Mechanical Properties Of Alloys Research Articles

Influence of Discontinuous Precipitation on Microhardness and Wear Resistance in (FeCoNi)86Al7Ti7 High‐Entropy Alloy

In this study, the effects of discontinuous precipitation, a process known to enhance mechanical properties in alloys, on the microstructure and mechanical properties of the (FeCoNi)86Al7Ti7 high‐entropy alloy (HEA) are investigated. Varying the aging temperatures leads to the formation of lamellar structures consisting of face‐centered cubic (FCC) and body‐centered cubic phases, which significantly influence the mechanical properties of the alloy. The aging treatments reveal an inverse relationship between temperature and microhardness, with values decreasing from 890 to 700 HV as the temperature rises from 550 to 650 °C. Despite this reduction, the alloy retains a high hardness level, suitable for wear‐resistant applications. The best wear resistance is observed at 550 °C, with a wear rate as low as 8.45 ± 1.6 × 10−5 mm3 N−1 m−1. This is attributed to stacking faults and dislocations within the FCC lamellae, which enhance resistance to dislocation glide. In this study, the critical role of microstructural engineering in optimizing the properties of HEAs is highlighted, providing valuable insights for developing high‐performance materials for specific engineering applications.

Effects of different heat treatment temperatures on the microstructure and mechanical properties of additive manufacturing Ti65 alloys

The advantages of additive manufacturing integrated molding have increased its use in aerospace applications. Heat treatment is crucial in changing the microstructure and improving the mechanical properties of additively manufactured samples. Herein, the effects of different heat treatment temperatures (750 °C - 1050 °C) on the microstructure and mechanical properties of additive manufacturing Ti65 alloys were systematically investigated. Concretely, the heat treatment in different temperature ranges led to significant variation in microstructure. HT-1050 specimens with widmanstatten microstructure exhibited high microhardness (415 HV), lowest wear rate (2.19 × 103 mm3/N × min), and superior frictional wear resistance. A detailed examination of the worn surfaces, considering the variations in the applied load, indicated that the predominant wear mechanisms during the sliding process were abrasion, delamination, oxidation, and adhesion. The as-deposited specimens' tensile strength and total elongation were 1115 ± 10 MPa and 2.1 ± 0.6 %, respectively. The elongation of the specimens increased significantly after heat treatment. The total elongation of the HT-1050 increased by 116 % compared to the as-deposited and had favorable strength-plasticity. This work elucidates the fundamental mechanisms underlying the effects of heat treatment on the microstructure and mechanical properties of alloys.

AZ31 Magnesium Alloy in the Aerospace Industry: A Review on the Effect of Composition, Microstructure, and Mechanical Properties on Alloy Performance

This comprehensive review article overviews AZ31, a highly researched magnesium alloy known for its exceptional mechanical properties, lightweight nature, and corrosion resistance. It covers the alloy's composition, microstructure, mechanical properties, applications, and prospects. AZ31's microstructure is influenced by its aluminum (Al) and zinc (Zn) composition, resulting in significant magnesium-aluminum intermetallic phase formation, critical for tailoring the alloy's properties to meet specific application needs. AZ31 exhibits impressive specific strength, excellent castability, and favorable ductility influenced by alloying elements, microstructure, and processing methods. The article discusses manufacturing processes like casting, rolling, and extrusion, which impact the alloy's microstructure and mechanical properties. It also explores the corrosion behavior of AZ31, emphasizing factors affecting corrosion resistance and strategies for improvement. Due to its lightweight properties, high strength-to-weight ratio, and electromagnetic shielding capabilities, AZ31 is widely used in various industries, including automotive, aerospace, electronics, and biomedical. Ongoing research focuses on alloy modifications, surface treatments, and additive manufacturing to enhance AZ31's properties and address challenges like limited formability and corrosion resistance. This review article is a valuable resource for researchers, engineers, and professionals exploring AZ31's potential for lightweight materials and diverse applications in different industries.

