Yuav ua li cas txhawm rau tungsten carbide?

    Tungsten Carbide cov khoom siv ntau yam kev siv, suav nrog cov cuab yeej txiav, drilling, xuas nrig ntaus, thiab ntau lwm yam kev siv. Cemented Carbide muab kev hnav zoo dua thiab ua kom ntev lub neej ntawm cov khoom siv coj los txiav thiab txiav. Ua rau nws cov ntsiab lus tseem ceeb yog tungsten, uas yog ib qho tsis tshua muaj thiab tsis tuaj yeem siv dua tshiab, tus nqi ntawm cov cemented carbide kuj siab heev. Tsis tas li ntawd, cemented carbide muaj qhov hardness siab, thiab nws lub zog dabtsi yog khoov qis dua li lwm cov hlau, xws li hlau. Rau ob qho laj thawj no, cemented carbide yuav tsum txuas nrog lwm cov hlau sib txawv, xws li los ntawm kev sib txuas xov, clamping, thiab vuam. Kab lus no tab tom tham txog yuav ua li cas txhawm rau tungsten carbide ntawm lwm cov hlau.

1. Dab tsi yog tungsten carbide?

    Tungsten carbide (WC), tseem hu ua cemented carbide, yog cov khoom sib xyaw tsim los ntawm cov txheej txheem hu ua hmoov metallurgy. WC hmoov yog tov nrog ib tug binder hlau, feem ntau cobalt los yog npib tsib xee, compacted nyob rau hauv ib tug preform tooling, thiab ces sintered nyob rau hauv lub cub tawg. Lo lus "cemented" yog hais txog cov tungsten carbide hais tau raug ntes nyob rau hauv cov khoom siv hlau nplaum thiab "cemented" ua ke, tsim cov hlau sib txuas ntawm tungsten carbide hais thiab cov ntawv khi (WC-Co), hauv cov txheej txheem sintering. Kev lag luam cemented carbide feem ntau hais txog cov khoom siv no tsuas yog "carbide", txawm hais tias cov ntsiab lus tungsten carbide thiab cemented carbide tau siv sib hloov.  Carbide nthuav tawm lub zog compressive siab, tiv thaiv deflection, thiab khaws nws cov hardness qhov tseem ceeb ntawm qhov kub thiab txias, cov cuab yeej siv lub cev tshwj xeeb tshwj xeeb hauv kev siv hlau txiav. 

2. Ob lub ntsiab lus los xyuas kom meej qhov kev vam meej hauv brazing tungsten carbide

A. Tswj cov kev ntxhov siab los ntawm kev nthuav dav sib txawv

B.Contraction tus nqi ntawm niam txiv cov ntaub ntawv thiab ntub ntawm cov carbide los ntawm braze alloy

    Thaum cua sov thiab cua txias, lub hauv paus niam txiv hlau feem ntau yuav nthuav dav thiab cog lus ntawm tus nqi siab dua li cov carbide.  Tungsten carbide muaj qhov thermal expansion ntawm kwv yees li 1/3 txog 1/2 ntawm cov hlau.  Thaum lub brazed sib dhos txias, qhov kev ntxhov siab seem yuav tsim nyob rau hauv cov carbide.  Kev ua kom qeeb qeeb ntawm cov carbide yog ib txwm pom zoo kom tsis txhob muaj kev ntxhov siab thiab ua rau tawg. quenching tsis pom zoo vim nws tuaj yeem ua rau tawg ntawm cov carbides vim qhov kev cog lus nrawm ntawm niam txiv lub hauv paus hlau.

3. Yuav ua li cas xaiv lub braze alloy

    Tungsten carbide yog qhov nyuaj rau ntub dej. Silver braze alloys nrog me me ntxiv ntawm Nickel (Ni) feem ntau yog siv los braze carbides rau hlau. Tau kawg, ob qho tib si carbide thiab hlau yuav tsum huv si kom cov molten braze alloy tuaj yeem ntub cov mating nto tag nrho. Sib tsoo cov carbide nto los tsim ib qho chaw huv si rau brazing yog tsim nyog. Sib tsoo kuj muaj qhov zoo ntawm flattening saum npoo topography ntawm carbide, uas tuaj yeem pab nrog braze alloy wetting thiab adhesion. Cov khoom siv hlau, zoo ib yam, yuav tsum tau muab ntxuav kom tshem tawm cov roj uas seem, roj, av, lossis lwm yam khoom paug.  

