Carbide yog cov khoom siv dav siv hauv high-speed machining (HSM) cov cuab yeej, uas yog tsim los ntawm cov hmoov hlau metallurgy txheej txheem thiab muaj cov tawv carbide (feem ntau tungsten carbide WC) cov khoom thiab cov hlau nplaum sib xyaw. Tam sim no, muaj ntau pua ntawm WC-raws li cemented carbides nrog sib txawv compositions, feem ntau siv cobalt (Co) ua ib tug binder, npib tsib xee (Ni) thiab chromium (Cr) kuj yog feem ntau siv binder ntsiab, thiab lwm yam kuj yuav muab ntxiv. . qee qhov alloying. Vim li cas thiaj muaj ntau qib carbide? Yuav ua li cas cov tuam txhab tsim cov cuab yeej xaiv cov cuab yeej zoo rau kev ua haujlwm tshwj xeeb? Txhawm rau teb cov lus nug no, cia peb xub saib ntau yam khoom uas ua rau cemented carbide yog cov khoom siv zoo tagnrho.
hardness thiab toughness
WC-Co cemented carbide muaj qhov tshwj xeeb zoo hauv ob qho tib si hardness thiab toughness. Tungsten carbide (WC) inherently nyuaj heev (ntau tshaj corundum los yog alumina), thiab nws hardness tsis tshua muaj txo thaum khiav hauj lwm kub nce. Txawm li cas los xij, nws tsis muaj qhov toughness txaus, yog ib qho khoom tseem ceeb rau cov cuab yeej txiav. Txhawm rau kom tau txais txiaj ntsig zoo ntawm qhov nyuaj siab ntawm tungsten carbide thiab txhim kho nws cov tawv nqaij, cov neeg siv cov ntawv cog lus hlau rau kev sib raug zoo ntawm tungsten carbide ua ke, kom cov khoom no muaj hardness deb tshaj li ntawm high-speed steel, thaum muaj peev xwm tiv taus feem ntau txiav. kev ua haujlwm. txiav quab yuam. Tsis tas li ntawd, nws muaj peev xwm tiv taus qhov kub txiav kub uas tshwm sim los ntawm kev kub ceev machining.
Niaj hnub no, yuav luag tag nrho WC-Co riam thiab cov ntxig yog coated, yog li lub luag haujlwm ntawm cov khoom siv hauv paus zoo li tsis tshua muaj txiaj ntsig. Tab sis qhov tseeb, nws yog lub siab elastic modulus ntawm cov khoom siv WC-Co (ib qho kev ntsuas nruj, uas yog kwv yees li peb zaug ntawm high-speed steel ntawm chav tsev kub) uas muab cov tsis-deformable substrate rau txheej. WC-Co matrix kuj muab qhov xav tau toughness. Cov khoom no yog cov khoom tseem ceeb ntawm WC-Co cov ntaub ntawv, tab sis cov khoom siv kuj tuaj yeem raug kho los ntawm kev kho cov khoom muaj pes tsawg leeg thiab microstructure thaum tsim cov cemented carbide hmoov. Yog li, qhov tsim nyog ntawm cov cuab yeej ua tau zoo rau ib qho kev ua haujlwm tshwj xeeb yog nyob ntawm qhov loj ntawm cov txheej txheem milling thawj zaug.
Cov txheej txheem milling
tungsten carbide hmoov yog tau los ntawm carburizing tungsten (W) hmoov. Cov yam ntxwv ntawm tungsten carbide hmoov (tshwj xeeb tshaj yog nws qhov loj me) feem ntau yog nyob ntawm seb qhov loj me ntawm cov khoom siv raw tungsten hmoov thiab qhov kub thiab txias thiab lub sijhawm ntawm carburization. Kev tswj tshuaj lom neeg kuj tseem ceeb heev, thiab cov ntsiab lus ntawm cov pa roj carbon monoxide yuav tsum tau nyob tas li (ze rau tus nqi stoichiometric ntawm 6.13% los ntawm qhov hnyav). Ib qho me me ntawm vanadium thiab / lossis chromium tuaj yeem raug ntxiv ua ntej kev kho mob carburizing txhawm rau tswj cov hmoov particle loj los ntawm cov txheej txheem tom ntej. Cov txheej txheem kev sib txawv hauv qab thiab qhov sib txawv siv qhov kawg yuav tsum muaj kev sib xyaw tshwj xeeb ntawm tungsten carbide particle loj, cov ntsiab lus carbon, cov ntsiab lus vanadium thiab chromium cov ntsiab lus, los ntawm qhov sib txawv ntawm cov hmoov sib txawv tungsten carbide tuaj yeem tsim tau. Piv txwv li, ATI Alldyne, lub chaw tsim khoom tungsten carbide hmoov, tsim 23 tus qauv qib ntawm tungsten carbide hmoov, thiab ntau hom tungsten carbide hmoov customized raws li tus neeg siv yuav tsum tau ncav cuag ntau tshaj 5 npaug ntawm cov qauv qib ntawm tungsten carbide hmoov.
