CBN cubic boron nitride

CBN cubic boron nitride

Cubic boron nitride (CBN), yog cov khoom siv hluavtaws super tawv, nws cov qauv atomic zoo ib yam li cov qauv carbon atomic hauv pob zeb diamond, yog li nws muaj cov yam ntxwv siab ntom ntom, hardness thib ob tsuas yog pob zeb diamond, feem ntau yog siv los ua cov khoom siv abrasive thiab cov cuab yeej siv.

Raws li thaum ntxov xyoo 1957, cov kws tshawb fawb los ntawm GE Lub Tuam Txhab hauv Tebchaws Meskas tau siv cov txuj ci dag los ua kom cov cubic boron nitride thawj zaug nyob rau hauv qhov kub thiab txias siab, tab sis lub ntuj cubic boron nitride tsis tau pom, yog li cubic boron nitride yog xam. los ua cov khoom siv hluavtaws thiab tsis muaj nyob hauv qhov xwm txheej.

Txog xyoo 2009, cov kws tshawb fawb los ntawm University of California, Riverside thiab Lawrence Livermore National Laboratory, nrog cov npoj yaig los ntawm cov tsev kawm tshawb fawb hauv Suav teb thiab lub teb chaws Yelemees, pom cov ntxhia hauv cov pob zeb uas muaj chromium nplua nuj nyob rau hauv ancient Marine crust txog 306 kilometers underground nyob rau sab qab teb ntawm lub roob. Tibetan Plateau hauv Suav teb. Cov crystals tsim ntawm qhov kub ntawm txog 1,300 degrees Celsius thiab siab ntawm 118,430 atmospheres.

Thaum Lub Yim Hli 2013, International Mineralogical Association tau lees paub cov pob zeb tshiab, cubic boron nitride.

Cubic boron nitride muaj cov qauv siv lead ua zoo sib xws rau pob zeb diamond, thiab cov lattice coefficients ntawm ob qhov zoo sib xws ({{0}}}.3567nm rau pob zeb diamond thiab 0.3615nm rau cubic boron nitride).

Cubic boron nitride yog ib qho sib xyaw ua ke ntawm nitrogen atoms thiab boron atoms, nrog rau cov tshuaj muaj pes tsawg leeg ntawm 43.6% boron thiab 56.4% nitrogen. Los ntawm kev teeb tsa ntawm cov atoms hauv cov siv lead ua, cov qauv ntawm cubic boron nitride yog tsim los ntawm lub ntsej muag-centered cubic lattice uas muaj B atoms thiab lub ntsej muag-centered cubic lattice muaj li ntawm N atoms staggered los ntawm 1/4 raws kab pheeb ces kaum.