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Magnesium alloys with homogeneous degradation and controlled degradation rate are desirable for biodegradable materials. In the present work, Mg-3 wt.%Zn-0.2 wt.%Ca alloys with different columnar structures were fabricated and the degradation in 0.9 wt.% NaCl were investigated. With the increase of the growth rate for the directional solidification, the microstructure of the directionally solidified (DSed) alloy evolved from cellular to dendritic coupled with the change of the spacing of the primary trunks (λ 1) and the volume fraction (f v) of Ca 2 Mg 6 Zn 3 phase. The results of the corrosion test suggested that the alloy with cellular structure experienced homogeneous corrosion and exhibited the lowest corrosion rate. The good corrosion resistance of the alloy with cellular structure was attributed to the protective corrosion products film (CPF), which was closely related to the f v of Ca 2 Mg 6 Zn 3 phase and λ 1. To evaluate the corrosion rates (CR) of the DSed Mg-Zn-Ca alloys with different microstructures, a parameter α was proposed in this work, which was calculated by λ 1 and the f v of Ca 2 Mg 6 Zn 3 phase. The fitting result showed that there was a linear relationship between CR and α, which was CR = 4.1899 + 0.00432α. This means that the CR of the DSed Mg-Zn-Ca alloy can be evaluated if the microstructure had been characterized. [ABSTRACT FROM AUTHOR]

Achieving high strength in Mg alloys is usually accompanied by ductility loss. Here, a novel Mg 97 Y 1 Zn 1 Ho 1 at.% alloy with a yield strength of 403 MPa and an elongation of 10% is developed. The strength-ductility synergy is obtained by a comprehensive strategy, including a lamella bimodal microstructure design and the introduction of nano-spaced solute-segregated 14H long-period stacking-ordered phase (14H LPSO phase) through rare-earth Ho alloying. The lamella bimodal microstructure consists of elongated un-recrystallized (un-DRXed) coarse grains and fine dynamically-recrystallized grains (DRXed regions). The nano-spaced solute-segregated 14H LPSO phase is distributed in DRXed regions. The outstanding yield strength is mainly contributed by grain-boundary strengthening, 18R LPSO strengthening, and fiber-like reinforcement strengthening from the nano-spaced 14H LPSO phase. The high elongation is due primarily to the combined effects of the bimodal and lamellar microstructures through enhancing the work-hardening capability. [ABSTRACT FROM AUTHOR]

In order to understand the effects of drawing velocity, initial grain size and texture on the microstructure evolution during directional annealing, a cellular automata model based on grain boundary (GB) curvature, GB energy and GB mobility was established with a modified calculation model of the GB curvature. The simulation results show that there is a lower limit and an upper limit to the drawing velocity for the formation of columnar grains, and the columnar grains can only be formed between the upper limit and the lower limit. The simulation results are consistent with the experimental results. When the drawing velocity is lower than the lower limit, the equiaxed grains grow at the front of the hot zone, which hinders the formation of the columnar grains. With the increase of initial grain size, the driving force of GB migration decreases, and the grain boundaries are difficult to move with the hot zone, which is not conducive to the formation of columnar grains. There is an upper limit of initial grain size for the formation of columnar grains. The abnormal growth induced by texture prevents the growth of columnar grains during directional annealing. The weaker the texture strength, the more conducive to the growth of columnar grains. [ABSTRACT FROM AUTHOR]

The evolution of the microstructure and microsegregation in a new type of Mg–6Al–4Zn–1.2Sn (wt%) cast magnesium alloy solidified at cooling rates from 4.5 × 101 °C s−1 to 2.3 × 103 °C s−1 is investigated. The results indicate that the secondary dendrite arm spacing and the average grain sizes decrease from 14.3 to 2.9 μm and from 187 to 78 μm, respectively, as the cooling rate increases from 4.5 × 101 °C s−1 to 2.3 × 103 °C s−1. The relationship between the secondary dendrite arm spacing (λ2) and cooling rate (R) is fitted as λ2 = 69.7 × R−0.42. When the alloy solidifies in the range of cooling rates, a new quasi‐crystalline I phase is formed due to faster solidification. The microsegregation ratios of Al, Zn, and Sn elements decrease significantly with the increase in cooling rate. Compared with the specimen solidified at 4.5 × 101 °C s−1, the microsegregation ratios of Al, Zn, and Sn of that solidified at a cooling rate of 2.3 × 103 °C s−1 decrease by 37.4%, 45.7%, and 31.6%, respectively. [ABSTRACT FROM AUTHOR]

