ADVANCED ALUMINUM ALLOYS FOR IMPROVED ROTORCRAFT RELIABILITY

This paper addresses the reliability approach for selecting and using advanced aluminum alloys in rotorcraft. A brief description is given of service corrosion concerns. An overview of the status of development programs at Bell Helicopter Textron, Inc. is given as well as the rationale and selection criteria used for the various individual test programs. Each advanced aluminum alloy is described in detail; this paper presents the specific advantages of the new alloys over conventional aluminum as well as any limitations in their use. The advanced aluminum alloys are categorized by form and are presented as a comparison between each new alloy and the alloy it is intended to replace. The mechanical properties of aluminum alloy 6016-T6 are highlighted along with aluminum alloy 2024-T42. The properties of extrusion alloys 7150, 7075, and 2024 are compared. Preliminary data for aluminum alloy 7093 is presented and compared with conventional aluminum forging alloys 7050-T74 and 7075-T73.