Selective Laser Melted High Mg‐Content Al–Si–Mg–Zr Aluminum Alloy with the Formation of Stacking Faults

The currently applied selective laser melted (SLMed) Al–Si–Mg aluminum alloys generally exhibit low strength. Increasing the Mg content is an effective method to enhance the strength of those alloys. However, an excessive Mg content reduces their processability and plasticity. Herein, Zr is chosen as the alloying element to enhance the processability and plasticity of the SLMed high Mg‐content Al–Si–Mg alloy. The results demonstrate that the alloying of the Zr element is beneficial for improving the alloy's processability and mechanical properties through grain refinement. Besides, the high‐concentration solid solution of low‐stacking fault energy (SFE) elements, including Mn, Zr, and Mg, effectively reduces the SFE of the alloy, thereby promoting the formation of stacking faults. The yield strength, ultimate tensile strength, and elongation of the alloy are 388 ± 3, 503 ± 6 MPa, and 5.1 ± 1%, respectively. The strength of the present alloy is higher than that of previously reported SLMed Al–Si–Mg aluminum alloys.

Phase evolution and mechanical properties of AlxCrTaTi refractory medium entropy alloys

In multi-principal refractory alloys (high-entropy alloys, medium-entropy alloys), the presence of the second phase has an important influence on the mechanical properties of the alloys. In this paper, AlxCrTaTi (x = 0, 0.25, 0.5, 1.0) refractory medium-entropy alloys were prepared by vacuum arc melting method, and the microstructure, density, and mechanical properties were investigated. The CrTaTi alloy consists of BCC dendritic and C15 Laves phases, whereas the AlxCrTaTi alloys consist of a two-phase eutectic organization (BCC phase and C14 Laves phase). With the increase of Al content, the content of the second phase increases from 15.97 % to 42.19 %, resulting in an increase in the yield strength of the alloy from 1491 MPa to 2354 MPa at 25 °C, and from 253 MPa to 426 MPa at 1000 °C. The addition of Al element changes the enthalpy, elemental distribution, and solidification process of the alloy, resulting in the formation of Cr-rich and Ti-rich two-phase eutectic organizations in the alloy. With the increase of Al, the second phase strengthening is the main reason for the enhancement of alloy properties.

The Thermomechanical, Functional and Biocompatibility Properties of a Au-Pt-Ge Alloy for PFM Dental Restorations.

A high-noble Au-Pt-Ge porcelain-fused-to-metal (PFM) dental alloy without the known adverse metallic elements and with the addition of germanium (Ge) was produced as a more cost-effective alternative to other precious alloying metals, with investigations for determining the functionality and clinical use of this alloy. The thermomechanical, biocompatibility, durability, workability and economic characteristics of the produced dental alloy were investigated. These properties were investigated with in vitro biocompatibility testing on human gingival fibroblasts (HGFs); static immersion testing for metal ion release; DSC analysis; hardness, tensile testing, density and coefficient of thermal expansion (CTE) measurements; metallographic and SEM/EDX microstructure investigations; and finally with the production of a test PFM dental bridge. The results of the thermomechanical testing showed alloy properties suitable for dental restorations and clinical use, with somewhat lower mechanical properties, making the alloy not suitable for extensive multiunit fixed restorations. The microstructure investigations showed segregations of Ge in the homogeneous alloy matrix, which reduce the alloy's mechanical properties. The produced PFM dental bridge showed excellent workability of the alloy in a dental laboratory setting, as well as a high standard of the final dental restoration. The ion release was negligible, well below any harmful quantities, while the cell viability examination showed significantly higher viability ratings on polished alloy samples as compared to as-cast samples. The results showed that a dental substructure in direct contact with oral tissue and fluids should be highly polished. The performed investigations showed that the produced PFM dental alloy is suitable for clinical use in producing high-quality dental restorations with high biocompatibility for patients prone to metal allergies.

Effect of cooling rate on AlFe primary and eutectic phase growth evolution in an Al-2Fe-1Mn alloy

A higher percentage of recycled Al often increases Fe content, promoting the formation of Fe-rich intermetallic phases with morphologies that detrimentally affect the alloy's mechanical properties. Nevertheless, there is a scarcity of research focusing on the impacts of cooling rate in the microstructural morphology in alloys containing Mn. This study aims to characterize the AlFe and Al(Fe,Mn) phases formed during the solidification of the Al-2 wt.% Fe-1 wt.% Mn alloy for samples at 1K/s and 3K/s. The methodology includes traditional 2D techniques, such as metallography, SEM-EDS, and EBSD, with non-destructive 3D X-ray Computed Tomography (XCT) analysis to evaluate the complex morphologies of the formed intermetallic phases. The presence of primary star-like Al13Fe4 and trefoil-like Al6(Fe,Mn) phase morphologies was observed in both 1K/s and 3K/s samples. The presence of Mn as an alloying element, combined with relatively increased cooling rates, reduces the fraction of primary phases, particularly the star-like phase at 3K/s. Moreover, the formation of the Al6(Fe, Mn) phase as part of the eutectic microconstituent with the Al phase was favored, transitioning from a divorced morphology to eutectic colonies with increasing cooling rate.

