Dab tsi yog Txoj Kev Ntsuas Zoo rau Hlau Txhaj Moulding?

Tus neeg twg uas tau khiav MIM cov kab ntau lawm ntev txaus paub qhov kev ntxhov siab no: ib pawg ntawm cov khoom zoo li zoo meej tom qab sintering, ntsuas qhov ntev, qhov chaw tiav yog huv si - tom qab ntawd peb lub lis piam tom qab, cov neeg siv khoom hu vim tias qhov chaw ua tsis tiav cov tshuaj tsuag ntsev. Lub hauv paus ua rau? Cov pa roj carbon residual los ntawm tsis tiav debinding uas tsis muaj leej twg ntes tau vim tias cov ntaub ntawv poob phaus saib "ze txaus."

MIM kev soj ntsuam zoo muaj nyob los tiv thaiv cov xwm txheej no. Tab sis ntawm no yog dab tsi feem ntau cov lus piav qhia yuav tsis qhia rau koj: cov txheej txheem uas tseem ceeb tshaj plaws nyob ntawm seb koj ua dab tsi thiab koj ua rau leej twg.

Qhov tseeb ntawm MIM Kev Tshawb Fawb Txog Kev Tshawb Fawb

Cia peb hais ncaj qha txog qhov MIM tiag tiag koom nrog. Koj tab tom noj cov hmoov hlau- cov khoom me me dua tib neeg cov plaub hau- sib tov nrog cov ntaub ntawv polymer ntawm kwv yees li 60/40 ntim piv, txhaj cov khoom sib tov rau hauv pwm, tshuaj lom neeg los yog thermally stripping tawm lub binder, tom qab ntawd cua sov txhua yam rau hauv qab melting point kom txog thaum cov hmoov nplej sib xyaw ua ke. Ib feem shrinks txog 15-20% nyob rau hauv tag nrho cov lus qhia thaum sintering.

Txhua ib qho ntawm cov kauj ruam no tuaj yeem qhia qhov tsis xws luag uas yuav tsis tshwm sim txog tom qab. Cov hmoov ntau nrog me ntsis sib txawv particle loj faib hloov koj cov khoom noj viscosity. Qhov kev hloov pauv viscosity txhais tau hais tias koj qhov kev txhaj tshuaj tsis ua haujlwm nag hmo tsis ua rau cov pwm zoo li niaj hnub no. Qhov kev txhaj tshuaj luv luv lossis qhov sib txawv ntawm qhov sib txawv yuav tsis pom tseeb txog thaum tom qab sintering, thaum koj twb tau nqis peev rau tag nrho cov nqi ua haujlwm.

Cov khoom xa tuaj uas tuaj yeem tiv thaiv teeb meem

Cov neeg muag khoom hmoov muab ntawv pov thawj ntawm kev soj ntsuam nrog txhua qhov ntau. Cov lus nug yog: Cov lej twg tseem ceeb rau koj daim ntawv thov?

Cov ntsiab lus carbon thiab oxygen tseem ceeb heev rau stainless hlau. Peb tau pom 17-4PH qhov chaw los ntawm tib lub pwm, tib yam kev ua tsis tau, qhia hardness variation ntawm 8-10 HRC cov ntsiab lus vim hmoov ntau muaj cov ntsiab lus carbon xws li 0.02% mus rau 0.07%. Ob leeg tau technically hauv spec. Tsis yog tus neeg muag khoom hmoov lossis peb qhov kev tshuaj xyuas tuaj tau chij nws. Cov neeg siv khoom QC chav haujlwm pom nws thaum lawv tau txais kev tshuaj xyuas, thiab peb tau siv ob lub lis piam txheeb xyuas cov khoom muag.

Particle loj tis muaj feem xyuam rau txhua yam downstream. Finer hmoov sinter sai dua thiab ua tiav ntau dua, tab sis lawv kuj nce feedstock viscosity, uas hloov tus cwj pwm filling. Thaum tus neeg muag khoom hmoov hloov cov khoom siv atomization los yog kho lawv cov txheej txheem kev faib tawm, D50 yuav nyob twj ywm tib yam thaum lub sij hawm faib cov duab hloov tag nrho. Khiav lub laser diffraction tsom xam ib ASTM B822 ntawm cov khoom tuaj yuav siv sij hawm 20 feeb thiab tau cawm peb ntawm ntau yam kev puas tsuaj.

