Abstract: The finite element numerical simulation for the formability of magnesium alloy AZ31B
sheets with thickness of 0.8mm and diameter of 140mm has been proceeded to investigate the
formability using the current finite element software. Under the condition with blank holder force of
8KN and deep drawing speed of 0.3mm/s at 200, the sytematic analysis and prediction of the
thickness change and the forming rule for thesimulation process of the blank has been carried out.
Under the same parameter, the drawing parts by deep drawing with a hydaulic machine were obtained
and the thickness tested. It has been found that thickness change rules and the forming rules of the
experimental results were in agreement with the numerical simulations.
Abstract: Cellular precipitation is reduced greatly by deformation at all ageing temperatures.
Precipitates within twins are often nodular and sluggish to grow, whereas dislocations created by
basal slip in matrices promote fast growth of plate-like precipitates. Recrystallization was observed
concurrent with precipitation above 310°C. Effective nucleation sites for recrystallization are
positions connecting twins and grain boundaries or the intersections of twin variants.
Abstract: Basal slip and tension twinning are dominant deformation mechanisms of polycrystalline
magnesium at low temperature. However, fracture originates mainly from compression twins or shear
bands developed from compression twins. This work compared firstly the morphological difference
of two types of twins. Then, the dependence of different deformation mechanisms on initial
orientations is computed by Schmid factor analysis and compared with measured matrix orientations
of twins. Finally, orientation relationships of compression twins with matrices are determined using
EBSD technique and compared with theoretical value.
Abstract: Addition of RE elements to Al-containing Mg alloys can improve properties of Mg alloys
at elevated temperatures. In the present investigation, hot-extruded AZ31+x%Nd.
(x=0.1,0.3,0.6and1.0 wt%) wrought Mg alloy were prepared .The effects of Nd on microstructures
and mechanical properties at room temperature of new alloy were investigated. The investigation
found that Nd can bring about two kind of precipitation phases . One is AlNd phase, the other is
AlNdMn phase, which were identified as Al11Nd3 and Al8NdMn4 by X-ray diffraction and TEM.
Abstract: Microstructures and tensile properties of Mg-8Zn-4Al-xCax=0.6wt.%, 1.0wt.%, 1.3wt.%,
named as alloy 1#, 2# and 3# , respectively)extruded magnesium alloy tube were studied at room and
elevated temperature. The results show that Ca can increase tensile strength of the alloy at 150 and
200°C significantly. At the temperature of 200°C, alloy 3# achieved optimal tensile properties, of
which the ultimate tensile strength, the yield strength and the elongation were 165.8MPa, 108.7Mpa
and 41.5% respectively. Compared with the properties of as cast ZAC8506 Magnesium alloy, it is
shown that the tensile properties of alloy 3# are much higher than that of ZAC8506 at both room
temperature and 150°C. Alloy 3# also gets better tensile performance than AZ91D extruded tube
produced in the same way at the temperature of 200°C Mg2Al3 and Ca2Mg5Zn13 phases are found in
the microstructure which should contribute to the higher performance of alloy 3# at elevated
Abstract: Microstructure and tensile properties of AZ31 rolled at different temperatures were
characterized. Rolling of extruded AZ31 plates was carried out at room temperature, 573K, 623K and
673K. Cold rolling of extruded AZ31 plates was difficult due to the poor formability at room
temperature. And deformation twinning plays an important role in rolling of AZ31 alloy at room
temperature. The microstructural analysis showed that the nucleation of dynamic recrystallization
(DRX) occurred at 573K, DRX was almost completed at 623K and grain growth was determined at
673K. The ultimate tensile strength (UTS) as large as 377MPa was achieved after rolled at 573K. And
the anisotropy in strength was obviously examined due to the rolling texture. The anisotropy reduced
as rolling temperature increasing from 573K to 673K and this may be attributed to the completion of
Abstract: The effect of second-phase particles on the grain refinement of AZ61 and AZ91 Mg-Al-Zn
alloys with different volume fractions of β-Mg17Al12 phase particles during equal channel angular
extrusion (ECAE) has been investigated. The microstructure were observed by optical microscopy
(OM), scanning electron microscopy (SEM) and transmission electron microscopy (TEM), which
revealed that grain refinement was enhanced by second phase particles at initial stage of ECAE. And
finer grains with the high angle grain boundaries (HAGBs) and disperse second-phase particles could
be obtained in AZ61 and AZ91 after 8 passes of ECAE.
Abstract: Microstructure and mechanical properties of Mg-6.0wt%Zn-0.5wt%Zr (ZK60) alloy were
studied as a function of cooling rate. The temperature field and cooling rate during the casting process
were investigated by use of finite element analysis (FEA) simulation. The results showed that the
microstructure was refined and the eutectic phase distributed much uniformly with the increase of
cooling rate. The increase of yield strength, ultimate strength and elongation can be ascribed to the
strengthening effect of fine grain. Relationship between grain size and yield strength is consistent
with the Hall-Petch formalism: 1/ 2 80.37 132.56 − = + d y σ .
Abstract: The microstructure and mechanical properties of Mg95.9Zn3.5Gd0.6 and
Mg94.4Zn3.5Gd0.6Cu1.5 alloys reinforced by icosahedral quasicrystalline phase (I-phase) and Laves
phase has been studied after extrusion at 573K. Extrusion can significantly refined the I-phase and
Laves phase, and the strengthening effect of I-phase and Laves phase has been analyzed. Large
volume of icosahedral phase in Mg95.9Zn3.5Gd0.6 has important role in its high UTS and elongation
due to strong bonding effect at the I-phase/matrix interface for low interface energy. The Laves phase
with cubic topological and close-packed structure in Mg94.4Zn3.5Gd0.6Cu1.5 alloy result in the higher
heat resistance at elevated temperatures.
Abstract: Uniaxial hot compression tests were performed at constant temperature (T) and strain rate
(ε& ) in the ranges of 200-500 °C at an interval of 50 °C and 0.001-20 s-1. The flow stress data were
used to develop the extrusion limit diagram for AZ31 and AM30 magnesium tubes. The extrusion
limit diagram shows a wide region available for extruding AZ31 and AM30 seamless tubes, and
comparison of the two extrusion limit diagrams shows that, the extrudability of AM30 alloy is better
than that of AZ31 alloy. Actual extrusion trials validated the predicted temperature rise limit curve
corresponding to the occurrence of surface cracking during the extrusion process. Magnesium tubes
were successfully extruded according to the safe regions identified by the extrusion limit diagram.