Koj paub, thaum cov neeg sab nraud ntawm kev lag luam hnov ' hmoov metallurgy', lawv feem ntau dhia ncaj nraim mus rau qhov nias - qhov kev cog lus ntawm qhov zoo, cov hmoov qhuav rau hauv qhov pom tau 'ntsuab'. Qhov ntawd yog qhov pom me ntsis. Tab sis qhov tseeb alchemy, qhov twg cov khoom siv tus ntsuj plig tau txiav txim siab tiag tiag, tshwm sim hauv qhov cub thaum lub sijhawm sintering. Nws yog ib lo lus yooj yim deceptively rau cov txheej txheem fraught nrog nuance. Tau txais nws yuam kev, thiab koj tsis yog saib ntawm qhov tsis muaj zog xwb; koj tab tom saib cov seem uas dhau los ntawm ntau cov kauj ruam kim tsuas yog ua tsis tiav ntawm qhov kawg, thermal hurd. Nws tsis yog 'kub nws' xwb; nws yog ib qho kev tswj kev seev cev ntawm kev sib kis, caj dab tsim, thiab pore rounding, tag nrho dai ntawm kev tswj xyuas meej ntawm lub sijhawm, qhov kub thiab txias.
Lub Atmosphere tsis yog tom qab Gas xwb
Thaum ntxov, kuv kawm qhov no nyuaj heev. Peb muaj ib pawg ntawm low-alloy steel flanges, nias zoo nkauj. Lub voj voog ntawm lub cub tawg tau teeb tsa los ntawm daim ntawv qhia qub qub. Tab sis kev tswj hwm huab cua tau muaj hnub so - qhov kev hloov pauv me ntsis hauv cov pa roj cua hauv endothermic, me ntsis dew point tshaj qhov zoo tagnrho. Qhov tshwm sim? Nto decarburization ntawm lub ntsej muag tseem ceeb load-bearing ntsej muag. Cov khoom zoo li tsis zoo, dhau qhov pom kev pom, tab sis nyob rau hauv kev sim microhardness, lawv pom cov tawv nqaij mos. Tsis muaj txiaj ntsig rau daim ntawv thov. Qhov ntawd yog thaum nws nyem: qhov chaw sintering tsis yog ib puag ncig passive; nws yog ib tug active koom. Rau cov hlau, nws yog hais txog kev tuav cov peev xwm carbon. Rau stainless, nws yog hais txog kev tiv thaiv chromium oxide tsim, uas tej zaum yuav txhais tau tias ib tug high-purity hydrogen los yog lub tshuab nqus tsev khiav. Kuv nco ntsoov muab cov roj tshwj xeeb los ntawm ib tus kws kho mob uas peb ntseeg siab, thiab qhov sib txawv ntawm qhov kawg qhov sib xws yog hmo ntuj thiab nruab hnub.
Qhov no khi rau hauv cov ntaub ntawv peb feem ntau siv. Ntawm QSY, nrog peb keeb kwm yav dhau los hauv kev nqis peev casting thiab machining tshwj xeeb alloys xws li npib tsib xee-raws li sawv daws yuav, lub tswv yim zoo sib xws tab sis qhov kev ua tiav txawv. Casting deals nrog molten hlau ntws; hmoov metallurgy sintering deals nrog solid-state diffusion. Tab sis cov ntaub ntawv kev paub hla dhau. Thaum tus neeg siv khoom tuaj nrog qhov kev thov rau cov khoom siv cobalt-chromium uas xav tau kev hnav tsis kam, peb paub los ntawm peb qhov kev paub txog kev ua haujlwm zoo li cas cov alloys no yog cov keeb kwm thermal. Kev txhais hais tias mus rau PM txoj kev txhais tau tias nkag siab tias qhov kub thiab txias rau qhov zoo li no tsis yog ib qho taw tes tab sis lub qhov rais nqaim - qis dhau, thiab qhov ntom ntom ntom ntom; siab dhau lawm, thiab koj yuav raug kev loj hlob ntau dhau los lossis txawm tias cov kua theem tsim uas cuam tshuam rau qhov. Lub qhov cub profile ua qhov tseem ceeb.
Koj tsis tuaj yeem tham nrog huab cua yam tsis tau kov lub tshuab nqus tsev vacuum. Lawv yog cov godsend rau cov ntaub ntawv reactive. Peb tau khiav qee qhov kev sim nrog 316L stainless hmoov compacts. Hauv huab cua hydrogen, koj tuaj yeem tau txais txiaj ntsig zoo, tab sis lub tshuab nqus tsev sintering? Nws tsim cov khoom uas muaj cov kab lis kev cai huv si thiab kev tiv thaiv corrosion zoo dua, tseem ceeb heev rau qee qhov ntawm cov khoom siv marine uas peb tau nug txog. Lub downside yog tus nqi thiab lub sij hawm voj voog. Nws yog qhov kev ntsuam xyuas tas mus li: qhov kev ua tau zoo tau txais txiaj ntsig zoo rau cov nqi tsim khoom? Qhov ntawd yog kev xam lub ntiaj teb tiag tiag peb ua txhua hnub, tsis yog cov lus nug hauv phau ntawv.
