Ternary Eutectic Structure Research Articles

Effect of al content on microstructure and corrosion resistance of Zn-Al-Mg alloy

In order to solve the solidification microstructure of Zn-1.7Al-1.1Mg alloy on the surface of steel plate during hot dip plating, the solidification path and microstructure of Zn-1.7Al-1.1Mg alloy were studied by Thermo-Calc thermodynamic software, differential thermal analysis (DSC) and scanning electron microscopy (SEM). The results show that during cooling from melting to room temperature, Zn-1.7Al-1.1Mg alloy begins to precipitate Zn-rich η phase at 386.5 °C, binary eutectic structure consisting of η phase and Mg2Zn11 at 350.0 °C, and ternary eutectic structure consisting of η phase, Al-rich metastable β phase and Mg2Zn11 at 343.4 °C,at 276.7 °C, β phase transforms into stable aluminum-rich α and η phases.

Study on corrosion behavior Ⅱ of hot-dipped Zn-6Al-3Mg alloy coating: Surface oxide layer and ternary eutectic corrosion

The oxide layer and ternary eutectic of Zn–6Al–3Mg alloy coating have an important effect on its corrosion behavior and corrosion resistance, but the influence of oxide layer on the corrosion behavior of the coating and the internal corrosion mechanism of ternary eutectic structure are still unclear. In this study, the oxide layer and ternary eutectic of the coating were characterized in detail, and the corrosion behavior of the oxide layer and ternary eutectic in the environment containing Cl were studied based on first principles of density functional theory. The results show that the surface oxide layer can initially prevent the erosion of Cl-, MgZn2 in ternary eutectic preferentially corrodes after the oxide layer dissolves, corrosion products are formed.

Effect of C content on microstructure evolution and mechanical properties of CoCrFeNiTa0.1 high entropy alloy

A series of CoCrFeNiTa0.1Cx (x = 0.1, 0.2, 0.3, 0.4, 0.5) high entropy alloys (HEAs) with different C content were prepared by vacuum melting technology. The influence of different C element contents on the alloy microstructure and mechanical properties have been systematically investigated using X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and a universal testing machine system. It is found that the introduction of trace amounts of C element content facilitates the precipitation of Laves phase in C0.1 alloy. As the C element content further increases, the volume fractions of both FCC matrix and Laves phases gradually decrease, while the volume fraction of M7C3 carbide increases. Notably, the CoCrFeNiTa0.1C0.3 HEA shows a ternary eutectic structure. Compression tests reveal an increase in yield strength from 342 MPa to 1475 MPa and hardness from 182 HV to 458 HV as the C content increases. The precipitation of Laves phase and M7C3 carbide is principally involved in the enhancement of strength and hardness. Nanoindentation tests indicate that the M7C3 carbide has a higher nano-hardness compared to FCC matrix and Laves phase. The fracture microstructure exhibits a mode transition from ductile fracture to cleavage fracture.

Enhanced 3D printing and crack control in melt-grown eutectic ceramic composites with high-entropy alloy doping

As a 3D printing method, laser powder bed fusion (LPBF) technology has been extensively proven to offer significant advantages in fabricating complex structured specimens, achieving ultra-fine microstructures, and enhancing performances. In the domain of manufacturing melt-grown oxide ceramics, it encounters substantial challenges in suppressing crack defects during the rapid solidification process. The strategic integration of high entropy alloys (HEA), leveraging the significant ductility and toughness into ceramic powders represents a major innovation in overcoming the obstacles. The ingenious doping of HEA particles preserves the eutectic microstructures of the Al2O3/GdAlO3(GAP)/ZrO2 ceramic composite. The high damage tolerance of the HEA alloy under high strain rates enables the absorption of crack energy and alleviation of internal stresses during LPBF, effectively reducing crack initiation and growth. Due to increased curvature forces and intense Marangoni convection at the top of the molt pool, particle collision intensifies, leading to the tendency of HEA particles to agglomerate at the upper part of the molt pool. However, this phenomenon can be effectively alleviated in the remelting process of subsequent layer deposition. Furthermore, a portion of the HEA particles partially dissolves and sinks into the molten pool, acting as heterogeneous nucleation particles, inducing the formation of equiaxed eutectic and leading primary phase nucleation. Some HEA particles diffuse into the lamellar ternary eutectic structures, further promoting the refinement of eutectic microstructures due to increased undercooling. The innovative doping of HEA particles has effectively facilitated the fabrication of turbine-structured, conical, and cylindrical ternary eutectic ceramic composite specimens with diameters of about 70 mm, demonstrating significant developmental potential in the field of ceramic composite manufacturing.