Thaum sib tov thiab sib tsoo tungsten carbide hmoov thiab hlau daim ntawv cog lus los tsim ib qib ntawm cemented carbide hmoov, ntau yam kev sib txuas tuaj yeem siv tau. Cov ntsiab lus siv cobalt feem ntau yog 3% - 25% (qhov hnyav piv), thiab yog tias xav tau los txhim kho corrosion kuj ntawm cov cuab yeej, nws yog ib qho tsim nyog yuav tsum tau ntxiv npib tsib xee thiab chromium. Tsis tas li ntawd, daim ntawv cog lus hlau tuaj yeem txhim kho ntxiv los ntawm kev ntxiv lwm cov khoom siv hlau. Piv txwv li, ntxiv ruthenium rau WC-Co cemented carbide tuaj yeem txhim kho nws cov tawv nqaij tsis muaj txo nws qhov tawv. Ntxiv cov ntsiab lus ntawm binder tuaj yeem txhim kho qhov toughness ntawm cemented carbide, tab sis nws yuav txo nws cov hardness.
Txo qhov luaj li cas ntawm tungsten carbide hais tuaj yeem ua rau cov khoom tawv tawv, tab sis qhov loj me ntawm tungsten carbide yuav tsum nyob twj ywm tib yam thaum lub sij hawm sintering. Thaum lub sij hawm sintering, cov tungsten carbide hais ua ke thiab loj hlob los ntawm ib tug txheej txheem ntawm dissolution thiab reprecipitation. Nyob rau hauv qhov tseeb sintering cov txheej txheem, nyob rau hauv thiaj li yuav tsim cov khoom siv ntom ntom ntom ntom ntom ntom, cov hlau sib khi ua kua (hu ua kua Theem Sintering). Kev loj hlob ntawm tungsten carbide hais tuaj yeem tswj tau los ntawm kev ntxiv lwm cov kev hloov pauv hlau carbide, suav nrog vanadium carbide (VC), chromium carbide (Cr3C2), titanium carbide (TiC), tantalum carbide (TaC), thiab niobium carbide (NbC). Cov hlau carbides feem ntau yog ntxiv thaum cov tungsten carbide hmoov sib tov thiab milled nrog ib daim ntawv cog lus hlau, txawm hais tias vanadium carbide thiab chromium carbide tuaj yeem tsim tau thaum tungsten carbide hmoov yog carburized.
Tungsten carbide hmoov kuj tseem tuaj yeem tsim los ntawm kev siv cov khoom siv pov tseg cemented carbide. Kev rov ua dua tshiab thiab rov siv dua ntawm cov khoom seem carbide muaj keeb kwm ntev hauv kev lag luam cemented carbide thiab yog ib feem tseem ceeb ntawm tag nrho cov kev lag luam hauv kev lag luam, pab txo cov nqi khoom siv, txuag cov peev txheej ntuj thiab zam cov khoom pov tseg. Kev pov tseg tsis zoo. Cov khib nyiab cemented carbide feem ntau tuaj yeem rov qab siv los ntawm APT (ammonium paratungstate) txheej txheem, zinc rov qab txheej txheem lossis los ntawm crushing. Cov "recycled" tungsten carbide hmoov feem ntau muaj qhov zoo dua, kev kwv yees qhov hnyav vim tias lawv muaj thaj chaw me dua li cov hmoov tungsten carbide ua ncaj qha los ntawm cov txheej txheem tungsten carburizing.