Effect of heat treatment on microstructure and mechanical anisotropy of direct energy deposited Ti-6.0Al-2.5Nb-2.2Zr-1.2Mo alloy

Ti-6.0Al-2.5Nb-2.2Zr-1.2Mo alloy (Ti-6321) exhibits excellent corrosion resistance and impact toughness, which can be used as a deep-sea pressure-resistant hull. However, the alloy tends to have high strength but low plasticity, poor impact toughness, and anisotropic mechanical properties by fabricating by direct energy deposition (DED) technology. In order to improve the impact toughness of DEDed Ti-6321 alloy while reducing its anisotropy of mechanical properties, this study manipulates the microstructure and mechanical properties of the alloy through heat treatment. The research finds that with the increase of the single-stage annealing temperature within the (α+β) two-phase region, the width of the α phase increases, the Ultimate Tensile Strength (UTS) remains essentially unchanged, the Yield Strength (YS) decreases, and the impact absorption energy significantly improves. For double annealing heat treatment at two-phase region, temperature increase at the first-stage annealing enlarges the width and decreases the aspect ratio of the primary α phase. Leading to the decrease of the UTS & YS and increase of the impact absorption energy, with a conversely tendency at 1000 °C. The increase in the second-stage annealing temperature raises the size and volume fraction of the secondary α phase, causing the alloy's UTS and YS to initially rise then fall, with a slight increase in impact absorption energy. The anisotropy in the mechanical properties of DEDed Ti-6321 alloy mainly addressed from the different distribution of α phase orientations at different loading directions, and can be eliminated through sufficient β single-phase zone annealing.

Co-evolution of M23C6 precipitates and cavities in a boron-free Ni-based alloy GH3617 under high-temperature He ion irradiation: Effects on cavity swelling and mechanical properties

Ni-based alloys are promising materials for advanced nuclear reactors operating at high temperatures due to their exceptional resistance to high temperatures and corrosion. Understanding the synergy of phase stability and helium effects is crucial for assessing the long-term performance and reliability of these alloys in advanced nuclear reactors. This study has investigated the co-evolution behavior of M23C6 precipitates and cavities in a boron-free solid solution strengthened Ni-based alloy GH3617 under high-temperature He ion irradiation, and its impact on alloy swelling and mechanical properties, by He ion irradiation experiments with the highest fluence of 1 × 1017 He/cm2 up to 800 °C. Transmission Electron Microscopy (TEM) and Nanoindentation are employed to investigate microstructural evolution and mechanical properties, respectively. The findings show that at room temperature and 500 °C, cavities and dislocation loops were the dominant irradiation defects, whereas at 800 °C, the density of cavities and dislocations reduced while the formation of M23C6 precipitates increased. These precipitates act as effective trapping sites for He and point defect, leading to cavity formation at the interfaces or within the precipitates. Moreover, increased irradiation fluence accelerates the co-evolution process, resulting in an increase in the density and size of both precipitates and cavities, ultimately leading to enhanced swelling. The {111} planes are favored interfaces between intragranular M23C6 precipitates and the matrix due to their minimal misfit, while the preferred interface planes between cavities with octahedral or cubo-octahedral shapes and the precipitate/matrix are also {111}, owing to their lower surface energy as well. The co-evolution of cavities and precipitates was found to influence mechanical properties, resulting in an irradiation hardening effect at lower fluences, while softening at higher fluences. This study provides novel insights into the degradation mechanisms of Ni-based alloys under coupling effect of He and high-temperature irradiation.

Effect of element N on microstructure and tribological properties of CoCrFeNiV alloy at severe temperature

In this study, CoCrFeNiV non-equiatomic high entropy alloys (HEAs) with varying N content were prepared using vacuum hot-press sintering. The effects of N content on the alloy's microstructure, mechanical properties, and tribological behavior at different temperatures were investigated. The results indicate that the N-added alloys primarily maintain an FCC phase. With increasing N content, the σ phase in the alloy gradually decreases, while the VN content increases, leading to grain refinement. This results in a 10.7 % increase in hardness, a 9 % increase in compression strength, and a 56 % increase in compression deformation. Below 400 °C, the primary wear mechanisms are adhesive wear, spalling wear, and slight oxidative wear, while above 600 °C, oxidative wear dominates. The addition of N reduced the wear rates of the alloy by 33.8 %, 8.1 %, and 31.3 % at RT, 200 °C, and 600 °C, respectively, and decreases the coefficient of friction at all temperatures. In summary, N addition improves the alloy's tribological performance at various temperatures.

