Co-based superalloys for friction stir welding tools

• Grant number: 14/13772-4
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: January 01, 2015
• End date: December 31, 2016
• Field of knowledge: Engineering - Materials and Metallurgical Engineering - Physical Metallurgy
• Agreement: Coordination of Improvement of Higher Education Personnel (CAPES)
• Principal Investigator: Andre Paulo Tschiptschin
• Grantee: Alex Matos da Silva Costa
• Host Institution: Centro Nacional de Pesquisa em Energia e Materiais (CNPEM). Campinas , SP, Brazil

Abstract

Materials commonly used for Friction Stir Welding (FSW) tools are divided into two groups: (1) to weld low melting temperature alloys, such as Al, Mg, and Cu alloys; and (2) to weld high melting temperature alloys, such as steels, Ni, Ti, and Zr alloys. Tool steels are commonly used to join low melting alloys. On the other hand, the processing temperature, stresses, and wear conditions associated to the FSW process of high melting temperature alloys limits the materials that can be used for these tools. The most successful tools available today to join steels and Ni-based alloys are based on W-25Re, reinforced with polycrystalline cubic boron nitride (pcBN). However, such advanced material has very limited supply and elevated production cost, and undergo important wear and presents limited toughness. Therefore, a great effort has been dedicated to the development and test suitable materials for the production of FSW tools for elevated melting temperature alloys. Thus, the recently developed Co-based superalloys, which are hardened by ³2 precipitation are considered some of the most promising materials. This alloy system, based on Co-Al-W, has outstanding wear and mechanical properties, and chemical stability at high temperature, which are fundamental for these FSW tools. This project will study such Co-based superalloys as possible FSW tool material, including detailed microstructural characterization, mechanical performance and even actual FSW tests. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

COSTA, A. M. S.; OLIVEIRA, J. P.; PEREIRA, V. F.; NUNES, C. A.; RAMIREZ, A. J.; TSCHIPTSCHIN, A. P.. Ni-based Mar-M247 superalloy as a friction stir processing tool. Journal of Materials Processing Technology, v. 262, p. 605-614, DEC 2018. (14/13772-4)

COSTA, A. M. S.; OLIVEIRA, J. P.; SALGADO, V, M.; NUNES, C. A.; LOPES, E. S. N.; MOGILI, N. V. V.; RAMIREZ, A. J.; TSCHIPTSCHIN, A. P.. Effect of Ta and Nb additions in arc-melted Co-Ni-based superalloys: Microstructural and mechanical properties. MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING, v. 730, p. 66-72, JUL 11 2018. (14/13772-4)