Pob zeb diamond muaj cov khoom siv kho qhov muag zoo heev, kho qhov muag, thermal, thiab lwm yam khoom, ua rau nws muaj peev xwm siv dav hauv ntau qhov chaw. Tam sim no, kev lag luam pob zeb diamond tau dhau los ua qhov tseem ceeb hloov pauv ntawm "cov cuab yeej hardness" mus rau "cov ntaub ntawv ua haujlwm." Raws li qhov sib txawv ntawm cov qauv siv lead ua, pob zeb diamond tuaj yeem muab faib ua ib qho -polycrystalline pob zeb diamond thiab pob zeb diamond polycrystalline. Txawm hais tias ob cov ntaub ntawv no muaj ntau yam zoo sib xws, lawv cov microstructures sib txawv ua rau muaj kev sib txawv loj hauv kev ua tau zoo, kev tsim khoom, thiab cov chaw siv.
01 Crystal Structure: Grain Boundaries txiav txim siab qhov sib txawv hauv qab
Ib leeg -pob zeb diamond siv lead ua muaj qhov ua tau zoo, yuav luag zoo tag nrho cov qauv siv lead ua. Ntawm qhov ntsuas atomic, cov pa roj carbon atom nthuav tawm nruj me ntsis rau peb - qhov ntev ntawm qhov kev npaj, nrog rau kev ua tiav thiab txuas ntxiv. Cov siv lead ua yog tsim los ntawm ib qho nucleus, loj hlob directionally raws cov kev qhia tshwj xeeb crystallographic, tsis muaj kev cuam tshuam ntawm cov qoob loo thoob plaws hauv txoj kev loj hlob. Qhov no microstructure ua rau ib tug uniform thiab symmetrical electron huab faib, tas li thiab kuj muaj zog daim ntawv cog lus, yog li ua kom ntseeg tau siab macroscopic uniformity ntawm lub cev zog.
Polycrystalline pob zeb diamond tuaj yeem pom tau tias yog polycrystalline aggregate tsim los ntawm ntau tus me me crystallites. Nws muaj ntau tus nano- nplai zoo cov khoom sib sau ua ke. Cov khoom no muaj cov qauv siv lead ua zoo ib yam li ntawm ib qho - Crystal pob zeb diamond, tab sis lawv tau teeb tsa tsis zoo nrog cov kev taw qhia random, sib txuas los ntawm cov ntawv cog lus tsis txaus ntseeg nrog cov ciam teb tseem ceeb. Tag nrho cov qauv uniformity tsis zoo, thiab qhov tsis xws luag yog qhov siab.
Nrog nws cov qauv lattice ua tiav, ib qho -pob zeb diamond crystal muaj cov khoom siv sab hauv xws li siab hardness, zoo optical transmittance, thiab siab thermal conductivity. Polycrystalline pob zeb diamond, los ntawm grain ciam teb engineering, ua tau zoo dua tawg toughness thaum khaws feem ntau ntawm cov saum toj no intrinsic zog, thiab kuj muaj zoo nyob rau hauv loj - cheeb tsam fabrication thiab nqi-effectiveness.
02 Sib txawv Synthesis Routes Shape Crystal Characteristics
Cov txheej txheem tseem ceeb ntawm pob zeb diamond fabrication tam sim no yog qhov siab -siab siab-kub (HPHT) txoj kev thiab cov tshuaj vapor deposition (CVD) txoj kev.
Txoj kev HPHT simulates qhov tsim ib puag ncig ntawm ntuj pob zeb diamond tob hauv lub ntiaj teb pob zeb. Los ntawm kev siv sab nraud ntawm qhov siab ntawm 5-7 GPa thiab kub ntawm 1300-1700 degree, nrog rau kev ua haujlwm catalytic ntawm cov kuab tshuaj hlau (xws li Fe-} thiab Ni-raws li alloys), graphite undergoes ib theem hloov mus rau pob zeb diamond.
