Abstract: The internal friction of alloys in martensite state is believed to be an M/M interface one, which can be explained by an expression deduced from the theory of dislocation internal fric- tion.The internal friction during martensitic transformation consists of two parts,including those of the M/M interface and of the phase transformation.The latter is further composed of two portions,the major one produced by reverse martensitic transformation and the other from stress-induced martensite.It was also found that the degradation of damping properties of the CuZnAl alloys is related to the dislocation,which is introduced from the exciting pro- cess,and tends to be of stable value after certain excitements.

Key words: damping property, CuZnAl alloy, martensite, martensitic transformation