The annealing process of beryllium copper wire is a process of copper grain recrystallization. As the annealing temperature rises, when the recrystallization temperature is reached, the copper grain begins to crystallize. As the temperature continues to rise, the copper grain recrystallization is completed and the accumulation recrystallization begins. With the continuous progress of industrial technology in the motor manufacturing industry and the popularization and application of automatic production lines, coil manufacturing equipment such as high-speed mechanical winding device, automatic winding device and CNC flapping machine have been more and more widely used in the motor coil manufacturing. In order to ensure the dimensional stability of coil forming, higher requirements are put forward for the flexibility of beryllium copper wire. That is, it is required to have high elongation, low stiffness, small rebound Angle, and to ensure that the above properties are small dispersion.

After drawing beryllium copper wire due to cold work hardening, stiffness and springback is very high, but the elongation is very small, with the increase of annealing temperature, elongation begins to increase, stiffness and springback Angle begins to decline, to the accumulation and recrystallization temperature, due to the rapid increase of grain, mechanical properties decline rapidly, elongation begins to decline, there is a high value near the accumulation and recrystallization temperature, the decline of springback Angle tends to be gentle.

All the actions in the post-process have obvious effects on the stiffness and rebound Angle of the beryllium copper wire, while the elongation does not change significantly in the post-process process. In the post-process process, in order to ensure the sintering quality, the copper wire after annealing and winding needs to be straightened and polished. In the process of straightening and polishing, the copper wire is subjected to external forces to produce processing stress, resulting in work hardening. As a result, the stiffness and springback Angle of the current are obviously increased.