Investigation of the Effect of Heating Rate in Non-isothermal Aging ‎Heat Treatment on the ‎Microstructure and Mechanical Properties ‎of in-situ Aluminum-Nickel Aluminide Composite

In this research, the effect of heating rate on non-isothermal aging behavior of AA2024 aluminum ‎alloy matrix composite reinforced with nickel aluminide has been studied. Nickel aluminide was ‎created in-situ in the AA2024 aluminum alloy matrix and as a result of adding 4.5 wt.% of nickel ‎during composite fabrication. The results showed that the addition of nickel reduces the ‎precipitation ability of the AA2024 aluminum alloy during non-isothermal heat treatment despite ‎the formation of nickel aluminide. Also, with the increase of the heating rate, the amount of S-‎Al2CuMg precipitates formed in the microstructure decreases during non-isothermal aging. By ‎increasing the heating rate, the maximum hardness is reduced during aging heat treatment and is ‎obtained at higher temperatures. Non-isothermal aging of AA2024 aluminum alloy matrix ‎composite reinforced with nickel aluminide at a heating rate of 5°C/min led to an increase in ‎hardness and ultimate tensile strength by 17 and 22%, respectively, compared to the AA2024 ‎aluminum alloy matrix.‎