A cast 7050 friction stir weld with scandium: microstructure, corrosion and environmental assisted cracking

C. S. Paglia; K. V. Jata; R. G. Buchheit

doi:10.1016/j.msea.2006.03.065

A cast 7050 friction stir weld with scandium: microstructure, corrosion and environmental assisted cracking

C. S. Paglia, K. V. Jata, R. G. Buchheit

Research output: Contribution to journal › Article › peer-review

41 Scopus citations

Abstract

Microstructure, corrosion and environmental cracking behavior of friction stir welded cast aluminum 7050 ingots alloyed with scandium additions was investigated. An over-aged (T7451) and a homogenization (24 h/475 °C) temper were applied to the as-cast plates before friction stir welding, while a post-weld heat treatment was applied to all welds to verify the changes in the corrosion behavior. It was found that the as-cast and heat treated friction stir weld samples exhibited a fully recrystallized equiaxed grain microstructure. The scandium did not significantly dissolve in any of the phases present and remained homogeneously distributed within the matrix. The as-cast friction stir weld microstructure exhibited apart from the nugget region coarse grain boundary phases, wide precipitate-free zones and coarse intragranular precipitates. The post-weld heat treatment (1 h/480 °C-1 h/100 °C boiling water and quench) increased the tensile strength of the as-cast weld, but decreased the strength of the heat treated welds. The heat treatment of the as-cast samples to an overaging (T7451) and homogenization (24 h/475 °C) temper increased the general corrosion susceptibility of the friction stir welds.

Original language	English
Pages (from-to)	196-204
Number of pages	9
Journal	Materials Science & Engineering A: Structural Materials: Properties, Microstructure and Processing
Volume	424
Issue number	1-2
DOIs	https://doi.org/10.1016/j.msea.2006.03.065
State	Published - May 25 2006

Bibliographical note

Funding Information:
The authors would like to thank the Materials and Manufacturing Directorate, AFRL, for the financial support, Mr. Ken Davidson program manager. R. Perez of the Boeing Company for providing the material and A.P. Reynolds, University of South Carolina for the welding.

Keywords

AA7050
As-cast microstructure
Corrosion
Environmental assisted cracking
Scandium

ASJC Scopus subject areas

Materials Science (all)
Condensed Matter Physics
Mechanics of Materials
Mechanical Engineering

Access to Document

10.1016/j.msea.2006.03.065

Cite this

@article{f5c4775846e84024bdbd8172302926d3,

title = "A cast 7050 friction stir weld with scandium: microstructure, corrosion and environmental assisted cracking",

abstract = "Microstructure, corrosion and environmental cracking behavior of friction stir welded cast aluminum 7050 ingots alloyed with scandium additions was investigated. An over-aged (T7451) and a homogenization (24 h/475 °C) temper were applied to the as-cast plates before friction stir welding, while a post-weld heat treatment was applied to all welds to verify the changes in the corrosion behavior. It was found that the as-cast and heat treated friction stir weld samples exhibited a fully recrystallized equiaxed grain microstructure. The scandium did not significantly dissolve in any of the phases present and remained homogeneously distributed within the matrix. The as-cast friction stir weld microstructure exhibited apart from the nugget region coarse grain boundary phases, wide precipitate-free zones and coarse intragranular precipitates. The post-weld heat treatment (1 h/480 °C-1 h/100 °C boiling water and quench) increased the tensile strength of the as-cast weld, but decreased the strength of the heat treated welds. The heat treatment of the as-cast samples to an overaging (T7451) and homogenization (24 h/475 °C) temper increased the general corrosion susceptibility of the friction stir welds.",

keywords = "AA7050, As-cast microstructure, Corrosion, Environmental assisted cracking, Scandium",

author = "Paglia, {C. S.} and Jata, {K. V.} and Buchheit, {R. G.}",

note = "Funding Information: The authors would like to thank the Materials and Manufacturing Directorate, AFRL, for the financial support, Mr. Ken Davidson program manager. R. Perez of the Boeing Company for providing the material and A.P. Reynolds, University of South Carolina for the welding. ",

year = "2006",

month = may,

day = "25",

doi = "10.1016/j.msea.2006.03.065",

language = "English",

volume = "424",

pages = "196--204",

number = "1-2",

}

TY - JOUR

T1 - A cast 7050 friction stir weld with scandium

T2 - microstructure, corrosion and environmental assisted cracking

AU - Paglia, C. S.

