Mass-Loss Testing in Magnesium AZ31 Friction Stir Spot Welds

The choice of welding parameters during friction stir welding of AZ31 magnesium alloy can significantly affect the morphology and extent of corrosion attack. Mass-loss testing in combination with optical analysis revealed that both tool rotation speed and dwell time significantly altered the corrosi...

Full description

Saved in:
Bibliographic Details
Published in:Corrosion (Houston, Tex.) Tex.), 2014-08, Vol.70 (8), p.858-866
Main Authors: SAVGUIRA, Y, LIU, W. H, MIKLAS, D. J, NORTH, T. H, THORPE, S. J
Format: Article
Language:English
Subjects:
Applied sciences
Beta phase
Constants
Corrosion
Corrosion environments
Corrosion rate
Corrosion resistance
Corrosion tests
Dwell time
Exact sciences and technology
Friction
Friction stir welding
Grain boundaries
Grain size
Joining, thermal cutting: metallurgical aspects
Localized corrosion
Magnesium
Magnesium alloys
Magnesium base alloys
Mechanical properties and methods of testing. Rheology. Fracture mechanics. Tribology
Metals. Metallurgy
Morphology
Optical analysis
Pitting (corrosion)
Polymethyl methacrylate
Rotation
Scanning reference electrodes
Shoulder
Spot welds
Testing
Welded joints
Welding
Welding parameters
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The choice of welding parameters during friction stir welding of AZ31 magnesium alloy can significantly affect the morphology and extent of corrosion attack. Mass-loss testing in combination with optical analysis revealed that both tool rotation speed and dwell time significantly altered the corrosion rate, morphology, and location of attack. With increasing tool rotation rate, the corrosion morphology shifted from general attack of the upper surface near the shoulder to mainly localized pitting within the shoulder surface for a constant dwell time. For a constant tool rotation rate, increased dwell time increased the susceptibility to localized corrosion but did not change the location. Both observations are consistent with the microstructural evolution of the thermo-mechanically affected zone during welding that is attacked preferentially. The scanning reference electrode technique (SRET) has shown the stir zone to be a noble region that increased in size with increasing rotational speed. The stir zone was found to be noble as a result of the reduced particle area fraction associated with β-phase dissolution during the welding process.
ISSN:0010-9312
1938-159X
DOI:10.5006/1145