Mechanical properties and microstructure of Cu-Ni-Zn/Cu-Cr/ Cu-Ni-Zn clad plate processed by High Pressure Torsioning (HPT)

摘要

Cu-1 wt. % Cr was clad between Cu-Ni-Zn plates to form 3-layered composite by high pressure torsioning (HPT) at room temperature and theirmicrostracture and mechanical propertieswereexamined. No intermetallic compounds were observed at the interfaces in the as-HPTed and heat-treated 3-layered composite plates. The strength of as-HPTed composite plate reached up to 650 MPa with the ductility of 7 %. After heat treatment at 500oC, Cu-Ni-Zn/Cu-Cr/Cu-Ni-Zn clad plate exhibited the strength up to 420 MPa and the ductility of 32 %. The clad plate fractured all together at the same time without discontinuous drop of the stress until fmal fracture. The excellent mechanical reliability and the good interfacial bonding strength can be attributed to the absence of detrimental interfacial reaction compounds between Cu-Ni-Zn and Cu-Cr.