Dab tsi koj tsis paub txog cov txheej txheem cemented carbide sintering

Cemented carbide yog tsim los ntawm ntau yam carbide thiab hlau ntsiab. Cov yam ntxwv ntawm cov ntaub ntawv no yog tias lawv tuaj yeem ncav cuag yuav luag 100% theoretical ntom ntom los ntawm cov kua theem sintering. Tom qab sintering, tsis tshua muaj porosity yog tus yuam sij kom ua tiav kev siv cov cemented carbide hauv kev ua haujlwm siab xws li hlau txiav, roj drilling khoom lossis hlau ua pwm.

Cemented carbide sintering yuav tsum tau ua tib zoo tswj kom tau qhov xav tau microstructure thiab tshuaj muaj pes tsawg leeg. Hauv ntau daim ntawv thov, cemented carbide yog siv nyob rau hauv lub xeev sintered. Qhov saum npoo ntawm sintered alloys feem ntau raug kev sib txhuam hnyav thiab kev ntxhov siab. Hauv cov ntawv txiav hlau feem ntau, qhov hnav qhov tob ntawm cov cuab yeej lub taub hau nto tshaj {{0}}.2 ~ 0.4mm, thiab cov cuab yeej raug txiav txim kom muab pov tseg. Yog li ntawd, nws yog ib qho tseem ceeb heev los txhim kho qhov kev ua tau zoo ntawm cov cemented carbide. Muaj ob txoj hauv kev rau cemented carbide sintering: ib qho yog hydrogen sintering-tswj cov muaj pes tsawg leeg ntawm cov khoom los ntawm theem cov tshuaj tiv thaiv kinetics hauv hydrogen thiab ntawm ib txwm siab, thiab lwm yam yog lub tshuab nqus tsev sintering-siv lub tshuab nqus tsev ib puag ncig los yog txo cov roj ambient siab los tswj. Kev sib xyaw ntawm cemented carbide los ntawm kev ua kom qeeb ntawm cov tshuaj tiv thaiv kinetics.

Nqus sintering muaj ntau yam kev siv hauv kev lag luam. Qee zaum, kub isostatic nias thiab kub isostatic nias kuj siv rau sintering. Cov thev naus laus zis no muaj qhov cuam tshuam tseem ceeb rau kev tsim cov cemented carbide. Hydrogen sintering: Hydrogen yog qhov txo qhov cua, tab sis thaum hydrogen reacts nrog sintering furnace phab ntsa los yog cov cab kuj, nws yuav hloov lwm yam Cheebtsam thiab muab ib tug haum carburization muaj peev xwm los tswj cov thermodynamic equilibrium nrog cemented carbide. Piv nrog hydrogen sintering, lub tshuab nqus tsev sintering muaj qhov zoo hauv qab no:

Ua ntej, lub tshuab nqus tsev sintering tuaj yeem tswj cov khoom muaj pes tsawg leeg zoo heev. Ntawm qhov siab ntawm 1.3 ~ 133pa, qhov sib pauv ntawm cov pa roj carbon thiab oxygen ntawm cov cua thiab cov hlau yog tsawg heev. Lub ntsiab tseem ceeb cuam tshuam qhov kev hloov pauv ntawm cov ntsiab lus yog cov ntsiab lus oxygen hauv carbide hais. Yog li, lub tshuab nqus tsev sintering muaj qhov zoo dua hauv kev tsim khoom ntawm sintered cemented carbide. Thaum lub sij hawm hydrogen sintering, lub peev xwm oxidation ntawm cov pa cua nyob rau hauv lub cub tawg nce vim yog infiltration ntawm hydrogen thiab cov tshuaj tiv thaiv ntawm hydrogen nrog ceramic rauv Cheebtsam. Lub tshuab nqus tsev sintering tsis muaj cov teeb meem no. Lub peev xwm oxidation hauv lub cub tawg yog qis dua li hauv hydrogen sintering. Yog li ntawd, lub tshuab nqus tsev sintering yog tsim nyog rau alloys uas muaj titanium carbide, tantalum carbide thiab niobium carbide, uas yog heev rhiab heev rau oxidation.

Qhov thib ob, lub tshuab nqus tsev sintering tuaj yeem hloov kho qhov system sintering, tshwj xeeb tshaj yog cov cua sov hauv cov cua sov theem, kom tau raws li qhov xav tau ntawm kev tsim khoom. Lub tshuab nqus tsev sintering yog kev ua haujlwm tsis sib xws, uas tuaj yeem hloov kho qhov xav tau sintering system, thaum hydrogen sintering feem ntau yog cov txheej txheem sintering tsis tu ncua, uas tuaj yeem tswj qhov kub ntawm txhua theem sintering.

Sintering kub isostatic nias: Sintering kub isostatic nias yog qee zaum kuj hu ua overpressure sintering thiab siab sintering. Lub tshuab hluav taws xob sintering tiag tiag yog lub tshuab nqus tsev sintering uas tuaj yeem ua kom muaj zog. Txhawm rau txo lossis tshem tawm cov voids seem, thaum kaw qhov pores yog tsim nyob rau hauv qhov chaw ntawm sintering kub, lub cub tawg yog ntim nrog inert roj los thov isostatic siab rau nws. Lub siab argon yog 1.5 ~ 10Mpa, uas yog qis dua qhov kub isostatic siab nyob rau hauv lub siab ib txwm. Cov txheej txheem sintering tshwj xeeb suav nrog kev tshem tawm cov roj nplua nyeem, txo oxide thiab carbide alloy sintering. Thaum kaw qhov pores tshwm nyob rau hauv lub sintering ntawm carbide, lub low-pressure kub static siab nyob rau hauv lub cub tawg yog nce mus rau ib tug ntau dua. Kub isostatic nias yog nqa tawm nyob rau hauv ib tug tshwj xeeb tsim high-pressure thawv, pressurized rau 100Mpa siv argon, thiab qhov kub thiab txias yog roughly tib yam li cov tsoos sintering kub. Feem ntau sintering yog ua ntej, thiab tom qab ntawd isostatic nias yog ua los tshem tawm ib qho me me ntawm cov seem seem uas tsis tuaj yeem tshem tawm los ntawm cov txheej txheem sintering ib txwm. Kub isostatic xovxwm yog lub ntsiab tseem ceeb peev. Raws li cov kauj ruam tom qab ua tiav ntawm sintering, nws ua rau cov nqi khiav lag luam, lub zog thiab roj siv, thiab cov voj voog ntau lawm. Cov cemented carbide ua los ntawm kub isostatic nias muaj cov yam ntxwv ntawm cov nplej zoo thiab cov ntsiab lus tsawg, yog li nws muaj zog dua. Txawm li cas los xij, txawm tias sintering kub isostatic nias los yog tom qab kub isostatic nias yog siv, tsuas yog los ntawm kev tsim kom muaj kev sib raug zoo ntawm lub sijhawm, qhov kub thiab txias tuaj yeem muaj zog ntau dua li hydrogen sintering thiab nqus sintering khoom.