Effect of Ta and Nb additions in arc-melted Co-Ni-based superalloys: Microstructural and mechanical properties

Autor(es)

Costa, A. M. S. ^[1] ; Oliveira, J. P. ^{[2, 3]} ; Salgado, V, M. ; Nunes, C. A. ^[4] ; Lopes, E. S. N. ^[5] ; Mogili, N. V. V. ^[1] ; Ramirez, A. J. ^[2] ; Tschiptschin, A. P. ^[6]

Afiliação do(s) autor(es)

^[1] Brazilian Nanotechnol Natl Lab CNPEM, Rua Giuseppe Maximo Scolfaro, BR-13083970 Campinas, SP - Brazil

^[2] Ohio State Univ, Dept Mat Sci & Engn, 1248 Arthur E Adams Dr, Columbus, OH 43221 - USA

^[3] Univ Nova Lisboa, Fac Ciencias & Tecnol, Dept Engn Mecan & Ind, UNIDEMI, Caparica - Portugal

^[4] Salgado, M., V, Univ Sao Paulo, EEL, Polo Urboind Gleba AI-6, Caixa Postal 116, BR-12602810 Sao Paulo - Brazil

^[5] Univ Estadual Campinas, Fac Mech Engn, Dept Mat Engn, BR-13083860 Campinas, SP - Brazil

^[6] Univ Sao Paulo, Dept Met & Mat Engn, BR-05508900 Sao Paulo, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING; v. 730, p. 66-72, JUL 11 2018.
• Citações Web of Science: 4

Resumo

The current work characterizes the microstructure and mechanical properties of two arc melted Co-Ni-based superalloys containing in atomic percent: 1) Co-40Ni-10Al-7.5W-10Cr-3Ta-0.0613-0.6 C and 2) Co-40Ni-10Al-7.5W-10Cr-3Nb-0.0613-0.6 C. These two materials named 3Ta and 3Nb, respectively, were characterized by X-Ray diffraction analysis, differential scanning calorimetry, scanning electron microscopy, energy dispersive spectroscopy, electron backscatter diffraction and transmission electron microscopy. Furthermore, compression tests were performed from room temperature up to 1000 degrees C. The 3Ta and 3Nb alloys showed different as-cast microstructures that were confirmed by microstructural characterization and Scheil simulations. The phase transformation temperatures of minor phases were measured and calculated using a thermodynamic approach and some discrepancies observed on the calculated gamma'-solvus temperatures reflect that the thermodynamic description of gamma' phase does not take into account the strong partition effect of Ta, Nb and Ti into gamma'. As shown by DSC results, the gamma' phase was stable for both alloys up to 1000 degrees C, being the main reason for the 3Ta and 3Nb alloys to keep the yield stress above 500 MPa. (AU)

• Processo FAPESP: 14/13772-4 - Estudo de superligas de Co para a produção de ferramentas para soldagem por atrito com pino não consumível
• Beneficiário: Alex Matos da Silva Costa
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado