Dej iav Kev nqis peev Casting txheej txheem

Kev nqis peev casting, tseem hu ua poob-wax casting, yog cov txheej txheem tsim khoom siv los tsim cov hlau nyuaj uas muaj qhov ua tiav zoo thiab qhov tseeb. Ntawm ntau yam peev txheej casting, dej iav peev casting (tseem hu ua sodium silicate{2}}bonded casting) sawv tawm rau nws cov nqi-kev ua tau zoo thiab kev ua tau zoo, tshwj xeeb tshaj yog rau me me mus rau nruab nrab-sized ntau lawm khiav.



Dej iav peev casting siv sodium silicate (Na₂SiO₃) raws li ib tug binder rau ceramic shells, muab ib tug ntau yig dua lwm txoj rau ethyl silicate - raws li systems. Cov txheej txheem ua tiav muaj rau rau theem tseem ceeb:



1.1 Tus Qauv Tsim

• Wax los yog 3D- cov qauv luam tawm polymer yog tsim nyob rau hauv qhov tseeb ntawm qhov xav tau

• Ntau tus qauv raug sib sau ua ke rau hauv lub hauv paus wax sprue los ua ib pawg casting



1.2 Shell Building

• Cov pawg tau dipping hauv sodium silicate tov (Be℃38-42 ntawm 20 degree)

• Tam sim ntawd stuccoed nrog cov ntaub ntawv refractory (feem ntau zircon hmoov rau cov tsho loj, ua raws li fused silica rau cov tsho tiv no)

• Txhua txheej yuav tsum tau 4-6 teev kom qhuav lub sij hawm ntawm kev tswj cov av noo (40-60% RH)



1.3 Kev txiav txim siab

• Cov pawg coated yog flash- tua ntawm 850-950℃rau 15-30 feeb

• Ib txhij hlawv tawm cov ciab thiab hloov sodium silicate rau ib daim ntawv cog lus ceramic



1.4 Hlau Pouring

• Preheated pwm (200{1}}400 degree) tau txais hlau molten los ntawm lub ntiajteb txawj nqus los yog nqus-pab pouring

• Cov alloys feem ntau muaj xws li carbon steels (1020-1045), stainless hlau (304/316), thiab txhuas alloys



1.5 Plhaub tshem tawm

Tom qab solidification, lub plhaub ceramic raug tshem tawm los ntawm:

• Mechanical vibration

• Siab - dej blasting

• Tshuaj lom neeg (5-10% NaOH tov rau cov residue tawv tawv)



1.6 Kev ua tiav tiav

• Txiav-tawm: Kev sib cais ntawm tus kheej castings los ntawm sprue

• Sib tsoo: Tshem tawm cov khoom seem ntawm lub rooj vag

• Kev kho cua sov: Kev ntxhov siab los yog kev daws teeb meem annealing raws li xav tau



Cov txiaj ntsig tseem ceeb suav nrog:



• 60-70% ceev plhaub ntau lawm piv rau ethyl silicate



• 40% qis dua cov nqi khoom siv



• Haum rau siab -melting- taw tes alloys (txog 1600 degree)



• Environmentally friendlier chemistry



3.1 Plhaub Strength Optimization

• Tswj Na₂O:SiO₂ molar ratio ntawm 1:2.0-2.4



• Tswj kom qhuav chav sov ntawm 22 ± 2 degree



• Txwv lub plhaub tuab rau 6-10mm nyob ntawm qhov loj me



3.2 Kev Tiv Thaiv Tsis Zoo

• Gas porosity: Siv lub tshuab nqus tsev degassing thaum pouring



• Kev suav nrog: Siv 80-100 mesh cov ntxaij lim dej hauv cov kav dej



• Cov kab nrib pleb: Ua kom zoo pwm preheating (kev tiv thaiv thermal shock)



• Automotive: Turbocharger vaj tse, cov khoom sib kis



• Twj/Valve: impellers, valve lub cev, hydraulic qhov chaw



• Kev Kho Mob: Orthopedic instrument prototypes



• Zog: Gas turbine hniav prototypes



• Tsawg qhov tseeb vs. qib siab binder systems (± 0.75mm vs ± 0.25mm)



• Plhaub brittleness yuav tsum tau ceev faj tuav



• Tsis zoo tagnrho rau superalloys uas yuav tsum tau purity heev



• Hybrid binders: Muab cov iav dej nrog colloidal silica rau kev txhim kho lub zog



• Additive manufacturing integration: 3D- luam tawm pwm nrog dej iav txheej



• AI-tsav ziab kom qhuav: Predictive algorithms optimizing humidity/temperature





Dej iav peev casting tseem yog qhov kev lag luam zoo tshaj plaws rau kev tsim cov khoom ntau ntawm 100-10,000 daim. Kev nce qib tsis ntev los no hauv kev tswj cov txheej txheem thiab cov khoom siv tshawb fawb txuas ntxiv nthuav dav nws cov peev xwm hauv cov khoom lag luam muaj txiaj ntsig siab.



Kev tswj xyuas kom zoo thiab kev tiv thaiv kev tiv thaiv tsis zoo tuaj yeem tsim cov castings uas ua tau raws li ISO 8062 GDCT4-6 cov qauv kev ua siab ntev thaum tuav cov nqi sib tw.