Calculation and Experimental Verification of Zn–Al–Mg Phase Diagram

The liquid phase projection diagram, three-dimensional phase diagram, and vertical section diagram of the Zn–x%Al–x%Mg alloy system was calculated using the phase diagram calculation software Pandat. Simultaneously making full use of the self-developed hot-dip galvanizing process simulation machine by China Steel Research produced a 75%Zn–19%Al–6%Mg coating. A method combining phase diagram calculations and experimental verification was used to investigate the equilibrium phases and solidification process of the alloy. The microstructure of the 75%Zn–19%Al–6%Mg coating was studied using scanning electron microscopy and energy dispersive spectrometry. The results indicate that the coating structure consists of primary Al dendrite phase, MgZn2 inter-metallic compound and Zn-rich phase. There is no ternary eutectic structure in the coating structure. Al dendrites grow on the surface of the coating, while there are no Al dendrites on the cross-section. The experimental results strongly concur with the calculated results from the Pandat phase diagram. The solidification sequence of the 75%Zn–19%Al–6%Mg coating is L→L + Al→L + Al + MgZn2→Al + MgZn2 + Zn. The phase diagram guides industrial production significantly, avoiding the waste of transitional materials and zinc caused by small scale trial and error experiments, thus reducing unnecessary production costs. The factory can select a reasonable coating composition designing scheme in the phase diagram, based on the performance requirements of customers for the coating.

Ternary eutectic growth and associated tensile properties of directionally solidified Al87Si11Ni2 alloy

The directional growth mechanism and associated tensile properties of ternary Al87Si11Ni2 eutectic alloy were investigated within a wide growth velocity range from 1 to 120 μm s−1 at a constant temperature gradient of 380 K cm−1. If eutectic growth velocity was below 40 μm s−1, this alloy exhibited a ternary lamellar eutectic structure composed of Si plates, Al3Ni chips and αAl matrix. As growth velocity increased to faster regime, the microstructure evolved into a complex structure characterized by primary αAl dendrites plus ternary eutectics. Correspondingly, the preferred crystalline orientation along solidification direction transformed from 101αAl //010Al3Ni // 101Si to 001αAl // 010Al3Ni //113Si. The tensile strength initially increased with the rise of growth velocity until 40 μm s−1, primarily due to the refinement of eutectic structure, and then decreased beyond this threshold, mainly resulting from the coarsening of primary αAl phase.

Corrosion behavior of erbium modified Zn-11Al-3Mg cast alloy in stagnant 3.5 wt% NaCl solution

Zn-11Al and Zn-11Al-3Mg-xEr (x=0, 0.05, 0.1, 0.5) alloys were prepared, and the microstructures and corrosion resistance of the alloys were investigated by scanning electron microscopy (SEM), x-ray diffraction (XRD), and electrochemical methods. The results show that the primary Al-rich phase in Zn-11Al alloys is corroded as the main anode. The electronegativity of the primary Al phase in Zn-11Al-3Mg alloys is higher than the primary MgZn2 phase, and the electronegativity of Al-rich and Mg2Zn11 phases is higher than that of the η-Zn phase in ternary eutectic structure. The primary Al-rich phase and Mg2Zn11 phases in the alloy are corroded as the main anodes. On the other hand, the erbium (Er) reacts with Al to form the AlEr phase, and the AlEr phase has a significant refining and homogenizing effect on the primary Al-rich phase in the Zn-11Al-3Mg alloy. When the content of Er is 0.05%, the primary Al phase transforms into fine discontinuous cellular structure. However, the increase of Er addition promotes the growth of primary Al-rich phase and the reduction of ternary eutectic, which weakens the corrosion resistance of the alloy.

