Mass-Loss Testing in Magnesium AZ31 Friction Stir Spot Welds

Savguira, Yuri; Liu, W.H.; Miklas, D.J.; North, T. H.; Thorpe, Steven J.

doi:10.5006/1145

Cited by 17 publications

(54 citation statements)

References 29 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The SZ region was found to be noble while the TMAZ, HAZ, and BM were active. The noble behavior of the stir zone as compared to the other weld regions has been documented and explained elsewhere [17,18]. It is important to note that the electrochemical behavior of the various weld regions did not change as a result of the stress relieving heattreatment.…”

Section: Resultsmentioning

confidence: 82%

“…Prior scanning reference electrode technique investigations (SRET) of FSSW joints confirmed that the SZ was more cathodic than the base material (BM) and therefore accelerated corrosion at the region adjacent to the weld (in the TMAZ and HAZ) [16,17]. This observation was further confirmed through microcapillary polarization, and mass loss testing of the welded joints [17][18][19].…”

Section: Introductionmentioning

confidence: 91%

See 1 more Smart Citation

Effect of grain size and residual stress on the corrosion resistance of friction stir spot welded AZ31B joints

Savguira

North

Thorpe

2016

Materials & Corrosion

Self Cite

View full text Add to dashboard Cite

Localized corrosion at the weld periphery of AZ31B friction stir spot welds has been associated with the formation of a galvanic cell between the stir zone material and the adjacent base metal. However, this explanation did not take into account the effects of residual stress and grain growth in material adjacent to the stir zone region. In this study, the influence of microstructural changes on the electrochemical characteristics of FSSW joints is investigated using a combination of microcapillary polarization, stress relief heat‐treatment and micro‐hardness testing. It is confirmed that residual stress has no significant effect on the corrosion resistance properties of completed joints. Also, based on a detailed examination of the electrochemical characteristics of materials in the stir zone, TMAZ and HAZ regions, grain growth had negligible influence on the corrosion resistance properties.

show abstract

Section: Resultsmentioning

confidence: 82%

Section: Introductionmentioning

confidence: 91%

Effect of grain size and residual stress on the corrosion resistance of friction stir spot welded AZ31B joints

Savguira

North

Thorpe

2016

Materials & Corrosion

Self Cite

View full text Add to dashboard Cite

show abstract

“…Previous studies have shown the SZ to be noble to the base metal, and produce a local galvanic cell that resulted in the accelerated corrosion of the TMAZ region . Mass loss studies by Savguira et al have confirmed their findings by showing enhanced corrosion rates associated with the welded samples, along with a preferential attack around the periphery of the joint . The morphology of localized corrosion was coincident with the TMAZ region of the weld.…”

Section: Introductionmentioning

confidence: 81%

“…The relative corrosion performance of welded and base metal specimens was evaluated through immersion testing adopted form ASTM G31‐12a . Complete details of the experimental procedure are found elsewhere . Twenty individual test cells were fabricated from polymethyl methacrylate ([C 5 O 2 H 8 ] n ) and placed within a borosilicate glass tray containing approximately 1.8 L of 0.086 M sodium chloride (NaCl) solution (pH = 6.1) held at 25 °C using an external water bath.…”

Section: Methodsmentioning

confidence: 99%

Effect of welding flash on the corrosion of friction stir spot welded AZ31B

Savguira

Liu

North

et al. 2016

Materials & Corrosion

Self Cite

View full text Add to dashboard Cite

The influence of welding flash on the corrosion resistance of friction stir spot welded (FSSW) AZ31B was examined by mass loss testing complimented with the scanning reference electrode and microcapillary polarization techniques. The microstructure of the flash was characterized by optical microscopy and the use of tungsten carbide tracer and correlated with the corrosion morphology of the joints. It was observed that the flash increased the corrosion rate of the welds, and its removal can reduce the corrosion rate by 20%. The increase in susceptibility for corrosion was explained by examining the electrochemical characteristics of the flash, and in particular to show the presence of a second stir zone (SZ) region in the flash. The electrochemical properties of the flash were correlated to second phase particle dissolution using a detailed microscopy analysis.The coupling of the two regions resulted in the formation of a local galvanic cell in the flash, leading to accelerated corrosion. Increases in dwell time and/or rotational speed of the tool during FSSW resulted in the formation of a larger SZ region in the flash, and produced a greater cathode to anode ratio. Materials and Corrosion 2017, 68, No. 4 Effect of welding flash on the corrosion of FSSW Figure 6. Influence of welding flash and exposure time on the location and morphology of corrosive attack. Important weld surfaces are labeled with letters that are consisted with the schematic in Fig. 1b. Abottom of pin hole surface, Cshoulder penetration surface, Fupper sheet surface, Iwelding flash www.matcorr.com

show abstract

“…A more detailed explanation of the technique can be found elsewhere (5). Samples were placed in individual beakers containing 600 ml of 0.086M NaCl solution held at 25 o C using an external water bath.…”

Section: Mass Loss Testingmentioning

confidence: 99%

Localized Corrosion Behaviour in Dissimilar AZ31/AZ80 Friction Stir Welds

2015

View full text Add to dashboard Cite

Corrosion of a dissimilar friction stir weld (FSW) made in AZ31/AZ80 magnesium alloys has been investigated using the scanning reference electrode technique (SRET), and microcapillary polarization technique. The corrosion rate of each of the base metals along with the welded specimen was estimated by mass loss testing and mixed potential theory. The stir zone material in both alloys showed a higher reduction potential than the base metal, due to the dissolution of β-Mg 17 Al 12, and Al-Mn intermetallic particles. The dissimilar welded specimen exhibited a higher corrosion rate compared to either AZ31 or AZ80. The governing corrosion mechanism in dissimilar welds was determined to be different from FSSW joints made with a singular material. The corrosion behaviour of the dissimilar FSW joint was governed by the galvanic coupling of the two alloys, and not by the microstructural evolution that occurred during the welding process.

show abstract

Mass-Loss Testing in Magnesium AZ31 Friction Stir Spot Welds

Cited by 17 publications

References 29 publications

Effect of grain size and residual stress on the corrosion resistance of friction stir spot welded AZ31B joints

Effect of grain size and residual stress on the corrosion resistance of friction stir spot welded AZ31B joints

Effect of welding flash on the corrosion of friction stir spot welded AZ31B

Localized Corrosion Behaviour in Dissimilar AZ31/AZ80 Friction Stir Welds

Contact Info

Product

Resources

About