Nyob rau hauv cov hniav nyiaj hniav kub, qhov peb hu ua "pob zeb diamond" yog ib qho tseem ceeb ib leeg - pob zeb diamond uas ua tau raws li lub pov haum - qib kho qhov muag thiab cov khoom siv zoo. Ntau tshaj 90% ntawm lab- cov pob zeb loj hlob yog tsim los ntawm HPHT txoj kev. Polycrystalline pob zeb diamond synthesized los ntawm HPHT nta siab hardness thiab muaj zog hnav tsis kam, thiab yog dav siv nyob rau hauv industrial daim ntaub ntawv xws li tej cuab yeej, laum khoom, thiab abrasives.
CVD txoj kev ua haujlwm nyob rau hauv qis siab (<27 kPa) and high temperature (800–1200°C). Through plasma excitation, carbon-containing gases (e.g., CH₄/H₂) are decomposed, allowing carbon atoms to deposit and grow on a substrate (such as silicon or diamond seed crystals) to form diamond.
Hauv CVD kev loj hlob ntawm ib zaug -pob zeb diamond siv lead ua, pob zeb diamond noob yuav tsum tau ua qhov pib substrate. Cov noob muab ib qho kev qhia tshwj xeeb crystallographic thiab kev loj hlob template rau carbon atom deposition, kom ntseeg tau tias cov pa roj carbon atoms npaj nyob rau hauv ib txwm ib zaug -crystal kev txiav txim, yog li tsim siab - zoo ib zaug - siv lead ua pob zeb diamond. Polycrystalline pob zeb diamond, ntawm qhov tod tes, muaj cov kev cai nruj me ntsis rau crystallographic orientation thiab cov qauv sib xws, yog li tsis muaj cov noob xav tau los coj kev loj hlob. Txoj kev loj hlob muaj feem cuam tshuam ncaj qha ntawm cov pa roj carbon - muaj cov pa roj carbon monoxide nyob rau hauv substrate, nrog cov pa roj carbon atoms random nucleating thiab loj hlob, tsim cov qauv polycrystalline uas muaj ntau cov nplej me.
03 Cov cuab yeej sib txawv Ua kom muaj ntau yam kev thov cov xwm txheej
(1) Kev siv tshuab
Ib leeg -pob zeb diamond yog ib qho nyuaj tshaj plaws paub cov ntaub ntawv, nrog rau Mohs hardness ntawm 10 thiab tsis tshua muaj siab hnav tsis kam. Nws txoj kev txiav tuaj yeem ua tiav atomic- theem ncaj thiab ntse, ua kom rov ua dua ntawm cov hniav zoo meej rau ntawm qhov chaw ua haujlwm, ua rau daim iav- zoo li ua tiav nrog kev ua haujlwm siab. Nws yog tsim rau ultra-thin txiav thiab ultra- precision machining.
Polycrystalline pob zeb diamond muaj qhov hardness me ntsis dua ib zaug -pob zeb diamond siv lead ua, tab sis tseem pom zoo hnav tsis kam. Tsis tas li ntawd, nws qhov tshwj xeeb toughness thiab nws tus kheej- cov cuab yeej ntse txhais tau hais tias thaum lub sij hawm sib tsoo thiab polishing, cov khoom ntxhib ua rau cov khoom me me, tsis tu ncua nthuav tawm cov npoo tshiab. Qhov no tsis tsuas yog ua kom cov polishing zoo ntawm workpiece nto tab sis kuj txhim kho kev sib tsoo efficiency, ua kom nws zoo dua rau kev sib tsoo workpieces uas muaj cov ntaub ntawv sib txawv hardness.
(2) Thermal Management Applications
Ib leeg-pob zeb diamond crystal muaj thermal conductivity txog li 2200 W / (m·K), tab sis nws cov nqi siab thiab qhov me me txwv nws qhov kev siv feem ntau raws li siab-kawg tshav kub kis rau hauv cov ntawv thov uas muaj cov cua kub dissipation siab heev thiab nruj precision, xws li tub rog radar thiab quantum xam chips, ua kom cov khoom siv hluav taws xob sai sai.