Effects of post-heat treatments on the microstructure and mechanical properties of Ti–6Al–4V alloy fabricated by selective laser melting

In this study, post-heat treatments were applied to Ti–6Al–4V (TC4) alloy fabricated by selective laser melting (SLM) to investigate the effects of annealing temperature (750–950 °C in 50 °C intervals) on the alloy's microstructure, residual stress and mechanical properties. The initial microstructure of as-SLMed TC4 alloy was dominated by needle-like α′ martensite with a high density of dislocations and minor β phase, resulting in high strength (1190 MPa) but limited ductility (2.2% elongation). Annealing led to the transformation of α′ martensite into α phase, with the β phase content remaining relatively stable. Increasing the annealing temperature caused the acicular martensite to evolve into bundles of coarse α laths, forming a basket-weave microstructure. Annealing at 750 °C for 2 h reduced the yield strength to 1040 MPa and improved elongation to 8.3%. Interestingly, both the strength and ductility decreased with further increases in annealing temperature. This unusual phenomenon was rarely mentioned in current literature and was considered to be associated with the abnormal variations in the Schmid factor of (0001) [11-20] slip system and the reduction of mobile dislocations within the coarsened α martensite. Additionally, annealing combined with air cooling effectively alleviated residual tensile stresses in the SLM-formed TC4 alloy.

Hierarchical ferrous medium entropy with heterogeneous precipitates embedded in core-shell grain structure for superior mechanical properties

Superalloys designed for high-temperature applications, featuring a face-centered cubic matrix and L12 precipitates, have shown excellent tensile properties at both room and elevated temperatures. However, the substantial Ni and Co, necessary for generating a high fraction of the ordered L12 phase within the matrix, results in high mass density and cost, subsequently limiting their widespread industrial application. It is important to increase Fe content over Ni and Co while preserving outstanding mechanical properties at ambient and high temperatures. In this study, we propose a novel approach to introduce a hierarchical structure in a 60-at%-Fe-based medium entropy alloy. The heterogeneous nano-precipitates embedded in harmonic (core-shell) grain structure reinforce mechanical contrast between soft and hard domains, achieving an excellent heterostructure. The present alloy incorporates hierarchical heterogeneity at multi-scales, combining heterogeneous grain at micrometers, precipitates at tens of nanometers, and elemental fluctuation at nanometers. This hierarchical structure shows superior mechanical properties at room and high temperatures comparable to those of conventional superalloys. Further, the high content of Fe in this alloy system shows excellent performance in alloy cost and mass density. This work suggests the unique hierarchical heterostructure to overcome the trade-off dilemma in alloy cost, mass density, and mechanical properties in room/elevated temperatures.

Effect of Pouring Temperature Variation on Cooling Rate, Hardness and Microstructure of Al-Zn in Aircraft Structures

Al-Zn alloys are widely utilized in industries such as automotive, aircraft manufacturing, and advanced military equipment due to their exceptional strength-to-weight ratio. Among various fabrication methods, metal casting is a commonly used technique for producing structural components from these alloys. However, a significant challenge with metal casting is the reduction in mechanical properties compared to the base material before melting. This reduction highlights the need for research to identify the optimal casting conditions, particularly the casting temperature, which plays a crucial role in maintaining and potentially enhancing the material's mechanical properties. Aluminum alloy 7075, known for its high strength, was selected for investigation. According to the Al-Zn phase diagram, the melting point of aluminum alloy 7075, based on the weight percentage specified by the Standard Aluminum Association, is approximately 660°C. Experiments were conducted by varying the pouring temperature during casting in 30°C increments above this melting point. Specifically, the alloy was melted and cast at three different temperatures: 690°C, 720°C, and 750°C. The mold temperature was consistently maintained at 220°C to isolate the effects of the pouring temperature. Results indicate that increasing the casting temperature significantly affects the alloy's microstructure and mechanical properties. As the casting temperature increases, the cooling rate decreases, leading to a finer grain structure. This finer grain size directly contributes to an increase in hardness, suggesting that higher casting temperatures can enhance the mechanical properties of Al-Zn alloys. These findings emphasize the importance of precise control over casting temperatures to optimize the performance characteristics of aluminum alloy 7075 in high-strength applications.

