Eur. Phys. J. Plus (2018) 133: 288
https://doi.org/10.1140/epjp/i2018-12150-7

Regular Article

Investigation of the thermal and microstructural changes of CuAlNiNb quaternary shape memory alloys by different niobium amount

¹ Inonu University, Vocational School of Health Service, Malatya, Turkey
² Fırat University, Faculty of Science, Department of Physics, Elazığ, Turkey

^* e-mail: deniz.yakinci@inonu.edu.tr

Received: 11 April 2018
Accepted: 8 June 2018
Published online: 30 July 2018

Abstract

Among the CuAl-based alloys, the most useful one is the CuAlNi ternary shape memory alloy. There are studies on the development of these alloys. In this study, -Nb element was added to the CuAlNi alloy as a fourth element at various rates. The effect of the doped Nb element on the martensitic transformation temperature of the CuAlNi-shape memory alloy was determined by differential scanning calorimetry (DSC). When the value of transformation temperature in quaternary CuAlNi alloys increased, as a result, austenite start and martensite start temperatures are close to each other. Crystalline structure analysis with X-ray diffractometer revealed that and phases were found in Cu_83.5Ni_3.5Al₁₃ alloy, which is the main alloy, while crystal structure of -Nb phase was also found with Nb addition. Likewise, the same phases were determined by SEM-EDX analysis. In addition, the result of Vickers hardness measurements indicated that the hardness value of CuAlNi alloys increased by extent of contribution of Nb.