Microstructure Features and Mechanical Properties of Casted CoFeB Alloy Target

CoFeB alloy, as a promising magneto-resistive material, has attracted extensive attention concerning the magnetic properties of its thin film in the field of magneto-resistive random memory (MRAM). Although there are many studies on the magnetic properties of CoFeB thin films, there is relatively little research on the microstructure and mechanical properties of casted CoFeB alloy. In this work, Co20Fe60B20 (at%) alloy was fabricated through the vacuum induction melting method, and its microstructure features and mechanical performance were studied. Scanning electron microscopy (SEM), electron back scatter diffraction (EBSD), and transmission electron microscopy (TEM) were utilized to characterize the microstructure, which consists of the coarse, needle-like Fe2B phase that crystallizes first, the primary lamellar binary eutectic structure (Fe2B + bcc-Fe), and the ternary eutectic structure (Fe3B + Fe2B + bcc-Fe phase). It is found that Fe3B precipitates on the Fe2B with a core–shell structure. The orientation of bcc-Fe is randomly distributed, while there are two main kinds of textures in Fe2B: {100} <001> and Gaussian texture {110} <001>. In terms of mechanical properties, Co20Fe60B20 alloy’s tensile strength is 140MPa, and the yield strength is 87MPa. Because the cracks are easy to generate and expand along the needle-shaped pre-crystallized Fe2B, the plasticity of Co20Fe60B20 alloy is very poor, only 1%.

Thermophysical properties and rapid solidification mechanism of liquid Zr<sub>60</sub>Ni<sub>25</sub>Al<sub>15</sub> alloy under electrostatic levitation condition

In this study, the thermophysical properties and rapid solidification mechanism of highly undercooled liquid Zr<sub>60</sub>Ni<sub>25</sub>Al<sub>15</sub> alloy are investigated through the electrostatic levitation technique. The maximum undercooling of this alloy reaches 316 K (0.25<i>T</i><sub>L</sub>). Both density and surface tension display a linear relationship with temperature, while viscosity is related to temperature exponentially. When alloy undercooling is less than 259 K, two significant recalescence events are observed during solidification, corresponding to the formation of pseudobinary (Zr<sub>6</sub>Al<sub>2</sub>Ni + Zr<sub>5</sub>Ni<sub>4</sub>Al) eutectic and ternary (Zr<sub>6</sub>Al<sub>2</sub>Ni + Zr<sub>5</sub>Ni<sub>4</sub>Al + Zr<sub>2</sub>Ni) eutectic. The growth velocity of the binary eutectic phase gradually increases with further undercooling and reaches a maximum undercooling value of 259 K. In contrast, once undercooling exceeds 259 K, a single recalescence event occurs, leading to the independent nucleation of all three compound phases from alloy melt and the rapid growth of a ternary anomalous eutectic structure. Notably, the growth velocity of the ternary eutectic phase exhibits a gradual decline with further undercooling. This diminishing trend of the growth velocity suggests that further undercooling might entirely suppress crystal growth dynamically at a threshold of 385 K. With classical nucleation theory and the Kolmogorov-Johnson-Mehl-Avrami (KJMA) model, the onsets of crystallization for the three phases are calculated, thereby constructing a time–temperature-transformation (TTT) diagram. This diagram elucidates the competitive nucleation among the three phases in the undercooled melt. Both theoretical and experimental evidence reveal that Zr<sub>6</sub>Al<sub>2</sub>Ni phase is primarily nucleated at lower undercooling levels, whereas under higher cooling condition, it is possible for all three phases to nucleate simultaneously.

