Resistance-Spot-Welded AZ31 Magnesium Alloys: Part I. Dependence of Fusion Zone Microstructures on Second-Phase Particles

2010 ◽  
Vol 41 (6) ◽  
pp. 1511-1522 ◽  
Author(s):  
L. Xiao ◽  
L. Liu ◽  
Y. Zhou ◽  
S. Esmaeili
Keyword(s):  
Magnesium Alloys ◽  
Fusion Zone ◽  
Second Phase ◽  
Resistance Spot ◽  
Second Phase Particles ◽  
Spot Welded ◽  
Az31 Magnesium Alloys

scholarly journals Alloying and Processing Effects on the Microstructure, Mechanical Properties, and Degradation Behavior of Extruded Magnesium Alloys Containing Calcium, Cerium, or Silver

Materials ◽  
2020 ◽  
Vol 13 (2) ◽  
pp. 391 ◽  
Author(s):  
Jan Bohlen ◽  
Sebastian Meyer ◽  
Björn Wiese ◽  
Bérengère J. C. Luthringer-Feyerabend ◽  
Regine Willumeit-Römer ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Magnesium Alloys ◽  
Processing Parameters ◽  
Second Phase ◽  
Degradation Behavior ◽  
Microstructure Development ◽  
Corrosion Properties ◽  
Second Phase Particles ◽  
Degradation Rates ◽  
The Relationship

Magnesium alloys attract attention as degradable implant materials due to their adjustable corrosion properties and biocompatibility. In the last few decades, especially wrought magnesium alloys with enhanced mechanical properties have been developed, with the main aim of increasing ductility and formability. Alloying and processing studies allowed demonstrating the relationship between the processing and the microstructure development for many new magnesium alloys. Based on this experience, magnesium alloy compositions need adjustment to elements improving mechanical properties while being suitable for biomaterial applications. In this work, magnesium alloys from two Mg-Zn series with Ce (ZE) or Ca (ZX) as additional elements and a series of alloys with Ag and Ca (QX) as alloying elements are suggested. The microstructure development was studied after the extrusion of round bars with varied processing parameters and was related to the mechanical properties and the degradation behavior of the alloys. Grain refinement and texture weakening mechanisms could be improved based on the alloy composition for enhancing the mechanical properties. Degradation rates largely depended on the nature of second phase particles rather than on the grain size, but remained suitable for biological applications. Furthermore, all alloy compositions exhibited promising cytocompatibility.

On the Impact of Second Phase Particles on Twinning in Magnesium Alloys

2011 ◽  
pp. 289-293
Author(s):  
M. R. Barnett ◽  
N. Stanford ◽  
J. Geng ◽  
J. Robson
Keyword(s):  
Magnesium Alloys ◽  
Second Phase ◽  
Second Phase Particles ◽  
The Impact

Friction Stir Processing: A Novel Approach for Microstructure Refinement of Magnesium Alloys

2010 ◽  
Vol 638-642 ◽  
pp. 1191-1196 ◽  
Author(s):  
Zong Yi Ma ◽  
B.L. Xiao ◽  
J. Yang ◽  
A.H. Feng
Keyword(s):  
Magnesium Alloys ◽  
Friction Stir Processing ◽  
Second Phase ◽  
Strain Rates ◽  
Friction Stir ◽  
Novel Approach ◽  
Second Phase Particles ◽  
Wide Range ◽  
Fine Microstructure ◽  
Higher Temperature

In this article, recent investigations on magnesium alloys by friction stir processing (FSP) are addressed. It indicates that remarkable grain refinement and breakup/dissolution of second-phase particles could be achieved simultaneously by FSP. High values of superplastic elongation were achieved in the FSP magnesium alloys at a wide range of strain rates and temperatures. The pinning of heat resistant particles on the grain boundaries in Mg-RE alloys stabilized the fine microstructure, leading to the occurrence of superplasticity at higher temperature and higher strain rate.

Influence of Second Phase Particles on Fracture Toughness in AZ31 Magnesium Alloys

2004 ◽  
Vol 261-263 ◽  
pp. 369-374 ◽  
Author(s):  
Taisuke Sasaki ◽  
Hidetoshi Somekawa ◽  
Akira Takara ◽  
Yukio Nishikawa ◽  
Kenji Higashi
Keyword(s):  
Fracture Toughness ◽  
Particle Size ◽  
Magnesium Alloys ◽  
Average Particle Size ◽  
Second Phase ◽  
Average Particle ◽  
Particle Spacing ◽  
Strain Fracture ◽  
Second Phase Particles ◽  
Good Agreement