Graphite powder was adopted to prevent AZ91D alloy from oxidizing during melting and casting. The microstructure of the resultant surface films, formed at 933 K, 973 K, 1013 K, and 1053 K (660 °C, 700 °C, 740 °C, and 780 °C) for 30 minutes, was investigated by scanning electron microscopy, energy dispersive spectrometer, and X-ray diffraction, and the phase composition of the surface films was analyzed by the standard Gibbs free energy change of the reactions between the graphite powder, the alloy melt, and the ambient atmosphere. The effect and mechanism of melt temperature on the resultant surface films were also discussed. The results indicated that the surface films, of which the surface morphology comprised folds and wrinkles, were composed of a protective layer and MgF particles. The protective layer was contributive to the prevention of the molten alloy from oxidizing, and consisted of magnesium, oxygen, fluorine, carbon, and a small amount of aluminium existing in the form of MgO, MgF, C, and MgAlO. The layer thickness was 200 to 900 nm. The melt temperature may affect the surface films through the increased interaction between the graphite powder, the melt, and the ambient atmosphere. The oxygen content and thickness of the protective layer decreased and then increased, while the height of the folds increased with melt temperature. [ABSTRACT FROM AUTHOR]

The dispersion of carbon nanotubes (CNTs) in AZ91D melt by ultrasonic processing and microstructure formation of CNTs/AZ91D composite were studied using numerical and physical simulations. The sound field and acoustic streaming were predicted using finite element method. Meanwhile, optimal immersion depth of the ultrasonic probe and suitable ultrasonic power were obtained. Single-bubble model was used to predict ultrasonic cavitation in AZ91D melt. The relationship between sound pressure amplitude and ultrasonic cavitation was established. Physical simulations of acoustic streaming and ultrasonic cavitation agreed well with the numerical simulations. It was confirmed that the dispersion of carbon nanotubes was remarkably improved by ultrasonic processing. Microstructure formation of CNTs/AZ91D composite was numerically simulated using cellular automation method. In addition, grain refinement was achieved and the growth of dendrites was changed due to the uniform dispersion of CNTs. [ABSTRACT FROM AUTHOR]

A new Mg–Al–Sn–RE alloy with high ductility at room temperature has been developed. Homogenized Mg–4Al–2Sn–0.5Y–0.4Nd plates 25 mm in thickness were hot-rolled to 1 mm at 673K. The microstructures were characterized as fully recrystallized grains with a lot of fragmented fine particles along the rolling direction. The sheet specimen possesses basal texture of (0002) with the basal pole tilting by about 15° from the normal direction toward the rolling direction. Meanwhile, the texture strength was weakened, which is resulted from the non-basal  slip and recrystallization texture. For the as-rolled alloy, the yield strength and tensile strength in transverse direction are both higher than those of rolling direction. The average Lankford value is 1.83, which is lower than conventional AZ31 rolled magnesium alloy sheets. The relatively high elongation and low planar anisotropy implies good formability at room temperature. [ABSTRACT FROM AUTHOR]

The dynamic microstructural evolution of the Mg–4Zn–2Al–2Sn (ZAT422) alloy during hot deformation was studied. The compression tests were carried out under the strain rate of 0.01 s −1 and 5 s −1 at 548 K and the strain rate of 5 s −1 at 648 K. It was shown that the operating mechanisms of dynamic recrystallization (DRX) of ZAT422 alloy during hot deformation were affected by both strain rate and temperature. Parallel or crossed {101¯2} tension twins appeared in the sample deformed to the strain of 0.04 under the strain rate of 0.01 s −1 at 548 K, while new grains with characteristics of discontinuous dynamic recrystallization (DDRX) occurred at corrugated grain boundaries. With the strain rate increasing from 0.01 s −1 to 5 s −1 , the effect of twin dynamic recrystallization (TDRX) increased, and necklace structure of DRXed grains formed along the original grain boundaries and the deformation twin boundaries. When the temperature increased to 648 K, continuous dynamic recrystallization (CDRX) occurred within the recrystallized grains, resulting in the further refinement of the microstructure. And it should be noted that TDRX still occurred at this temperature. [ABSTRACT FROM AUTHOR]

