Thaum koj hnov 'hlau txhaj tshuaj molding cov ntaub ntawv', feem ntau lub siab dhia ncaj nraim mus rau cov hmoov hlau. Qhov ntawd yog lub hauv paus ntsiab lus, tseeb. Tab sis yog tias koj tau siv txhua lub sijhawm ntawm lub khw hauv pem teb, koj paub tias zaj dab neeg tiag tiag pib nrog lub kaw lus kaw lus thiab xaus nrog lub tshuab cua sov. Nws yog tag nrho cov cocktail uas tseem ceeb, tsis yog tus ntsuj plig xwb. Kuv tau pom ntau qhov chaw nres tsheb vim tias ib tus neeg tau txais qhov zoo nkauj, kheej kheej 17-4PH hmoov tab sis tau ua ke nrog cov khoom siv hluav taws xob-polymer uas tsis tuaj yeem tuav qhov seem ntawm qhov geometry, ua rau muaj kev puas tsuaj loj heev thaum lub sij hawm debinding. Cov khoom siv tsis yog hlau xwb; nws yog cov khoom noj. Qhov ntawd yog thawj, thiab feem ntau kim tshaj, zaj lus qhia.
Kev sib npaug Feedstock: Ntau Art than Science
Tau txais cov khoom noj muaj cai zoo li alchemy qee zaum. Qhov zoo tshaj plaws piv ntawm cov hmoov thauj khoom - qhov ntim feem pua ntawm cov hmoov hlau hauv cov ntawv khi - yog txoj kev taug kev nruj. Thawb nws siab dhau rau qhov nyuaj, thiab koj poob qhov flowability heev uas MIM yog khoom plig rau. Kev txhaj tshuaj molding tshuab tawm tsam, koj tau txais cov kab, voids. Tsawg dhau, thiab ib feem shrinks unpredictably thaum sintering, xaus ntawm spec. Rau kev hnav khaub ncaws siab peb ib zaug khiav, siv cov hmoov zoo, roj-atomized 316L hmoov, peb yuav tsum hu rau qhov chaw thau khoom me ntsis los ntawm phau ntawv pom zoo. Vim li cas? Qhov chaw muaj ib tug ridiculously nyias hla ntu uas nyob ib sab mus rau ib tug tuab hub. Standard loading ua rau cov cim dab dej. Peb cuam tshuam rau ntawm qhov qis qis kom ntseeg tau tias sau, tom qab ntawd tweaked sintering profile kom them nyiaj. Nws ua haujlwm, tab sis nws tsis nyob hauv ib phau ntawv.
Qhov no yog qhov uas tus binder lub luag hauj lwm yog criminally underrated. Nws tsis yog kua nplaum ib ntus xwb. Nws decomposition kinetics thaum lub sij hawm thermal los yog hnyav debinding yuav tsum tau zoo kawg nkaus synced nrog cov hmoov ntim. Ib qho tsis sib haum ntawm no, thiab koj tau mob plab, tawg, lossis 'ntsuab ntsuab' tawg. Kuv nco qab ib pawg uas tus neeg muag khoom binder hloov lub catalyst yam tsis tau ceeb toom. Cov khoom zoo meej los ntawm pwm, tab sis nyob rau hauv qhov cub debind, lawv slumped zoo li nkees mov paj. Tag nrho poob. Cov hmoov zoo tib yam, cov ntsiab lus hlau tsis hloov. Qhov tsis ua hauj lwm yog nyob rau hauv ib qho 'me' feem ntawm lub binder system.
