Obtenção e caracterização de ligas Cu-Al-Be-Fe para aplicações relacionadas à memória de forma

Abstract

In the present work a study of the influence of the Fe precipitates on the thermomechanical properties of Cu-Al-Be-Fe alloys was carried out, with shape memory effect. The aim of this work was the preparation of alloys (87,6-X) Cu-11,8Al-0,6Be-XFe; to evaluate the viability of Fe as an inoculant, in relation to grain refining; the influence of the Fe precipitates on the thermo-mechanical properties of the alloy; determination of transformation temperatures via DSC; and determination of thermomechanical properties by tensile tests. The alloys were prepared under ambient atmosphere, varying the percentage of Iron and using Copper to balance. Thermal treatments were also carried out at different temperatures, with the objective of evaluating the nucleation behavior regarding grain size and differences in their respective mechanical properties. Based on the results obtained, it was observed that the higher the Iron percentage, the smaller the grain size found, however, from an increase of 2% there was no change. The heat treatments performed in the convenient alloy (2.5% Fe) showed that the alloy annealed at 750 ° C maintained the same grain size as the annealed alloy at 850 ° C, while the alloy granules at 950 ° C had an increase of proportion. The calorimetry assay can not be performed in its entirety, but the data obtained were elucidated as a graph and will serve as an adjustment parameter for future performance. The Cu-11.8Al-0.6Be-2.5Fe alloy tensile test was performed successfully, and the values obtained can already be used for further studies.