The relationship between morphology and crystallography of an entangled lathy ferrite during directional solidification in Fe–Cr–Ni alloy has been investigated. During solidification, morphology of the lathy ferrite depends on the orientation relationship between the lathy ferrite and austenite. When the plane in the austenite substrate is ${(1\bar 11)_{\rm{\gamma }}}$, “Y-shaped” lathy ferrite grows in an entangled cluster and the orientation relationship between the lathy ferrite and austenite is the Nishiyama–Wassermann relationship. Lathy ferrite is preferentially elongated along ${\langle 211\rangle _{\rm{\gamma }}}$ and ${\langle 011\rangle _{\rm{\gamma }}}$ directions on ${(1\bar 11)_{\rm{\gamma }}}$ plane due to lower misfit. The included angle among the “Y-shaped” lathy ferrite is about 120° because the angle between each pair of ${[21\bar 1]_{\rm{\gamma }}}$, ${[\bar 112]_{\rm{\gamma }}}$, and ${[\bar 1\bar 2\bar 1]_{\rm{\gamma }}}$ crystal directions is equal to 120°. Formation mechanism of the perpendicular lathy ferrite has also been analyzed according to the relationship between ${\langle 211\rangle _{\rm{\gamma }}}$ and ${\langle 011\rangle _{\rm{\gamma }}}$ on ${(1\bar 11)_{\rm{\gamma }}}$ plane. This indicates that required crystal morphology of the lathy ferrite in the solidified microstructure can be obtained by controlling the crystal plane of austenite. [ABSTRACT FROM AUTHOR]

Microstructures, elemental partition behavior, phase stabilities and mechanical properties of Nb- and W-containing Co-V-Ti-based superalloys were investigated. Elemental partition coefficients (KX = Cγ’/Cγ) of Nb and W in Co-V-Ti-based superalloys are 2.07 and 1.10, respectively. The γ’ solvus temperatures are determined as 1023 °C, 1055 °C and 1035 °C in Co-12V-4Ti, Co-10V-4Ti-2Nb and Co-10V-4Ti-2W alloys, which are higher than those of Co-9Al-9W alloy (1000 °C). The mass densities of quaternary Co-10V-4Ti-2Nb and Co-10V-4Ti-2W alloys are about 8.31 and 8.50 g·cm−3, respectively, which are 15% lower than Co-Al-W-based superalloys (9.8 g·cm−3). All examined alloys exhibit an anomalous positive dependence on temperature rising from 600 to 750 °C. Strengths of all examined alloys are higher than those of MarM509 (traditional Cobalt-based superalloy) and Co-9Al-9W at all temperatures that we investigated. The maximum flow stress of Co-V-Ti-Nb alloy is about 638 MPa at 750 °C while that of Co-V-Ti-W alloy is about 588 MPa at 700 °C. [ABSTRACT FROM AUTHOR]

The microstructure and corrosion resistance of directionally solidified Mg–2 wt.% Zn alloy with different growth rates were investigated. Optical microscopy observations showed that the microstructure of directionally solidified Mg-2Zn alloy transformed from coarse cellular to fine cellular, undeveloped dendritic and finally dendritic structures as the growth rate increased from 20 μm/s to 60 μm/s, 120 μm/s and 200 μm/s, respectively. The results of electrochemical measurement and immersion test in 0.9 wt.% NaCl solution revealed that the corrosion resistance of directionally solidified Mg-2Zn alloy strongly depends on the microstructure. The samples with fine cellular structure have the highest corrosion resistance, which mainly due to the reduction of susceptible grain boundaries and homogenous distribution of Zn element. [ABSTRACT FROM AUTHOR]

Abstract A new Mg-5Zn-3.5Sn-1Mn-0.5Ca-0.5Cu alloy with high strength is developed and the microstructure and mechanical properties of the alloy in the as-cast, extruded and aged states are investigated. The as-cast alloy contains α-Mg, MgZn 2 , Mg 2 Sn and MgSnCa phase. The extrusion process refines the microstructure and leads to fully dynamic recrystallized grains with a tilted basal texture, which results in moderate mechanical properties of the extruded alloy. Ca acts synergistically with Cu in promoting age hardening and the combined addition of Ca and Cu significantly enhances the peak hardness of the alloy after double aging treatment, the effect is more obvious than the alloys with single addition of Ca or Cu. Fine and densely distributed Mg–Zn and Mg 2 Sn precipitate after double aging treatment, which contributes to the strengthening of the alloy. The yield strength, ultimate tensile strength and elongation of the alloy after double aging treatment reach 392 MPa, 401 MPa and 7%, respectively. Highlights • The cast alloy contains α-Mg, MgZn 2 , Mg 2 Sn and MgSnCa phase. • Addition of Ca and Cu enhances the peak hardness of the aged alloy. • The yield strength of the aged alloy reaches 392 MPa. [ABSTRACT FROM AUTHOR]