Joining mechanism, microstructure, and mechanical properties of AZ31/6061 joint prepared by pouring fusion welding process assisted with Zn-xSn brazing filler

In this study, AZ31/6061 dissimilar metal joints were manufactured using pouring fusion welding assisted with Zn-xSn brazing filler, and the process, microstructure and mechanical properties of Mg/Al joint were investigated. During welding, the addition of molten Zn-xSn brazing filler completely isolates the direct contact of Mg/Al, preventing the formation of Mg-Al intermetallic compounds. As the Sn content changes, the microstructure of the joints also changes. When the Sn content is 25 wt.%, the microstructure of the AZ31 side is dominated by Mg-Al-Zn ternary eutectic structure, Al6Mg11Zn11, (β-Zn + MgZn2), Al-Zn-Sn (SS), Sn (SS) and Mg2Sn. And the microstructure of the 6061 side is dominated by Al-Zn-Sn (SS), β-Zn, Al-Zn-Sn (SS), and Sn (SS). The width of the Mg-Al-Zn ternary eutectic structure layer decreases with the increase of Sn content. In addition, high Sn content and high heat input promote the formation of Mg2Sn, and large amounts of Mg2Sn are generated with Zn-40Sn interlayer. The average microhardness of the joint gradually decreases with the increase of Sn content. However, the shear strength of the joint first increases and then decreases, and the shear strength of the joint with the Zn-25Sn interlayer is the highest, which is 50.60 MPa. Fracture mode is cleavage fracture.

Microstructural evolution during low-temperature brazing of WC-Co cemented carbide to AISI 4140 steel using a silver-based filler alloy

The joining of cemented carbides to steels used in the drilling/excavation industries due to their distinct characteristics has posed a significant challenge. This research systematically investigates the effect of brazing temperature (650, 700, and 750 °C) and time (5, 10, and 15 min) as the most effective brazing parameters on the phase transformations and interfacial microstructure of WC-Co/AISI 4140 steel joints. Low-temperature brazing due to eliminating the destructive η carbides at the cermet interface, makes it a more appropriate procedure, as compared to fusion-welding methods, as per the findings of the current study. It was revealed that the optimal condition for the process is at 650 °C for a duration of 10 min, in which the eutectic structure is refined and the distribution of primary dendrites is uniform. The microstructure of the brazed area presents a multiphase structure, comprised of a copper-rich solid solution (Cu,Zn), a silver-rich solid solution (Ag,Cd), a eutectic structure as well as the β′-CuZn ordered phase. The β embedded in ternary eutectic structure was partially transformed to β′ during the cooling cycle of the brazing process. Diffusion of silver and cadmium in cemented carbide, as well as the formation of Co-Fe-Cu reaction product, were proposed as the bonding mechanisms. The effectiveness of brazing temperature in enlarging the cobalt-depleted zone appearing in WC-Co is comparatively higher than that of brazing time. It is also concluded that by increasing the brazing temperature and duration, the fraction of copper solid-solution dendrites distributed in the joint area decreases, however, the size increases.

TiO2@C catalyzed hydrogen storage performance of Mg-Ni-Y alloy with LPSO and ternary eutectic structure

A designed Mg88.7Ni6.3Y5 hydrogen storage alloy containing 14H type LPSO (long-period stacking ordered) and ternary eutectic structure was prepared by regulating the alloy composition and casting. The hydrogen storage performance of the alloy was improved by adding nano-flower-like TiO2@C catalyst. The decomposition of the LPSO structure during hydrogenation led to the formation of plenty of nanocrystals which provided abundant interphase boundaries and activation sites. The nanoscale TiO2@C catalyst was uniformly dispersed on the surface of alloy particles, and the "hydrogen overflow'' effect of TiO2@C accelerated the dissociation and diffusion of hydrogen on the surface of the alloy particles. As a result, the in-situ endogenous nanocrystals of the LPSO structure decomposition and the externally added flower-like TiO2@C catalyst uniformly dispersed on the surface of the nanoparticles played a synergistic catalytic role in improving the hydrogen storage performance of the Mg-based alloy. With the addition of the TiO2@C catalyst, the beginning hydrogen desorption temperature was reduced to 200 °C. Furthermore, the saturated hydrogen absorption capacity of the sample was 5.32 wt.%, and it reached 4.25 wt.% H2 in 1 min at 200 °C and 30 bar.

