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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Ni-based Mar-M247 superalloy as a friction stir processing tool

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Costa, A. M. S. [1] ; Oliveira, J. P. [2, 3] ; Pereira, V. F. [1] ; Nunes, C. A. [4] ; Ramirez, A. J. [2] ; Tschiptschin, A. P. [5]
Total Authors: 6
[1] Brazilian Nanotechnol Natl Lab CNPEM, Polo 2 Alta Tecnol Campinas, 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] Escola Engn Lorena USP, Polo Urboind Gleba AI-6, Caixa Postal 116, BR-12602810 Lorena, SP - Brazil
[5] Univ Sao Paulo, Dept Met & Mat Engn, BR-05508900 Sao Paulo, SP - Brazil
Total Affiliations: 5
Document type: Journal article
Source: Journal of Materials Processing Technology; v. 262, p. 605-614, DEC 2018.
Web of Science Citations: 1

Ni-based superalloy Mar-M247 was evaluated as a potential tool material for friction stir processing (FSP) of X70 steel. The superalloy consists of a gamma-gamma' structure and minor precipitates, such as MC carbide. FSP tests evaluated the tool performance at different rotation and welding speeds and the effect of shielding gas was also analyzed. Prior to FSP tests, hot compression tests showed that the tool material microstructure was stable below 950 degrees C, which affected positively its mechanical strength. It was observed the FSP tool overheating at rotation speed of 400 rpm. In this condition the gamma-gamma' structure was destabilized forming ``gamma' free zones{''} at the tool shoulder. In these zones new gamma-grains were formed by recrystallization. Oxygen diffusion occurred at gamma-grain boundaries embritding the gamma' free zones that were ripped out by abrasion during FSP tests. The tool wear damage was mitigated by controlling friction processing parameters, such as rotation and welding speeds, Z-force values and gas shielding. The FSP made in this work improved surface properties of X70 steel. (AU)

FAPESP's process: 14/13772-4 - Co-based superalloys for friction stir welding tools
Grantee:Alex Matos da Silva Costa
Support type: Scholarships in Brazil - Post-Doctorate