Determination of the Young's modulus in CuAlBe shape memory alloys with different microstructures by impulse excitation technique

The Young's modulus (E) was determined in samples of CuAlBe shape memory alloys with selected grain sizes using the non-destructive technique of impulse excitation. The variation of E with the quenching temperature reached after a slow cooling from 1073 K was also studied and the microstructure of quenched samples was characterized by optical microscopy. A strong dependence of E with the grain size was found and a comparison of the obtained results with values reported in the literature was done. The behavior of E with the quenching temperature was analyzed considering the formation of γ2 and α' precipitates, the presence of martensite in the β matrix, the reordering process and the vacancy concentration. The impulse excitation experimental device was specifically developed and mounted. An evaluation of its performance was made by means of measurements of the modulus E in samples of materials commonly used (commercial aluminum and copper) and using different vibration modes. The obtained results evidence the potentialities of the impulse excitation technique for the determination of the modulus E in alloys with a complex microstructure, which allows to characterize the behavior of E with the quenching temperature in the alloy studied.