Effect of Y2O3 contents on microstructural, mechanical, and antioxidative characteristics of Al2O3-ZrO2-Y2O3 coatings

The Al2O3-ZrO2-Y2O3 ternary ceramic coatings (AZY-TCC) with different Y2O3 contents were successfully prepared by thermal explosion spraying assisted rapid solidification. The microstructural, mechanical, and antioxidative characteristics of different solidification morphologies for AZY-TCC were tested and analyzed. The results show that, along the solidification direction, AZY-TCC mainly contained nanocrystalline, nano-eutectic, submicro-eutectic and micro-eutectic regions. According to the growth rate of these areas, the solidification morphology mapping of AZY-TCC with different Y2O3 contents was drawn. As the Y2O3 contents increased from 1.5 mol% to 16 mol%, ZrO2 gradually changed from m-phase to t-phase, and finally stabilized to c-phase. When the Y2O3 content was up to 12 mol%, the excess Y2O3 and Al2O3 formed a small amount of Y3Al5O12 (YAG) phase, and a typical Al2O3-ZrO2-YAG ternary eutectic structure appeared with 16 mol% Y2O3. The hardness and fracture toughness of AZY-TCC with different Y2O3 contents reached up to 23.57 ± 0.66 GPa and 5.35 ± 0.38 MPa·m1/2, which were much higher than those of other ceramic coatings with the same composition, and AZY-TCC with 3 mol% Y2O3 had excellent friction and wear resistance and oxidation resistance. Consequently, the high-performance AZY-TCC provides theoretical guidance for its microstructural evolution under rapid solidification.

Selective laser melting of MoSiBTiC alloy with plasma-spheroidized powder: Microstructure and mechanical property

Spherical MoSiBTiC alloy powder with little internal gas pores and cracks was successfully fabricated using plasma-spheroidization method. This powder fabrication process significantly decreased the oxygen content of the raw crushed powder. Then, MoSiBTiC alloy samples were fabricated via selective laser melting (SLM) with the plasma-spheroidized powder, and the microstructural characteristics and mechanical property were investigated. The as-built MoSiBTiC alloy exhibited a bimodal microstructure; the microstructure inside the melt pool (MP) was different from that at a melt pool boundary (MPB). The microstructure inside the MP consisted of primary Mo solid solution (Moss) dendrites, and other constituent phases, such as Mo5SiB2 (T2) phase, were formed at the inter-dendritic regions. On the other hand, (Ti,Mo)C precipitates around the Moss dendrites were preferentially coarsened at the MPB, forming a heat affected zone (HAZ) at the underside within the MPB. At the upside within the MPB, the microstructure of the previous layer was partially remelted, and ternary eutectic lamellar structure (Moss/T2/(Mo,Ti)2C) was newly formed. The as-built samples were subsequently subjected to heat treatment at different temperatures of 1600, 1700, and 1800 °C for 4 h. With increasing in the heat-treatment temperature, the Moss dendritic microstructure decomposed, and other constituent phases were coarsened at the inter-dendritic regions. Through a detail microstructural characterization of both the as-built and heat-treated samples, it was confirmed that any large oxide was not formed in this study. Rapid solidification via SLM resulted in the refinement of microstructure and the formation of a supersaturated Moss phase, which hardened the as-built sample but simultaneously decreased the crack resistance of the Moss phase.

