Bonded structure, method of manufacturing same, electric motor, and method of manufacturing same

A bonded structure, comprising a Zn-based brazing filler metal and bonding objects including a Cu-based bonding object and an Al-based bonding object, the Zn-based brazing filler metal and each of the bonding objects being bonded to each other,

• wherein the bonded structure comprises a joint including a first alloy phase, a second alloy phase and a third alloy phase between the Zn-based brazing filler metal and the Cu-based bonding object,
• wherein the Zn-based brazing filler metal comprises 0.1 wt % or more and less than 15 wt % of Al, with the balance being Zn and inevitable impurities,
• wherein the first alloy phase is an alloy phase having a basic composition of Cu5Zn8 and being formed on a Cu-based bonding object side of the joint,
• wherein the third alloy phase is an alloy phase having a basic composition of CuZn4 or CuZn5 and being formed on a Zn-based brazing filler metal side of the joint, and in which part of a surface thereof on the Cu-based bonding object side is in contact with the first alloy phase,
• wherein the second alloy phase is an alloy phase having a basic composition of CuZn3 and being formed at an interface between the first alloy phase and the third alloy phase, and
• wherein, in a cross section parallel to a bonding direction, when a total length of a length of the interface in which the first alloy phase is in contact with the third alloy phase and a length of the second alloy phase formed at the interface between the first alloy phase and the third alloy phase is defined as 100%, a ratio of the length of the second alloy phase formed at the interface between the first alloy phase and the third alloy phase is less than 80%.