Deformation dynamics study of a wrought magnesium alloy by real-time in situ neutron diffraction

2013 ◽  
Vol 69 (5) ◽  
pp. 358-361 ◽  
Author(s):  
Wei Wu ◽  
Ke An ◽  
Lu Huang ◽  
Soo Yeol Lee ◽  
Peter K. Liaw
Keyword(s):  
Magnesium Alloy ◽  
Neutron Diffraction ◽  
Real Time ◽  
Wrought Magnesium Alloy ◽  
Deformation Dynamics ◽  
In Situ Neutron Diffraction

scholarly journals Bending Behavior of a Wrought Magnesium Alloy Investigated by the In Situ Pinhole Neutron Diffraction Method

Crystals ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 348 ◽  
Author(s):  
Wei Wu ◽  
Alexandru Stoica ◽  
Dunji Yu ◽  
Matthew Frost ◽  
Harley Skorpenske ◽  
...  
Keyword(s):  
Magnesium Alloy ◽  
Neutron Diffraction ◽  
Spatial Resolution ◽  
Diffraction Method ◽  
Middle Layer ◽  
Mapping Method ◽  
Step Size ◽  
Four Point Bending ◽  
Wrought Magnesium Alloy

The tensile twinning and detwinning behaviors of a wrought magnesium alloy have been investigated during in situ four-point bending using the state-of-the-art high spatial resolution pinhole neutron diffraction (PIND) method. The PIND method allowed us to resolve the tensile twinning/detwinning and lattice strain distributions across the bending sample during a loading-unloading sequence with a 0.5 mm step size. It was found that the extensive tensile twinning and detwinning occurred near the compression surface, while no tensile twinning behavior was observed in the middle layer and tension side of the bending sample. During the bending, the neutral plane shifted from the compression side to the tension side. Compared with the traditional neutron diffraction mapping method, the PIND method provides more detailed information inside the bending sample due to a higher spatial resolution.

Real-Time In Situ Neutron Diffraction Investigation of Phase-Specific Load Sharing in a Cold-Rolled TRIP Sheet Steel

JOM ◽  
2018 ◽  
Vol 70 (8) ◽  
pp. 1576-1586 ◽  
Author(s):  
Dunji Yu ◽  
Lu Huang ◽  
Yan Chen ◽  
Piyamanee Komolwit ◽  
Ke An
Keyword(s):  
Neutron Diffraction ◽  
Real Time ◽  
Sheet Steel ◽  
Load Sharing ◽  
Specific Load ◽  
Cold Rolled ◽  
In Situ Neutron Diffraction

scholarly journals Tracing Phase Transformation and Lattice Evolution in a TRIP Sheet Steel under High-Temperature Annealing by Real-Time In Situ Neutron Diffraction

Crystals ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 360 ◽  
Author(s):  
Dunji Yu ◽  
Yan Chen ◽  
Lu Huang ◽  
Ke An
Keyword(s):  
Phase Transformation ◽  
High Temperature ◽  
Neutron Diffraction ◽  
Real Time ◽  
Retained Austenite ◽  
Sheet Steel ◽  
Carbon Diffusion ◽  
Structure Evolution ◽  
In Situ Neutron Diffraction

Real-time in situ neutron diffraction was used to characterize the crystal structure evolution in a transformation-induced plasticity (TRIP) sheet steel during annealing up to 1000 °C and then cooling to 60 °C. Based on the results of full-pattern Rietveld refinement, critical temperature regions were determined in which the transformations of retained austenite to ferrite and ferrite to high-temperature austenite during heating and the transformation of austenite to ferrite during cooling occurred, respectively. The phase-specific lattice variation with temperature was further analyzed to comprehensively understand the role of carbon diffusion in accordance with phase transformation, which also shed light on the determination of internal stress in retained austenite. These results prove the technique of real-time in situ neutron diffraction as a powerful tool for heat treatment design of novel metallic materials.

scholarly journals Inclusion removal and grain refinement of magnesium alloy castings

2021 ◽  
Author(s):  
Abdallah Elsayed
Keyword(s):  
Magnesium Alloy ◽  
Neutron Diffraction ◽  
Grain Refinement ◽  
Magnesium Alloys ◽  
Ex Situ ◽  
Inclusion Removal ◽  
Carbon Inoculation ◽  
Aluminum Silicon Carbide ◽  
In Situ Neutron Diffraction

Magnesium alloys show promise to be materials for lightweighting of automotive and aerospace vehicles improving fuel efficiencies and vehicle performance. A majority of magnesium alloy components are produced using casting where susceptibility to forming inclusions and coarse grain sizes could result. Development of effective inclusion removal techniques and better understanding of grain refinement of magnesium alloys could help in improving their mechanical properties to advance them to more structurally demanding applications. This research aimed to develop an environmentally friendly alternative to the grain refinement and inclusion removal capabilities of carbon based hexachloroethane as it releases dioxins, chlorine gas and corrodes foundry equipment. A secondary aim was to pioneer in-situ neutron diffraction to examine the solidification of magnesium alloys. The research involved preparing tensile samples of AZ91E magnesium alloy using permanent mould casting. Inclusion removal was conducted by using filtration and argon gas bubbling. Castings grain refined using hexachloroethane (0.25, 0.50 and 0.75 wt.%) were compared against ex-situ aluminum-silicon carbide and in-situ aluminum-carbon based grain refiners combined with filtration and argon gas bubbling. Further, in-situ neutron diffraction was utilized for phase analysis and fraction solid determination of magnesium-zinc and magnesium-aluminum alloys. There was a significant improvement in yield strength, ultimate tensile strength and elongation with filtration plus argon bubbling, carbon inoculation or both filtration plus argon bubbling and carbon inoculation. The results indicated that the mechanism of the observed ~20% reduction in grain sizes with carbon inoculation (hexachloroethane, ex-situ aluminum-silicon carbide and in-situ aluminum-carbon) was explained through duplex nucleation of Mn-Al and Al-Mg-C-O (likely Al2MgC2) phases. Finally, in-situ neutron diffraction was used to follow the formation of Mg17Al12 eutectic phase in a magnesium-9 wt.% aluminum alloy. For the magnesium-zinc alloys, in-situ neutron diffraction enabled characterization of the effects of zirconium to the fraction solid growth of (1010), (0002) and (1011) α-Mg planes. The societal and environmental impact of this research is significant. There is a clear demonstration of alternatives to the universally used hexachloroethane grain refiner promoting harmful emissions. Improved mechanical properties resulting from new grain refinement and iv inclusion filtration are a major advancement in promoting weight reduction, improved castability and decreased environmental impact for automotive and aerospace industries.