Effect of Oxide Scale on Hot Dip Zn-Al-Mg Alloy Coating Prepared by Reduction Combined with Induction Heating

Hot dipping Zn-Al-Mg coatings were prepared by rapid induction heating combined with gas protection. The influence of oxide scale on the structure and surface quality of a hot-dip Zn-6Al-3Mg alloy coating was studied in this paper. The results showed that the reaction of Fe-Al was suppressed by the scale on the surface of the steel plate. When the thickness of scale was 10 μm and the steel entry temperature was 900 °C, the surface quality of the coating was good. The Zn-Al-Mg coatings mainly consisted of the ternary eutectic structure of Zn/Al/MgZn2 and Fe4Al13 at the interface. When the scale thickness was 2–3 μm with the same steel entry temperature, the surface quality of the coating was poor, and serious stripe-like protrusion defects were formed on the surface of the coating, which was mainly caused by the Fe4Al13 phase separating from the substrate / coating interface into the overlay.

Microstructural characteristics of laser surface melted MoSiBTiC alloy

The microstructural characteristics of a TiC-added Mo-Si-B (MoSiBTiC) alloy fabricated by laser surface melting were investigated. The microstructure inside a melt pool consisted of many cells, and each cell was composed of an ultrafine ternary eutectic lamellar structure with Mo solid solution (Moss), Mo5SiB2, and (Mo,Ti)2C phases. The lamellar structure completely disappeared in a heat affected zone (HAZ) formed by multi tracks test, and a fine round (Ti,Mo)C phase newly precipitated in the HAZ together with other phases. The chemical composition analyses identified the elemental supersaturation of Si and Ti in the Moss phase and of Ti in the T2 phase in the lamellar structure.

A High-Strength and Biodegradable Zn–Mg Alloy with Refined Ternary Eutectic Structure Processed by ECAP

In this study, the microstructure, mechanical properties and corrosion behaviors of a Zn–1.6Mg (wt%) alloy during multi-pass rotary die equal channel angle pressing (RD-ECAP) processing at 150 °C were systematically investigated. The results indicated that a Zn + Mg2Zn11 + MgZn2 ternary eutectic structure was formed in as-cast Zn–Mg alloy. After ECAP, the primary Zn matrix turned to fine dynamic recrystallization (DRX) grains, and the network-shaped eutectic structure was crushed into fine particles and blended with DRX grains. Owing to the refined microstructure, dispersed eutectic structure and dynamically precipitated precipitates, the 8p-ECAP alloy possessed the optimal mechanical properties with ultimate tensile strength of 474 MPa and elongation of 7%. Moreover, the electrochemical results showed that the ECAP alloys exhibited similar corrosion rates with that of as-cast alloys in simulated body fluid, which suggests that a high-strength Zn–Mg alloy was successfully developed without sacrifice of the corrosion resistance.

Corrosion behavior of lithium silicate-based Zn-5.5Al-4.5Mg-0.3Ce coating

The effects of Ce on the microstructure of Zn-5.5Al-4.5Mg alloy and the corrosion mechanism of Zn-5.5Al-4.5Mg-0.3Ce alloy and its coatings were investigated in this research. The results show that the structure of Zn-5.5Al-4.5Mg-0.3Ce alloy is composed of hcp-Zn, fcc-Al and ternary eutectic structure (Zn/Al/MgZn2/Mg2Zn11), without dendritic tissue and MgZn2. The salt spray corrosion performance of Zn-5.5Al-4.5Mg-0.5CMC-2C coating was significantly better than that of Zn-5.5Al-4.5Mg-0.3Ce coating and Zn-5.5Al-4.5Mg-0.5CMC coating. The corrosion current density of Zn-5.5Al-4.5Mg-0.5CMC-2C coating was 3.217 μA cm−2, which was significantly lower than 3.96 μA cm−2 of Zn-5.5Al-4.5Mg-0.3Ce alloy and 5.879 μA cm−2 of Zn-5.5Al-4.5Mg alloy. Sodium carboxymethylcellulose and graphene improve the film formation and electrical conductivity of water-based lithium silicate resin. During corrosion of Zn-5.5Al-4.5Mg-0.3 Ce series alloy and coatings, Zn and Mg2Zn11 dissolved preferentially to form corrosion products of Zn5(OH)6(CO3)2 and Zn5(OH)8Cl2·H2O. Mg6Al2(OH)16CO3·4H2O and Zn4Al2(OH)12CO3·3H2O bimetallic hydroxide colloidal membranes were formed, which attached and wrapped on the surface of early corrosion products. Mg6Al2(OH)16CO3·4H2O and Zn4Al2(OH)12CO3·3H2O, preventing the dissolution of soluble corrosion products, improved the corrosion resistance of Zn-5.5Al-4.5Mg-0.3Ce alloy.

