How Does Heat Treatment Improve The Performance Of Copper Terminal Blocks?

Cold-processed copper terminal block is prone to material embrittlement, which is related to changes in its internal microstructure. When copper undergoes plastic deformation such as cold rolling and cold drawing, the grain structure undergoes work hardening, and the accumulated residual stress makes the material susceptible to cracking. Annealing effectively mitigates this problem.

During material processing, cold deformation refines the grains but disrupts the structure, increasing strength while decreasing ductility. In this state, copper distribution block is prone to brittle fracture at stress concentration points when subjected to external loads. By controlling the annealing temperature (typically 500–650°C) and holding time, grain rearrangement and growth can be promoted, restoring the disordered crystal structure to an ordered state.

The core function of annealing is to release accumulated energy within the material, driving the recrystallization process. When copper terminal strip is heated to above the recrystallization temperature, new grains begin to form, replacing the deformed old grains. The material's hardness and strength gradually decrease, but its plasticity and toughness significantly improve, and the risk of brittle fracture is greatly reduced. The application of a protective atmosphere (low oxygen, low humidity) is equally important for preventing surface oxidation, which directly affects the surface quality of the final product.