The interpretable descriptors for fatigue performance of wrought aluminum alloys

Aluminum alloys are extensively utilized in the transportation and aerospace industries due to their excellent processability and corrosion resistance. A key aspect affecting the application of aluminum alloys is fatigue failure, with fatigue strength constituting an essential indicator for assessing the failure mode. In this study, 859 data sets were collected to evaluate the effects of aluminum alloy composition and mechanical properties on fatigue strength. To comprehensively evaluate the features that exert a great influence on the fatigue strength of wrought aluminum alloys, atomic physical quantities of aluminum alloys were added to the original data set. To improve the computational efficiency and physical interpretability of the model, Spearman correlation analysis, optimal subset method, and other methods were used to perform feature selection on the atomic feature quantities and mechanical properties in the data set. Finally, a mathematical relationship between material descriptors and fatigue strength was established based on the alloy composition and the three most relevant features in the feature screening, which helps to better understand and predict the fatigue behavior of wrought aluminum alloys.

Metastable phase transformations and mechanical properties of an as-extruded TiAl-based alloy during two-step heat treatment

Metastable phase transformations of TiAl-based alloys provide a pathway for grain refinement and performance improvement. In this paper, the microstructure evolution of an as-extruded Ti-47Al-2Cr-0.2Mo alloy during quenching and tempering was investigated by scanning electron microscope (SEM), electron backscatter diffraction (EBSD) and transmission electron microscope (TEM), and the mechanical properties of the alloy were further evaluated by tensile tests. The results indicated that the analogous Σ3 coincidence site lattice (CSL) and γ/γ true twin interface appeared in both the Widmanstätten structure (γw) and feathery structure (γf), implying that sympathetic nucleation mechanism was responsible for the nucleation of the metastable phases. A 6 H intermediate phase with the long period stacking ordered structure (LPSO) was discovered after short-term water quenching, which provided an evidence supplement of the sympathetic nucleation mechanism. The transformation path of the metastable γw phase was proposed to follow the sequence of α/α2→6 H→γ. Apparent refinements of both grains and α2/γ lamellar colonies ((α2+γ)L) were exhibited after metastable phase transformation. The ultimate tensile strengths of the heat-treated alloy at whether room temperature (RT) or 800 °C were obviously improved, and the elongation at RT also kept at a considerable level.

Effect of drawing deformation on microstructure and mechanical properties of Fe-Cr-Co-W alloy

The mechanical properties of strain gauge wire are intricately linked to the process of drawing deformation, playing a pivotal role in the performance of associated sensors. This study delves into the impact of varying degrees of drawing deformation on both the mechanical properties and microstructure of FeCrCoW strain gauge alloy wires. Through a comprehensive analysis of tensile testing, XRD, SEM, and TEM, a detailed and systematic exploration was conducted on the influence of different tensile deformation variables on the mechanical properties of alloys, while also exploring fracture mechanisms. The research results showed that the yield strength and fracture strength of FeCrCoW alloy gradually increase with the tensile deformation raising, while the fracture strain and work hardening rate gradually decrease. Advanced TEM investigations have elucidated that the phenomenon of grain refinement and the concomitant rise in dislocation density within the alloy escalates markedly with escalating levels of drawing deformation. This enhanced microstructural evolution is posited as the principal driver linking the alloy's mechanical properties to the magnitude of deformation experienced. Concurrently, the dynamic interplay between tungsten (W)-rich nanoparticles and the alloy's dislocations during the drawing process is identified as a significant contributor to the observed alterations in mechanical behavior. The synergistic effects of these microstructural changes are likely responsible for the nuanced shifts in the alloy's mechanical attributes.

Effect of welding current on the mechanical properties of Al 5083 alloy processed using high-current gas metal arc welding

This study investigated the effect of welding current during gas metal arc welding (GMAW) on the microstructure and composition of an Al 5083 alloy. As the welding current increased from 650 to 950 A, several changes were observed in the heat-affected zone (HAZ): grain coarsening and the formation of liquation cracks, and in the weld zone (WZ): increasing average secondary arm spacing and Mg loss. Therefore, the welding currents above 800 A are likely to cause liquation cracks in the HAZ and deterioration of the alloy's mechanical properties. Thus, welding condition with low heat input must be applied to improve the mechanical properties of the welds. This study provides a correlation between the weldability of Al 5083 alloy and welding current, offering a competitive advantage of liquid hydrogen storage containers.