Rau cov khoom noj khoom haus-txawm tias koj sib xyaw hauv- tsev lossis yuav los ntawm tus neeg muag khoom- ntsuas qhov ceev uas siv lub pycnometer lossis Archimedes txoj kev qhia rau koj tam sim yog tias cov hmoov- rau -binder ratio yog lawm. Ib qho 2% qhov sib txawv ntawm qhov sib txawv tsis zoo li ntau txog thaum koj paub tias nws txhais mus rau qhov ntsuas qhov sib txawv tom qab sintering.

Dab tsi los saib xyuas thaum Moulding

Qhov hnyav yog ib qho tseem ceeb tshaj plaws tiag tiag - lub sijhawm ntsuas qhov zoo thaum txhaj tshuaj molding. Nws cuam tshuam ncaj qha nrog ntim ntim, thiab ntim ntim txiav txim siab qhov ntev sintered. Qhov hnyav txhua txhua 15-20 txhaj tshuaj yuav siv sijhawm vib nas this. Thaum qhov hnyav pib drifting, ib yam dab tsi tau hloov pauv - cov khoom kub, pwm kub, txhaj tshuaj ceev, kos valve hnav-thiab koj tuaj yeem tshawb xyuas ua ntej tsim ntau pua qhov xav tau.

Kev saib xyuas qhov nkhaus xav tau cov cuab yeej siv ntau dua tab sis muab kev ceeb toom ua ntej ntawm cov teeb meem. Txhaj siab profile duab qhia txog kev coj tus cwj pwm ua haujlwm -ib qho nkhaus zoo ib yam nrog tib lub siab siab thiab tus nqi nce txhais tau hais tias ua kom zoo ib yam. Niaj hnub nimno molding tshuab sau cov ntaub ntawv no tau txais. Kev tshuaj xyuas cov nkhaus yuav siv sij hawm ntau qhov kev tsim tawm ntau zaus tsis tso cai, tab sis rau qhov tseem ceeb lossis thaum daws teeb meem, cov ntaub ntawv tsis muaj nuj nqis.

Kev tshuaj xyuas qhov muag ntsuab pom pom qhov tsis xws luag: kev txhaj tshuaj luv luv, flash, cov cim hauv lub dab dej, qhov pom ntawm cov kab vuam. Qhov tsis yooj yim yog paub txog qhov pom cov yam ntxwv kwv yees teeb meem tom qab sintering thiab cov kev txhawj xeeb ntawm cov tshuaj pleev ib ce uas ploj thaum ua. Qhov kev paub ntawd los ntawm kev paub txog kev sib raug zoo ntawm ntsuab ib feem nrog sintered qhov zoo-tsis muaj qhov hloov pauv rau nws.

Debinding Verification

Debinding yog qhov twg ntau MIM kev khiav hauj lwm poob tswj tsis tau paub txog nws. Lub polymer binder yuav tsum tau tawm tag nrho, tab sis ceev heev thiab koj tawg qhov chaw; qeeb dhau lawm thiab koj plam throughput.

Kev ntsuas qhov hnyav yog qhov yooj yim: ntsuas qhov khoom ua ntej debinding, ntsuas lawv tom qab, xam qhov feem pua ​​​​tawm tawm. Rau cov khoom noj nrog 40% binder los ntawm ntim (kwv yees li 8% los ntawm qhov hnyav rau stainless hlau), koj yuav tsum pom qhov poob phaus nce mus txog 8%. Tau txais tsuas yog 6% poob phaus txhais tau tias tseem ceeb binder tseem nyob rau hauv ib feem. Qhov seem uas nyob hauv phau ntawv no dhau los ua cov pa roj carbon seem thaum lub sijhawm sintering, thiab cov pa roj carbon residual hauv stainless hlau rhuav tshem corrosion kuj.

