Numéro
J. Phys. Colloques
Volume 43, Numéro C4, Décembre 1982
ICOMAT-82
International Conference on Martensitic Transformations
Page(s) C4-761 - C4-766
DOI https://doi.org/10.1051/jphyscol:19824124
ICOMAT-82
International Conference on Martensitic Transformations

J. Phys. Colloques 43 (1982) C4-761-C4-766

DOI: 10.1051/jphyscol:19824124

GRAIN-REFINEMENT AND THE RELATED PHENOMENA IN QUATERNARY Cu-Al-Ni-Ti SHAPE MEMORY ALLOYS

K. Sugimoto1, K. Kamei1, H. Matsumoto2, S. Komatsu1, K. Akamatsu1 et T. Sugimoto1

1  Department of Metallurgical Engineering, Faculty of Engineering, Kansai University, Japan
2  Department of Mechanical Engineering, Faculty of Engineering, Osaka Industrial University, Japan


Abstract
It was reported that the addition of a small amount of titanium (0.5 - 3.99%) to a Cu-13.93%Al-3.36%Ni ternary alloy resulted in a remarkable grain-refining. The original grain-size of about 750 microns under hot-rolled and quenched conditions of the ternary alloy was reduced to that of the order of about 100 microns by addition of tiatanium. It was suggested that several technical improvements of the mechanical properties of Cu-Al-Ni shape memory alloys, such as better formability, less cracking tendency at grain-boundaries, higher fatigue strength and hence higher reliability on application, might be expected in this way. The mechanism of the grain-refinement was explained by the presence of finely dispersed titanium-rich x-phase particles which might act as an obstacle against the grain-boundary migration. The particles on the other hand increased the thermal hysteresis of the transformation, as observed by the temperature changes in electrical resistivity and internal friction. This was again shown to be due to the obstacle effect of the x-phase particles against the movement of the interface between the betaphase and the martensite phase.