Kub thiab Sijhawm: Nws yog Profile, tsis yog qhov chaw
Lwm qhov pitfall yog kho qhov kub ntawm sintering raws li ib tus lej koj teem thiab tuav. Hauv kev muaj tiag, tus nqi nce siab, lub sij hawm ntub dej ntawm qhov nruab nrab kub (xws li rau binder hlawv-tawm hauv cov hmoov txhaj tshuaj molded qhov chaw), thiab tus nqi txias yog tag nrho ib feem ntawm 'profile'. Kuv nco qab txog qhov project rau ib lub iav complex uas peb tau ntsib tawg thaum lub caij txias. Tus neeg ua txhaum? Ceev heev txias los ntawm sintering kub. Cov thermal gradients induced stresses tias qhov tseem-consolidating microstructure ua tsis tau. Peb yuav tsum tau hloov kho qhov kev pab cuam rau qhov cub kom suav nrog thaj chaw tswj qeeb-txias. Nws ntxiv teev rau lub voj voog tab sis tau txais kev cawmdim tag nrho.
Qhov no yog qhov kev xav tau los rau hauv. Cov phau ntawv muab rau koj cov duab kos thiab theoretical density curves. Tab sis nyob rau hauv pem teb khw, koj tab tom saib rau cov paib. Cov xim ntawm cov khoom tawm los, lub suab uas lawv ua thaum maj mam rub tawm (lub suab npub piv rau lub nplhaib faint), txawm tias txoj hauv kev uas lawv zaum ntawm lub tais sintering-warpage yog ib qho khoom plig tuag ntawm cov cua sov tsis sib xws lossis kev txhawb nqa tsis zoo thaum lub caij sov. Nws yog cov kev kuaj xyuas zoo, honed dhau sijhawm, uas ntes teeb meem ua ntej CMM lossis tensile tester ua.
Txuas qhov no rov qab rau peb lub peev xwm sib xyaw ua ke ntawm Qingdao Qiangsenyuan Technology Co., Ltd. (QSY), cov kauj ruam sintering tsis yog kob. Ib feem tuaj yeem tawm ntawm qhov cub ntawm 95% theoretical ntom ntom. Rau ntau daim ntawv thov, qhov zoo. Tab sis rau lub cev hydraulic lub cev xav tau qhov tsis sib xws-tightness, nws yuav xav tau kev ua haujlwm thib ob xws li resin impregnation. Los yog, nws yuav ncaj nraim mus rau peb lub tshuab CNC machining hlwb rau kev ua tiav ntawm qhov tseem ceeb ntawm qhov loj me-drilling qhov tseeb, threading, tsim cov sealing nto. Qhov tseeb tias peb tswj cov txheej txheem sintering thiab tom ntej machining nyob rau hauv ib lub ru tsev txhais tau tias peb to taub yuav ua li cas lub sintered microstructure coj thaum lub sij hawm txiav. Ib qho tsis zoo sintered tuaj yeem ua rau abrasive thiab zom los ntawm cov cuab yeej; ib tug zoo-sintered ib lub tshuab cleanly. Qhov kev tawm tswv yim voj voog ntawm lub tshuab hluav taws xob thiab lub chaw machining yog qhov tseem ceeb.
Green Part's Legacy
Txhua yam hauv sintering yog predetermined los ntawm lub xeev ntawm ntsuab compact. The density gradient from pressing, any lamination flaws, the uniformity of powder distribution—these don't get healed in the furnace; lawv tau amplified. Ib qho kev sib txawv me ntsis tuaj yeem ua rau qhov sib txawv ntawm qhov sib txawv, tig ib qho me me ntawm qhov tsis zoo rau hauv qhov loj me ntawm qhov tsis lees paub tom qab sinter. Peb ib zaug muaj teeb meem nrog tus pin ntev, nyias. Lawv pheej tawm tuaj khoov. Tom qab chasing furnace profiles, peb thaum kawg saib rov qab ntawm cov cuab yeej. Ib qho me me misalignment hauv xovxwm tau ua rau cov hmoov tsis sib xws thiab, yog li ntawd, tsis sib xws ntsuab ntom. Kho cov xovxwm, kho qhov sintered. Zaj lus qhia: sintering feem ntau tau raug liam rau cov teeb meem yug ntxov hauv cov txheej txheem saw.
