Damping and mechanical properties of novel CuAlNi/Al composites prepared by infiltration technique

CuAlNi shape memory alloy is chosen as damping reinforced phase, then novel jujube-cake shaped CuAlNi/Al composites were designed and prepared. The whole preparation process can be summarized as two steps, i.e. initial production of parent CuAlNi foam by powder metallurgy process basing on space occupation and dissolution of pore-forming agent and subsequent fabrication of CuAlNi/Al composites by negative pressure infiltration. The microstructure, damping and compressive mechanical properties of the composites were investigated in details. Internal friction measurements indicate that the CuAlNi/Al composites can obtain ultrahigh damping capacity, and the value of damping near the room temperature is even 6 times relative to pure Al. The excellent damping capacity of the composite is rationalized not only to relate to high intrinsic damping of CuAlNi reinforcement, but also to associate with the weak-bonding interface damping introduced between CuAlNi and pure Al and the additional damping arising from the residual micro-pores in the composites. Moreover, the composites exhibit similar compressive stress-strain curves and deformation mechanism as pure Al when the Al volume percent in the composite is more than 59.5vol%, but higher compressive mechanical strength and energy absorption capacity. © 2024 Beijing University of Aeronautics and Astronautics (BUAA). All rights reserved.