Cov txheej txheem ua tiav ntawm kev sib xyaw sib xyaw ntawm tungsten carbide hmoov thiab hlau daim ntawv cog lus kuj tseem yog cov txheej txheem tseem ceeb. Ob txoj kev siv milling feem ntau yog pob milling thiab micromilling. Ob txoj kev ua kom muaj kev sib xyaw ntawm cov hmoov milled thiab txo qhov me me. Txhawm rau ua kom lub zog ua haujlwm tom qab muaj lub zog txaus, tswj cov duab ntawm lub workpiece, thiab pab kom tus neeg teb xov tooj lossis tus neeg siv khoom tuaj tos lub workpiece rau kev ua haujlwm, feem ntau yuav tsum tau ntxiv cov organic binder thaum sib tsoo. Cov tshuaj muaj pes tsawg leeg ntawm daim ntawv cog lus no tuaj yeem cuam tshuam qhov ntom thiab lub zog ntawm cov khoom siv nias. Txhawm rau ua kom yooj yim tuav, nws raug nquahu kom ntxiv cov ntaub ntawv muaj zog, tab sis qhov no ua rau qis qis qis thiab tuaj yeem tsim cov pob uas tuaj yeem ua rau muaj qhov tsis xws luag hauv cov khoom kawg.
Tom qab milling, cov hmoov feem ntau yog tshuaj tsuag-qhuav kom tsim cov av dawb-ntws agglomerates tuav ua ke los ntawm cov organic binders. Los ntawm kev kho qhov muaj pes tsawg leeg ntawm cov organic binder, cov flowability thiab nqi ceev ntawm cov agglomerates tuaj yeem raug kho raws li qhov xav tau. Los ntawm kev tshuaj xyuas cov coarser los yog finer particles, cov particle loj tis ntawm lub agglomerate tuaj yeem raug kho ntxiv kom zoo txaus thaum thauj mus rau hauv pwm kab noj hniav.
Workpiece kev tsim khoom
Carbide workpieces tuaj yeem tsim los ntawm ntau txoj hauv kev. Nyob ntawm qhov loj ntawm lub workpiece, theem ntawm cov duab complexity, thiab ntau lawm batch, feem ntau txiav inserts yog molded siv sab saum toj- thiab hauv qab-siab rigid tuag. Txhawm rau kom tswj tau qhov sib xws ntawm qhov hnyav thiab qhov loj me thaum lub sijhawm nias, nws yog ib qho tsim nyog yuav tsum xyuas kom meej tias cov hmoov nplej (ntau thiab ntim) ntws mus rau hauv kab noj hniav yog tib yam. Lub fluidity ntawm cov hmoov yog tsuas yog tswj los ntawm qhov loj me me ntawm cov agglomerates thiab cov khoom ntawm cov organic binder. Moulded workpieces (los yog "blanks") yog tsim los ntawm kev siv lub molding siab ntawm 10-80 ksi (kilo pounds ib square feet) rau cov hmoov loaded rau hauv pwm kab noj hniav.
Txawm tias nyob rau hauv lub siab heev molding siab, lub zog tungsten carbide hais yuav tsis deform los yog tawg, tab sis cov organic binder yog nias rau hauv qhov sib txawv ntawm tungsten carbide hais, yog li kho txoj hauj lwm ntawm cov khoom. Qhov siab dua, qhov kev sib txuas ntawm cov tungsten carbide ntau dua thiab cov compaction ceev ntawm lub workpiece ntau dua. Cov khoom molding ntawm qib ntawm cemented carbide hmoov yuav txawv, nyob ntawm seb cov ntsiab lus ntawm cov hlau nplaum, qhov loj thiab cov duab ntawm tungsten carbide hais, qib ntawm agglomeration, thiab muaj pes tsawg leeg thiab ntxiv cov organic binder. Txhawm rau muab cov ntaub ntawv ntau ntxiv txog cov khoom sib txuas ntawm cov qib ntawm cov cemented carbide hmoov, kev sib raug zoo ntawm molding ntom thiab molding siab feem ntau yog tsim thiab tsim los ntawm cov khoom siv hmoov. Cov ntaub ntawv no ua kom ntseeg tau tias cov hmoov nkag tau zoo nrog cov cuab yeej tsim cov txheej txheem molding.