Heretofore, understandings about the effects of scandium on properties of magnesium alloys for biodegradable implant applications are extremely limited. In the present study, four Mg–1.5Zn–0.6Zr– x Sc (ZK21– x Sc, x  = 0, 0.2, 0.5, 1.0 wt%) alloys were fabricated and investigated with respect to the microstructure and mechanical properties. Microstructure characterization indicated that grain sizes were refined and more precipitated particles were observed with increasing Sc addition. Mechanical testing revealed that improved yield strength and decreased elongation were obtained after Sc being added. Compared with other developed Mg alloys, the ZK21–0.2Sc alloy demonstrates balanced combination of strength and elongation, which shows great potential in biodegradable materials application. [ABSTRACT FROM AUTHOR]

A new high-strength Mg-6Zn-4Al-0.5Cu alloy was fabricated by direct squeeze casting and the effects of applied pressure on the microstructure and mechanical properties of the squeeze-cast alloy were systematically investigated. The results showed that the squeeze-cast Mg-6Zn-4Al-0.5Cu alloy exhibits finer and much more uniform microstructure compared with gravity-cast one, but increasing the applied pressure doses not result in further grain refinement. The porosities are decreased markedly with increasing applied pressure and eventually disappear when the applied pressure is 90 MPa. The ultimate tensile strength and elongation of the alloy are obviously improved with the application of pressure, which is mainly attributed to the full density of the samples. In addition, the strength is further improved significantly after heat treatment. When the applied pressure is 60 MPa, the heat-treated Mg-6Zn-4Al-0.5Cu alloy exhibits the optimal tensile properties with the yield strength, the ultimate tensile strength and elongation of 216 MPa, 337 MPa and 12%, which are improved by 66%, 20% and 13% respectively as comparing with that of the as-cast sample. [ABSTRACT FROM AUTHOR]

The microstructure and mechanical properties of as-cast and heat treated Mg-6Zn-4Al-xCu (x=0, 0.5, 1.0 and 1.5 wt%) alloys were investigated in this work. The results show that the grain sizes of the alloys decrease considerably with increasing Cu addition, and the eutectics are refined with 0.5% Cu addition. The icosahedral quasi-crystalline phase is observed in Mg-6Zn-4Al and Cu-containing alloys，and the MgAlCu phase forms in the Cu-containing alloys because of Cu addition. Compared with Mg-6Zn-4Al alloy, the Cu-containing alloys exhibit improved age-hardening response during single-aging treatment. In addition, high-density fine precipitates are formed in the matrix during double-aging treatment, resulting in remarkable improvement of the tensile strength. The double aged Mg-6Zn-4Al-0.5Cu alloy shows the relatively optimal tensile properties. The yield strength, ultimate tensile strength and elongation are 202 MPa, 312 MPa and 7%, respectively, which is attributed to the combined effects of fine grains and the uniform distribution of high-density fine precipitates. It is noticed that the ductility of as-aged Cu-containing alloys is lower than that of the as-aged Mg-6Zn-4Al alloy due to the stress concentration during the tensile stress caused by the residual phases distributed along the grain boundaries after solution treatment. [ABSTRACT FROM AUTHOR]

