EFFECT OF THE ADDITION OF THE SMALL AMOUNTS OF Al, Mn, Sn, Fe AND Ni ON THE TEMPER-BRITTLENESS OF SILZIN-BRONZE.

Abstract

In view of inquiring into the cause of the temper-brittleness in Silzin-Bronzes and their improvement, the microscopic and mechanical tests (hardness and impact tests) were performed with some Silzin-Bronzes (Si 4%, Zn 10%) containing 1-2% respectively of Al, Mn, Sn and Fe. According to the result, the temper-brittleness was accounted for by the dccomposition of or the precipitation from the super-cooled κ-phase, which was found in the Cu-Si system and the Cu-Si-Zn system. The addition of the small amount of Al or Mn to Silzin-Bronzes showed almost no effect, while the least addition of Fe or Ni considerably spoiled the impact value, owing to the co-existence or the brittle γ-phase.