Laser Additive Manufacturing Research Articles

Design and coherent strengthening of ultra-high strength refractory high entropy alloys based on laser additive manufacturing

The WNbMoTa-based refractory high entropy alloy (RHEA) is expected to become a new generation of high-temperature materials due to its high thermal stability, which can be used in aerospace, nuclear energy and other fields. In this paper, TN10 (TN is the abbreviation of Ti and Ni elements), TN15, TN20 and TN25 non-equimolar WNbMoTa-based RHEAs were designed based on phase engineering and formed by laser powder bed fusion (LPBF) technology. The solidification thermodynamics, microstructure and mechanical properties (compressive strength at 25 °C) of the four alloys were analyzed, and the strengthening mechanism of TN20 alloy was studied. The compressive yield strength of the four alloys exceeds 2050 MPa, the ultimate compressive strength exceeds 2550 MPa, and the elongation exceeds 9%. The compressive yield strength of TN20 alloy is 2513 MPa, the ultimate strength is 3127 MPa, and the elongation is 11.38%. The room temperature (25 °C) compressive yield strength of TN20 alloy is the highest among the high entropy alloys studied so far. TN20 alloy is composed of BCC matrix phase and grain boundary phase containing three different structures, which are B2 TiNi phase, Ni55Nb25Ti15Ta5 phase generating stacking faults and Ni70Ti20Nb10 secondary precipitated phase. The micrometer matrix phase and nanometer grain boundary phase of TN20 alloy show a network distribution in fine crystal region. After the matrix phase cracks due to high thermal stress, the flow TiNi-rich grain boundary phases precipitate to fill the cracks. The grain boundary phase with high proportion in this region is enhanced by the secondary phase and its nanoprecipitated phase. In other regions, stacking faults are generated by the Ni55Nb25Ti15Ta5 phases, which convert the thermal stress that induces crack into lattice defects of the crystal. On the other hand, the content of B2 phase is the highest in grain boundary phase, and the grain boundary between B2 phase and matrix phase is a coherent grain boundary, which realizes the high quality combination of grain boundary phase and matrix phase. The design and strengthening of WNbMoTa-based non-equimolar RHEAs are studied in this paper, which is expected to provide a reference for the design of a new generation of high entropy alloy.

Constructing process maps for pulsed wave laser additive manufacturing with interpretable machine learning

Oxide dispersion strengthened (ODS) steels have found increasing applications in advanced fission and fusion reactors due to their excellent strength and resistance to radiation damage. The traditional powder metallurgy (PM) methods for fabricating ODS steels are costly and time-consuming. To address these limitations, attempts have been made to fabricate ODS steels with emerging additive manufacturing (AM) technology, such as laser powder bed fusion (L-PBF). However, up to now, the AM-fabricated ODS steels have not been able to match the quality of those from the conventional PM processes. In this work, we explore pulsed wave (PW) laser AM, as opposed to the conventional single mode continuous wave (CW) laser AM, for ODS steel fabrication. In particular, based on available experimental data of PW laser fabricated ODS steel parts, we construct a two-dimensional (2D) process map using two PW features (engineered using operating parameters) to define and visualize the parameter space that is directly linked to the quality assessment of the parts. Additional process maps are constructed to quantitatively model the density and nano-hardness of the parts. These process maps are constructed through rational feature engineering, supervised feature selection, and interpretable machine learning techniques. The constructed process maps for quality classification, density and nano-hardness regression analyses are validated by experiments. The process maps help us further understand the physical phenomena that produce good or bad quality parts.

Origin of hot cracking formation and suppression method in laser additive manufactured nickel-based superalloys

Although laser additive manufacturing is a promising technique for fabricating nickel-based single crystal superalloy components, reducing hot cracking during the deposition is still a challenge. In this study, the cracking susceptibility and microstructures with different substrates are investigated. Results show that samples exhibit much lower cracking susceptibility when using the directional solidified substrates than the cast polycrystalline substrates. Hot cracking is attributed to a stable liquid film dependent on the misorientation angle. Besides, liquation cracking first occurs in the substrate and could propagate by extension into solidification cracks along the high angle grain boundaries. Based on these findings, a crack-free nickel-based superalloy with a polycrystalline substrate is successfully prepared using a continuous scanning strategy.

