MgZn2 Phase Research Articles

Influence of T5 Aging Heat Treatment on Microstructure and Mechanical Properties of as-extrued ZK80 Mg alloy

The micrstructure and mechanical properties of as-extruded ZK80 Mg alloy after artificial aging heat treatment was investigated. The results show that the hardness of the alloy first increases with the increase of time under different aging temperature, and then begins to decrease after reaching the peak value. Under the condition of the same aging temperature and different holding time, the hardness increases gradually with the increase of aging temperature, and then decreases with the increase of aging temperature. The best aging temperature of ZK80 Mg alloy is 180°C, the ultimate comprehensive mechanical properties of ZK80 alloy aging at 180°C for 7h reaches the maximum, which σb, σ0.2, δ, HBR, respectively is 326.7 MPa, 236.7 MPa, 10% and 77.8 HB, and the mechanical properties of untreated extruded state increased by 39.4%, 28.8% and 19%, respectively, The reason is that during the aging treatment, finely dispersed MgZn and MgZn2 phases are precipitated in the alloy structure, so that the mechanical properties of the extruded ZK80 magnesium alloy are optimized.

Improved strengthening efficiency of nanoreinforcements realized by a novel melt spinning process

Abstract

Interfacial microstructures and mechanical properties of Mg/Al bimetal produced by a novel liquid-liquid compound casting process

In the present work, a novel method was proposed to produce Mg/Al bimetal using the lost foam casting (LFC) liquid-liquid compound process with a Zn interlayer, and the interfacial microstructures and mechanical properties of the Mg/Al bimetal were investigated for the first time. Obtained results reveal that a compact metallurgical interface was formed between the AZ91D magnesium alloy substrate and the A356 aluminum alloy substrate. The metallurgical interface included two reaction layers. The reaction layer adjacent to the AZ91D substrate was composed of α-Mg, Al5Mg11Zn4 and MgZn phases, and the reaction layer adjacent to the A356 substrate consisted of α-Al, Mg32(Al, Zn)49 and Mg2Si phases. The addition of the Zn interlayer not only prevented different liquid metals from directly mixing, but also restrained the formation of Mg-Al intermetallics. The microhardnesses of the reaction layers were much higher than those of the substrates, and the reaction layer close to the A356 substrate had the highest microhardness. The shear strength of the Mg/Al bimetal was about 10.91 MPa, and the fracture surface of the Mg/Al bimetal exhibited a brittle fracture nature.

Lattice Correspondence and Growth Structures of Monoclinic Mg4Zn7 Phase Growing on an Icosahedral Quasicrystal

Mg 4 Zn 7 phase, with a monoclinic unit cell, a layered structure and a unique axis showing pseudo-tenfold symmetry, grows over icosahedral quasicrystalline phase in a manner similar to a decagonal quasicrystal. In this study, the relationship of this phase to icosahedral quasicrystal is brought out by a transmission electron microscopy study of Mg 4 Zn 7 phase growing on icosahedral phase in a cast Mg-Zn-Y alloy. Lattice correspondences between the two phases have been determined by electron diffraction. Planes related to icosahedral fivefold and pseudo-twofold symmetry are identified. Possible orthogonal cells bounded by twofold symmetry-related planes have been determined. Mg 4 Zn 7 phase growing on an icosahedral phase exhibits a number of planar faults parallel to the monoclinic axis, presumably to accommodate the quasiperiodicity at the interface. Two faults were identified, which were on {200} and { 2 ¯ 01} planes. Their structures have been determined by high resolution imaging in TEM. They produce two different unit cells at the interface.

Glass-forming ability and corrosion performance of Mn-doped Mg–Zn–Ca amorphous alloys for biomedical applications

In the present work, ribbon and 2-mm rod samples of Mg–Zn–Ca–Mn alloys were prepared by melt-spinning and copper mold injection methods, respectively. Effects of Mn doping on glass-forming ability and corrosion performance in simulated body fluid of Mg65Zn30Ca5 alloy were studied through X-ray diffraction, scanning electron microscopy, differential scanning calorimeter, and electrochemical and immersion tests. Results show that with the Mn addition increasing, all the ribbon samples are completely in amorphous state. However, the microstructure of 2-mm rod samples transfers from fully amorphous for the Mn-free alloy to almost polycrystalline state with precipitated Mg, Mn, and MgZn phases. Glass-forming ability of Mg65Zn30Ca5 alloy is decreased by Mn addition. Results of electrochemical and immersion tests demonstrate that the Mn-doped samples exhibit more negative corrosion potential and larger corrosion current density, suggesting that the corrosion resistance decreases with doping amount of Mn element increasing.