Loj-loj carbide workpieces los yog carbide workpieces nrog siab nam piv (xws li shanks rau kawg mills thiab xyaum) yog feem ntau tsim los ntawm uniformly nias qib ntawm carbide hmoov nyob rau hauv ib lub hnab hloov tau yooj yim. Txawm hais tias lub voj voog ntau lawm ntawm txoj kev sib npaug sib npaug ntev dua li ntawm txoj kev molding, cov nqi tsim khoom ntawm cov cuab yeej qis dua, yog li txoj kev no yog qhov tsim nyog rau cov khoom me me.
Cov txheej txheem no yog muab cov hmoov tso rau hauv lub hnab, thiab muab lub hnab ntim rau hauv lub qhov ncauj, thiab tom qab ntawd muab lub hnab ntim cov hmoov ntim rau hauv lub chamber, thiab siv lub siab ntawm 30-60ksi los ntawm lub tshuab hydraulic los nias. Pressed workpieces feem ntau machined rau tej geometry ua ntej sintering. Qhov luaj li cas ntawm lub hnab yog nthuav kom haum raws li lub workpiece shrinkage thaum lub sij hawm compaction thiab muab cov npoo txaus rau kev sib tsoo. Txij li thaum lub workpiece yuav tsum tau ua tiav tom qab nias, qhov yuav tsum tau rau qhov sib xws ntawm kev them nyiaj tsis yog nruj raws li cov txheej txheem molding, tab sis nws tseem tsim nyog los xyuas kom meej tias tib cov hmoov ntim rau hauv lub hnab txhua zaus. Yog tias qhov kev them nyiaj ntawm cov hmoov me me dhau lawm, nws yuav ua rau cov hmoov tsis txaus hauv lub hnab, ua rau cov khoom ua haujlwm me dhau thiab yuav tsum tau muab pov tseg. Yog tias qhov ntim ntawm cov hmoov nplej siab dhau lawm, thiab cov hmoov ntim rau hauv lub hnab ntim ntau dhau lawm, lub workpiece yuav tsum tau ua tiav kom tshem tawm cov hmoov ntxiv tom qab nws nias. Txawm hais tias cov hmoov ntau dhau raug tshem tawm thiab cov khoom ua haujlwm uas tau muab tshem tawm tuaj yeem rov ua dua, ua li ntawd txo cov khoom lag luam.
Carbide workpieces kuj tuaj yeem tsim siv extrusion tuag lossis txhaj tshuaj tuag. Cov txheej txheem extrusion molding yog qhov tsim nyog rau kev tsim cov khoom loj ntawm axisymmetric duab workpieces, thaum cov txheej txheem txhaj tshuaj molding feem ntau yog siv rau cov khoom loj ntawm cov duab ua haujlwm. Nyob rau hauv ob qho tib si txheej txheem molding, qib ntawm cemented carbide hmoov raug tshem tawm hauv cov organic binder uas muab cov tshuaj txhuam hniav zoo li sib xws rau cov cemented carbide mix. Lub compound yog ces extruded los ntawm ib lub qhov los yog txhaj rau hauv kab noj hniav rau daim ntawv. Cov yam ntxwv ntawm qib ntawm cemented carbide hmoov txiav txim siab qhov zoo tshaj plaws piv ntawm cov hmoov rau binder nyob rau hauv qhov sib tov, thiab muaj ib qho tseem ceeb ntawm cov flowability ntawm cov sib tov los ntawm extrusion qhov los yog txhaj rau hauv kab noj hniav.
Tom qab lub workpiece yog tsim los ntawm molding, isostatic nias, extrusion los yog txhaj molding, cov organic binder yuav tsum tau muab tshem tawm los ntawm lub workpiece ua ntej sintering kawg theem. Sintering tshem tawm cov porosity ntawm lub workpiece, ua kom nws tag nrho (los yog loj) ntom. Thaum lub sij hawm sintering, hlau daim ntawv cog lus nyob rau hauv lub xovxwm-tsim workpiece ua kua, tab sis lub workpiece khaws nws cov duab nyob rau hauv lub ua ke ntawm capillary rog thiab particle linkage.
Tom qab sintering, lub workpiece geometry tseem zoo li qub, tab sis qhov ntev yog txo. Txhawm rau kom tau txais qhov yuav tsum tau ua haujlwm loj tom qab sintering, tus nqi shrinkage yuav tsum tau txiav txim siab thaum tsim cov cuab yeej. Qib ntawm carbide hmoov siv los ua txhua lub cuab yeej yuav tsum tau tsim kom muaj qhov tseeb shrinkage thaum compacted nyob rau hauv lub siab tsim nyog.
