Development, heat treatment optimization and microstructural characterization of Nb3Sn superconductor wire

Autor(es)

Rodrigues, Carlos A. ; Machado, João Paulo B. ; Rodrigues Junior, Durval ^[3]

• Tipo de documento: Artigo Científico
• Fonte: IEEE Transactions on Applied Superconductivity; v. 13, n. 2, p. 3426-3429, June 2003.
• Área do conhecimento: Engenharias - Engenharia de Materiais e Metalúrgica
• Assunto(s): Supercondutividade Tratamento térmico

Resumo

The optimization of the heat treatment profile for Nb/sub 3/Sn superconductor wires is one of the most difficult steps to process this material. The present work had the objective to optimize the heat treatment profile to form the Nb/sub 3/Sn phase. It was developed an internal-tin Nb/sub 3/Sn strand with 1.0 mm in diameter, 12 065 Nb filaments with average diameter of 3.4 /spl mu/m, 26 cores of Sn and internal stabilization of Cu surrounded by Ta diffusion barrier. Samples were removed for heat treatment optimization using different profiles to analyze the Sn diffusion and CuSn formation at temperatures up to 575 /spl deg/C. A final treatment at 700 /spl deg/C was used to form the Nb/sub 3/Sn phase. After the heat treatments, samples were removed for microstructural characterization. Measurements of T/sub c/ and J/sub c/ were performed to analyze the influence of the heat treatments on the superconducting phase and on the transport properties. It was concluded that the use of a two step heat treatment of 575 /spl deg/C/100 h + 700 /spl deg/C/100 h is as efficient as the use of a heat treatment with more low temperature steps. (AU)

• Processo FAPESP: 97/11020-8 - Aquisição de microscópio eletrônico de varredura com espectrômetro de energia dispersiva e analisador de imagens
• Beneficiário: Daltro Garcia Pinatti
• Modalidade de apoio: Auxílio à Pesquisa - Programa Infraestrutura - Equipamentos
• Processo FAPESP: 00/10305-3 - Análise de aprisionamento de fluxo magnético em supercondutores de Nb3Sn com centros de aprisionamento artificiais de Cu(Sn) em escala nanométrica
• Beneficiário: Carlos Alberto Rodrigues
• Modalidade de apoio: Bolsas no Brasil - Doutorado