Damping behavior of a novel porous CuAlMn shape memory alloy fabricated by sintering‐dissolution method

Abstract

60204125A novel porous Cu-11.7Al-2.49Mn (wt%) shape memory alloy (SMA) was fabricated by sintering-dissolution method. Damping behavior of the resulting specimen was investigated by internal friction (IF) technique through the method of forced vibration. An IF peak arises at around 200 8C during heating. This peak has been ascribed to the reverse martensitic transformation (MT). Heat treatments of solution and quenching have important influences on the IF background and the IF peak due to the changes of microstructures and phase constitution of the matrix. Compared with bulk specimen, the porous specimen has a significantly enhanced IF background and a decreased IF peak. It is suggested that the enhancement of IF background originates from the effect of pores and the production as well as movement of dislocations, while the decrease of IF peak from the existence of multifarious defects around pores.

Grain‐boundary relaxation peak correlated to the precipitation in Cu–20.4Al–8.7Mn shape‐memory alloy

“…They are listed as follows: (1) the phase transformation IF peak associated with a martensitic transformation or reverse transformation 10; (2) the pseudo‐first‐order phase transition IF peak resulting from the thinning process of the twins; These two types of IF peaks exhibit similar IF characteristics as strongly depending on the heating rate but the peak temperature is independent of measuring frequency 11. (3) the third IF peak associated with a thermal‐activation relaxational process with an activation energy of 1.85 ± 0.17 eV arising from Zener relaxation 12. Ren and Fan et al in recent years systematically studied another relaxational IF peak originated from the interaction of hydrogen atoms with the twin boundaries, which appears in the martensitic temperature region and has been observed in many types of SMA besides Cu‐based SMA 13, 14.…”

Characterization and Comparative Study of Pseudo-Elastic Cu-Zn-Al Foams Synthesized by Two Different Methods

“…The possibility of developing technological applications in the field of martensitic transformations is very promising. Recently, it has been reported the possibility of manufacturing pseudoelastic Cu-based foams [1][2][3][4]. In particular, Cu-Zn-Al foams present good pseudoelastic properties and they are potential candidates for damping applications [1][2].…”