Enhanced hydrogen absorption kinetics by introducing fine eutectic and long-period stacking ordered structure in ternary eutectic Mg–Ni–Y alloy

We employ a ternary eutectic Mg76.87Ni12.78Y10.35 alloy to achieve a fine eutectic structure with long-period stacking ordered (LPSO) structure, and investigate the corresponding hydrogen storage behavior. The as-cast Mg76.87Ni12.78Y10.35 alloy is composed of Mg15NiY, Mg2Ni, MgNi4Y and Mg phases. A high density of stacking faults and 14H-type LPSO structures form in the Mg15NiY phase. This fine ternary eutectic structure has shown significant improvement in promotion of the activation and following hydrogen absorption kinetics compared with as-cast non-eutectic structure. Pressure-Composition-Temperature (PCT) curves demonstrate two major pressure platforms due to the presence of Mg15NiY and Mg2Ni in our Mg–Ni–Y alloys. Nanosized Mg2NiHx, MgH2 and YHx are insitu generated from the decomposition of LPSO structure during hydrogenation. The fine ternary eutectic structure and dispersed nanocatalysts from decomposition of LPSO structure synergistically facilitate the activation and hydrogen absorption kinetics of ternary eutectic Mg–Ni–Y alloy.

Effects of Ce and In on microstructure and corrosion properties of Zn-9Al-2.5Mg alloy

The effects of Ce and In on microstructure and corrosion properties of Zn-9Al-2.5Mg had been investigated in this research. The corrosion product morphology and the corrosion mechanism were observed and discussed. The microstructure and the corrosion product morphology were seen by OEM and SEM respectively. The phases were determined by XRD and the elements in micro region were used by EDS. The corrosion behavior was determined by full immersion corrosion method and electrochemical test method. Results show that the phases of Zn-9Al-2.5Mg alloy are constituted by Zn-rich solid solution, Al-rich solid solution and ternary eutectic structure (Zn-Al-MgZn2/Mg2Zn11). After adding 0.1% Ce, the grain size of the Zn-9Al-2.5Mg alloy is obviously refined. After adding 0.1%Ce and 0.05% In, the amount of Al-rich solid solution is inhibited and dendritic Zn-rich solid solution increased. The amount of ternary eutectic structure (Zn-Al-MgZn2/Mg2Zn11) decreases gradually. Compared with Zn-9Al-2.5Mg alloy, the corrosion potential of Zn-9Al-2.5Mg-0.1Ce increased slightly and the corrosion current density is basically unchanged, which remains at 5.97 × 10−6 A cm−2. It’s half the corrosion rate of pure Zn. When the content of In increases from 0.05% to 0.1%, the current density increases from 8.71 × 10−6 A cm−2 to 20.42 × 10−6 A cm−2. The corrosion products of pure Zn and Zn-9Al-2.5Mg alloys are Zn5(OH)6(CO3)2 and Zn5(OH)8Cl·H2O, Which present sphere (petal and rod) assembly structure. The difference is that the formation of Zn-Al and Mg-Al layered double hydroxides (Zn4Al2(OH)12CO3·3H2O and Mg6Al2(OH)16CO3·4H2O)-LDH are observed for Zn-9Al-2.5Mg alloys. After adding Ce to Zn-9Al-2.5Mg alloy, the LDH film is rather compact. But the LDH film is thin and floccus after In added. It leads to a lower resistance of corrosion products and accelerate the corrosion process.