Thiab cia peb tham txog cov yam ntxwv ntawm hmoov. Sphericity and particle size distribution (PSD) yog txhua yam. Qhov nqaim PSD tuaj yeem muab cov kev xav ntim zoo, tab sis tswj tau zoo, me ntsis kev faib tawm feem ntau ntws zoo dua hauv kev xyaum thiab cov neeg ua txhaum ntau dua. Rau kev cog qoob loo cobalt-chrome kho mob, peb tau tawm tsam cov teeb meem porosity kom txog thaum peb sib xyaw ob cov hmoov sib txawv kom tau txais txoj cai PSD nkhaus. Cov nplooj ntawv spec rau txhua qhov ntau yog 'tau txais', tab sis cov khawv koob nyob hauv qhov sib xyaw. Koj tsis kawm qhov ntawd los ntawm cov ntaub ntawv; koj kawm tau nws los ntawm scrapped batch.
Sintering: Qhov twg cov ntaub ntawv tiag tiag
Qhov no yog lub ntsiab lus ntawm tsis rov qab los. Koj tau molded thiab debinded ib qho yooj yim 'xim av ib feem'. Tam sim no, nyob rau hauv lub qhov cub sintering, cov hlau hais fuse thiab cov khoom muaj tseeb tshwm sim. Qhov no yog qhov uas koj xaiv cov khoom siv hauv paus - stainless hlau, cov cuab yeej steel, tshwj xeeb alloy - ntsib nws qhov kev sim los ntawm hluav taws. Huab cua tswj yog huab tais. Cov pa me me hauv cov pa hydrogen-nitrogen thaum sintering cov hlau uas muaj chromium xws li 17-4PH tuaj yeem txiav cov pa roj carbon monoxide thiab ua kom puas corrosion. Peb tau kawm los khiav dummy qhov chaw ua ntej txhua qhov tseem ceeb batch rau 'sim' lub qhov cub cua sov, ib txoj cai pov hwm pheej yig.
Lub voj voog sintering nws tus kheej yog ib daim ntawv qhia cov khoom siv tshwj xeeb. Ramp tus nqi, tuav qhov kub, txias ceev - lawv txhua tus dictate qhov kawg microstructure. Rau ib qhov project uas yuav tsum tau ib tug mos magnetic alloy (xws li Fe-50% Ni), qhov cua txias npaum li cas los ntawm sintering kub yog ib qho tseem ceeb los tsim kom tau qhov xav tau magnetic permeability. nrawm dhau, thiab peb nco lub qhov rais khoom. Nws coj peb lub cub tawg khiav nrog kev hloov maj mam txias tweaks los ntaus tus spec. Cov 'khoom siv' ntawm kev yuav khoom tsuas yog Fe-50Ni. Cov khoom siv ua haujlwm tau tsim nyob rau hauv qhov cub.
Shrinkage yog lwm qhov sib txawv loj, ncaj qha mus rau cov khoom noj. Peb tsom rau isotropic shrinkage, tab sis nws yeej tsis zoo ib yam. Rau cov khoom siv precision, peb yuav tsum tsim cov pwm kab noj hniav raws li qhov ua tau raws li qhov ua tau raws li qhov kev xav tau peb tau tsim rau qhov tshwj xeeb 4140 alloy feedstock, tsis yog tus neeg muag khoom generic 15-18% thov. Peb qhov tseem ceeb yog 16.7% ± 0.3% hauv lub dav hlau tseem ceeb. Qhov kev txiav txim siab ntawd tau los ntawm kev ntsuas ntau pua ntawm sintered qhov chaw thiab sib cuam tshuam rov qab. Qhov ntawd yog hom kev paub txog cov ntaub ntawv uas nyob hauv ib lub tuam txhab cov ntaub ntawv sab hauv.
Vim li cas Alloys Li Cobalt thiab Nickel Hloov Cov Kev Ua Si
Txav los ntawm cov hlau tsis sib xws rau hauv thaj chaw zoo li cobalt-based alloys los yog Nickel-raws li alloys rau MIM yog ib qho kev hloov pauv hauv kev nyuaj thiab nqi. Cov no tsis yog 'facier steels' xwb. Lawv sintering qhov rais tuaj yeem nqaim heev. Ib tug cobalt-chromium-molybdenum alloy rau biomedical siv tej zaum yuav sinter nyob rau hauv ib tug 20-degree Celsius qhov rais kom ua tau tag nrho cov ntom yam tsis muaj grain loj hlob. Nco nws, thiab koj tau txais cov porosity residual los yog embrittlement.
