ZrO2 refractories Flashcards

1
Q

What is added to ZrO2 refractories? Why?

A

~ Y2O3, MgO, or CaO are added to form a solid solution upon firing that has cubic symmetry over broad temp range

~ if it didn’t have cubic symmetry, the 3-4 vol% change w/ monoclinic–> tetragonal polymorphic transf. would cause it to crack

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2
Q

What are the characteristics of stabilized zirconia?

A

~ stable against acidic and basic slags and molten Fe

~expensive, but good erosion and thermal shock resistance

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3
Q

What are stabilized zirconia refractories used in?

A

~ metering nozzles, slide gate valves in steel manufacture

~ glass tanks for corrosive glass fiber compositions as they are not easily wetted by molten glass

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