كلراسيون زيركونياي آسيابكاري شده

Chlorination of Ball-milled Zirconia

The effects of mecbunochemical treatment of monoclinic zirconia in high energy planetary ball mill on its phase transformation were investigated. The mechanical treatment in hall mill reduces the grain size, increases micros/rain, and causes phase transition to metastable nanostructured tetragonal and cubic phases. XRD and TEM results show considerable amounts of amorphous ptiose during ball milling. Surface area measurements by BET method o..er long milling times reveal that ZrOz particles are agglomerated with an amorphous phase as a binder. The mechanical treatment increases the reactivity ofzirconia in chlorine gas. Annealing of ball milled zirconia in the chlorine atmosphere produces oxygen vacancy in zirconia (ZrOl.) and causes the amorphous phose 10 be crystallized and to chunge into cubic and tetragonal ,,-/ruses. Th~ c1J~oril~e atmosphere inc~eas~s tire stabllitv temperatures ofcubic and tetragonal pltases ((J 800°C and lOOO°C, respeon:ely. In this «uuanon, tire energy oj grain boundary .and oxygen "acallcy ploy important roles in tlte stability of tetragonal und cubic phu.ʹilʹs.