Dab tsi yog qhov txawv ntawm alumina thiab dawb corundum?

Alumina yog lub siab hardness compound nrog lub melting point ntawm 2054 degrees Celsius thiab boiling point ntawm 2980 degrees Celsius. Nws feem ntau yog siv los ua cov khoom siv refractory. Lub ntsiab tseem ceeb ntawm corundum yog α-alumina, uas yog thib ob tsuas yog pob zeb diamond hauv hardness. Ruby thiab sapphire yog cov zoo corundum uas muaj me me ntawm cov hlau oxides sib txawv. Ruby feem ntau yog liab vim nws muaj me me ntawm chromium, thiab sapphire yog xiav vim nws muaj me me ntawm hlau thiab titanium. Rau

Corundum yog ib hom alumina siv lead ua nrog zoo crystallization, thiab kev sib raug zoo ntawm ob yog zoo li kev sib raug zoo ntawm cov siv lead ua thiab quartz hmoov.