Abstract: The invention relates to products forged in aluminum based alloys with a very low hydrogen content. These products are endowed with an isotropic structure of equi-axial grains, which furnish mechanical features substantially equal in all directions and they have a particularly low critical hardening speed. They are obtained by heat treatment at a temperature slightly higher than the temperature of the solid state. They allow a substantial lightening of certain parts, particularly in aeronautic constructions and the application of hardening in boiling water or even in air without substantial reduction of the mechanical characteristics.

Abstract: The invention relates to a method of heat treatment which is applied to forged aluminum alloys, whereby the mechanical characteristics and resistance against corrosion under tension are increased considerably. This method is characterized by heating prior to tempering, above the temperature of eutectic melting, while remaining below the temperature of the start of the melting at equilibrium. The liquid phase formed temporarily is resorbed progressively, while the formation of pores is avoided by a sufficiently low hydrogen content of the metal. The application of this procedure to several aluminum alloys made it possible to observe increases of the limit of elasticity and of the break load of the order of 7% and a non-rupture stress under tension in 30 days at least equal to 30 hb.