qhov tuab ntawm lub plhaub ib txwm muaj: 0.8–1.2 mm), ua kom lub voj voog tsim plhaub luv dua.
(2) Cov txiaj ntsig ntawm ib puag ncig
Nrog cov hlau hnyav tsawg heev (< 0.01%), alumina dawb fused ua tau raws li ISO 14001 tus qauv ib puag ncig. Cov xuab zeb pov tseg yog 100% rov ua dua tshiab thiab tuaj yeem siv dua hauv kev tsim khoom refractory.
Cov Ntawv Thov Uas Tau Pom Zoo
Cov khoom siv no tau siv dav hauv cov teb qib siab xws li cov hniav turbine aerospace thiab cov khoom siv kho mob precision castings. Cov xwm txheej ib txwm qhia tau tias nws tuaj yeem ua rau cov khoom dhau los ntawm 85% mus rau 97%.