Silicon hlauNyob rau hauv Aluminium Alloy Production: Vim li cas Si Yog Tus Tswv Alloying Element

Silicon hlau - kuj hu uaindustrial siliconlos yogmetallurgical-qib silicon- yog ib qho tseem ceeb tshaj plaws alloying ntxiv rau txhuas. Los ntawm kev tsim cov theem nyuaj intermetallic thiab txo qhov melting point ntawm aluminium -silicon eutectic, nws transforms mos, corrosion-nruj ntshiab txhuas rau hauv castable, siab -lub zog alloys siv nyob rau hauv automotive powertrains, tsim extrusion, thiab aerospace qauv thoob ntiaj teb.

Kev lag luam aluminium thoob ntiaj teb siv ntau lab tonnes ntawmsilicon hlautxhua xyoo, thiab feem ntau ntawm qhov kev thov no yog los ntawm ib daim ntawv thov: alloying. Tsis zoo li cov hlau, qhov chaw alloying muaj ntau heev thiab feem ntau sib hloov tau, aluminium cia siab rau silicon raws li nws tus tswv alloying tus khub. Cov laj thawj yog ob qho tib si metallurgical thiab kev lag luam. Silicon muaj ntau, tus nqi - zoo, thiab - qhov tseem ceeb tshaj plaws - nws muab kev sib xyaw ua ke ntawm castability, mechanical zog, corrosion resistance, thiab thermal stability uas tsis muaj lwm yam khoom tuaj yeem rov ua dua ntawm tus nqi sib piv. Kab lus no tshuaj xyuas cov txheej txheem metallurgical tom qab silicon lub luag haujlwm, cov tsev neeg hlau tshwj xeeb uas nyob ntawm nws, thiab kev tswj hwm kev lag luam.silicon hlaukev xaiv rau aluminium ntau lawm.

 

 

Metallurgical Mechanisms: Yuav ua li cas Silicon Transforms Aluminium

Aluminium -silicon binary system yog ib qho ntawm feem ntau kawm hauv metallurgy, thiab yog vim li cas. Ntshiab aluminium yog mos, tsis muaj zog, thiab muaj kev hnav tsis zoo. Silicon, thaum yaj los yog dispersed nyob rau hauv lub txhuas matrix, fundamentally hloov cov khoom los ntawm ob peb txawv mechanisms.

Eutectic Tsim thiab Fluidity Enhancement

Cov aluminium -silicon eutectic tshwm sim ntawm kwv yees li 12.6% silicon los ntawm qhov hnyav thiab yaj ntawm kwv yees li 577 degrees Celsius - qis dua li cov ntshiab aluminium qhov melting point ntawm 660 degrees Celsius. Thaum silicon ntxiv rau txhuas nyob rau hauv 5-12% ntau yam, lub resulting alloy exhibits zoo heev fluidity thaum lub sij hawm casting. Lub xub ntiag ntawm qhov qis- melting eutectic theem tso cai rau cov hlau molten ntws mus rau hauv nyias- cov phab ntsa pwm thiab cov geometries nyuaj uas yuav ua tsis tau nrog txhuas tsis muaj hlau. Cov cuab yeej no ua rau silicon{12}}cov kabmob alloys tseem ceeb rau kev siab -siab tuag casting ntawm cav blocks, kis vaj tse, thiab cov khoom siv hauv tsheb.

Ntxiv dag zog los ntawm cov theem intermetallic

Silicon tsis tsim ib qho kev daws teeb meem txuas ntxiv nrog txhuas hla txhua qhov sib xyaw ua ke. Xwb, thawj silicon hais los yog eutectic silicon lamellae precipitate thaum solidification. Cov txheej txheem nyuaj, nkig silicon ua raws li cov khoom siv ntxiv nyob rau hauv lub softer aluminium matrix, nce tensile zog, hardness, thiab hnav tsis kam. Qhov loj me, morphology, thiab kev faib tawm ntawm cov khoom siv silicon yog tswj los ntawm cov khoom siv casting, yaj kev kho nrog sodium los yog strontium modifiers, thiab kev kho cua sov tom qab. Fine, fibrous eutectic silicon - ua tiav los ntawm kev hloov kho - yields superior mechanical zog piv rau ntxhib, phaj-zoo li cov qauv tsis hloov.

