[eric2011 (OP)]

Hi people. Does anybody know the eutectic point of the aluminum oxide silica boron oxide eutectic point system? I have serched online without find any info

Thanks

[Bored chemist]

That's going to be complicated; boron oxide is quite volatile.
This might be interesting, thought I doubt you will find it much use.
https://www.researchgate.net/publication/309658879_Formation_microstructure_and_properties_of_aluminum_borate_ceramics_obtained_from_alumina_and_boric_acid

[paul cotter]

A mix of oxides like described could easily produce a glass, eg borosilicate glass aka pyrex. In that case I don't think one can talk of eutectics as a glass is a supercooled liquid.