Which is suitable for vacuum brazing, CU-ETP or CU-OF?
Selection and Recommendations
It is recommended to prioritize TU2 oxygen-free copper for vacuum brazing/vacuum diffusion bonding. With an oxygen content of ≤0.003% and
higher purity (Cu+Ag ≥ 99.95%), it offers advantages such as no hydrogen embrittlement, high electrical and thermal conductivity, and excellent
welding/brazing performance. This makes it particularly suitable for electric vacuum applications and high-reliability sealing connections.
In contrast, T2 represents ordinary copper (Cu ≥ 99.90%, oxygen≤ 0.06%) and is more prone to "hydrogen disease" and embrittlement
risks in vacuum/reducing atmospheres. This phenomenon is caused by the reaction between grain boundary Cu₂O and hydrogen, making T2 generally unsuitable as a
preferred base material for vacuum brazing.
