Epoxy to bond smooth aluminium to chipboard?
Glue doesn't work by &quot;being absorbed into the wood&quot; as you say.  It forms a bond to the wood surface.
The problem here is your choice of material, chipboard.  This s simply a compressed mass of wood chips held together with some glue.  As you have discovered, those particles are not held together all that strongly.
It's not clear why you can't use some other means of fastening to this board but perhaps you might consider changing to something that has more going for it than chipboard.
If you must use the chipboard, you should consider using some thru-bolts with washers to spread out the load on the chipboard side.  Alternatively some screws which are designed to hold well in such materials.
Particle Board Screws