COLD SPRAY TECHNOLOGY FOR STRUCTURAL RESTORATION OF SEA-BASED AVIATION STRUCTURAL MATERIALS

摘要

Additive manufacturing and thermal spray technologies are slowly transitioning to the Department of Defense as a method for restoring or manufacturing of obsolete or worn out parts. Specifically, among all thermal spray technologies, cold spray (CS) has proved to be an effective geometric restoration method which has the potential to repair, restore and enhance the airworthiness of aging aircraft. In general, CS involves the introduction of metallic powders (5 - 45 μm) into a gas stream and subsequently accelerated to a velocity range of 450 - 1200 meters/second. The powder particles that exit the nozzle impact the substrate in a solid state creating mechanical or mechanical/metallurgical bond depending on the substrate and the process parameters. Recently the Federal Aviation Administration (FAA) approved CS for dimensional repair of several non-structural aircraft parts. This research, focuses on a Office of Naval Research funded program to examine the CS technology qualification and approval process for repair and restoration of corrosion damage specifically for aircraft structural components. The paper provides preliminary results on microstructure evaluation, mechanical properties and galvanic corrosion studies on a 7075 Al plate repaired using CS technology.