Effects of uniaxial constant pressures on the joint properties of REBCO coated conductors

We studied the effects of uniaxial constant pressures by using some weights on the properties of the diffusion joints using Ag stability layers of REBa₂Cu₃O_7-X (REBCO, RE=Y, Gd) coated conductors. Two tapes were stuck in a face to face manner with Ag surfaces in contact, and were pressed uniaxially during the joining under a constant pressure at 673K in a pure oxygen atmosphere. The Ag area at the joint was 6×5 mm² for YBCO coated conductors produced by modified metal-organic deposition (MOD) process using precursor solution of trifluoroacetates (TFA) for Y and Ba and F-free salt for Cu. A very low resistance of about 10 nΩcm² across the joint was achieved by the diffusion joining under the pressure of 10 MPa. The relations between the joint resistance, the joint structure and the joint pressure were investigated.