For damage tolerance dominant applications, 2xxx-T3xxx type products are commonly used for a desired balance of strength and fracture toughness. 

However, -T3 type temper products have several inherent limitations. These include poor    SCC resistance (Stress Corrosion Cracking Resistance), product gauge limitations, limited product forms and limited manufacturing processes.   Therefore, aerospace designers have expressed interest to develop a new 2xxx –T8xx temper product having desirable combination of strength, fracture toughness and fatigue resistance without limitations of -T3 type temper product 

Alcan developed Alloy 2139 to meet such requirement.  Evaluation of 1 inch gauge 2139-T8 plate demonstrated that damage tolerance capability of 2139 –T8 plate exceeded that of 2xxx-T3xx product without having limitations of –T3xx temper product.  Alloy 2139 also demonstrated excellent ballistic performance exceeding other incumbent alloys. To explore the potential applications for thicker gauge plate, Alcan produced additional plate with gauges up to 6 inches.   This paper will discuss damage tolerance capability of 2139-T8xx (an Al-Cu-Mg-Ag based alloy) plate product at various gauges by presenting combined properties of strength, fracture toughness and fatigue resistance. Comparisons to incumbent alloy products will be discussed.    
Application for 2139-T8 alloy product may include lower wing skin plate, wings and spas and armor plate. 2139 plate product would be especially suitable for damage tolerant applications in thermally affected areas where 2xxx-T3xx and 7xxx-T7xxx type products are not suitable.