[kuriouskemist]

I have come across about 10 pounds of very fine zirconium oxide powder. I was wondering what this can be used for? 

[Arkcon]

As one of the best studied ceramic materials*, zirconia has many uses.  http://en.wikipedia.org/wiki/Zirconium_oxide#Uses  I'm curious about the second part of your title, however -- what do you mean by 'HfO2'?

[kuriouskemist]

HfO2 is Hafnium. I believe I am spelling that correctly.

The material I have is mostly fine grade Zirconium oxide powder around 94%. I believe the Hafnium is a trace element with in it. The remainder of it is as follows.

Yttrium Oxide 5%
Aluminum Oxide less than 1%


I was thinking of making a polishing material with it or something else. Possibly some sort of media blasting agent, although it may be to fine apowder for that.

[Arkcon]

I'm so silly.  I actually thought that was some hydrofluoric compound miscapitalized.   Anyway, yes, it seems from Googling that you do have some polishing compound.

[Enthalpy]

Such a powder may have many more uses... But mixed-in yttria suggests your zirconia is meant for sintering ceramic parts.

That is, zirconia is well-known as a refractory ceramic, but its crystal changes twice with heat, making it break as it cools back. Yttria in it stabilizes at room temperature the crystal form that prevails at the highest temperature, allowing zirconia to go through temperature cycles without getting brittle.

Not only as massive parts: a present use and research topic is to coat refractory alloys with zirconia to protect them against corrosion in hot air or exhaust, at turbine blades, piston engines...

Hafnia is a sought refractory ceramic as well, but here it must be an impurity from yttria.