Microstructure and mechanical properties of friction stir welding of AZ31B magnesium alloy added with cerium

Yu, Sirong; Chen, Xianjun; Huang, Zhiqiu; Liu, Yaohui

doi:10.1016/s1002-0721(09)60104-6

Cited by 59 publications

(31 citation statements)

References 14 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The test samples were then embedded in epoxy to expose the cross sectional surface of the welded joint. Samples were progressively ground and polished to a final surface finish of 1 4 μm using diamond paste.…”

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Corrosion Mechanisms in Dissimilar AZ31/AZ80 Friction Stir Welds

Savguira

North

Thorpe

2018

J. Electrochem. Soc.

View full text Add to dashboard Cite

Corrosion of dissimilar friction stir welds (FSW) made in AZ31/AZ80 magnesium alloys was investigated using the scanning reference electrode technique (SRET), and microcapillary polarization technique, complemented by optical and SEM/EDX microscopy. The corrosion rate of the base metals along with the welded specimen was estimated by mass loss testing. The stir zone material in both alloys showed a higher corrosion potential than the base metal due to the partial dissolution of β-Mg 17 Al 12 and Al-Mn particles. The basic corrosion mechanism in dissimilar welds was determined to be different from that of a similar joint. The corrosion behavior of the dissimilar FSW joint was governed by the galvanic coupling of the two alloys, and not by the microstructural evolution occurring during the welding process. The corrosion behavior of the joint was governed by the galvanic coupling between the α-Mg matrix in AZ31 and the Al-rich intermetallics in AZ80. The welded specimens exhibited the highest corrosion rate, while AZ80 was the most corrosion resistant material. Magnesium alloys can be successfully joined by friction stir welding (FSW) to achieve excellent mechanical integrity in completed welds. 1,2 One challenge arising from the utilization of this joining method is an increased susceptibility to localized corrosion in the material immediately adjacent to the welded joint. 3-6 Previous microcapillary polarization and scanning reference electrode technique (SRET) studies have revealed that the stir zones in AZ31B spot and seam welds are more cathodic than the bulk material. [3][4][5][6] Due to the difference in electrochemical potentials, a macrogalvanic cell is formed causing pitting corrosion in the thermo-mechanically affected zone (TMAZ) and the heat affected zone (HAZ) regions, which are located between the noble stir zone and the active base metal. 5 The differences in the electrochemical behavior of different regions in completed joints have been related to their microstructural evolution that occurred during the welding operation. The stir zone microstructure comprised a dynamically recrystallized matrix which was nominally devoid of intermetallics. The increase in the corrosion potential of the stir zone has been attributed to the dissolution of β-Mg 17 Al 12 and Al-Mn particles via two mechanisms: 4,5 1. Dissolution of intermetallics, which increases the concentration of Al in the α-Mg matrix, resulting in a higher corrosion potential of this region, 7 and 2. The absence of the intermetallics, which eliminates the microgalvanic coupling between the intermetallic particles (IMPs) and the α-Mg matrix, and reduces the susceptibility of the welded joint to localized pitting corrosion. [8][9][10][11] Many industrial applications require joining of dissimilar alloys, and therefore it is essential to understand the influence of the welding process on the corrosion behavior of dissimilar joints. It is currently unknown whether the corrosion behavior of dissimilar welds is governed by the microstructural changes o...

show abstract

Section: Methodsmentioning

confidence: 99%

“…The solution comprised 100 g/l CrO 3 , and 5 g/l AgNO 3 in distilled water. The weight of each sample was measured before (m i ) and after (m f ) exposure to the corrosion medium, and the corrosion rate (CR AW ) was calculated as the change in mass divided by the total area of the sample (A Total ) and the exposure time (t) as per Equation 1.…”

Section: Methodsmentioning

confidence: 99%

Corrosion Mechanisms in Dissimilar AZ31/AZ80 Friction Stir Welds

Savguira

North

Thorpe

2018

J. Electrochem. Soc.

View full text Add to dashboard Cite

show abstract

“…This incomparably broadens the scope of employing Mg alloys to numerous applications. Different alloys of Magnesium including AZ31, ZK60, AZ61, AM50 etc have been fabricated successfully by FSW process and numerous experimental investigations were conducted during the FSW of these Mg alloys [8][9][10][11][12]. For example, Rajakumar et al [9] made an examination during FSW of ZK60 Mg alloys at an 800 rpm rotation rate and 100 mm/min traverse speed.…”

Section: Literature Reviewmentioning

confidence: 99%

Influence of The Arrangement of Materials and Microstructural Analysis During FSW of AZ80A & AZ91C Mg Alloys

Sevvel

Jaiganesh

2017

Archives of Metallurgy and Materials

View full text Add to dashboard Cite

The main objective of this paper is to produce defect free weldments with improved properties during friction stir welding of dissimilar Mg alloys. The influence of the anisotropic arrangement of materials when AZ80A Mg alloy is taken as advancing side and AZ91C Mg alloy as retreating side and vice versa with respect to their mechanical properties and microstructural characteristics were investigated. The effects of various FSW parameters on the quality of these joints were also analyzed and best optimized FSW parameters were suggested. Defect free sound joints with excellent mechanical properties were produced when AZ80A Mg alloy was positioned at retreating side. At the same time, it seems a little bit difficult to obtain good quality joints with the contrary arrangement of materials. These investigations revealed that materials having inferior plastic deformability must be kept at the advancing side to obtain sound joints during FSW of dissimilar alloys of Magnesium.

show abstract

“…Mg sheets can be used in the fabrication of automobile body parts including semi-structural and non-structural applications [1,2]. Conventional welding processes are unsuitable for fabricating alloys of Mg due to their high requirement of energy and easy tendency for corrosion towards copper electrode.…”

Section: Introductionmentioning

confidence: 99%