Hauv aluminium casting-tshwj xeeb hauvTsawg Siab Tuag Casting (LPDC)- thermal shock resistance yog ib qho ntawm cov khoom tseem ceeb tshaj plaws. Cheebtsam xws li covaluminium titanate riser rajthiab lwm yam siab- qhov kub ntawm cov khoom siv ceramic yog raug rau cov cua kub ceev thiab cua txias. To taub covThermal shock mechanism ntawm Al₂TiO₅ (Aluminium Titanate)pab foundries xaiv txoj caial2TiO5 cevrau lub sij hawm ntev - stability thiab kev ua tau zoo.
1. Yog vim li cas thermal Shock Matters hauv LPDC
Nyob rau hauv LPDC systems, molten txhuas nyob ib ncig ntawm 680-750℃yog pheej thauj mus los ntawm ib tug riser raj los ntawm lub tuav rauv rau hauv pwm. Thaum lub sijhawm ua haujlwm, lub raj muaj kev paub txog:
Sudden kub gradients
Intermittent hlau sib cuag
Rauv pib- nres cycles
Localized kub chaw
Ib tug pa ceramic riser raj yuav tawg vim thermal stress accumulated. Thaum micro- tawg tawm, xau, oxidation, thiab ntau lawm downtime ua raws. Tias yog vim li cas xaiv cov khoom siv rau ib qhoaluminium titanate riser rajyog qhov tseem ceeb.
2. Cov Khoom Siv Crystal Cim ntawm Al₂TiO₅
Qhov tshwj xeeb thermal shock tsis kam ntawm Al₂TiO₅ yog los ntawm nwsanisotropic siv lead ua qauv.
Aluminium Titanate muaj:
Tsawg nruab nrab thermal expansion coefficient (~ 1 × 10⁻⁶ / K)
Strong directional expansion sib txawv nyob rau hauv nws siv lead ua lattice
Microcrack- tswj cov qauv sab hauv
Qhov no tswj microcracking mechanism yog tus yuam sij rau kev nkag siab vim li cas ib qhoal2TiO5 cevciaj sia qhov kub hloov pauv.
3. Microcrack Toughening Mechanism
Tsis zoo li cov tsoos ceramics uas ua rau muaj kev puas tsuaj loj thaum muaj kev ntxhov siab, Al₂TiO₅ tsim lub network ntawm microscopic tawg thaum lub caij txias tom qab sintering.
Cov microcracks no:
Absorb thermal lim
Txo kev ntxhov siab sab hauv
Tiv thaiv kom tawg loj propagation
Txo cov elastic modulus zoo
Thaum muaj qhov kub thiab txias hloov tam sim ntawd, lub pre{0}}cov qauv microcrack uas twb muaj lawm ua rau "kev ntxhov siab tsis zoo." Tsis txhob xav txog kev ntxhov siab hauv ib cheeb tsam, nws disperses zog thoob plaws hauv cov khoom.
Rau ibaluminium titanate riser rajHauv LPDC casting, qhov no txhais tau tias:
Tsawg qhov kev pheej hmoo ntawm kev tawg sai sai
Kev tiv thaiv ntau dua rau cov cua kub ceev
Qhov kev ua haujlwm ruaj khov ntawm qhov kev ua tau zoo tshaj qhov rov ua dua
4. Tsawg Thermal Expansion=Tsawg Thermal Stress
Thermal stress (σ) yog proportional rau:
Elastic modulus × thermal expansion coefficient × kub hloov
Al₂TiO₅ ib txwm txo qis ob ntawm cov xwm txheej no:
Tsawg thermal expansion coefficient
Txo qhov ua tau zoo modulus vim microcracking
Yog li ntawd, txawm tias nyob rau hauv cov cua kub ceev thaum molten aluminium nkag mus rau hauv lub raj, qhov kev ntxhov siab nyob rau hauv ib qhoal2TiO5 cevtseem qis dua li cov khoom siv refractory pa.
Qhov no yog vim li cas Aluminium Titanate tau siv dav hauvLPDC ceramic riser rajdaim ntawv thov.
5. Kev ua tau zoo hauvAluminium Titanate Riser Tubes
Hauv LPDC qhov chaw tsim khoom tiag tiag, qhov siab - zooaluminium titanate riser rajmuab:
Kev tiv thaiv zoo heev los pib- nce thermal shock
Txo qhov tawg ntawm flange thiab qhov chaw sib koom ua ke
Lub neej ua haujlwm ntev dua
Stable molten hlau ntws
Tsawg txij nkawm ntau zaus
Piv nrog rau cov ntaub ntawv uas muaj ntau dua expansion coefficients, lub Al₂TiO₅ raj tswj kev ncaj ncees ntawm cov qauv txawm tias tom qab rov ua dua.
6. Kev txwv thiab cov khoom siv kom zoo
Thaum Aluminium Titanate muaj cov thermal shock tsis kam, nws muaj qhov nruab nrab cov neeg kho tshuab lub zog piv rau qee cov ceramics siab heev. Yog li, kev tsim khoom zoo yog qhov tseem ceeb:
Tswj sintering kub
Optimized grain loj faib
Cov tshuaj tiv thaiv ntxiv (yog tias xav tau)
Precision machining rau LPDC riser raj qhov ntev
Tsuas yog tsim kho kom raugaluminium titanate riser rajtuaj yeem siv tag nrho cov thermal shock mechanism ntawm Al₂TiO₅.
Xaus
Lub thermal poob siab tsis kam ntawm Al₂TiO₅ tsis yog xwm txheej - nws yog qhov tshwm sim ntawm nws cov cim crystal anisotropy thiab microcrack toughening mechanism. Qhov kev ntxhov siab sab hauv no -cov qauv nyem ua raual2TiO5 cevtshwj xeeb tshaj yog tsim nyog rau kev thov LPDC daim ntawv thov.
Rau cov foundries tsom rau aluminium casting efficiency, durability, thiab txheej txheem stability, to taub lub thermal shock mechanism ntawm Aluminium Titanate yog qhov tseem ceeb. Xaiv lub siab - zooaluminium titanate riser rajtsim tshwj xeeb rau LPDC cov xwm txheej ua kom lub sijhawm ntev - kev ntseeg siab thiab ua kom zoo tshaj qhov ua tau zoo.