Thermal Expansion thiab Dimensional Stability

Lwm qhov feem ntau- saib tsis pom qhov txiaj ntsig ntawm silicon hauv aluminium alloys yog qhov txo qis ntawm cov thermal expansion coefficient. Automotive pistons thiab lub tog raj kheej taub hau ua haujlwm nyob rau hauv lub caij ntuj sov hnyav, thiab kev nthuav dav ntau dhau tuaj yeem ua rau kev tshem tawm, scuffing, thiab ua tsis tiav ntxov. Silicon-cov kabmob aluminium alloys nthuav tawm qis dua thermal expansion dua li cov ntshiab aluminium, txhim kho qhov ruaj khov thiab ua kom nruj dua tsim kev kam rau siab hauv siab - daim ntawv thov kub.

Corrosion Resistance nyob rau hauv Marine thiab Atmospheric Exposure

Thaum silicon nws tus kheej tsis yog tshwj xeeb yog corrosion-resistant nyob rau hauv acidic ib puag ncig, nws muaj nyob rau hauv txhuas alloys yuav txhim kho tag nrho corrosion kev ua tau zoo nyob rau hauv nruab nrab thiab me me alkaline tej yam kev mob. Silicon-nplua nuj zaj duab xis uas tsim thaum lub sij hawm ntuj oxidation tuaj yeem ua teeb meem rau kev tawm tsam huab cua ntxiv. Hauv kev siv dej hiav txwv thiab ntug dej hiav txwv, 6xxx series alloys - uas ua ke nrog silicon nrog magnesium - muaj kev tiv thaiv zoo heev rau ntsev tsuag thiab atmospheric corrosion, ua rau lawv cov khoom xaiv rau lub qhov rais thav duab, kab hlau rhuav phab ntsa, thiab cov txheej txheem extrusion nyob rau hauv ib puag ncig hnyav.

Aluminium Alloy Tsev Neeg thiab Silicon Cov ntsiab lus

Lub Koom Haum Koom Haum Txhuas Txhuas Txheej Txheem cais cov wrought thiab nrum alloys rau hauv tsev neeg raws li lawv cov ntsiab lus alloying. Silicon nta tseem ceeb nyob rau hauv 4xxx thiab 6xxx wrought series, nrog rau hauv ntau cov qauv cam khwb cia hlau.

Lub 4xxx Series: Silicon ua tus Thawj Coj Tus Thawj Coj Alloying Element

Nyob rau hauv wrought 4xxx alloys, silicon yog qhov tseem ceeb alloying ntxiv. Alloy 4043, muaj kwv yees li 5% silicon, yog siv dav siv txhuas vuam muab tub lim hlau. Cov ntsiab lus ntawm silicon ua kom muaj dej zoo heev thaum lub sij hawm vuam, txo qhov kub ntawm qhov tawg, thiab ua kom du, zoo nkauj pleasing weld hlaws. Siab dua -silicon alloys xws li 4343 thiab 4045, nrog 7-13% silicon, yog ua hauj lwm raws li cov ntawv brazing thiab clad cov ntaub ntawv nyob rau hauv lub tshav kub exchangers, qhov tsawg - melting silicon- nplua nuj txheej txheej ua rau lub cub tawg brazing yam tsis muaj ntxiv muab tub lim.

6xxx Series: Magnesium-Silicide Precipitation Hardening

6xxx series sawv cev rau qhov loj tshaj plaws tonnage ntawm extruded aluminium khoom thoob ntiaj teb. Alloys xws li 6061, 6063, thiab 6082 ua ke silicon nrog magnesium nyob rau hauv proportions uas tsim cov metastable Mg2Si (magnesium silicide) precipitate thaum lub sij hawm tsim kev laus. Cov nag lossis daus no-txheej txheem txheej txheem xa tawm qhov muaj zog ntawm 240-310 MPa ntau - txaus rau cov qauv siv - thaum tuav cov extrudability zoo heev, corrosion kuj, thiab weldability. Cov ntsiab lus ntawm silicon nyob rau hauv 6xxx alloys yog txhob txwm khaws cia hauv qab ntawm aluminium-silicon eutectic muaj pes tsawg leeg, kom ntseeg tau tias ib qho -theem solidification thiab zam qhov tsim ntawm ntxhib thawj silicon hais uas yuav degrade nto tiav thiab anodising teb.