Three kinds of thin AZ31 wrought magnesium alloys sheets were used in order to investigate the influence of the second phase particles on fracture toughness. From the theoretical model, the ratio of λp/dp would be estimated 5~ 6. On the other hand, from the microstructural observation, average particle spacing on each material was sample A: 13.1µm, sample B: 14.1, and sample C: 12 µ. In addition, average particle size on each sample was sample A: 2.1, sample B: 1.9, and sample C: 2.3 µm. Therefore, the ratio of λp/dp calculated from fracture surface observation would be predicted 6 ~ 7. In comparison with the result of the prediction by theoretical analysis was in good agreement with the result of fracture toughness observation. It was found that the variation in plane-strain fracture toughness on AZ31 were affected by both of particle spacing and particle size.

scholarly journals Formability of Magnesium Alloys AZ80 and ZE10

2014 ◽  
Vol 622-623 ◽  
pp. 284-291 ◽  
Author(s):  
Timotius Pasang ◽  
V. Satanin ◽  
M. Ramezani ◽  
M. Waseem ◽  
Thomas Neitzert ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Magnesium Alloys ◽  
Strain Ratio ◽  
Grain Structure ◽  
Second Phase ◽  
Plastic Strain Ratio ◽  
Heat Treated ◽  
Second Phase Particles ◽  
Az80 Alloy ◽  
Hardening Coefficient

Formability of two magnesium alloys, namely, AZ80 and ZE10, has been investigated. Both alloys were supplied with a thickness of 0.8 mm. The grain structure of the as-received AZ80 alloy showed dislocations, twins and second-phase particles and-/or precipitates distributed uniformly within grains. These were not obvious on the ZE10 alloy. The investigations were carried out at room temperature for both alloys in the as-received and heat treated conditions (410oC for 1 hour followed by water quench). The heat treatment significantly changed the grain structure of the AZ80 alloy, but did not affect the ZE10 alloy apart from grain enlargement. The formability was studied on the basis of plastic strain ratio (r) and strain hardening coefficient (n) by means of tensile testing. In the as-received condition, the ZE10 alloy had a slightly better formability () than AZ80 alloy. Following heat treatment, however, the formability of the AZ80 alloy was improved significantly (by about 26%), while the ZE10 alloy did not show any significant change.

Effect of silica content on mechanical and microstructure behaviour of resistance spot welded advanced automotive TRIP steels

2021 ◽  
Author(s):  
Paranthaman V ◽  
Shanmuga Sundaram K ◽  
L Natrayan
Keyword(s):  
Fusion Zone ◽  
Resistance Spot Welding ◽  
Spot Welding ◽  
Welding Process ◽  
Tensile Shear ◽  
X Ray Diffraction ◽  
X Ray ◽  
Trip Steels ◽  
Resistance Spot ◽  
Spot Welded

Abstract This research investigates the effect of SiC wt% on mechanical and microstructure behavior of transformation induced plasticity (TRIP) 780 steels by resistance spot welding. The resistance spot welded samples were characterized for their properties such as hardness, tensile shear, scanning electron microscope, X-ray diffraction, ductility ratio and elongation. Results showed that the width of the nugget was closely associated with shear failure of the spot welds. X-ray diffraction analysis illustrated that the weld steels chemical composition improved in the heat-affected zones and retained austenite detected due to the influence of Si and C. Sample 4 microstructure exposed the equiaxed dimple and finer dendrites in the fusion zone. It also exhibited maximum force and fracture energy. Nano hardness was significantly decreased in the fusion zone of sample 4 due to the interface among micro alloying elements and the formation of nonmetallic presences that affected the TRIP steel hardness. Low ductility ratios were observed in steel 4 than the other weld steels due to higher tensile shear strength (TSS) and cross-tension strength (CTS) results. Fracture analysis exhibited ductile fracture with dimples and dendrites in the TRIP steels surface. The spot-welded samples mechanical properties are correlated to chemical elements, mainly Si existing in casted TRIP steels through the cooling phase of the resistance spot welding process.

scholarly journals Improving the mechanical performance of a resistance spot welded 1200 MPa TBF steel

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Manfred Stadler ◽  
Ronald Schnitzer ◽  
Martin Gruber ◽  
Christina Hofer
Keyword(s):  
Fusion Zone ◽  
Mechanical Performance ◽  
Electron Backscatter Diffraction ◽  
Bainitic Ferrite ◽  
Maximum Force ◽  
Resistance Spot ◽  
Weld Properties ◽  
Ferrite Steel ◽  
Backscatter Diffraction ◽  
Spot Welded

Abstract In the present work different approaches to improve the mechanical properties of a resistance spot welded 1200 MPa transformation induced plasticity-aided bainitic ferrite steel are evaluated. An extension of the welding time results in coarsening of the microstructure of the outer fusion zone and the maximum force derived by the cross tension strength test did not improve significantly. A temper pulse after a long cooling time leads to pronounced softening of the fusion zone, as determined by hardness mapping, which resulted in enhanced weld properties. A recrystallization pulse modifies the shape of the prior austenite grains at the outer fusion zone, which was visualized with electron backscatter diffraction. This also resulted in a significant improvement of maximum force. For all approaches the failure mode improved, which can be attributed to an increased fraction of high angle grain boundaries at the edge of the fusion zone.

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