Effect of Heating Rate on Creep Aging Behavior of 2219 Aluminum Alloy

Abstract

Effect of heating rate on creep aging behavior and mechanical properties in the process of creep aging forming of 2219 aluminum alloy was studied. In order to simulate the temperature conditions of the component in autoclave, heating rate was reduced to 0.75℃/min and heating time was prolonged to 4h(real creep aging heating time for a typical component). Creep aging experiments were carried out under three kinds of stress conditions of 0,150,210MPa and different aging time, tensile mechanical properties and microstructures (TEM) of materials were analyzed. The results show that lowering heating rate improves mechanical properties of material and prolongs the arrival time of material strength peak compared to heating time of 0.5h(5.5℃/min) in material standard; shape factor of precipitate phase of aluminum alloy increases with the aging time, and then decreases after reaching the peak; when lowering heating rate, significant creep deformation occurs in materials heating stage, creep strain of heating stage are accounted for 29.28% and 21.56% of total creep strain in two kinds of stress conditions of 150MPa and 210MPa, creep strain and steady-state creep rate increase with the rise of stress; therefore, it is necessary to further consider the effect of heating rate on the forming and mechanical property evolution in the study on the characterization of creep aging behavior of component based on the creep aging research of material standard(standard creep specimen).

Keywords

• creep aging
• heating rate
• mechanical property
• microstructure