Yuav luag txhua qhov xwm txheej, kev kho tom qab sintering ntawm sintered workpiece yog xav tau. Txoj kev kho mob yooj yim tshaj plaws ntawm cov cuab yeej txiav yog txhawm rau txhawm rau txiav ntug. Ntau cov cuab yeej xav tau kev sib tsoo ntawm lawv cov geometry thiab qhov ntev tom qab sintering. Qee cov cuab yeej xav tau kev sib tsoo sab saum toj thiab hauv qab; lwm tus xav tau kev sib tsoo peripheral (nrog lossis tsis muaj qhov txiav ntug). Tag nrho cov carbide chips los ntawm kev sib tsoo tuaj yeem rov ua dua.
Workpiece txheej
Feem ntau, cov khoom ua tiav tiav yuav tsum tau coated. Cov txheej txheej muab lubricity thiab nce hardness, nrog rau qhov sib txawv ntawm qhov sib txawv ntawm lub substrate, tiv thaiv oxidation thaum raug kub. Cov cemented carbide substrate yog qhov tseem ceeb rau kev ua haujlwm ntawm txheej txheej. Ntxiv nrog rau kev txiav cov khoom tseem ceeb ntawm cov hmoov matrix, cov khoom nto ntawm cov matrix kuj tuaj yeem raug txiav los ntawm kev xaiv tshuaj thiab hloov txoj kev sintering. Los ntawm kev tsiv teb tsaws ntawm cobalt, ntau cobalt tuaj yeem ua kom muaj txiaj ntsig zoo nyob rau hauv txheej txheej sab nraud ntawm cov hniav hauv qhov tuab ntawm 20-30 μm txheeb ze rau qhov seem ntawm cov khoom ua haujlwm, yog li muab cov nplaim ntawm cov substrate zoo dua lub zog thiab toughness, ua rau nws ntau dua. resistant rau deformation.
Raws li lawv tus kheej tsim cov txheej txheem (xws li dewaxing txoj kev, cua sov tus nqi, sintering lub sij hawm, kub thiab carburizing voltage), lub tuam txhab tsim khoom yuav muaj ib co tshwj xeeb yuav tsum tau rau qib ntawm cemented carbide hmoov siv. Qee tus neeg tsim khoom tuaj yeem sinter lub workpiece nyob rau hauv lub tshuab nqus tsev vacuum, thaum lwm tus neeg yuav siv lub kub isostatic nias (HIP) sintering rauv (uas pressurizes lub workpiece nyob ze rau qhov kawg ntawm lub voj voog txheej txheem kom tshem tawm tej yam residues) pores). Cov workpieces sintered nyob rau hauv lub tshuab nqus tsev vacuum kuj yuav tsum tau kub isostatically nias los ntawm ib tug ntxiv txheej txheem los ua kom qhov ceev ntawm lub workpiece. Qee cov tuam txhab lag luam tuaj yeem siv lub tshuab nqus tsev sintering ntau dua los ua kom cov sintered ntom ntom ntawm cov khoom sib xyaw nrog cov ntsiab lus cobalt qis, tab sis txoj hauv kev no yuav coarsen lawv cov microstructure. Txhawm rau kom tswj tau qhov loj me me, cov hmoov nplej nrog cov khoom me me ntawm tungsten carbide tuaj yeem xaiv. Txhawm rau kom phim cov khoom siv tshwj xeeb, cov dewaxing tej yam kev mob thiab carburizing voltage kuj muaj cov kev cai sib txawv rau cov ntsiab lus ntawm cov cemented carbide hmoov.
Qib qeb
Kev sib xyaw ua ke ntawm ntau hom tungsten carbide hmoov, sib tov muaj pes tsawg leeg thiab cov ntsiab lus hlau binder, hom thiab tus nqi ntawm cov nplej loj hlob inhibitor, thiab lwm yam, ua rau ntau yam cemented carbide qib. Cov kev ntsuas no yuav txiav txim siab qhov microstructure ntawm cemented carbide thiab nws cov khoom. Qee qhov kev sib txuas tshwj xeeb ntawm cov khoom tau dhau los ua qhov tseem ceeb rau qee qhov kev ua haujlwm tshwj xeeb, ua rau nws muaj txiaj ntsig los faib ntau qib cemented carbide.
