Arconic’s 7XXX Thick Plate Alloy Solutions to Meet Tomorrow’s Aerospace Needs

The unique characteristics of Arconic’s very thick plate (VTP) stretcher, which has the largest pull force and cross-sectional capability in the world, have enabled high performance plate products in dimensions that were not previously available in the market. Since the commissioning of the VTP stretcher in 2017, production trials have been undertaken to develop optimized fabrication flow paths for a range of 7xxx plate products so they could be supplied in thicker gauges and/or wider widths while meeting OEM property requirements. With several customer qualifications already completed for 7050-T7451 thick plate, Arconic’s focus has been to further improve very thick gauge properties up to 9” thick, such as tensile elongations, fracture toughness, smooth axial fatigue and fatigue crack growth. A detailed set of mechanical and corrosion test results will be presented along with an updated timeline regarding commercialization steps for gauge expansion of AMS 4050 and corresponding MMPDS allowables.

Additionally, Arconic has been developing a new 7xxx thick plate alloy to address specific OEM requirements around enhanced SCC resistance in a range of environments, resistance to fatigue crack deviation/crack branching, as well as cold hole expandability while achieving a higher strength/toughness trade-off over 7050. This presentation will introduce the new alloy, a discussion on the relevance of test methods used to characterize enhanced property attributes, and technical results on production lots for 4” to 8” plate product.