Silver-bearing Al-Cu-Mg alloy and heat treatment method for silver-bearing Al-Cu-Mg alloy to obtain high-strength P structure

The invention discloses silver-bearing Al-Cu-Mg alloy and a heat treatment method for the silver-bearing Al-Cu-Mg alloy to obtain the high-strength P structure. The heat treatment method comprises thesteps that an Al-Cu-Mg-(Ag) hot rolled plate is subjected to recrystallization annealing at 300-450 DEG C/60-240 min at first and then subjected to solid solution quenching treatment at 480-510 DEG C/20-120 min, and natural aging is conducted for at least 96 h. Al-Cu-Mg-(Ag) alloy comprises the following components of Al, Cu, Mg, Ag, Mn and Ti. According to the silver-bearing Al-Cu-Mg alloy and the heat treatment method for the silver-bearing Al-Cu-Mg alloy to obtain the high-strength P structure, the technology is simple and reasonable, the high-strength P structure is obtained by adding theAg element and applying the appropriate annealing and solid solution technology, thus, many {111} faces in hot-rolled Al-Cu-Mg-(Ag) alloy crystalline grains are in the direction close to the maximumadditional shear stress, sliding of dislocation under alternating stress is facilitated, stress concentration is relieved, and accordingly, the fatigue resistance is improved; and in addition, large torsion angle interfaces between P crystalline grains and crystalline grains surrounding the P crystalline grains exist, crack deflection is prone to be induced, a large deflection angle and a rough broken plane are caused, and thus, energy consumed by crack growth is increased, the obvious fatigue crack closure effect is generated, the fatigue crack growth rate is decreased; and accordingly, the alloy has good fatigue resistance and is suitable of industrial application.