In this work, Mg-6Zn-3Sn-0.5Mn (ZTM630) alloy was prepared with different heat treatment states including as-cast, homogenization, hot extrusion and double-age. The microstructure and tensile mechanical properties of the alloy with four states were investigated. The very high cycle fatigue (VHCF) tests have been performed to evaluate long-term service properties of the extruded and double-aged alloys. Fatigue strength and fatigue crack initiation mechanism were analyzed. After double-aging, the secondary phase in size of dozens nanometers distributes evenly in the matrix, α-Mn phase distributed at the grain boundary effectively inhibits the grain growth, and the double-aged alloys has the highest tensile mechanical strength. The fatigue ratios σ − 1 / σ b of the extruded and double-aged alloys are 0.44 and 0.37, respectively, which means that ZTM630 alloys in the two states possess an excellent fatigue performance. As the activity of slipping is limited in the double-aged ZTM630 alloy, twinning behavior induces fatigue crack initiation during the VHCF test, while slip-dominated fatigue crack initiation of the extruded ZTM630 alloy. • The microstructure and tensile mechanical properties of the four types of Mg-6Zn-3Sn-0.5Mn (ZTM630) alloys are obviously different. The strengths of the extruded and double-aged alloys are much higher than those of the as-cast and homogenized states. • Fatigue strength of the double-aged alloy at 109 cycles is about 150 MPa, while that of the extruded alloy is about 130 MPa. The fatigue ratio σ − 1 /σ b is calculated as 0.44 for the extruded alloy and 0.37 for the double-aged alloy, respectively. • The VHCF crack initiation site either inside or at the subsurface of the specimen. The VHCF crack initiation mechanism of the extruded alloy is determined as slip-dominated, while that of the double-aged alloy is twinning-dominated. [ABSTRACT FROM AUTHOR]

Abstract: A high strength Mg–8.0Zn–1.0Al–0.5Cu–0.5Mn(wt.%) magnesium alloy with outstanding ductility was developed using a common casting technique and heat treatment. The microstructure of the as-cast alloy is composed of α-Mg, MgZn, MgZnCu and Al–Mn phases. After the solution treatment and subsequent two-step aging treatment, the yield strength (YS), ultimate tensile strength (UTS) and elongation of the alloy at peak hardness reach 228MPa, 328MPa and 16.0% at room temperature, respectively. The comprehensive mechanical properties of the alloy are superior to almost all other high performance casting Mg alloys. [Copyright &y& Elsevier]

Abstract: Microstructure and mechanical properties of Mg–4Al–2Sn and Mg–4Al–2Sn–xY–yNd (x + y =0.9wt.%) alloys have been investigated. The microstructure of as-cast Mg–4Al–2Sn alloy consists of α-Mg, eutectic α-Mg+Mg17Al12, divorced eutectic Mg17Al12, and second phase Mg2Sn. Addition of Nd and Y results in fine plate-like Al2Nd and Al2Y phases which reduce the content of Mg17Al12 phase to improve the plasticity. Among the tested Mg–4Al–2Sn–xY–yNd alloys, Mg–4Al–2Sn–0.5Y–0.4Nd alloy represents the best mechanical properties. The tensile strength is increased from 220 to 225MPa and elongation from 15.6% to 23.2%. Significant improvement of the plasticity is attributed to fine second precipitates and low anisotropy. The Mg–4Al–2Sn–0.5Y–0.4Nd alloy provides important potentials to develop high performance wrought magnesium alloys. [Copyright &y& Elsevier]

The coarsening behavior of the γʹ precipitates and compression deformation mechanism of the γʹ-strengthened CoNi-base superalloys are investigated. By substituting 1 at.% Ta for 1 at.% W, the 4W2Ta alloy exhibits a higher γʹ solvus temperature of 1218 °C and a lower mass density of 8.93 g/cm3. During the aging process from 900 to 1000 °C, both of the 5W1Ta and 4W2Ta alloys show stable γ/γʹ two-phase microstructure. The coarsening behavior of the γʹ precipitates in the two alloys follows the classical Lifshitz-Slyozov-Wagner (LSW) model. The coarsening rate constant of the 4W2Ta alloy is approximately two times lower than that of the 5W1Ta alloy, which is attributed to its larger lattice mismatch due to the addition of Ta. Besides, compared with the 5W1Ta alloy, the 4W2Ta alloy has higher high-temperature strength and shows different deformation behavior. When the deformation temperature is lower than 800 °C, pairs of dislocations shear the γʹ precipitates and γ matrix. At 800 °C, stacking faults (SFs) appear in the γʹ precipitates and increase with the increasing temperature, whereas most of dislocations bypass the γʹ precipitates at 1000 °C. [ABSTRACT FROM AUTHOR]