JPMA specification hu rau cov ntsiab lus carbon kawg hauv qab 0.03% hauv sintered stainless hlau qhov chaw. Kev ntaus lub hom phiaj yuav tsum tau ua kom tiav debinding. Peb tau pom cov khw ua haujlwm thermal debinding cycles uas lawv cov neeg ua haujlwm cog lus tias yog lawm, tab sis cov khoom tsis tu ncua tsis tu ncua chemistry vim qhov tseeb qhov cub kub qhov profile tsis phim cov programmed profile. Thermocouple pov thawj thiab qee zaus kev xeem khiav nrog cov thermocouples embedded nyob rau hauv qhov chaw yog tib txoj kev kom paub meej.

Kev tshuaj xyuas tsis raug tom qab kev debinding teeb meem vim tias cov kab nrib pleb uas tsim thaum lub sij hawm tshem tawm yog pom nyob rau theem no. Kev ntes lawv ua ntej sintering txuag lub cub hluav taws xob muaj peev xwm thiab tiv thaiv tsis meej pem txog thaum qhov teeb meem tshwm sim.

Kev ntsuam xyuas Sintered Part

Dimensional ntsuas tom qab sintering xyuas tias tag nrho cov txheej txheem saw tsim tau raws li qhov yuav tsum tau kos duab. CMM tshuaj xyuas rau qhov loj me, kev sib piv kho qhov muag rau cov profiles, mus / tsis yog - mus ntsuas qhov ntau lawm -txoj kev tshwj xeeb yog nyob ntawm qhov yuav tsum tau ua thiab kev soj ntsuam ntim.

Cov ntsiab lus tseem ceeb: MIM qhov peev xwm loj yog feem ntau ± 0.3% rau ± 0.5% ntawm nominal dimension. 10mm feature tuav ± 0.03 rau ± 0.05mm. Qhov ntawd zoo dua li feem ntau cov txheej txheem casting tab sis tsis nruj li precision machining. Cov khoom uas yuav tsum tau ua kom nruj dua yuav tsum tau ua haujlwm ua haujlwm thib ob, thiab cov nqi suav hloov raws li.

Kev ntsuas qhov ntom ntom siv cov txheej txheem Archimedes rau ASTM B962 lees paub sintering tiav kev sib sau ua ke. Lub hom phiaj txheeb ze rau kev siv cov txheej txheem yog feem ntau 96% yam tsawg kawg nkaus, nrog ntau yam tshwj xeeb xav tau 97% lossis siab dua. Qhov ntom ntom qis txhais tau tias muaj qhov porosity ntau dua, uas txo cov khoom siv kho tshuab thiab tuaj yeem tsim txoj hauv kev hauv cov kua dej- tuav cov khoom.

Daim ntawv sau ntau lawm: Kev ntsuas qhov ceev yuav tsum muaj kev paub tseeb ntawm theoretical ntom ntom rau koj qhov tshwj xeeb alloy muaj pes tsawg leeg. Siv phau ntawv txhais lus tseem ceeb rau "316L stainless hlau" thaum koj cov khoom siv hmoov cov khoom sib txawv tuaj yeem cuam tshuam koj cov kev suav kom txaus los lees txais qhov tsis zoo lossis tsis lees txais qhov zoo.

Mechanical Test thiab Metallography

Kev tshuaj xyuas metallographic-txiav ib feem, mounting, polishing, thiab tshuaj xyuas nyob rau hauv lub tshuab ntsuas tshuab- nthuav tawm cov ntsiab lus microstructural uas tsis muaj lwm txoj kev qhia. Grain loj, pore faib, sintering caj dab tsim, theem qauv, carbide nag lossis daus: tag nrho cov pom nyob rau hauv ib tug zoo npaj ntoo khaub lig-section. Nws yog kev puas tsuaj thiab lub sijhawm-siv, yog li nws feem ntau yog tshwj tseg rau cov txheej txheem kev txhim kho, kev daws teeb meem, thiab kev siv tau raws sij hawm tsis yog kev tshuaj xyuas ntau lawm.

Rau cov ntawv thov tseem ceeb, metallography paub meej tias koj qhov kev soj ntsuam cov txheej txheem qhia dab tsi. Rau kev daws teeb meem, nws feem ntau nthuav tawm lub hauv paus ua rau thaum lwm txoj kev tsuas pom cov tsos mob.

