Boron nitride (BN) yog ib qho sib xyaw ua ke ntawm boron thiab nitrogen atoms, thiab nws muaj nyob rau hauv ntau hom qauv sib txawv. Feem ntau cov qauv ntawm BN yog hexagonal boron nitride (h-BN) thiab cubic boron nitride (c-BN), txhua tus nrog nws cov cim tshwj xeeb ntawm cov atoms. Kab lus no muab cov ntsiab lus dav dav ntawm cov qauv ntawm BN, piav qhia cov yam ntxwv, cov khoom, thiab kev siv ntawm ob qho tib si h-BN thiab c-BN.
Cov qauv ntawm Hexagonal Boron Nitride
h-BN muaj cov txheej txheem txheej zoo ib yam li cov graphite. Nyob rau hauv h-BN, boron thiab nitrogen atoms alternate nyob rau hauv ib tug hexagonal lattice, tsim stacked txheej. Nyob rau hauv txhua txheej, boron thiab nitrogen atoms yog teem nyob rau hauv ib tug honeycomb qauv, nrog boron atoms bonded rau peb nyob sib ze nitrogen atoms thiab vice versa. Cov khaubncaws sab nraud povtseg tau tuav ua ke los ntawm cov tsis muaj zog van der Waals, tso cai rau lawv yooj yim swb dua ib leeg. Cov cuab yeej no muab h-BN nws cov khoom lubricating thiab ua rau nws muaj cov roj nplua nyeem zoo heev hauv qhov kub thiab txias ib puag ncig.
Cov khoom ntawm Hexagonal Boron Nitride
Cov qauv hexagonal ntawm h-BN ua rau muaj ntau yam khoom tshwj xeeb. Nws muaj cov thermal conductivity siab, piv rau cov graphene, ua rau nws yog ib qho khoom zoo heev rau kev siv thermal tswj. Tsis tas li ntawd, h-BN muaj qhov dav bandgap, ua rau nws muaj hluav taws xob insulator. Nws cov hluav taws xob tawg siab thiab zoo heev dielectric zog ua rau nws haum rau cov khoom siv hluav taws xob, xws li insulating txheej, substrates, thiab cov khoom ntim. h-BN kuj tseem tiv taus tshuaj lom neeg cov tshuaj tiv thaiv thiab oxidation, muab kev ruaj ntseg thiab ruaj khov nyob rau hauv ib puag ncig hnyav.
Cov qauv thiab cov yam ntxwv ntawm Cubic Boron Nitride
Ntawm qhov tod tes, c-BN muaj cov qauv zoo li pob zeb diamond, nrog rau txhua boron atom sib raug zoo rau peb cov nitrogen atoms nyob sib ze thiab rov ua dua. Kev npaj ntawm atoms hauv c-BN muab nws cov qauv siv lead ua peb sab, zoo ib yam li pob zeb diamond. Cov qauv tshwj xeeb no muab qhov tshwj xeeb hardness rau c-BN, ua rau nws yog ib qho ntawm cov ntaub ntawv nyuaj tshaj plaws. Nws muaj ib tug hardness thib ob rau pob zeb diamond, ua rau nws haum rau daim ntaub ntawv uas yuav tsum tau heev abrasion kuj thiab txiav kev ua tau zoo. c-BN feem ntau yog siv los ua superabrasive hauv cov cuab yeej txiav, sib tsoo lub log, thiab cov txheej txheem abrasive.
Lwm cov qauv ntawm Boron Nitride
Ntxiv rau h-BN thiab c-BN, lwm cov qauv ntawm boron nitride muaj xws li turbostratic boron nitride (t-BN) thiab rhombohedral boron nitride (r-BN). t-BN yog ib qho kev tsis sib haum xeeb ntawm BN, qhov twg cov khaubncaws sab nraud povtseg yog random stacked yam tsis muaj cov qauv zoo. Nws nthuav tawm cov khoom nruab nrab ntawm h-BN thiab c-BN thiab pom cov ntawv thov hauv lubrication, thermal tswj, thiab cov ntaub ntawv sib xyaw. r-BN muaj cov qauv zoo sib xws rau graphite, tab sis nrog me ntsis distortion hauv cov lattice. Nws muaj cov khoom zoo ib yam li h-BN thiab pom cov ntawv thov hauv insulators, catalyst kev txhawb nqa, thiab cov txheej txheem kub.
Nyob rau hauv ib lub ntsiab lus, boron nitride nthuav tawm ntau yam qauv nrog kev sib txawv ntawm boron thiab nitrogen atoms, txhua tus muaj cov khoom tshwj xeeb thiab kev siv. h-BN muaj cov txheej txheem txheej, muab cov thermal conductivity zoo, hluav taws xob rwb thaiv tsev, thiab tshuaj lom neeg ruaj khov. Nws pom cov ntawv thov hauv thermal tswj, hluav taws xob, thiab kev tiv thaiv txheej. c-BN muaj cov qauv zoo li pob zeb diamond, muab tshwj xeeb hardness thiab abrasion tsis kam, ua rau nws haum rau cov cuab yeej txiav thiab abrasives. Lwm cov qauv, xws li t-BN thiab r-BN, muaj cov khoom siv ntxiv thiab kev siv hauv ntau qhov chaw. Cov txheej txheem sib txawv ntawm boron nitride ua rau nws muaj ntau yam khoom siv nrog ntau yam kev siv thoob plaws hauv kev lag luam.