Non-isothermal aging of a high-Zn-containing Al–Zn–Mg–Cu alloy: microstructure and mechanical properties

ABSTRACTThe non-isothermal aging behaviour of a newly developed Al–Zn–Mg–Cu alloy containing 17 wt-% Zn was investigated. Hardness and shear punch tests demonstrated that during non-isothermal aging, the mechanical properties of the alloy first increased and then decreased. The best properties were obtained in a sample which was non-isothermally aged upto 250°C with heating rate of 20°C min−1, due to the presence of η′/η (MgZn2) phases. This was confirmed by differential scanning calorimetery. After homogenisation, residual eutectic phases remained at triple junctions or in a spherical form. During aging, these phases transformed into rodlike S (Al2CuMg)-phase at 400°C, with sizes ranging from 50 to 250 nm. The precipitation sequence in this high-Zn alloy was similar to that for conventional Al–Zn–Mg–Cu alloys.

Structure and Stoichiometry of MgxZny in Hot-Dipped Zn–Mg–Al Coating Layer on Interstitial-Free Steel

Correlations of stoichiometry and phase structure of MgxZny in hot-dipped Zn–Mg–Al coating layer which were modified by additive element have been established on the bases of diffraction and phase transformation principles. X-ray diffraction (XRD) results showed that MgxZny in the Zn–Mg–Al coating layers consist of Mg2Zn11 and MgZn2. The additive elements had a significant effect on the phase fraction of Mg2Zn11 while the Mg/Al ratio had a negligible effect. Transmission electron microscope (TEM) assisted selected area electron diffraction (SAED) results of small areas MgxZny were indexed dominantly as MgZn2 which have different Mg/Zn stoichiometry between 0.10 and 0.18. It is assumed that the MgxZny have deviated stoichiometry of the phase structure with additive element. The deviated Mg2Zn11 phase structure was interpreted as base-centered orthorhombic by applying two theoretical validity: a structure factor rule explained why the base-centered orthorhombic Mg2Zn11 has less reciprocal lattice reflections in the SAED compared to hexagonal MgZn2, and a phase transformation model elucidated its reasonable lattice point sharing of the corresponding unit cell during hexagonal MgZn2 (a, b = 0.5252 nm, c = 0.8577 nm) transform to intermediate tetragonal and final base-centered orthorhombic Mg2Zn11 (a = 0.8575 nm, b = 0.8874 nm, c = 0.8771 nm) in the equilibrium state.

Effect of Heat Treatment on the Microstructure and Wear Properties of Al–Zn–Mg–Cu/In-Situ Al–9Si–SiCp/Pure Al Composite by Powder Metallurgy

This study examined the effects of heat treatment on the microstructure and wear properties of Al–Zn–Mg–Cu/in-situ Al–9Si–SiCp/pure Al composites. Pure Al powder was used to increase densification but it resulted in heterogeneous precipitation as well as differences in hardness among the grains. Heat treatment was conducted to solve this problem. The heat treatment process consisted of three stages: solution treatment, quenching, and aging treatment. After the solution treatment, the main dissolved phases were η′(Mg4Zn7), η(MgZn2), and Al2Cu phase. An aging treatment was conducted over the temperature range, 100–240 °C, for various times. The GP zone and η′(Mg4Zn7) phase precipitated at a low aging temperature of 100–160 °C, whereas the η(MgZn2) phase precipitated at a high aging temperature of 200–240 °C. The hardness of the sample aged at 100–160 °C was higher than that aged at 200–240 °C. The wear test was conducted under various linear speeds with a load of 100 N. The aged composite showed a lower wear rate than that of the as-sintered composite under all conditions. As the linear speed was increased to 1.0 m/s, the predominant wear behavior changed from abrasive to adhesive wear in all composites.

