How do I proceed to mechanically expand aluminium?
Hydro Aluminium Precision Tubing: Like any machine setup, the expansion equipment must be tested on the product to be produced with respect to expansion rate and size of expansion bullet. The relatively ductile properties of aluminium make aluminium grooves prone to flattening. However, Hydro’s groove geometries have been carefully designed to maintain a fully acceptable grooving height after expansion.

Is this different from copper tube mechanical expansion?
Hydro Aluminium Precision Tubing: No. The process is the same.