Banca de QUALIFICAÇÃO: RIVALDO LINS ROCHA FILHO

INFLUENCE OF THE ADDITION OF NITINOL IN DURALUMINUM ALLOYS BY THE CONVENTIONAL SOLIDIFICATION METHOD AND ITS MECHANICAL PROPERTIES

aluminum, nitinol, self-repair, casting, microstructure.

The use of smart materials, such as shape memory alloys, in the form of reinforcement in metal matrix composites is a new method to replicate self-healing behavior. Depending on the process used, heat treatable aluminum alloys can undergo significant changes in their mechanical properties. Self-healing metals, when mechanically stimulated, may exhibit termination of crack growth or a reduction in the rate of crack growth as a result of the introduction of local compressive stresses linked to dynamic precipitation of intermetallic phases. This opens up a range of possibilities that can expand to engineering projects involving metallic materials, especially with regard to the aeronautical industry. In this study, the behavior of hardness and microcrack closure of a metal matrix composite made of copper aluminum alloy (AlCu) as matrix and short strips of NITINOL (NiTi) shape memory alloy (LMF) as reinforcement is investigated. . The samples were manufactured in different % vol. of NiTi reinforcement (0, 1%, 5%) and analyzed in the molten state and after formed by hot rolling, verifying their mechanical properties through Vicker Microhardness and uniaxial Tensile test (ASTM E8/E8M) of the laminates, all characterized microstructurally via Optical Microscopy (OM), X-Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM) with Energy Dispersive Spectroscopy (EDS). The results showed the formation of the main constituent phases in the state of thermodynamic equilibrium, the significant formation of intermetallics, due to the intrinsic presence of Nickel and Titanium as impurities in aluminum alloys.