Qhov no yog tshwj xeeb tshaj yog muaj tseeb rau cov duab complex. Nyob rau hauv peev casting, uas yog QSY lwm yam tseem ceeb muaj peev xwm, cov pwm txhais cov duab. Hauv PM, qhov tuag txhais tau hais tias nws pib, tab sis tom qab ntawd qhov kev poob qis thaum lub sij hawm sintering - thiab nws tsis tas yuav shrink isotropically. Kev tsim cov cuab yeej yuav tsum tau cia siab tias qhov no anisotropic shrinkage, uas los ntawm cov kev taw qhia nias thiab particle orientation. Nws yog ib qho kev kos duab empirical ntau npaum li kev tshawb fawb. Peb muaj cov tsev qiv ntawv ntawm shrinkage yam rau cov khoom sib txawv thiab ib feem geometries, ua tau ntau xyoo, uas coj peb cov cuab yeej tsim. Koj yuav tsis pom cov lej tseeb hauv phau ntawv qhia.
Thaum Tej Yam Ua Tsis Zoo
Kev puas tsuaj loj heev - melting, loj distortion - yog pom tseeb. Cov kws kho mob yog cov kws kho mob tshwj xeeb. Incipient melting ntawm grain ciam teb vim hais tias koj nudged heev ze rau cov solidus kab. Tshaj-sintering ua rau tsam plab, qhov chaw kaw qhov pores swell nrog cov pa roj. Los yog nyob rau hauv-sintering, tawm hauv ib feem nrog lub zog tsis txaus, qhov tsis zoo uas tsuas yog tshwm sim hauv kev sim qaug zog ntev tom qab xa khoom. Kuv ceev faj tshwj xeeb nrog cov alloys. Peb ua hauj lwm nrog tshwj xeeb alloys nyob rau hauv casting muab peb ib tug noj qab nyob zoo kev hwm rau lawv theem stability. Siv qhov ntawd rau PM, sintering nickel-based superalloy tivthaiv tsis yog hais txog kev ua tiav qhov ntom ntom; Nws yog hais txog kev ua kom qhov tseeb gamma prime precipitate tsim thaum lub sij hawm txias, uas dictates nws high-temperature kev ua tau zoo. Qhov ntawd yuav tsum tau muaj kev kho mob tshwj xeeb tom qab sinter, feem ntau ua ke rau hauv lub voj voog txias ntawm lub cub tawg nws tus kheej.
Kev tswj xyuas zoo tom qab sinter tsis yog kev kuaj xyuas qhov ntev xwb. Nws yog metallography. Txiav ib feem los ntawm txhua lub cub tawg load, mounting, polishing, thiab etching nws mus saib lub pore qauv thiab grain loj. Puas yog cov pores sib npaug thiab cais (zoo) lossis sib cuam tshuam (tsis zoo)? Puas yog cov qauv qoob loo loj hlob dhau lawm? Qhov kev tsom xam ntawm tes no tsis yog sib tham. Nws yog daim ntawv qhia kawg rau cov txheej txheem sintering. Qee lub sij hawm, koj pom ib yam dab tsi npaj txhij txog - zoo li oxide suav nrog cov hmoov tsis huv - thiab kev tshawb nrhiav yuav tsum taug qab rov qab txawm tias ua ntej nias.
Sintering raws li tus nqi rooj vag
Thaum kawg, nyob rau hauv ib qho kev sib tw toj roob hauv pes, cov txheej txheem sintering yog lub rooj vag loj rau kev ntxiv tus nqi - lossis poob nws. Koj tuaj yeem muaj cov hmoov zoo meej, zoo meej nias, tab sis nruab nrab sintering, thiab koj xaus nrog cov khoom nruab nrab. Conversely, mastering sintering tuaj yeem qhib tag nrho cov peev txheej ntawm cov khoom siv, tso cai rau koj muab cov khoom sib tw wrought lossis cam khwb cia cov ntaub ntawv, tab sis nrog cov txiaj ntsig zoo ntawm PM. Rau ib lub tuam txhab xws li QSY, uas spans casting, machining, thiab koom nrog PM cov txheej txheem, qhov kev xav yog holistic. Peb pom sintering tsis yog ib qho kev sib cais thermal kauj ruam, tab sis raws li qhov tseeb microstructural tsim tshwm sim hauv PM saw. Nws yog qhov twg cov hmoov nplej tsis ua rau tib neeg thiab dhau los ua cov khoom sib xyaw ua ke, cov khoom siv engineering. Tau txais nws txoj cai yog dab tsi cais cov seem uas tsuas yog muaj los ntawm cov khoom uas ua tau zoo hauv thaj chaw. Thiab qhov ntawd, thaum kawg, yog dab tsi kev tsim khoom yog txhua yam hais txog.