Effects of heat treatment on microstructure and mechanical properties of Mg-6Zn-4Sm-0.4Zr alloy

A new rare earth magnesium alloy (Mg-6Zn-4Sm-0.4Zr, wt.%) was prepared by permanent mould casting. The microstructure and mechanical properties of the alloy sample in as-cast and various heat treatment situations were characterized with an optical microscope (OM), X-ray diffractometer (XRD), scanning electron microscope (SEM) equipped with energy dispersive spectroscope (EDS), transmission electron microscope (TEM) and mechanical tests at room temperature, respectively. The experimental results show that the as-cast alloy mainly consists of α-Mg, eutectic Mg2Zn3, MgZnSm and Mg41Sm5. These eutectic phases with continuous or semicontinuous morphology principally distribute along grain boundaries. Almost all the eutectic compounds dissolve in a-Mg and the grains have no obvious growth trend after optimum solution treatment at 490 °C for 18 h. Meanwhile, the ultimate tensile strength (UTS) of 229 MPa and elongation (EL) to rupture of 9.78% can be achieved through the optimal solution treatment, which increase by 37 MPa and 57.74%, respectively, compared with that of the as-cast alloy. Further aging treatments at 200 °C for different durations lead to the conspicuous increment of mechanical properties and prominent age-hardening response. Peak-aged alloy (treated at 200 °C for 12 h) reveals better mechanical properties (UTS 258 MPa, EL 9.42%, hardness 73.4 HV) compared with the same alloy treated in other aging conditions, which is mainly ascribed to precipitated Mg2Zn3 and MgZn2 phases. Fracture analysis demonstrates that the as-cast alloy belongs to inter-granular and cleavage fracture patterns, while the solutionized alloy (treated at 490 °C for 18 h) reveals trans-granular and quasi-cleavage fracture modes. For the peak-aged alloy, the fracture pattern obeys the mixture of trans-granular and cleavage modes.

Microstructure and texture development of 7075 alloy during homogenisation

The microstructure evolution of Al–Zn–Mg–Cu alloy during homogenisation was studied by optical microscope, field emission scanning electron microscope, energy dispersive X-ray Spectroscopy, differential scanning calorimetry and X-ray diffraction in detailed. It has been found that primary cast structure consisted of primary α (Al), lamellar eutectic structure η Mg(Zn, Cu, Al)2 and a small amount of θ (Al2Cu) phase. A transformation of primary eutectic phase from η Mg(Zn, Cu, Al)2 to S (Al2CuMg) was observed after 6 h of homogenisation treatment. The volume fraction of dendrite network structure and intermetallic phase was decreased with increase in holding time and finally disappeared after 96 h of homogenisation, which is consistent with the results of homogenisation kinetic analysis. Crystallographic texture of this alloy after casting and 96 h of homogenisation was also studied. It was found that casting process led the development of strong Goss, Brass, P and CuT components, while after homogenisation Cube, S and Copper components became predominant. Mechanical tests revealed higher hardness, yield strength and tensile strength for cast materials compared to homogenised alloys due to the presence of coarse micro-segregation of MgZn2 phase. The significant improvement of ductility was observed after 96-h homogenisation, which was attributed to dissolution of second phase particles and grain coarsening. Fracture surfaces of the cast samples indicated the presence of shrinkage porosity and consequently failure occurred in the interdendritic regions or grain boundaries with brittle mode, while homogenised alloys failed under ductile mode as evident by the presence of fine dimple surfaces.

Effect of He+ fluence on surface morphology and ion-irradiation induced defect evolution in 7075 aluminum alloys

The evolution of microstructure for 7075 aluminum alloys with 50 Kev helium ions irradiation were studied by using optical microscopy (OM), scanning electron microscopy (SEM), x-ray diffraction (XRD) and transmission electron microscopy (TEM). The fluences of 1 × 1015, 1 × 1016 and 1 × 1017 ions cm−2 were selected, and irradiation experiments were conducted at room temperatures. The transmission process of He+ ions was simulated by using SRIM software, including distribution of ion ranges, energy losses and atomic displacements. Experimental results show that irradiated pits and micro-cracks were observed on irradiation sample surface, and the size of constituent particles (not including Mg2Si) decreased with the increasing dose. The x-ray diffraction results of the pair of peaks is better resolved in irradiated samples might indicate that the stressed structure consequence due to crystal defects (vacancies and interstitials) after He+ implantation. TEM observation indicated that the density of MgZn2 phase was significantly reduced after helium ion irradiation which is harmful to strength. Besides, the development of compressive stress produced a large amount of dislocation defects in the 1015 ions cm−2 sample. Moreover, higher fluence irradiation produced more dislocations in sample. At fluence of 1016 ions cm−2, dislocation wall formed by dislocation slip and aggregation in the interior of grains, leading to the refinement of these grains. As fluence increased to 1017 ions cm−2, dislocation loops were observed in pinned dislocation. Moreover, dislocation as effective defect sink, irradiation-induced vacancy defects aggregated to these sinks, and resulted in the formation of helium bubbles in dislocation.

