Influence of Chromium in the phase transformation temperature of a CuAlNi Shape Memory Alloy
Camila Aguiar Teixeira1; Rodrigo Estevam Coelho1; Pedro Cunha de Lima1; Lorena Couto Conrado1; Erick Silva Mendonça1; Murilo Santana Santos1; Gabriel Kabir de Abreu Costa2; Cristiane Oliveira Carvalho1; Emmanuel Pacheco Rocha Lima2
1 Instituto Federal de Educação, Ciência e Tecnologia da Bahia - IFBA; 2 University of Brasília - UnB
doi:10.20906/CPS/COB-2015-1725
Resumo
The thermomechanical recovery, inherent of Shape Memory Alloys (SMA), is directly related to martensitic transformation. Furthermore, the activation temperatures of martensite-austenite transformation depends of, among other factors, the alloy's grain size. In the present study, it was verified the influence that the addition of Chromium, in different percentages, in a Copper-Aluminum-Nickel SMA, has in the grain size. In addition, it was associated grain size with the beginning and ending temperatures of phase transformation. The CuAlNiCr alloy was obtained through plasma melting, equipment of the brand EDG model Discovery, which each sample was submitted four times to have a more homogeneous material. Posteriorly, it underwent heat treatment of betatization at temperature of 900°C. All of the obtained samples were sanded, polished and chemically attacked with Ferric Chloride. For the purpose of material characterization, it was applied Scanning Electron and Optical Microscopy, X-ray Diffraction (DRX) and Differential Scanning Calorimetry (DSC). As a result, with the addition of Chromium it is expected the refinement of the CuAlNi microstructure in order to have a better application.
Palavras-chave: Phase Transformation Temperature; Grain Size; CuAlNi Alloy; Influence of Chromium