I wonder why is sapphire corrosion resistence? Which property helps to determine that this material is corrosion resistant?

Corrosion is mechano-chemical damage of material. Sapphire is really enough resistent to corrosion, because he has very strong chemical bonds in structure Al2O3 - alpha modification. For example, Sapphire enough resistence in melt of Na by 1200K: his mass is decreasing on 1% only.

Similar questions


Physical properties of synthetic sapphire
I have found information that after special treatment corundum has tensile strength 2 GPa. Can you confirm this information? Who may manufacture such corundum?
The 2 GPa tensile strength of corundum has not been confirmed by anyone else, either. So I will assume that the tensile strength of sapphire monocrystal is 400 MPa. I have further questions: 1) if sapphire is subjected to essentially constant tension of e.g. 350 MPa, does it experience fatigue? 2) Can you make a sapphire plate, whose width is given by a given Gaussian function (maximum e.g. 40 mm in the center), thickness about 1 mm, and length about 200 mm?
I would like to have thermal properties of r-plane.
May you write me what is the difference between the fusion and latent melting heats in the case of sapphire, please? What their physical meanings are?
I would like to ask you to send me further thermal data of sapphire. May you write me the heats of fusion and evaporation of sapphire, please?
What is meaning of Repture modulus?
I wonder why is sapphire corrosion resistence? Which property helps to determine that this material is corrosion resistant?
I am designing a scratch resistant watch for my sophomore year-end project. My extensive research had shown that sapphire glasses are used widely in watch industry. Hence, I would like to ask what are the exact physical properties (numerical range) a scratch resistant watch should have and is there other alternative material that are similar to sapphire.
Do you have numbers for internal transmission of sapphire from UV to past 6 microns?
Can Sapphire change the colour by heat? Which chemicals are use for change the colour of Sapphire?
Can you tell me the internal transmission of sapphire at 300nm? Please ensure that the sample length is quoted with the internal transmission number.
Can Sapphire change the colour by heat? Which chemicals are use for change colour of Sapphire?
Are there any differences in the physical properties of a-plane vs. c-plane sapphire wafers?
Does the flexure strength of sapphire increase with thickness; for example 0.7 vs. 1.4 mm thick; Is this size and shape and shape dependent? 2" or 3" diameter or 2" or 3" rectangular piece.
Do you have any detail on how the IR transmission changes as the temperature of sapphire heats up from ambient to 1500°C?

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