Black corundum mankhwala katundu

Black corundum, yomwe imadziwikanso kuti low alumina corundum, ili mu ng'anjo ya arc, yosungunuka ya bauxite ndipo imapangidwa ndi mtundu wa α-Al2O3 ndi chitsulo spinel monga gawo lalikulu la mchere wa imvi wakuda crystal, yomwe imadziwika ndi zochepa za Al2O3, ndi kuchuluka kwa Fe2O3 (10% kapena kupitilira apo), kotero imakhala ndi kuuma kwapakati, kulimba kwambiri, kukana kutentha kwambiri, mawonekedwe a kutentha kwanyengo.Amagwiritsidwa ntchito popera kwaulere, monga kugaya movutikira pamaso pa zinthu za electroplating, zomwe zimagwiritsidwa ntchito ngati chitsulo chosapanga dzimbiri, zinthu zachitsulo, magalasi owoneka, nsungwi ndi zinthu zamatabwa kupukuta ndi kupukuta mchenga, ndikupanganso gudumu lopukutira utomoni, kudula zidutswa, nsalu za emery novel abrasive. .