Ultrafine-bubble-water-promoted nanoceramic decoration of metal powders for additive manufacturing

The design of composite powders for exploiting the multifunctionality of metallic nanocomposites via laser additive manufacturing (AM) is challenging. Conventional ball-milling processes are prone to cause uncontrollable powder morphology and reduced flowability, while recently developed nanodecoration technologies are limited by complicated processing and impurity inclusion. Herein, a facile and scalable approach was developed using ultrafine bubble (UFB)-assisted heteroagglomeration to fabricate high-concentration, impurity-free nanoceramic/metal composite powders. Individual ZrO2 or Al2O3 nanoparticles up to ~10 wt% were homogeneously decorated on the surface of Ti-6Al-4V powders through the bridging effect of the negatively charged UFBs, leading to enhanced flowability and laser absorptivity. The nanoceramics were completely decomposed and dissolved into the matrix upon laser irradiation; therefore, a unique Ti nanocomposite exhibiting both high strength and ductility was obtained. Our work provides new insights into the application of UFBs and the fabrication of multifunctional AM components.

Enhancement of Microstructure and Mechanical Properties of High Nb-TiAl Alloys Prepared Using Laser Additive Manufacturing by Annealing Treatment

The microstructure, phase composition, hardness, and tensile properties of the Ti-48Al-2Cr-5Nb alloy have been systematically investigated using laser additive manufacturing technology. Results indicate that both the as-deposited and annealed microstructures contain both the α2 (Ti3Al) and γ (TiAl) phases. As the annealing temperature increased, the structure changed significantly from a large block structure to a fine equiaxed structure and finally to a large lamellar structure. Nevertheless, the amount and distribution of precipitation of α2 phase are obviously different, especially during the annealing at 1260 °C, where the fine α2 phases are evenly distributed on the γ phase matrix. The hardness value of the as-deposited sample is the highest, with a HV value of 484 at the room temperature, while the hardness value of the annealed sample at 1260 °C is the smallest, with a HV value of 344. An annealed sample at 1260 °C exhibits the highest tensile strength and elongation at room temperature, with values of 598 MPa and 2.1%, respectively. These values are increased by 1.15 times and 1.4 times compared to the as-deposited sample (519 MPa, 1.5%).

Study on the Properties of Iron-based Alloys 17-4PH Powder Manufactured by Laser Additive Manufacturing

Background: Laser additive manufacturing has been used for surface repair and remanufacturing due to fast laser processing speed, high energy density, and dense microstructure. However, the properties of coating samples produced by laser additive manufacturing of ironbased alloys vary considerably, resulting in a large amount of data that needs to be accumulated and analyzed. Methods: The coating properties of iron-based alloy powders manufactured by laser cladding are studied. The optimal process parameters of the laser cladding are determined by exploring and comparing the macroscopic appearance, hardness, and conductivity of the junction of the cladding. Results: From the macroscopic appearance, when the ratio of the height to the width of the cladding layer is 3.615, the surface of the cladding layer has a smooth surface and is closely combined with the substrate. Conclusions: The hardness of the cladding layer is found to increase significantly, with an average hardness of 663 HV. Besides, it is found that the blackhead's hole causes the conductivity change. The ratio of the largest hole area to the smallest hole area is 8.29 times, and the depth ratio is 1.91 times, but the average resistance ratio is about 1.6 times.

