Process for manufacturing aluminum alloy products, with high toughness and fatigue resistance comprising: (a) preparing an aluminum alloy bath, (b) adding a refining agent containing particles of AlTiC type phases into the bath, (c) casting an as-cast form such as an extrusion ingot, a forging ingot or a rolling ingot, (d) hot transforming the as-cast form, possibly after scalping, to form a blank or a product with final thickness, (e) optionally cold transforming the blank to a final thickness, (f) applying a solution heat treatment and quenching the product output from (d) or (e), followed by relaxation by controlled stretching with permanent elongation between 0.5 and 5%, and optionally annealing, wherein the quantity of refining agent is chosen such that the average casting grain size of the as-cast form is more than 500 .mu.m. The present invention may be used, for example, to manufacture fuselage sheet or light-gauge plates made with 6056 alloy.