Fracture behaviors and microstructure evolution of an Al–Mg–Mn-Sc-Zr alloy at elevated and cryogenic temperature

The mechanical properties and fracture behavior of Al-5.8Mg-0.4Mn-0.25Sc-0.1Zr alloy were investigated across cryogenic temperatures (−196.15 °C ∼ −56.15 °C) and elevated temperature (room temperature ∼ 250 °C), with results indicating sensitivity of the alloy's mechanical properties to temperature. Firstly, the tensile test at elevated temperatures shows a decrease in strength and strain hardening exponent (n) due to thermal softening effects, while elongation increases and then decreases, peaking at 100 °C. Within the temperature range of −196.15 °C ∼ −56.15 °C, the yield stress (YS), ultimate tensile strength (UTS), and ductility tend to increase with the decreasing temperature gradually, which can be attributed to the decrease in lattice thermal vibration energy at low temperatures, resulting in an elevated external force requirement for dislocation motion. Meanwhile, throughout the entire high-temperature range, the alloy exhibits ductile fracture, with the number of dimples peaking at 100 °C. Differently, when the alloy is deformed at low temperatures, dislocations tend to accumulate within the grains, and with the grain boundaries acting as weak bonding areas between grains and experiencing significant stress concentration, the fracture mechanism gradually transitions from transgranular to intergranular fracture. Microstructural analysis at low temperatures shows minimal texture content changes, while at elevated temperatures, regular changes in texture components occur due to grain orientation rearrangement. Furthermore, high-resolution transmission electron microscopy was employed to investigate the evolution of precipitates at various temperatures, and the results shows that uniform and fine Al3(Sc1−x, Zrx) precipitates are distributed within the crystal, acting as effective dislocation pinning sites and leading to a uniform intragranular dislocation arrangement after tensile test at cryogenic temperature. Notably, after tensile test at higher temperatures, a few precipitates lose coherency with the matrix and started growing, which diminishing grain boundary pinning effect and promoting recrystallization.

A strategy for high-entropy copper alloys composition design assisted by deep learning based on data reconstruction and network structure optimization

Complex mapping relationships between high-entropy alloy compositions and performances struggle to precisely elucidate by traditional machine learning models, hindering the accurate and efficient design of high-performance alloys. In this work, a novel alloy design strategy combined self-decision deep neural network, data reconstruction with network structure optimization was proposed, which effectively enhanced the model's ability to predict the mapping relationships between high-dimensional composition spaces and mechanical properties of alloy. Compared to other machine learning methods, significantly improves model prediction accuracy (hardness model: 97.98%; strength model: 94.40%). Through above model, the mechanical properties of 308 new (CuNiMn)-X high-entropy copper alloys was studied added other elements such as Al, Ti, Cr, and Fe, which designed and produced a novel (CuNiMn)60Al20Cr20 alloy with high hardness of 474 HV, high compressive strength of 2322 MPa, and high fracture strain of 25.20%. The primary factors influencing alloy performance and their respective thresholds were also quantitatively revealed (hardness: electronegativity deviation (0.02, 0.1) and nuclear charge deviation (0, 0.25); compressive strength: mean nuclear charge (25, 30) and mean atomic radius (134 p.m.)). These findings provide a new perspective and approach for the design and mechanism understanding of high-performance alloys with complex compositions.

Effect of elastic strain energy on precipitation process of Co81Al5V14 alloy based on microscopic phase field method

The L12 phase volume fraction, size, microstructure significantly influences alloy's important physical and mechanical properties in Co-Al-V superalloy. Based on microscopic phase field method and microelasticity theory, precipitation of ordered L12 phase in Co81Al5V14 alloy were studied. The results indicate that precipitation sequence of Co81Al5V14 alloy is minimally influenced by elastic strain energy and precipitation sequence can be divided into four stages. Elastic strain energy does not significantly affect incubation period of alloy, but it does promote the formation of transitional ordered phase L10 with a single orientation and facilitates precipitation of ordered phase L12. Elastic strain energy causes precipitates to grow and coarsen along specific elastic "soft" direction ([100] and [001]). Elastic strain energy promotes process of ordering and atomic occupancy of the alloy. The effects of elastic strain energy on precipitation mechanism, microstructure and atomic occupancy are discussed in this work, which provides theoretical guidance for the design of Co-Al-V alloys with better properties.