Porosity yog ib qho kev sib xws hauv cov xuab zeb, tsis zoo cuam tshuam cov khoom siv tshuab, siab nruj me ntsis, thiab saum npoo. Nws tshwm sim los ntawm cov pa nkag, shrinkage, lossis cov neeg tsis raug xws li tuaj pwm.
1. Nkag siab porosity tsim
Pority nyob rau hauv Aluminium castings tuaj yeem muab faib ua ob hom tseem ceeb:
Porosity Porosity: tshwm sim los ntawm hydrogen nqus thaum melting lossis noo noo decomposition hauv pwm.
Shrinkage Porosity: tshwm sim vim muaj kev pub mis tsis txaus thaum lub sijhawm sandolification, ua rau voids.
Txheeb xyuas cov hauv paus hauv paus ua rau yog qhov tseem ceeb rau kev xaiv cov txheej txheem kev tso cai kom haum.
2. Melting thiab hlau kho
a. Degassing Techiques
Degassing: txhaj cov roj av (Arcon lossis nitrogen) los ntawm kev sib hloov hloov impeller tshem tawm cov hydrogen.
Fluxing cov neeg sawv cev: chloride fluoses (piv txwv li, Hexachatheane) (Txo cov ntsiab lus hydrogen
Nqus Plawv: Muaj txiaj ntsig zoo rau kev loj ncaj ncees nrib tab sis nce cov nqi ntau lawm.
b. Alloy Composition Kev Tswj Xyuas
Silicon cov ntsiab lus hloov kho: hypoutectic al-Si alloys (piv txwv li, A356) pom zoo cov yam ntxwv pub dawb, txo cov yam ntxwv zoo
Cov tshuaj ntsuab (tib₂, Al-Ti-b): Txhawb nqa cov qauv nplej zoo, txo cov microspority.
3. Pwm thiab Cov Ntsiab Lus Ua Kom Zoo
a. Kev Xaiv Xuab Zeb
Tsawg-noo noo Resins: Phenolic Urethane lossis Furan Binders txo cov roj ntau tiam piv rau cov xuab zeb ntsuab.
Inorganic binders (piv txwv li, sodium silicate / cated 15): Tshem tawm cov roj organic roj tab sis yuav xav tau cov pwm muaj zog.
b. Pwm Qhov Chaw Tsim Tshuaj
Kev Ua Yeeb Ncees Tsim Tshuaj: Cov neeg siv hluav taws xob uas muaj kev tso cai khiav tawm ntawm cov pa roj kom dim ua ntej cov solerification ua ntej.
Kev tswj kav dej: Kev pom cov xuab zeb zoo tshaj plaws loj (AFS 50-70) cov nqi zog thiab roj permeability.
c. Pwm Kom Qhuav Thiab Preheating
Baking Cores: Cov pwm cua sov rau 150-200 degree tshem tawm cov dej noo uas muaj kev cia siab.
Pwm ce: Refractory choneings (piv txwv li, zirconia) txo cov tshuaj tiv thaiv hlau thiab roj.
4. Solidification thiab Pub Cov Tswv Yim
a. Riser tsim
Directional Solidification: siv risaped ua kom muaj txiaj ntsig ua kom muaj kev sib tw ua ntu zus mus rau tus feeder.
Exothermic riser Tsho Tsho: ncua sijhawm pub mis, txo qis shrinkage voids.
b. Chilling Techniques
Nws yog xim hlau chills: nrawm txias txias hauv cov ntu tuab, txo cov virtage porcase.
Cov nqi cua txias: Cov me nyuam txias hauv cov ntu nyias tiv thaiv kev ua kua kub.
5. Txheej Txheem xyuas xyuas thiab tswj kev nyab xeeb
Tiag tiag-lub sij hawm hydrogen kuaj: txo cov kev ntsuas siab (RPT) lossis xovtooj Telegas saib zoo li yaj.
X-ray soj ntsuam: kuaj pom sab hauv cov nplaim pleev rau cov khoom siv hluav taws xob siab.
Txheej txheem simulation (MagmasToft,, Print): Kev kwv yees shrinkage thiab kev ua kom zoo tshaj plaws / riser tsim.
Tag
Txo porcase hauv aluminos hauv almitt ua kom tau txoj kev ze, suav nrog MlT kev kho, cov pwm ua kom zoo nkauj, thiab tswj tau zoo. Sib txuas ua ke degassing, venting kom raug, thiab kev qhia ua kom zoo tshaj plaws tau txhim kho casting kev ncaj ncees. Cov cuab yeej sim cais ntxiv ntxiv cov txheej txheem ua kom tsis txhob muaj kev txwv, ua kom muaj cov khoom siv zoo, muaj cov khoom siv hauv tsheb thiab cov ntawv thov aerospace.