Indirectly extruded biodegradable Zn-0.05wt%Mg alloy with improved strength and ductility: In vitro and in vivo studies

As compared to permanent orthopedic implants for load-bearing applications, biodegradable orthopedic implants have the advantage of no need for removing after healing, but they suffer from the “trilemma” problem of compromising among sufficiently high mechanical properties, good biocompatibility and proper degradation rate conforming to the growth rate of new bones. In the present work, in vitro and in vivo studies of a Zn-0.05wt%Mg alloy (namely, Zn-0.05Mg alloy) were conducted with pure Zn as a control. The Zn-0.05Mg alloy is composed of a small amount of Mg2Zn11 phase embedded in the refined Zn matrix with an average grain size of ∼20 μm. The addition of 0.05 wt% Mg into Zn significantly increases the ultimate tensile strength up to 225 MPa and the elongation to fracture to 26%, but has little influence on the in vitro degradation rate. Both Zn and Zn-0.05Mg alloy exhibit homogeneous in vitro degradation with a rate of about 0.15 mm/year. Based on the cytotoxicity evaluation, Zn and Zn-0.05Mg alloy do not induce toxicity to L-929 cells, indicating that they have little toxicity to the general functions of the animal. An in vivo biocompatibility study of Zn and Zn-0.05Mg alloy samples by placing them in a rabbit model for 4, 12 and 24 weeks, respectively did not show any inflammatory cells, and demonstrated that new bone tissue formed at the bone/implant interface, suggesting that Zn and Zn-0.05Mg alloy promote the formation of new bone tissue. The in vivo degradation of Zn and Zn-0.05Mg alloy does not bring harm to the important organs and their cell structures. More interestingly, Zn and Zn-0.05Mg alloy exhibit strong antibacterial activity against Escherichia coli and Staphylococcus aureus. The above results clearly demonstrate that the Zn-0.05Mg alloy could be a potential biodegradable orthopedic implant material.

Effects of hot extrusion and heat treatment on microstructure and properties of industrial large-scale spray-deposited 7055 aluminum alloy

The industrial large-scale 7055 aluminum alloy fabricated by spray forming technology was subjected to hot extrusion and heat treatment to achieve high strength and ductility. Microstructure of the as-deposited alloy indicates that higher density billets with equiaxed grains (20–40 μm) were fabricated rather than a typical dendritic microstructure of the as-cast alloy. The grains of the as-extruded alloy exhibit fibrous morphology, the original boundaries disappear and fined second phases with size about 0.5–5 μm distribute along with extrusion direction. Meanwhile, the defects could be eliminated by hot extrusion, which resulted in good strength as well as ductility. The ultimate tensile strength, yield strength and elongation of the as-extruded alloy are 345 MPa, 236 MPa and 18.5%, respectively. After heat treatment, the partial recrystallization is observed around the un-recrystallized grains and sub-grains. And the platelet/rod-shaped precipitates (MgZn2) show a uniform distribution in the matrix alloy. The alloy reaches the maximum tensile strength of 730 MPa after T6 temper treatment, associated with a fine precipitation (MgZn2). However, with further deepen aging degree (from T6 to T73 temper), the size of dominant precipitated phases (MgZn2) grows obviously, the grain boundary precipitates transform from continuous to individual ones and the width of precipitate free zone increases. The result shows that the alloy after T7X temper treatment exhibits higher electrical conductivity (>35 %IACS) and facture toughness (>25.6 MPa m1/2) although a 8%–17% reduction in strength compared with that at T6 temper.

