Microstructural Analysis of Friction Stir Butt Welded Al-Mg-Sc-Zr Alloy Heavy Gauge Sheets

Autor: Tatiana Kalashnikova, Andrey Chumaevskii, Kirill Kalashnikov, Sergei Fortuna, Evgeny Kolubaev, Sergei Tarasov
Jazyk: angličtina
Rok vydání: 2020
Předmět:
Zdroj: Metals, Vol 10, Iss 6, p 806 (2020)
Druh dokumentu: article
ISSN: 2075-4701
DOI: 10.3390/met10060806
Popis: Friction stir welding (FSW) on a heavy gauge sheet of a hereditary fine-grained Al-Mg-Sc-Zr alloy was carried out to study the specifics of plasticized metal flow and microstructural evolution in different sections and zones of the joint. It was found that the stir zone (SZ) macrostructure may contain either a single or many nugget zones depending on the metal sheet thickness and the seam length. The effect of grain kinking in a thermomechanically affected zone (TMAZ) under pressure from the stir zone metal was discovered. The stir zone metal was fine-grained but had a microhardness lower than that of the base metal, which may be explained by the overaging effect of FSW on the Al3Sc precipitates. The tensile strength of the joint was almost equal to that of the base metal (BM). The grain size distributions were obtained in different sections below the sheet surface and away from the exit hole, which allowed us to suggest the specific adhesion-assisted layer-by layer metal transfer mechanism in FSW.
Databáze: Directory of Open Access Journals