    · Kev lag luam muaj nyiaj braze alloys nrog me me ntxiv ntawm npib tsib xee (Ni) thiab Manganese (Mn) yuav yooj yim ntub cemented carbide nto. Cov braze alloys feem ntau pom zoo ntub dej ntawm tungsten carbides.  Nws raug nquahu kom xaiv lub brazing muab tub lim hlau nrog qhov qis tshaj qhov ua tau brazing kub kom txo qis cov kev ntxhov siab nyob hauv qhov sib koom ua ke.  

Rau applications nrog rau brazing ntawm loj carbides, ib tug sandwich braze alloy feem ntau yog siv.  Yog tias cov carbide me me (1/2 nti 2) tsis tuaj yeem siv tau, lub sandwich alloy muaj txiaj ntsig zoo hauv kev tiv thaiv kev tawg thiab warpage ntawm carbide. Cov trimetals yog clad nrog ib tug braze muab tub lim rau ob sab ntawm ib tug tooj liab core.  

    · Txawm hais tias ntau qhov kev sib tham tau nyob ib puag ncig ntawm kev sib tsoo ntawm tungsten carbide (WC), peb yuav ploj yog tias peb tsis tau hais txog polycrystalline pob zeb diamond lossis PCD. Lub brazing kub rau PCD feem ntau khaws cia qis dua 1382 ° F (750 ° C) kom tsis txhob degradation ntawm pob zeb diamond.  Feem ntau, cov tuam txhab ntawm PCD cov lus qhia rau lub cev steel yuav siv qhov kub thiab txias, high-silver braze muab tub lim hlau, xws li BAg-24 braze alloy.  Qee cov tuam txhab lag luam siv cov hlau tsis muaj npib tsib xee lossis manganese, xws li BAg-5 lossis BAg-7 braze alloy, nrog rau qhov kub thiab txias thiab tsis ntub dej ntawm cov carbide thiab hlau.

    Lub brazing flux yog siv los tiv thaiv oxidation ntawm qhov chaw yuav tsum tau koom nrog thaum cua sov ntawm lub rooj sib txoos.  Flux hmoov yog siv nrog cov nyiaj braze alloys.  Dub flux hmoov feem ntau pom zoo los ntawm braze thiab flux manufacturers vim nws muaj qhov sib ntxiv ntawm boron thiab ua haujlwm zoo dua ntawm qhov kub thiab txias.

    Muaj ob peb lub brazing alloys siv rau carbide. Cov classic yog BAG-3, 50% nyiaj nrog Cadmium.  Qhov no yog ib qho khoom zoo heev, tab sis nws muaj Cadmium. Feem ntau siv yog BAG-7, 56% nyiaj nrog Tin, vim nws ntub tawm yooj yim; Txawm li cas los xij, nws yog ib qho tsis muaj zog brazing alloy, thiab kev sib koom ua ke tsis ua haujlwm feem ntau nrog cov hlau no. Qhov muaj zog tshaj plaws uas tsis yog-Cadmium alloy yog BAG-22, 49% nyiaj nrog manganese, tab sis nws yog me ntsis gummy hauv cov dej ntws. BAG-24, 50% Nyiaj, tsis muaj cadmium thiab tsis muaj kev cuam tshuam.  Nws ntws zoo tab sis yog li 40% tsis muaj zog dua li BAG-3 thiab BAG-22.

    Peb xav tau Dub Flux, txawm hais tias muaj ntau yam braze ua tiav nrog Dawb Flux. Nyob rau hauv ob qho tib si, lawv yog kom meej meej kub fluxes. Nyob rau hauv tas li ntawd, peb pom hais tias purified Black Flux muab zoo ndlwg thiab muaj zog pob qij txha zoo tib yam Black Flux.  

    Qhov kawg ntawm qhov kev ua yuam kev yog qhov sib koom ua ke. Kev cob qhia welder feem ntau xav sib sau ua ke thiab tom qab ntawd khiav cov hlaws. Thaum lawv braze, lawv xav sib sau ua ke cov khoom thiab ces wick lub brazing alloy rau hauv kev sib koom tes.   

    Thaum brazing carbide, nws feem ntau ua haujlwm zoo dua rau cov sab thiab hauv qab ntawm qhov thais, tom qab ntawd muab cov ntaub ntawv ntawm cov xaim hlau nyob hauv qab carbide.  Txhua yam koj ua ces yog cua sov kom txog thaum lub carbide nyob rau hauv qhov chaw.   

    Tus qauv yuav tsum yog cov carbide ruptures los yog cov hlau rips ua ntej kev sib koom ua tsis tiav.