Ob qhov feem ntau siv carbide faib tshuab rau machining daim ntawv thov yog C thiab lub npe ISO system. Txawm hais tias tsis yog ob qho tib si cuam tshuam txog cov khoom siv uas cuam tshuam rau kev xaiv cov qib cemented carbide, lawv muab qhov pib rau kev sib tham. Rau txhua qhov kev faib tawm, ntau lub tuam txhab muaj lawv cov qib tshwj xeeb, uas ua rau muaj ntau yam carbide qib.
Cov qib carbide kuj tuaj yeem raug cais los ntawm kev muaj pes tsawg leeg. Tungsten carbide (WC) qib tuaj yeem muab faib ua peb hom: yooj yim, microcrystalline thiab alloyed. Cov qib yooj yim muaj feem ntau ntawm tungsten carbide thiab cobalt binders, tab sis kuj tseem tuaj yeem muaj me me ntawm cov nplej loj hlob inhibitors. Cov qib microcrystalline yog tsim los ntawm tungsten carbide thiab cobalt binder ntxiv nrog ntau txhiab ntawm vanadium carbide (VC) thiab (lossis) chromium carbide (Cr3C2), thiab nws cov nplej loj tuaj yeem ncav cuag 1 μm lossis tsawg dua. Cov qib alloy yog tsim los ntawm tungsten carbide thiab cobalt binders uas muaj ob peb feem pua titanium carbide (TiC), tantalum carbide (TaC), thiab niobium carbide (NbC). Cov kev ntxiv no tseem hu ua cubic carbides vim lawv cov khoom sintering. Qhov tshwm sim microstructure nthuav tawm cov qauv peb-theem inhomogeneous.
1) Cov qib yooj yim carbide
Cov qib no rau kev txiav hlau feem ntau muaj 3% mus rau 12% cobalt (los ntawm qhov hnyav). Qhov loj ntawm tungsten carbide nplej yog feem ntau ntawm 1-8 μm. Raws li nrog rau lwm qib, txo qhov me me ntawm tungsten carbide ua rau nws cov hardness thiab transverse rupture zog (TRS), tab sis txo nws cov toughness. Lub hardness ntawm hom ntshiab yog feem ntau ntawm HRA89-93.5; lub transverse rupture lub zog yog feem ntau ntawm 175-350ksi. Cov hmoov ntawm cov qib no tuaj yeem muaj cov khoom siv rov ua dua tshiab.
Cov qib yooj yim tuaj yeem muab faib ua C1-C4 hauv qib C, thiab tuaj yeem faib raws li qib K, N, S thiab H qib hauv qib ISO. Cov qib yooj yim nrog cov khoom nruab nrab tuaj yeem muab faib ua cov hom phiaj dav dav (xws li C2 lossis K20) thiab tuaj yeem siv rau kev tig, milling, npaj thiab tho txawv; Cov qib nrog cov nplej me me lossis cov ntsiab lus cobalt qis dua thiab muaj zog dua tuaj yeem raug cais raws li qib tiav (xws li C4 lossis K01); Cov qib nrog cov qoob loo loj dua lossis cov ntsiab lus cobalt siab dua thiab zoo dua tuaj yeem raug cais raws li qib roughing (xws li C1 lossis K30).
Cov cuab yeej ua hauv cov qib Simplex tuaj yeem siv rau kev ua haujlwm cam khwb cia hlau, 200 thiab 300 series stainless hlau, txhuas thiab lwm yam hlau tsis-ferrous, superalloys thiab hardened steels. Cov qib no tseem tuaj yeem siv rau hauv cov ntawv txiav tsis yog hlau (xws li cov cuab yeej pob zeb thiab geological drilling), thiab cov qib no muaj cov nplej loj ntawm 1.5-10μm (los yog loj dua) thiab cov ntsiab lus cobalt ntawm 6% -16%. Lwm qhov tsis yog hlau txiav siv cov qib carbide yooj yim yog nyob rau hauv kev tsim cov tuag thiab xuas nrig ntaus. Cov qib no feem ntau muaj qhov nruab nrab cov nplej loj nrog cov ntsiab lus cobalt ntawm 16% -30%.
