Low frequency internal friction spectra of Cu<inf>0·81</inf> Pd<inf>0·19</inf> alloy

Results on the internal friction of disordered and partially ordered Cu0·81Pd0·19 alloy in the temperature range 160-300 K and frequency range 1-2 Hz are reported. All the peaks are classified into three groups. Two prominent peaks of the first group occurring between 180 and 200 K are observed only in completely disordered samples. A long annealing treatment removes these peaks. These peaks may be due to interaction of dislocations with preferentially clustered palladium atoms in the disordered alloy. A second group of peaks in the temperature range 210-270K is sensitive to the microstructure and are presumably related to dislocation-dislocation interactions. In partially ordered samples new peaks appear at between 210 and 285 K. Activation parameters of these peaks are presented. © 1988 the Indian Academy of Sciences.