i have trex 450 se v2(silver). i hearth something about this main frame. my friend said me it is not a real carbon fiber. it is silver surface graphite. and it produced with aleminyum and carbon. is it true?

Do you mean aluminum? It is very much CF just as it would be if it were black/red/green or purple. When they make it, the manufacturer dyes the polymer epoxy a color so when it is pressed and heated it comes out said color. carbon fiber reinforced plastic (is the "scientific name" for it) is made out of graphite and plastic.

If i completely missed your point, let me know

no. i dont say %100 aleminium. it is carbon. but is it include aleminium or glass fibers for the colour?
on the cross section - i think middle part should be carbon but what are top and bottom?

I think it is aluminized glass on the outside layer. If you measure them the silver is slightly thicker so I believe that they just add two layers of aluminized glass to the carbon frame. Why does it matter anyway?

it doesnt matter. only curiosity