Kev tshem tawm cov ntawv khi rau cov hlau ua haujlwm siab no kuj yog qhov nyuaj dua. Lawv cov hmoov yog feem ntau reactive, yog li catalytic debinding (siv nitric acid vapor, piv txwv li) tej zaum yuav nyiam dua qeeb thermal txoj kev kom tsis txhob muaj kab mob. Qhov no ntxiv cov txheej txheem complexity thiab nqi. Tab sis cov nyiaj them poob haujlwm yog cov khoom uas ze ze rau cov khoom siv-xav txog lub dav hlau cav roj injector swirlers ua los ntawm MIM los ntawm nickel superalloy. Tus nqi yog nyob rau hauv net-puab complexity, tsis yog tsuas yog cov khoom nqi.
Qhov no yog ib qho chaw uas sib sib zog nqus foundry thiab machining kev ua invaluable. Lub tuam txhab uas muaj keeb kwm ntev hauv peev casting thiab machining tshwj xeeb alloys, zoo li Qingdao Qiangsenyuan Technology Co., Ltd. (QSY), coj qhov kev xav txawv rau MIM. Lawv tau raug soj ntsuam nrog metallurgy ntawm tshwj xeeb alloys rau kaum xyoo dhau los ntawm lawv lub plhaub thiab kev nqis peev casting ua haujlwm. Qhov kev paub txog kev paub txog cov hlau no coj li cas hauv qab cua sov, lawv cuam tshuam li cas nrog huab cua, thiab lawv tuaj yeem ua tiav li cas yog qhov khoom muaj nqis loj heev thaum venturing rau hauv molding lawv. Lawv nkag siab tias lub xeev tom qab sintering tsuas yog qhov pib dawb paug rau ntau qhov chaw, uas yuav xav tau qhov tseeb CNC machining kom ua tau raws li qhov ua siab ntev zaum kawg ntawm cov yam ntxwv tseem ceeb. Cov txheej txheem MIM thiab xaiv cov khoom yog tsim los nrog cov kauj ruam tom ntej hauv lub siab.
Lub Machining Txuas: MIM Tsis Yog Ib txwm txhais tau tias 'Tiav'
Ib qho kev xav tsis zoo yog tias MIM qhov chaw tawm ntawm lub cub tawg npaj siv. Rau ntau, yog. Tab sis rau kev siv high-precision, sintering yog ua raws li kev ua haujlwm thib ob. Qhov no yog qhov tseem ceeb rau kev xaiv cov khoom siv. Koj tuaj yeem xaiv qib pre-hardened, los yog ib qho uas yuav tsum tau kho cua sov tom qab sintering. Tab sis koj kuj yuav tsum xav txog machinability. Ib qho sintered MIM muaj qhov zoo, zoo li microstructure, tab sis nws tsis yog ib txwm npau suav rau tshuab. Nws tuaj yeem ua abrasive.
Peb muaj ib rooj plaub nrog 440C stainless hlau MIM qhov uas xav tau lub qhov tapping. Ib feem yog tag nrho ntom thiab nyuaj tom qab sintering. Tapping nws ncaj qha yog zom cov cuab yeej. Peb yuav tsum tau kho lub voj voog sintering kom tawm hauv lub xeev me ntsis softer rau machining, tom qab ntawd ntxiv ib qho kev kho cua sov tom ntej. Cov txheej txheem 'cov ntaub ntawv' yog li no: feedstock formulation -> molding -> debinding -> sintering (mos) -> CNC machining -> tshav kub kho -> khoom kawg. Cov khoom siv taug kev tsis dhau tom qab qhov cub.
