Corundum yog dab tsi?

Corundum yog ib daim ntawv crystalline ntawm txhuas oxide (Al2O3) feem ntau muaj cov kab hlau, titanium, vanadium thiab chromium.

Corundum yog ib daim ntawv crystalline ntawm txhuas oxide (Al2O3) feem ntau muaj cov kab hlau, titanium, vanadium thiab chromium. Nws kuj yog cov khoom siv pob tshab, tab sis tuaj yeem muaj xim sib txawv nyob ntawm qhov muaj qhov hloov pauv hlau impurities hauv nws cov qauv crystalline. Corundum muaj ob lub pov haum tseem ceeb: ruby ​​thiab sapphire. Rubies yog liab vim muaj chromium, thiab sapphires nthuav tawm ntau yam xim nyob ntawm seb cov hlau hloov pauv li cas. Ib hom tsis tshua muaj sapphire, padparadscha sapphire, yog paj yeeb-txiv kab ntxwv.

Lub npe "corundum" yog muab los ntawm Tamil-Dravidian lo lus kurundam (ruby-sapphire) (tshem tawm hauv Sanskrit li kuruvinda).

Vim yog corundum hardness (ntshiab corundum txhais tau tias muaj 9.0 ntawm Mohs nplai), nws tuaj yeem khawb yuav luag txhua lwm yam ntxhia. Nws yog feem ntau siv los ua abrasive rau txhua yam ntawm cov ntawv xuab zeb mus rau cov cuab yeej loj siv hauv machining hlau, yas, thiab ntoo. Qee cov emery yog ib qho kev sib xyaw ntawm corundum thiab lwm yam tshuaj, thiab cov khoom sib xyaw yog tsawg dua abrasive, nrog rau qhov nruab nrab Mohs hardness ntawm 8.0 .

Ntxiv rau nws qhov hardness, corundum muaj qhov ntom ntawm 4.02 g / cm3 (251 lb / cu ft), uas yog qhov txawv txav rau cov pob zeb pob tshab uas muaj cov ntsiab lus tsawg-atomic loj ntawm txhuas thiab oxygen.

Los ntawm Wikipedia