Casting Alloys: Los ntawm Eutectic rau Hypereutectic

Aluminium-silicon casting alloys nthuav dav tag nrho cov txheej txheem ntawm hypo-eutectic mus rau hypereutectic. Qhov dav siv A356 alloy, nrog 7% silicon thiab 0.35% magnesium, muaj qhov sib npaug zoo ntawm castability, lub zog, thiab ductility tom qab T6 kho cua sov. Ntawm lwm yam, hypereutectic alloys xws li 390.0 muaj 16-18% silicon thiab yog khoom plig rau lawv qhov tshwj xeeb hnav tsis kam hauv tsheb pistons thiab compressor vaj tse. Nyob rau hauv cov alloys, thawj silicon particles - uas crystallize ua ntej cov tshuaj tiv thaiv eutectic - txhob txwm refined los ntawm phosphorus ntxiv kom ua tau raws li qhov ntau thiab tsawg hauv qab 50 micrometers, ua kom cov machinability thiab toughness.

Kev xyaum ua lag luam: xaivSilicon hlauQib rau Aluminium Alloying

Tsis yog tag nrhosilicon hlauyog sib npaug rau aluminium alloying lub hom phiaj. Kev xaiv ntawm qib nyob ntawm lub hom phiaj alloy muaj pes tsawg leeg, txoj kev melting, thiab qhov kawg ntawm daim ntawv thov.

Cov Qib: 553, 441, thiab 3303

Suav thiab thoob ntiaj teb cov neeg tsim khoom faib cov hlau silicon los ntawm plaub tus lej - tus lej uas sawv cev rau cov ntsiab lus siab tshaj plaws ntawm cov hlau thiab txhuas hauv ib txhiab. Qib 553, piv txwv li, tso cai rau 0.5% hlau thiab 0.5% txhuas. Qib 441 tso cai 0.4% hlau thiab 0.4% txhuas. Qib 3303 tso cai 0.3% hlau, 0.3% aluminium, thiab 0.03% calcium. Rau qhov dav - lub hom phiaj aluminium alloying, 553 thiab 441 yog tus nqi- zoo thiab siv dav. Rau cov ntawv thov hwm zoo xws li aerospace castings thiab siab -purity brazing alloys, 3303 lossis 2202 qib - nrog rau qis qis qis qis qis qis - tej zaum yuav raug teev los xyuas kom meej cov khoom zoo ib yam thiab txo kev suav nrog.

Melting Methods thiab Silicon Recovery

Silicon hlau yog nkag mus rau hauv aluminium melts ntawm ntau txoj kev. Nyob rau hauv cov thawj aluminium smelters loj, silicon yog ntxiv ncaj qha rau molten txhuas nyob rau hauv casting furnaces, qhov twg dissolution thiab homogenisation tshwm sim nyob rau hauv kev tswj kub thiab nplawm. Hauv kev ua haujlwm thib ob (recycled) aluminium, silicon-cov kabmob seem yog sib xyaw nrog cov hlau tseem ceeb thiab cov khoom siv hluav taws xob silicon ntxiv kom ua tiav cov hom phiaj sib xyaw. Tus nqi rov qab ntawm cov silicon ntxiv - cov feem uas ua tau yaj thiab tseem nyob hauv qhov kawg alloy - feem ntau yog li ntawm 92% mus rau 98%, nyob ntawm qhov kub thiab txias, oxidation tej yam kev mob, thiab slag tsim.

Impurity Control thiab nws qhov tshwm sim

Cov kab tsis huv hauv cov hlau silicon tuaj yeem muaj qhov cuam tshuam loj heev ntawm cov khoom siv txhuas alloy. Hlau, txawm tias nyob rau theem qis dua 0.5%, ua cov nkig intermetallic tebchaw nrog txhuas thiab silicon uas txo cov ductility thiab tawg toughness. Calcium, tam sim no nyob rau hauv qee qib silicon ntawm 0.03-0.10%, ua raws li kev hloov pauv tsis zoo ntawm eutectic silicon, muaj peev xwm cuam tshuam nrog kev tswj hwm sodium lossis strontium kev hloov kho. Phosphorus - qee zaum muaj nyob rau hauv silicon uas ua los ntawm phosphate- cov khoom siv nplua nuj - tuaj yeem tshuaj lom kho hloov kho thiab txhawb nqa cov qauv silicon ntxhib. Rau cov laj thawj no, aluminium foundries nce qhia tsis yog cov ntsiab lus silicon nkaus xwb tab sis kuj muaj tag nrho cov impurity spectrum ntawm lawv cov khoom siv silicon hlau.