Qhov kev pom kev sib xyaw no yog qhov tseem ceeb. Nws yog vim li cas qee tus neeg ua tau zoo tshaj plaws tsis yog MIM cov khw muag khoom. Lawv yog cov tuam txhab kev koom ua ke, zoo li QSY, uas ua ke cov txheej txheem. Lawv tuaj yeem saib cov duab kos rau ib qho nyuaj, cov khoom siv hlau nplaum thiab txiav txim seb puas yog peev casting, MIM, los yog ib qho kev sib xyaw ua ke yog qhov zoo tshaj plaws raws li geometry, khoom siv, thiab ntim. Lawv 30 xyoo nyob rau hauv casting thiab machining txhais tau tias lawv xaiv MIM cov ntaub ntawv nrog kev nkag siab tag nrho ntawm cov saw hlau tsim, tsis yog cov txheej txheem molding thiab sintering. Lawv paub tias tus nqi tseeb ntawm cov khoom muaj xws li nws coj li cas hauv txhua qhov haujlwm tom ntej.
Failures thiab Lessons Lawv Imprint
Koj tsis kawm cov ntaub ntawv los ntawm kev ua tiav. Koj kawm tau los ntawm cov khoom khib nyiab. Thaum ntxov, peb tau sim khiav ib qho khoom siv qis-alloy steel feedstock meant rau tsheb qhov chaw. Cov seem sintered zoo, saib zoo heev. Tab sis nyob rau hauv kev ntsuam xyuas ntsev tsuag, lawv rusted nyob rau hauv cov sij hawm, thaum ib txwm machined ib feem ntawm cov qib tib lub sij hawm ntev lub lis piam. Tus neeg ua txhaum? Carbon poob thaum lub sij hawm sintering vim qhov cua tsis zoo tuned rau cov hmoov tshwj xeeb saum npoo chemistry. Cov khoom siv 'qib' tau raug, tab sis cov txheej txheem tau hloov kho nws cov txiaj ntsig zoo. Peb yuav tsum tau hloov mus rau cov hmoov engineered rau MIM, nrog rau qhov sib txawv deg passivation, thiab zawm lub qhov cub raws tu qauv. Daim ntawv spec tsis muaj txiaj ntsig yog tias peb tsis tswj cov txheej txheem uas tsim cov khoom kawg.
Lwm lub sij hawm, peb tshawb fawb siv MIM-tungsten hnyav alloy. The density was fantastic, but the feedstock was notoriously difficult to mold consistently. Peb tau siv ntau lub hlis rau ntawm lub rooj vag thiab khiav tsim, pwm kub, kev txhaj tshuaj tsis haum. Peb tau txais cov khoom siv ua haujlwm, tab sis cov txiaj ntsig tsis muaj txiaj ntsig zoo rau lub ntim. Peb khaws nws. Cov ntaub ntawv tau cog lus rau ntawm daim ntawv, tab sis qhov tseeb ntawm kev hloov pauv nws los ntawm cov khoom noj rau cov khoom siv txhim khu kev qha tua tau qhov project. Qhov ntawd yog qhov kev txiav txim tseem ceeb hu koj tsuas yog ua los ntawm kev sim thiab ua tsis tiav.
Yog li thaum kuv xav txog hlau txhaj molding cov ntaub ntawv tam sim no, kuv tsis tsuas pom daim ntawv teev cov alloys. Kuv pom ib qho kev txiav txim siab: hmoov cov duab thiab qhov loj me, cov khoom siv hluav taws xob, cov khoom siv hmoov, cov txheej txheem debind, qhov cub cua qhov profile, kev kho cua sov, thiab qhov tsim nyog thib ob machining. Cov khoom yog tag nrho cov saw no. Nws yog tus txheej txheem-txhais chaw. Tau txais nws txoj cai txhais tau tias hwm txhua qhov txuas, thiab qhov kev paub ntawd tsis yog yuav - nws tau tsim los ntawm ib feem, ua tsis tiav los ntawm kev ua tsis tiav, ntau xyoo. Nws yog qhov sib txawv ntawm kev xaj cov hmoov thiab engineering ib feem.
