Effects of interface characteristics of Cu/Cr phases on the contact performance of Cu-25Cr alloy contact material

The microstructure and interface of Cu/Cr phases in vacuum casting Cu-25Cr alloy and sintered CuCr25 p/m contact materials were investigated by transmission electron microscopy (TEM). Some fine secondary Cr-dendrites have preferred orientation relationships of (110)
_Cr
// (111)
_Cu
and [011]
_Cr
// [1macr12]
_Cu
, and a single set of misfit dislocations separated by a space of ~6 nm are distributed on the semicoherent interfaces of Cr/Cu phases, which shown that the interface structure of two phases in the Cu-25Cr alloy material is better coordination. In contrast to the Cu-25Cr alloy material, incoherent interface between Cr/Cu particles in CuCr25 p/m material were formed by frictional force, and a few inclusions of Al
₂
O
₃
and Cr
₂
O
₃
were aggregated on the lose bonding interface of Cr/Cu particles in the materials. Thereby the effects of interface structure of Cr/Cu phases in the CuCr contact materials on the mechanical properties, fracture characteristics and contact performance of contact materials are discussed.