scholarly journals Inclusion removal and grain refinement of magnesium alloy castings

2021 ◽  
Author(s):  
Abdallah Elsayed
Keyword(s):  
Magnesium Alloy ◽  
Neutron Diffraction ◽  
Grain Refinement ◽  
Magnesium Alloys ◽  
Ex Situ ◽  
Inclusion Removal ◽  
Carbon Inoculation ◽  
Aluminum Silicon Carbide ◽  
In Situ Neutron Diffraction

Magnesium alloys show promise to be materials for lightweighting of automotive and aerospace vehicles improving fuel efficiencies and vehicle performance. A majority of magnesium alloy components are produced using casting where susceptibility to forming inclusions and coarse grain sizes could result. Development of effective inclusion removal techniques and better understanding of grain refinement of magnesium alloys could help in improving their mechanical properties to advance them to more structurally demanding applications. This research aimed to develop an environmentally friendly alternative to the grain refinement and inclusion removal capabilities of carbon based hexachloroethane as it releases dioxins, chlorine gas and corrodes foundry equipment. A secondary aim was to pioneer in-situ neutron diffraction to examine the solidification of magnesium alloys. The research involved preparing tensile samples of AZ91E magnesium alloy using permanent mould casting. Inclusion removal was conducted by using filtration and argon gas bubbling. Castings grain refined using hexachloroethane (0.25, 0.50 and 0.75 wt.%) were compared against ex-situ aluminum-silicon carbide and in-situ aluminum-carbon based grain refiners combined with filtration and argon gas bubbling. Further, in-situ neutron diffraction was utilized for phase analysis and fraction solid determination of magnesium-zinc and magnesium-aluminum alloys. There was a significant improvement in yield strength, ultimate tensile strength and elongation with filtration plus argon bubbling, carbon inoculation or both filtration plus argon bubbling and carbon inoculation. The results indicated that the mechanism of the observed ~20% reduction in grain sizes with carbon inoculation (hexachloroethane, ex-situ aluminum-silicon carbide and in-situ aluminum-carbon) was explained through duplex nucleation of Mn-Al and Al-Mg-C-O (likely Al2MgC2) phases. Finally, in-situ neutron diffraction was used to follow the formation of Mg17Al12 eutectic phase in a magnesium-9 wt.% aluminum alloy. For the magnesium-zinc alloys, in-situ neutron diffraction enabled characterization of the effects of zirconium to the fraction solid growth of (1010), (0002) and (1011) α-Mg planes. The societal and environmental impact of this research is significant. There is a clear demonstration of alternatives to the universally used hexachloroethane grain refiner promoting harmful emissions. Improved mechanical properties resulting from new grain refinement and iv inclusion filtration are a major advancement in promoting weight reduction, improved castability and decreased environmental impact for automotive and aerospace industries.

scholarly journals Monitoring by in situ neutron diffraction of simultaneous dehydration and Ni2+ mobility in partially exchanged NaY zeolites

2016 ◽  
Vol 40 (5) ◽  
pp. 4228-4235 ◽  
Author(s):  
Florence Porcher ◽  
Jean-Louis Paillaud ◽  
Lucia Gaberova ◽  
Gilles André ◽  
Sandra Casale ◽  
...  
Keyword(s):  
Neutron Diffraction ◽  
Real Time ◽  
Structural Changes ◽  
Diffraction Patterns ◽  
In Situ Neutron Diffraction ◽  
Nay Zeolites

The incoherent signal in neutron diffraction patterns allows correlating in real time hydration–dehydration levels and structural changes in zeolites.

In Situ Neutron Diffraction Studies of the Pseudoelastic-Like Behaviour of Hydrostatically Extruded Mg-Al-Zn Alloy

2008 ◽  
Vol 571-572 ◽  
pp. 107-112 ◽  
Author(s):  
Ondrej Muránsky ◽  
David G. Carr ◽  
Petr Šittner ◽  
E.C. Oliver ◽  
P. Dobroň
Keyword(s):  
Magnesium Alloy ◽  
Neutron Diffraction ◽  
Diffraction Data ◽  
Driving Force ◽  
Extrusion Direction ◽  
Neutron Diffraction Data ◽  
Tensile Stresses ◽  
In Situ Neutron Diffraction ◽  
Zn Alloy

In-situ neutron diffraction has been used to study the pseudoelastic-like behaviour of hydrostatically extruded AZ31 magnesium alloy during stress-strain cycles in compression and tension along the extrusion direction. It has been confirmed that the activation of reversal twinning processes during unloading is responsible for the macroscopically observed hysteresis effect. Moreover, neutron diffraction data reveals the existence of high tensile stresses in grains which have just experienced significant twinning activity prior to the start of the unload cycle. It is thus proposed that this tensile stresses provides the necessary driving force for the activation of untwinning in already twinned grains.

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