AU - Jata, K. V.

AU - Buchheit, R. G.

N1 - Funding Information: The authors would like to thank the Materials and Manufacturing Directorate, AFRL, for the financial support, Mr. Ken Davidson program manager. R. Perez of the Boeing Company for providing the material and A.P. Reynolds, University of South Carolina for the welding.

PY - 2006/5/25

Y1 - 2006/5/25

N2 - Microstructure, corrosion and environmental cracking behavior of friction stir welded cast aluminum 7050 ingots alloyed with scandium additions was investigated. An over-aged (T7451) and a homogenization (24 h/475 °C) temper were applied to the as-cast plates before friction stir welding, while a post-weld heat treatment was applied to all welds to verify the changes in the corrosion behavior. It was found that the as-cast and heat treated friction stir weld samples exhibited a fully recrystallized equiaxed grain microstructure. The scandium did not significantly dissolve in any of the phases present and remained homogeneously distributed within the matrix. The as-cast friction stir weld microstructure exhibited apart from the nugget region coarse grain boundary phases, wide precipitate-free zones and coarse intragranular precipitates. The post-weld heat treatment (1 h/480 °C-1 h/100 °C boiling water and quench) increased the tensile strength of the as-cast weld, but decreased the strength of the heat treated welds. The heat treatment of the as-cast samples to an overaging (T7451) and homogenization (24 h/475 °C) temper increased the general corrosion susceptibility of the friction stir welds.

AB - Microstructure, corrosion and environmental cracking behavior of friction stir welded cast aluminum 7050 ingots alloyed with scandium additions was investigated. An over-aged (T7451) and a homogenization (24 h/475 °C) temper were applied to the as-cast plates before friction stir welding, while a post-weld heat treatment was applied to all welds to verify the changes in the corrosion behavior. It was found that the as-cast and heat treated friction stir weld samples exhibited a fully recrystallized equiaxed grain microstructure. The scandium did not significantly dissolve in any of the phases present and remained homogeneously distributed within the matrix. The as-cast friction stir weld microstructure exhibited apart from the nugget region coarse grain boundary phases, wide precipitate-free zones and coarse intragranular precipitates. The post-weld heat treatment (1 h/480 °C-1 h/100 °C boiling water and quench) increased the tensile strength of the as-cast weld, but decreased the strength of the heat treated welds. The heat treatment of the as-cast samples to an overaging (T7451) and homogenization (24 h/475 °C) temper increased the general corrosion susceptibility of the friction stir welds.

KW - AA7050

KW - As-cast microstructure

KW - Corrosion

KW - Environmental assisted cracking

KW - Scandium

UR - http://www.scopus.com/inward/record.url?scp=33747172768&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=33747172768&partnerID=8YFLogxK

U2 - 10.1016/j.msea.2006.03.065

DO - 10.1016/j.msea.2006.03.065

M3 - Article

AN - SCOPUS:33747172768

SN - 0921-5093

VL - 424

SP - 196

EP - 204

JO - Materials Science & Engineering A: Structural Materials: Properties, Microstructure and Processing

JF - Materials Science & Engineering A: Structural Materials: Properties, Microstructure and Processing

IS - 1-2

ER -

A cast 7050 friction stir weld with scandium: microstructure, corrosion and environmental assisted cracking

Abstract

Bibliographical note

Keywords

ASJC Scopus subject areas

Access to Document

Other files and links

Fingerprint

Cite this