Designing microstructures to enhance the plasticity of wrought magnesium alloys

The data examines the design of magnesium alloys for improved ductility by the edition of rare earth elements. These elements, such as cerium and gadolinium modify the texture of wrought products and also refine the grain size.

On the impact of second phase particles on twinning in magnesium alloys

Deformation twinning is an important deformation mode in magnesium alloys. Despite this, little is known on the extent to which the stress for twinning can be altered by a dispersion of second phase particles. The current paper presents a series of findings on the role of differently shaped particles on both the stress required for twinning and the characteristics of the twins that form. It is shown that plate shaped particles are, as one might expect, an effective strengthener to {10-12} twinning. When precipitate plates form on the basal planes, the relative hardening of basal slip is minor in comparison to that seen for twinning. This provides opportunity for the alloy designer to control the apparent critical resolved shear stresses (CRSS) for the different deformation modes. Possible sources for the hardening of twins are discussed.

Ionic liquid pretreatment as a means to control the corrosion behavior of magnesium alloys in simulated body fluid

Recently, the use of magnesium alloys as metallic implant materials for biodegradable coronary artery stents has been steadily growing in interest. However, AZ31 magnesium alloys present poor corrosion resistance in the body environment. This work reports on the use of a treatment with low-toxicity IL Trimethyl (butyl) phosphonium diphenyl phosphate P₁₄₄₄DPP, which provides corrosion protection for magnesium alloy AZ31 in simulated body fluid (SBF). Before IL treatment, surface was cleaned by HNO₃ and H₃PO₄ acid pickling solution. The effect of ionic liquid treatment on the corrosion performance of magnesium alloys AZ31in simulated body fluid has been investigated by electrochemical tests and the observation of surface morphology. The results show that this IL treatment succeeded in increasing the corrosion resistance of AZ31 when exposed to SBF.

Recrystallisation of magnesium alloys containing rare-earth elements

The static recrystallisation behaviour of two magnesium alloys after hot rolling have been examined. The alloys chosen for study were the conventional alloy AZ31, and an alloy containing the rare earth element Gadolinium. The recrystallisation kinetics were lower for the rareearth alloy at low annealing temperatures, but at high annealing temperatures the kinetics were higher for the rare-earth alloy. It is suggested that this change in the comparative recrystallisation kinetics is a result of the improved mobility of the rare-earth solute at higher temperatures. This affects the recrystallisation kinetics through solute partitioning to the grain boundaries. The effect of this segregation on the recrystallisation texture is also discussed.

Texture selection mechanisms in uniaxially extruded magnesium alloys

Extrusion textures in magnesium alloys are of high interest due to their influence on yield asymmetry. This data supports work describing three mechanisms of texture selection that may play a role during extrusion. These mechanisms involve localized differences in deformation at the grain level, the change in local environment experienced by grain boundary bulges and shear banding. The work employs visco-plastic crystal plasticity and electron backscattering diffraction.

Deformation of magnesium alloys during laboratory scale in-situ x-ray diffraction

In this research work we developed a new laboratory based transmission X-ray diffraction technique to perform in-situ deformation studies on a far more regular basis that is not possible at large scale synchrotron and neutron facilities. We studied the deformation mechanisms in light weight magnesium alloys during in-situ tensile testing.