A novel cryogenic treatment for reduction of residual stresses in 2024 aluminum alloy

作者：Araghchi M^*; Mansouri H; Vafaei R; Guo Yina

来源：Materials Science and Engineering A-Structural Materials Properties Microstructure and Processing, 2017, 689: 48-52.

DOI：10.1016/jansea.2017.01.095

• 2024 aluminum alloy
• Residual stresses
• Cryogenic treatment

Residual stresses induced during quenching of aluminum alloys cause distortion and have a negative effect on their properties. The purpose of this study is to reduce the residual stresses and improve mechanical properties by using a novel cryogenic treatment. Water quenched samples were cooled down by immersion in liquid nitrogen at 196(circle)C, following by rapid heating in hot oil at 180(circle)C and finally they were artificially aged. Residual stresses was measured by the hole drilling strain gauge method. The mechanical properties and microstructure of a heat treated samples were investigated by means of hardness measurements, tensile tests and transmission electron microscopy. The results showed that this treatment can relieve up to 71% of the residual stresses compared to 29% related to the traditional cryogenic treatment that used boiling water as the reheating medium. In addition, there is a considerable increase of about 75 MPa in the ultimate tensile strength in comparison to the T6 heat-treated alloy. TEM observations revealed that the S ' precipitates were fine and uniformly distributed in the microstructure due to deformation during reheating in hot oil.

• 出版日期2017-3-24