Aging behaviors of the Al–Cu alloy via ultrasound-promoted thermal treatments

Abstract

Aging treatments have been widely utilized for enhancing the mechanical properties of many materials, such as Al–Cu alloys. In conventional aging treatments, there is a trade-off between the aging conditions (e.g., aging times and temperatures) and the mechanical properties (e.g., hardness and strength). There is usually compensation in the aging treatments, such as deteriorated hardness of the alloys, when tuning the aging conditions. The ultrasound-promoted aging treatments were conducted in this study to solve the aforementioned conventional difficulties since it is believed that the ultrasound could accelerate the diffusion of the atoms and thus shorten the aging time while keeping the aging temperature low. The Al-4 wt.% Cu alloys were utilized for the verification of the influence of the ultrasound on the mechanical properties of the alloys since the Al-4 wt.% Cu alloys have been widely studied. It was found that with the promotion of the ultrasound, the micro Vickers hardness of the alloys could be enhanced. On the other hand, the alternations of strength and elongation by applying an ultrasound were limited. It is therefore concluded that the ultrasound could have certain positive effects on the enhancement of the alloy properties, such as micro Vickers hardness.

Keywords

• Aging behavior
• Aging hardening
• Al–Cu alloys
• GP-Zone
• Ultrasound
• Micro Vickers hardness