Study of transformations in beryllium bronzes by means of internal friction

Conclusions

• 1. Microalloying of beryllium bronze with magnesium and phosphorus changes the character of the amplitude dependences of internal friction in the quenched condition, which is due to a difference in the concentrations and mobility of point defects, depending on the energy of the bond with impurity atoms.

• 2. For beryllium bronze of the BNT1.9 type there is a correlation between the changes in the basic parameters of internal friction characterizing the increase of resistance to movements of structural defects and the elastic limit.

• 3. For beryllium bronzes microalloyed with magnesium or with magnesium and phosphorus there is no correlation between the changes in the parameters of internal friction and the elastic limit. Microalloying has a stronger effect in the early stages of aging than in the later stages, since the pinning of structural defects is considerably larger than in standard bronze.

• 4. Two stages were noted in the process of hardening of beryllium bronzes microalloyed with magnesium and with magnesium and phosphorus. These stages in the increase of the reversible mobility of structural defects are distinguishable after aging at 340°C for 2 h.