Impact of a Variable-Rate Non-isothermal Aging Process on the Microstructure and Properties of 2024 Aluminum Alloy
摘要
To enhance the comprehensive performance of the 2024 aluminum alloy, a variable-rate non-isothermal aging treatment is employed. This process begins with the quenched alloy being subjected to a high-temperature variable-rate treatment, starting at an initial temperature of 100 °C. The temperature is then increased to 150 °C at a rate of 10 °C/h, followed by a rise to peak temperatures of 230 °C, 240 °C, 250 °C, 260 °C, and 270 °C at a rate of 30 °C/h. After reaching these peak temperatures, the alloy is cooled to 150 °C at 30 °C/h, and subsequently down to 100 °C at 10 °C/h. The effects of this variable-rate non-isothermal aging process on the structure and properties of the 2024 aluminum alloy are evaluated using a variety of techniques, including hardness assessments, friction wear tests, spalling corrosion evaluations, intergranular corrosion examinations, electrochemical corrosion analyses, and both scanning and transmission electron microscopy. The findings indicate improvements in hardness, wear resistance, and corrosion resistance for the TP250 aluminum alloy. Furthermore, the distribution of matrix precipitation phases has become more uniform, characterized by an increased number of phases and a gradual coarsening in size. Notably, the precipitation phases at the grain boundaries have transitioned from a continuous distribution to an intermittent one.