Impression creep behavior of magnesium alloy ZK60

Abstract Creep behavior of the ZK60 magnesium alloy was investigated using impression creep technique. The tests were carried out under constant punching stress at high temperatures (175, 200 and 225 °C) under low stresses (25, 50, 75 and 100 MPa) and at low temperatures (100, 125 and 150 °C) under high stresses (100, 125, 150 and 175 MPa). The creep mechanism of the extruded ZK60 magnesium alloy is grain boundary sliding by dislocation climbing obtained at low temperature and high pressure. At high temperature and under low pressure, the creep mechanism of the extruded ZK60 magnesium alloy is grain boundary diffusion by grain boundary sliding. The initial microstructure of the extruded ZK60 magnesium alloy was composed of mainly Mg phase and a little MgZn phase. Under the conditions of low temperature and high pressure, MgZn2 phase precipitated during creep deformation. Under the conditions of high temperature and low pressure, MgZn2 phase and a small amount of Zr-Zn phase precipitated during creep deformation. The creep resistance of magnesium alloy ZK60 under the conditions of low temperature and high pressure is better than under the conditions of high temperature and low pressure.

Effect of solid solution treatment on in vitro degradation rate of as-extruded Mg-Zn-Ag alloys

Abstract The degradation behaviors of the as-extruded and solution treated Mg-3Zn-xAg (x=0, 1, 3, mass fraction, %) alloys, as well as as-extruded pure Mg, have been investigated by immersion tests in simulated body fluid (SBF) at 37 °C. The as-extruded Mg-Zn(-Ag) alloys contained Mg51Zn20 and Ag17Mg54. While the quasi-single phase Mg-Zn(-Ag) alloys were obtained by solution treatment at 400 °C for 8 h. The quasi-single phase Mg-Zn(-Ag) alloys showed lower degradation rate and more homogeneous degradation than corresponding as-extruded Mg alloys. Degradation rate of solid-solution treated Mg-3Zn-1Ag and Mg-3Zn-3Ag was approximately half that of corresponding as-extruded Mg alloy. Moreover, the degradation rate of solid-solution treated Mg-3Zn and Mg-3Zn-1Ag was equivalent to that of as-extruded pure Mg. However, heterogeneous degradation also occurred in quasi-single phase Mg-Zn-Ag alloys, compared to pure Mg. So, preparing complete single-phase Mg alloys could be a potential and feasible way to improve the corrosion resistance.

Characterization of soldering alloy type Zn-In-Mg and the study of direct soldering of silicon and copper

The aim of study was to characterize the Zn-In-Mg soldering alloy type and investigate the direct soldering of silicon and copper. The Zn-In-Mg solder type has a broad interval of melting, which depends on the indium content in the solder. Solder microstructure is formed of a matrix with pure Zn. The MgZn2 phases and solid solution (In) β-In are precipitated along the grain boundaries. Tensile strength attains values from 46 to 124MPa and is dependent on indium content. The bond with silicon is formed due to the reactions of active metals - In and Mg with the substrate surface. Diffraction analysis has also revealed the In13Mg7 phase. In spite of that, the bond formation with a copper substrate in not affected by In and Mg content. The bond is formed owing to interaction between the zinc from the solder and copper substrates. Two phases, namely CuZn4 and Cu5Zn8 were observed. The shear strength of Cu/Zn-In-Mg/Cu joints attains values from 56 to 62MPa and the shear strength of Si/Zn-In-Mg/Cu joint is within 34–42MPa.

Hydrogenation Properties of Laves Phases LnMg2 (Ln = La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Ho, Er, Tm, Yb).

The hydrogenation properties of Laves phases LnMg2 (Ln = La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Ho, Er, Tm, Yb) were investigated by thermal analysis, X-ray, synchrotron, and neutron powder diffraction. At 14.0 MPa hydrogen gas pressure and 393 K, PrMg2 and NdMg2 take up hydrogen and form the colorless, ternary hydrides PrMg2H7 (P41212, a = 632.386(6) pm, c = 945.722(11) pm) and NdMg2H7 (P41212, a = 630.354(9) pm, c = 943.018(16) pm). The crystal structures were refined by the Rietveld method from neutron powder diffraction data on the deuterides (PrMg2D7, P41212, a = 630.56(2) pm, c = 943.27(3) pm; NdMg2D7, P41212, a = 628.15(2) pm, c = 940.32(3) pm) and shown to be isotypic to LaMg2D7. The LaMg2D7 type of hydrides decompose at 695 K (La), 684 K (Ce), 684 K (Pr), 672 K (Nd), and 639 K (Sm) to lanthanide hydrides and magnesium. The Laves phase EuMg2 forms a hydride EuMg2Hx of black color. Its crystal structure (P212121, a = 664.887(4) pm, b = 1136.993(7) pm, c = 1069.887(7) pm) is closely related to the hexagonal Laves phase (MgZn2 type) of the hydrogen-free parent intermetallic. GdMg2 and TbMg2 form hydrides GdMg2Hx with orthorhombic unit cells (a = 1282.7(4) pm, b = 572.5(2) pm, c = 881.7(2) pm) and TbMg2Hx (a = 617.8(3) pm, b = 1045.8(8) pm, c = 997.1(5) pm), presumably also with a distorted MgZn2 type of structure. CeMg2H7 and NdMg2H7 are paramagnetic with effective magnetic moments of 2.49(1) μB and 3.62(1) μB, respectively, in good agreement with the calculated magnetic moments of the free trivalent rare-earth cations (μcalc(Ce3+) = 2.54 μB; μcalc(Nd3+) = 3.62 μB).

