High entropy brasses and bronzes – Microstructure, phase evolution and properties

A family of new high entropy, or compositionally complex, alloy brasses and bronzes has been developed with strengths and hardnesses considerably higher than those of conventional brasses and bronzes and exceptional compressive ductility. By utilising the extended solid solution range of the ternary Cu–Mn–Ni alloy system, stepwise additions of Al, Sn and/or Zn have been added to an equiatomic CuMnNi alloy base. The resulting fcc and bcc crystal structures often follow similar phase evolution trends to those observed in regular brasses and bronzes as Al, Sn and Zn solute contents increase. Due to specific structural ordering, some of these alloys exhibit respectable soft magnetic properties. Reported are the specific microstructures, phase evolution upon heat treatment, mechanical properties and observed basic magnetic response of these alloys.