• Ta and W are strongly partitioning to γ′ phase in Co-Ti-based superalloys. • The Co-Ti-V-W-Ta alloy exhibits a good combination of low lattice misfit (+0.33%) and high γ′ solvus temperature (1131 °C). • The yield strength (880 MPa at 750 °C) of designed alloy is higher than that of Co-12Ti-4Mo alloy. The microstructure, phase transformation temperature, γ/γ′ lattice misfit, and mechanical properties of Co-4Ti-10V-2W-2Ta (at. %, referred to as 2Ta) quinary alloy were investigated in detail. In addition, the results show that Ti, W, and Ta exhibit a strong partitioning tendency to the γ′ phase, resulting in a high γ′ solvus temperature (~1131 °C) in the studied alloy. The γ/γ′ lattice misfit of the 2Ta alloy was found to be ~+0.33%, which is much lower than those of Co-Ti binary and Co-Ti-Mo/W/Re/Cr ternary alloys. Moreover, the designed alloy also exhibits excellent yield strength (880 MPa at 750 °C), which is comparable to Co-12Ti-4Mo alloy. [ABSTRACT FROM AUTHOR]

In this study, CoCr 2 Ni 2 AlTi, Co 2 Cr 2 Ni 2 AlTi and CoCr 2 Ni 3 AlTi alloys are prepared using vacuum arc melting furnace. The morphology, microstructure, compositions and corrosion behavior in 3.5 wt% NaCl solution or 0.5 M H 2 SO 4 solution are investigated by means of scanning electron microscope (SEM), X-ray diffraction (XRD), energy dispersive spectrometer (EDS) and electro-chemical workstation, respectively. The results show that all high entropy alloys (HEAs) display analogous petal-like equi-axed dendrite and the dendrite arms are thin-like strip. The BCC1 phase is mainly rich in Al–Ni–Ti elements, the BCC2 is rich in Cr element and the FCC phase is composed of Co–Ti elements. Besides, the high contents of Co can promote distribution of Cr into inter-dendrite and can promote the formation of the nano-particles. In addition, all HEAs have better corrosion resistance than 304 stainless steel or other corrosion resistant HEAs and Co 2 Cr 2 Ni 2 AlTi has the best corrosion resistance in three HEAs under NaCl solution or H 2 SO 4 solution. Cr element can form the passivation film Cr 2 O 3 , which has an important role in improving corrosion resistance. Co element can increase the stability of the passivation film and attenuates the hydrolysis of Cr3+. Ni element cannot increase the stability of the passivation film and promote the hydrolysis of Cr3+ in H 2 SO 4 solution. • Co and Ni can promote the formation of FCC phase. • Co can increase the stability of the Cr 2 O 3 passivation film. • XRD test of the surface after sulfuric acid corrosion shows that Ni is not good for improving the corrosion resistance of the HEAs. • Co 2 Cr 2 Ni 2 AlTi HEAs has the best corrosion resistance. [ABSTRACT FROM AUTHOR]

A comparative study on the microstructures and mechanical properties of the extruded Mg-xCa/Mn/Ce (x = 0.25, 0.5, 1, 2.0 wt%) alloys and pure Mg has been carried out. It was found that when the addition of Ca, Mn and Ce was more than 0.25 wt%, 0.5 wt% and 0.5 wt% respectively, microstructures with fine grain sizes smaller than 5 μm can be achieved by extruding at 375 °C with a extrusion ratio of 30 and a ram speed of 0.8 mm/s. While the grain size of pure magnesium extruded under the same condition was 26.6 μm. The addition of Ca, Mn or Ce has significant effects on the textures of the extruded Mg-xCa/Mn/Ce alloys. The maximum intensity peaks in PF and IPF of Mg are all deviated by a certain degree with the addition of Ca, Mn or Ce. In the 12 extrusion alloys, Mg-0.5Ca、Mg–2Mn and Mg–1Ce exhibited better mechanical properties, whose ultimate tensile strength and elongation are 243.6 MPa, 233.7 MPa, 321.5 MPa and 25.6%, 20.7%, 7.6%. While the ultimate tensile strength and elongation of as-extruded pure Mg is 173.8 MPa and 16.0% respectively. Mg-xCa and Mg-0.25Ce alloys with weak texture showed weaker tension-compression asymmetry. The experimental results showed that it is feasible to prepare fine grained (<5 μm) Mg-xCa/Mn/Ce alloys with much improved mechanical properties using conventional extrusion. [ABSTRACT FROM AUTHOR]