(2) Microcrystalline cemented carbide qib
Cov qib no feem ntau muaj 6%-15% cobalt. Thaum lub sij hawm ua kua theem sintering, qhov sib ntxiv ntawm vanadium carbide thiab / los yog chromium carbide tuaj yeem tswj cov qoob loo loj hlob kom tau txais cov qauv zoo nplej nrog qhov me me ntawm tsawg dua 1 μm. Qhov no zoo-grained qib muaj hardness siab heev thiab transverse rupture zog tshaj 500ksi. Kev sib xyaw ua ke ntawm lub zog siab thiab muaj zog txaus tso cai rau cov qib no siv lub kaum sab xis zoo dua qub, uas txo cov kev txiav quab yuam thiab ua kom nyias nyias los ntawm kev txiav es tsis txhob thawb cov khoom siv hlau.
Los ntawm kev txheeb xyuas qhov zoo ntawm ntau yam khoom siv raw hauv kev tsim cov qib ntawm cov cemented carbide hmoov, thiab kev tswj nruj ntawm cov txheej txheem sintering los tiv thaiv kev tsim cov nplej loj loj hauv cov khoom siv microstructure, nws muaj peev xwm kom tau txais cov khoom tsim nyog. Txhawm rau kom cov qoob loo me me thiab tsis sib xws, cov hmoov siv rov ua dua tshiab yuav tsum tsuas yog siv yog tias muaj kev tswj xyuas tag nrho ntawm cov khoom siv raw thiab cov txheej txheem rov qab, thiab kev kuaj xyuas zoo.
Cov qib microcrystalline tuaj yeem raug cais raws li qib M qib hauv qib ISO. Tsis tas li ntawd, lwm txoj kev faib tawm hauv qib C thiab qib ISO yog tib yam li cov qib ntshiab. Cov qib microcrystalline tuaj yeem siv los ua cov cuab yeej uas txiav cov khoom ua haujlwm softer, vim tias cov cuab yeej saum npoo tuaj yeem ua tau zoo heev thiab tuaj yeem tswj tau qhov kev txiav tawm tsis tshua muaj siab.
Cov qib microcrystalline kuj tuaj yeem siv los ua cov tshuab nickel-based superalloys, vim lawv tuaj yeem tiv taus qhov kub txog li 1200 ° C. Rau kev ua cov superalloys thiab lwm yam khoom siv tshwj xeeb, kev siv cov cuab yeej qib microcrystalline thiab cov cuab yeej qib ntshiab uas muaj ruthenium tuaj yeem txhim kho lawv cov hnav tsis kam, deformation kuj thiab toughness. Cov qib microcrystalline kuj tseem tsim nyog rau kev tsim cov cuab yeej tig xws li kev xyaum ua kom muaj zog shear. Muaj ib lub laum ua los ntawm cov qib sib xyaw ntawm cemented carbide. Hauv qee qhov chaw ntawm tib lub laum, cov ntsiab lus cobalt nyob rau hauv cov khoom sib txawv, kom lub hardness thiab toughness ntawm lub laum yog optimized raws li kev xav tau.
(3) Alloy hom cemented carbide qib
Cov qib no feem ntau yog siv los txiav cov hlau, thiab lawv cov ntsiab lus cobalt feem ntau yog 5% -10%, thiab cov nplej loj li ntawm 0.8-2μm. Los ntawm kev ntxiv 4% -25% titanium carbide (TiC), qhov kev nyiam ntawm tungsten carbide (WC) kom diffuse rau saum npoo ntawm cov hlau chips tuaj yeem txo. Cov cuab yeej muaj zog, qhov hnyav hnyav hnav tsis kam thiab thermal shock kuj tuaj yeem txhim kho los ntawm kev ntxiv txog 25% tantalum carbide (TaC) thiab niobium carbide (NbC). Qhov sib ntxiv ntawm xws li cubic carbides kuj ua rau cov liab hardness ntawm lub cuab tam, pab kom tsis txhob thermal deformation ntawm lub cuab tam nyob rau hauv hnyav txiav los yog lwm yam kev khiav hauj lwm qhov twg lub txiav ntug yuav ua rau kub kub. Tsis tas li ntawd, titanium carbide tuaj yeem muab qhov chaw nucleation thaum lub sij hawm sintering, txhim kho qhov sib xws ntawm cubic carbide tis nyob rau hauv lub workpiece.