Tsis yog -Txoj kev puas tsuaj rau sab hauv

X-Kev tshuaj xyuas hluav taws xob thiab kev lag luam CT scanning pom cov voids sab hauv, suav nrog, thiab cov kab nrib pleb yam tsis muaj qhov cuam tshuam. Rau kev cog qoob loo kho mob thiab cov khoom siv hauv aerospace uas muaj qhov tsis xws luag sab hauv tsis tuaj yeem lees txais, cov txheej txheem no feem ntau yuav tsum tau ua.

Qhov kev muaj tiag: kev lag luam CT nrog kev daws teeb meem txaus kom pom MIM- qhov porosity cuam tshuam yog kim, qeeb, thiab xav tau kev txawj txhais lus. Nws yog qhov tsim nyog rau qhov muaj txiaj ntsig siab - qhov chaw uas qhov ua tsis tiav yog qhov hnyav. Rau cov khoom lag luam, kev ua piv txwv nrog kev kuaj xyuas metallographic puas tsuaj feem ntau muab kev lees paub txaus ntawm tus nqi qis.

Matching Inspection rau Daim Ntawv Thov

Lub 316L bracket tuav lub npog ntsej muag hauv cov neeg siv khoom siv tsis xav tau tib yam kev tshuaj ntsuam xyuas raws li 17-4PH locking mechanism hauv lub qhov rooj dav hlau. Paub txog qhov no thiab ntsuas cov dej num zoo tsim nyog cais cov haujlwm ua haujlwm tau zoo los ntawm cov neeg poob rau hauv cov nqi kuaj xyuas tsis tsim nyog lossis, qhov phem dua, xa cov khoom tsis zoo vim lawv hla cov tshev uas tsim nyog.

Cov neeg siv khoom yuav xav tau tsuas yog kev txheeb xyuas qhov ntev thiab kev tshuaj xyuas qhov muag, nrog rau cov khoom siv kho tshuab siv tau thaum tsim nyog tsim nyog thiab saib xyuas los ntawm cov txheej txheem tswj es tsis yog ib feem - los ntawm - qhov kev xeem ib feem.

MPIF Standard 35 muab cov khoom vaj tse tshwj xeeb uas ua haujlwm raws li kev siv thoob plaws hauv kev lag luam. Nws txhais cov cuab yeej yam tsawg kawg nkaus los ntawm kev tsim cov khoom siv, tso cai rau cov neeg yuav khoom thiab cov neeg muag khoom sib txuas lus kom meej.

Qhov no txhais li cas hauv kev xyaum

Kev ntsuam xyuas zoo rau MIM tsis yog daim ntawv teev npe uas koj siv ib yam rau txhua qhov chaw. Nws yog ib qho system uas txheeb xyuas txhua kauj ruam yog tsim cov khoom tsim tawm, ntsuas kom haum rau qhov tshwm sim ntawm qhov tsis xws luag mus txog tus neeg siv khoom.

Cov hauv paus ntsiab lus tseem nyob tsis tu ncua: txheeb xyuas cov ntaub ntawv tuaj, saib xyuas molding kom zoo ib yam, paub meej tias ua tiav debinding, validate sintered qhov ntev thiab ntom, kuaj cov khoom tsim nyog rau daim ntawv thov. Yuav nruj npaum li cas koj siv txhua lub caij, thiab cov txheej txheem ntxiv koj ntxiv, nyob ntawm seb koj ua dab tsi.

Kev ua haujlwm nrog MIM cov txheej txheem ua haujlwm tau zoo- suav nrog cov chaw uas tau kho cov txheej txheem no thoob plaws ntau xyoo dhau los ntawm kev tsim khoom- txhim kho cov txheej txheem tshuaj xyuas uas ntes cov teeb meem tiag tiag yam tsis tsim lub tswb cuav lossis siv cov peev txheej ntau dhau. Qhov nyiaj tshuav ntawd yuav siv sij hawm thiab saib xyuas los tsim, tab sis nws yog qhov cais cov neeg xa khoom ntseeg tau los ntawm cov neeg dhau los ntawm - tshuaj xyuas lawv tus kheej tawm ntawm cov txiaj ntsig lossis hauv qab - tshuaj xyuas lawv tus kheej hauv cov neeg siv khoom tsis txaus siab.