Microstructure and mechanical properties of as-cast Mg-Sn-Zn-Y alloys

The effects of yttrium(Y) addition on the microstructure and mechanical properties of the as-cast Mg-5Sn-3Zn have been investigated. Results indicate that the addition of Y to Mg-5Sn-3Zn not only refines the grains but also promotes the precipitation of MgSnY phase with high stability. An increase addition of Y form 0.2–0.8 wt% increases the amount and size of MgSnY which would influence the mechanical properties of the as-cast alloys. The precipitation behavior of Mg2Sn and MgZn2 was also discussed. It was found that the MgZn2 phase is tend to precipitates attach to the Mg2Sn phase because the mismatch degree between them is relatively low, which have some guiding role in increase the amount of MgZn2 by Sn addition to enhance the performance of Mg-Sn-Zn alloys. In addition, Y to the Mg-5Sn-3Zn alloy general improves the mechanical properties but over does of Y would make it decrease, especially the elongation, which is affected by the grains and precipitates, improved significantly. The addition of 0.5 wt% Y gives the alloy favorable properties that the ultimate tensile strength reaches to 229 MPa and the elongation peaks at 19.2% at room temperature.

Microstructure evolution during solution treatment of extruded Al-Zn-Mg profile containing a longitudinal weld seam

In this study, the microstructure evolution during solution treatment of extruded Al-Zn-Mg profile containing a longitudinal weld seam was firstly reported. The porthole die extrusion experiment was conducted to obtain the extruded profile. The solution treatment was performed at 470 °C for 15 min, 60 min and 120 min, respectively, and the aging was performed at 120 °C for 24 h. The secondary phase distribution, grain morphology, grain size and texture evolution of welding zone during solution were investigated. Moreover, the hardness and tensile properties after aging were analyzed. The results show that the solution for 15 min is sufficient for the dissolution of MgZn2 phase, while Al2CuMg and Al23CuFe4 phases cannot be dissolved even the solution time is prolonged to 120 min. The main texture components of {110}<111> and {110}<115> are formed after extrusion process, and these textures are remained after solution treatment. With increasing solution time, the intensity and volume fraction of texture firstly increases and then decreases. Furthermore, both the average size and aspect ratio of grains in welding zone increase with increasing solution time. The best hardness, tensile strength and elongation was obtained in the Al- Zn-Mg profile after solution treated for 15 min.

The precipitation behavior of MgZn2 and Mg4Zn7 phase in Mg-6Zn (wt.%) alloy during equal-channel angular pressing

Abstract As-extruded Mg-6Zn (wt.%) Alloy was subjected to severe plastic deformation (SPD) by the equal-channel angular pressing(ECAP) at 160 oC. The results of tensile tests at room temperature showed that two passes ECAP resulted in a remarkable improvement of strength, yield strength from 200 to 265 MPa and ultimate tensile strength from 260 to 340 MPa. However, with the deformation increasing, the samples processed by ECAP for four or six passes had insignificant difference than that processed by two-pass ECAP. Massive precipitates were observed in all the Mg-6Zn alloys specimens processed by ECAP. Transmission electron microscope and X-ray diffraction results indicated that ECAP treatment induced the precipitation of laves MgZn2 phase and transition Mg4Zn7 phase. The spherical MgZn2 particles and irregular shape Mg4Zn7 particles coexist in the microstructure of Mg-6Zn alloy after six pass ECAP.