Feem ntau hais lus, qhov nyuaj ntawm cov alloy-hom cemented carbide qib yog HRA91-94, thiab lub zog tawg ntawm lub zog yog 150-300ksi. Piv nrog rau cov qib ntshiab, cov qib alloy muaj kev hnav tsis zoo thiab qis zog, tab sis muaj kev tiv thaiv zoo dua rau cov nplaum hnav. Cov qib alloy tuaj yeem muab faib ua C5-C8 hauv qib C, thiab tuaj yeem faib ua raws li qib P thiab M qib hauv qib ISO. Cov qib alloy nrog cov khoom nruab nrab tuaj yeem muab faib ua cov hom phiaj dav dav (xws li C6 lossis P30) thiab tuaj yeem siv rau kev tig, tapping, npaj thiab milling. Cov qib nyuaj tshaj plaws tuaj yeem raug cais raws li qib tiav (xws li C8 thiab P01) rau kev ua tiav txoj haujlwm tig thiab tho txawv. Cov qib no feem ntau muaj qhov me me thiab cov ntsiab lus cobalt qis kom tau txais qhov xav tau hardness thiab hnav tsis kam. Txawm li cas los xij, cov khoom zoo sib xws tuaj yeem tau txais los ntawm kev ntxiv cov cubic carbide ntau dua. Cov qib uas muaj lub siab tawv siab tshaj plaws tuaj yeem muab faib ua qib roughing (xws li C5 lossis P50). Cov qib no feem ntau muaj qhov nruab nrab ntawm cov nplej loj thiab cov ntsiab lus cobalt siab, nrog qis ntxiv ntawm cubic carbides kom ua tiav qhov xav tau tawv los ntawm inhibiting kev loj hlob tawg. Hauv kev cuam tshuam kev ua haujlwm, kev ua haujlwm txiav tuaj yeem txhim kho ntxiv los ntawm kev siv cov qib cobalt-nplua nuj hais saum toj no nrog cov ntsiab lus cobalt ntau dua ntawm cov cuab yeej nto.
Cov qib alloy nrog qis dua titanium carbide cov ntsiab lus yog siv los ua cov hlau tsis muaj steel thiab cov hlau tsis zoo, tab sis kuj tuaj yeem siv rau kev ua cov hlau tsis muaj hlau xws li npib tsib xee-based superalloys. Cov nplej loj ntawm cov qib no feem ntau tsawg dua 1 μm, thiab cov ntsiab lus cobalt yog 8% -12%. Cov qib nyuaj, xws li M10, tuaj yeem siv los tig cov hlau tsis zoo; Cov qib tougher, xws li M40, tuaj yeem siv rau milling thiab npaj steel, lossis tig stainless hlau lossis superalloys.
Alloy-type cemented carbide qib kuj tuaj yeem siv rau cov hom phiaj tsis yog hlau txiav, feem ntau yog siv los ua cov khoom hnav-tiv taus. Qhov loj me ntawm cov qib no feem ntau yog 1.2-2 μm, thiab cov ntsiab lus cobalt yog 7% -10%. Thaum tsim cov qib no, feem ntau ntawm cov khoom siv rov ua dua tshiab feem ntau yog ntxiv, ua rau muaj txiaj ntsig zoo hauv cov khoom siv hnav. Hnav cov khoom yuav tsum tau zoo corrosion kuj thiab siab hardness, uas tuaj yeem tau los ntawm kev ntxiv npib tsib xee thiab chromium carbide thaum tsim cov qib no.
Yuav kom ua tau raws li cov kev cai thiab kev lag luam ntawm cov tuam txhab tsim khoom, carbide hmoov yog lub hauv paus tseem ceeb. Cov hmoov tsim los rau cov tuam txhab tsim cov khoom siv machining thiab cov txheej txheem tsis ua haujlwm kom ua tiav cov haujlwm ua tiav thiab tau ua rau ntau pua qib carbide. Cov khoom siv rov ua dua tshiab ntawm cov ntaub ntawv carbide thiab muaj peev xwm ua haujlwm ncaj qha nrog cov khoom siv hmoov tso cai rau cov neeg tsim khoom los tswj lawv cov khoom zoo thiab cov nqi khoom.
Post lub sij hawm: Oct-18-2022
