04.1 - Aerospace Grade Materials, Structural Analysis, Fatigue and Damage Tolerance
HIGH IMPACT AND DAMAGE TOLERANT MULTICOMPONENT ALLOY FOR HIGH STRAIN RATE APPLICATIONS
M. Atif¹, X.Z. Shi¹, M.A. Raza¹, M.Z. Sheikh¹, J. Shen, Joint International Research Center of Impact Dynamics and Its E, China; Y. Li, School of Civil Aviation, Northwestern Polytechnical University, China; ¹Northwestern Polytechnical University, China
Many engineering applications, including aerospace and defense, demand advanced materials with extraordinary properties to make the service structures more durable with maximized safety. The aforesaid applications come across high-velocity impact and strain rate scenarios, for example, aircraft landing gears, where facilities may encounter loading conditions that are entirely different from static counterparts. A new era of materials, namely, multicomponent alloys, that deviate from the conventional alloying strategy, are being promised to replace the traditional materials in futuristic engineering applications. The reasons for this specific and huge commitment are their extra ordinary mechanical performance at room and cryogenic temperatures. These alloys provide a consortium of properties that can outclass many materials currently in use. Such an alloy with equiatomic, five-element material system (CoCrNiMnFe), has been tested under low and high strain rates and cryogenic temperature. It has been found that an elevation of about 80 % in yield strength without any decline in ductility is obtained (with no fracture). Also, the strain rate dependence of flow stress imparts remarkable strain hardening ability to the material, making it an excellent candidate for shock absorption and impact resistance and damage tolerance applications specifically in aerospace. The microstructures have been characterized before and after deformation using SEM, EBSD, and governing microscopic mechanisms have been discussed.