Kev siv hauv Automotive thiab Kev Tsim Kho

Qhov thib ob loj tshaj plaws kawg -siv sectors rau silicon- bearing aluminium alloys - automotive thiab kev tsim kho - qhia qhov dav ntawm silicon cov kev pab cuam.

Automotive Lub teeb yuag

Automotive manufacturers ntsib lub siab tsis tu ncua kom txo lub tsheb hnyav kom ua tau raws li kev cai emissions thiab txuas ntxiv hluav taws xob tsheb ntau. Aluminium alloys muaj qhov ntom ntom ntawm ib qho - thib peb ntawm cov hlau, thiab silicon- cov kabmob cam khwb cia hlau tau hloov chaw cam khwb cia hlau thiab hlau hauv lub cav thaiv, lub tog raj kheej taub hau, kis tau tus mob, thiab cov khoom raug tshem tawm. Ib qho txhuas lub cav thaiv lub cav muaj 7-10% silicon, thiab lub tsheb niaj hnub yuav muaj 80-150 kilograms ntawm silicon-cov kabmob txhuas castings. Lub 6xxx series extrusions, lub sijhawm no, tsim cov txheej txheem pob txha ntawm txhuas- cov tsheb loj xws li qhov chaw- cov qauv tsim thiab cov roj teeb ntim rau lub tsheb fais fab.

Kev tsim kho Extrusion thiab Architectural Systems

Hauv kev tsim kho, 6xxx series extrusion ua lag luam rau lub qhov rais thav duab, kab hlau rhuav phab ntsa, qhov rooj thav duab, thiab kev txhawb nqa glazing. Alloy 6063, nrog kwv yees li 0.4% silicon thiab 0.7% magnesium, yog tus neeg ua haujlwm ntawm kev tsim vaj tse extrusion vim nws qhov tshwj xeeb extrudability - ua kom muaj cov hollow profiles - thiab nws lub peev xwm los txais cov hniav anodised thiab pleev xim tiav. Cov ntsiab lus silicon tau ua tib zoo tswj xyuas kom ntseeg tau tias muaj qhov sib txawv ntawm qhov chaw tom qab cov tshuaj ci ntsa iab thiab anodising, vim tias silicon- cov theem nplua nuj tuaj yeem ua rau staining lossis xim txawv yog tias muaj ntau dhau los yog tsis yog -cov xim sib txawv.

Sustainability thiab Recycling Considerations

Aluminium yog ib qho ntawm cov khoom siv uas siv tau zoo tshaj plaws, thiab silicon -cov kabmob alloys tsis muaj qhov tshwj xeeb. Recycled aluminium seem - txawm tias los ntawm kev xa ntawv - cov neeg siv khoom noj cov kaus poom, lub tsev puas tsuaj, lossis cov khoom siv hluav taws xob hauv tsheb rov qab - khaws nws cov ntsiab lus silicon los ntawm ntau lub voj voog remelting. Tsis zoo li qee cov ntsiab lus alloying uas oxidise los yog cais tawm thaum lub sij hawm remelting, silicon qhia tau hais tias siab tuav thiab kwv yees tus cwj pwm nyob rau hauv theem nrab melts. Qhov kev ncig no yog qhov tseem ceeb ntawm kev lag luam: ua txhuas los ntawm cov khoom siv rov ua dua tshiab yuav tsum muaj kwv yees li 5% ntawm lub zog xav tau rau thawj cov khoom lag luam los ntawm bauxite, thiab cov nqi silicon embedded yog khaws cia. Txawm li cas los xij, kev sib sau ntawm cov khoom siv xws li hlau, tooj liab, thiab zinc hauv cov kwj deg tuaj yeem txwv qhov tsim nyog ntawm cov khoom siv thib ob rau siab -silicon premium alloys, yuav tsum tau ua tib zoo saib xyuas cov khib nyiab thiab dilution nrog thawj hlau.