Autoclave age forming large aluminum aircraft panels

The forming of large aluminum panels to attain airfoil sections and complex curvatures for use in modern metal aircraft and aerospace structures poses many problems that are not easily resolved by conventional mechanical forming methods. Textron Aerostructures has developed a forming method that has proven to be highly viable for forming large aluminum panels. This method is called autoclave age forming. The method uses the heat and pressure capabilities of an autoclave along with special tooling and techniques to enhance and exploit the basic stress relaxation phenomenon that occurs during the artificial aging of metal. This paper begins by describing the concept behind the autoclave age forming method. It continues by comparing the forming mechanisms used and the residual stress levels imparted by age forming and cold mechanical forming methods. Then, it will review the enhancements made to age forming by the use of an autoclave and special tooling. Finally, the paper will conclude by presenting production applications of the autoclave age forming method.