Tib -polycrystalline (sab laug) thiab polycrystalline (txoj cai) pob zeb diamond tshav kub kis. Duab qhov chaw: Worldia
Polycrystalline pob zeb diamond, vim yog cov ciam teb thiab lwm yam, muaj cov thermal conductivity tsawg dua ib zaug -crystal pob zeb diamond, tab sis tseem mus txog ~ 2000 W / (m·K), uas yog ntau tshaj 5 npaug ntawm cov khoom siv substrate SiC thiab 13 npaug ntawm Si. Nws kuj tseem muaj qhov zoo ntawm kev tsim cov khoom siv thiab cov nqi khoom siv piv rau ib zaug -pob zeb diamond. Hauv cov khoom siv hluav taws xob semiconductor xws li IGBT modules, nws tuaj yeem ua lub cua sov-dissipating substrate ze ze rau sab nraub qaum ntawm cov nti kom ua tau zoo thaum tshav kub kub. Nyob rau hauv siab - lub zog LED teeb pom kev zoo, nws yog siv los ua cov khoom siv hluav taws xob los yog cov khoom ntim kom txo tau cov luminous lwj thiab txuas ntxiv lub neej kev pab cuam. Nws kuj tseem ua haujlwm ua lub dab dej kub rau laser diodes, pab txhim kho laser tso zis zog thiab ruaj khov.
Thaum Lub Ob Hlis Ntuj xyoo no, Huanghe Whirlwind tau tshaj tawm nws cov kab ntau lawm rau 8-inch polycrystalline pob zeb diamond tshav kub kis, cim qhov kev hloov pauv tseem ceeb los ntawm kev sim tshuab mus rau ntau lawm. Tsis ntev los no, Huifeng Pob zeb tseem tshaj tawm ruaj khov ntawm kev tsim khoom siab - zoo 8-nti CVD polycrystalline pob zeb diamond tshav kub kis. Raws li qhov loj me, ntau cov khoom siv hluav taws xob tuaj yeem raug txiav los ntawm tib lub substrate, txhim kho kev siv cov khoom siv, txo cov nqi tsim khoom, thiab ntxiv kom haum rau cov khoom ntim khoom semiconductor thiab batch manufacturing.
(3) Kev siv kho qhov muag
Pob zeb diamond tsis yog ib qho zoo heev thermal conductor; nws cov khoom kho qhov muag kuj ua rau nws muaj txiaj ntsig zoo hauv thaj chaw kho qhov muag. Ib leeg-pob zeb diamond crystal muaj qhov ntsuas siab refractive thiab tsis tshua muaj siab nqus coefficient, uas ua rau lub teeb poob tsawg heev thaum sib kis. Thaum polished, nws tuaj yeem siv rau lub qhov rais infrared optical, siab -kawg lub hom phiaj tsom iav, thiab ntau dua. High-zoo ib leeg- Crystal pob zeb diamond npaj los ntawm CVD tuaj yeem ua tsis muaj xim thiab pob tshab, nrog rau kev xa tawm zoo heev los ntawm ultraviolet mus rau infrared thiab txawm microwave ntau yam. Polycrystalline pob zeb diamond raug kev txom nyem los ntawm qhov tsis sib xws ntawm cov khoom siv kho qhov muag vim yog cov ciam teb tawg, tab sis tom qab cov txheej txheem tshwj xeeb ua kom zoo los tswj cov qoob loo thiab txo cov qoob loo - ciam teb cov teebmeem, nws tuaj yeem siv rau hauv thaj chaw uas tus nqi rhiab heev thiab cov kev xav tau kho qhov muag pom tau zoo, xws li qee yam teeb pom kev zoo thiab cov khoom siv.