Microstructure and mechanical properties of 2319 aluminum alloy deposited by laser and cold metal transfer hybrid additive manufacturing

Wire and arc additively manufactured aluminum alloys are prone to porosity, leading to poor mechanical properties in samples, which hinders their broad industrial application. Laser and arc hybrid processes have garnered increasing attention for their potential to reduce porosity, stabilize the arc, and enhance deposition efficiency. This paper investigates the porosity, element distribution, microstructure evolution, and mechanical properties of 2319 aluminum alloy produced through the laser and cold metal transfer (laser-CMT) hybrid additive manufacturing process. In comparison with the as-deposited samples, the laser-CMT hybrid process decreases porosity, enhances element distribution, mitigates Cu element segregation, and results in increased θ′′ phase precipitation. Following T6 heat treatment, the ultimate tensile strength (UTS), yield strength (YS), and elongation of the x-direction specimens from the laser-CMT hybrid process are 450.0 MPa, 318.1 MPa, and 10.0%, respectively. These values are 11.27%, 7.03%, and 36.65% higher than those of the as-deposited samples. To validate the findings, a large-scale load-carrying frame for a commercial aircraft was fabricated, demonstrating the efficacy of the process. The paper also presents a detailed analysis of the strengthening mechanism. Samples deposited using the laser-CMT method exhibit reduced porosity and excellent mechanical properties, making this process promising for a wide range of applications.

High specific yield strength and superior ductility of a lightweight refractory high-entropy alloy prepared by laser additive manufacturing

High specific yield strength and superior ductility of a lightweight refractory high-entropy alloy prepared by laser additive manufacturing

Laser additive manufacturing of new α+β titanium alloy with high strength and ductility

The capability to control volume fraction and morphology of α phase in α+β titanium alloys makes this group of alloys a suitable choice to develop new compositions to deal with the formidable requirement of industrial development. However, further alloying is challenged because of the difficulty of uniform mixing during the melting process and the severe segregation during solidification. Due to the intense convection within small melt pool, additive manufacturing (AM) can achieve uniform concentration distribution and thus is a perfect alloying strategy to exert the potential of more species of alloying elements. To fulfil the potential of alloying, an α+β titanium alloy with new composition was additively manufactured in this study by laser directed energy deposition (LDED). The as-deposited new α+β titanium alloy exhibited near equiaxed prior β grains and intragranular ultrafine basket-weave microstructure in which the thickness of α lath is 0.4 ± 0.1 μm. A fibrous root morphology of primary α (αp) whose thickness is 1.4 ± 0.2 μm formed by macroscopic diffusion in the subsequent annealing process and this special morphology is the main reason of the improvement of ductility. With the aid of this special morphology and the nucleation of fine secondary α (αs), the ultimate tensile strength (UTS) and ductility can reach 1247±3 MPa and 9.2 ± 0.2%. The achievement of high strength and good ductility indicates that the development of new titanium alloys is suitable for AM and thus could be the future direction for titanium alloys research.

Optimizing process for pulsed laser additive manufacturing of nickel-based single crystal superalloy

The relationship between pulsed laser processing parameters and epitaxial growth of alloy is essential to additive manufacturing technology in repairing and manufacturing nickel-based single crystal (SX) superalloys. In this paper, orthogonal experiments of Laser Direct Energy Deposition (DED-L) process have been designed to optimize the process for the epitaxial growth of the SX superalloy. The relationship between process parameters and epitaxial growth of SX superalloy is established in a radar map, which shows that low laser power, pulse width and powder feeding rate help epitaxial growth in the DED-L process. It is implied that increasing the powder feeding rate value in the process range decreases the epitaxial growth rate of the molten pool and increases manufacturing efficiency. The size of the cladding layer width is greatly influenced by laser power (reached 44%) and pulse width (reached 38%). The deposited heigh of the cladding layer is mainly influenced by pulse width (reached 45%) and powder feeding rate (reached 42%). The process parameters have a similar level (approximately 33%) of influence on the powder using efficiency.

Laser-directed energy deposition of ZrH2 particles reinforced Al7075 alloy: Cracks elimination and strength enhancement

Metal-based laser additive manufacturing, particularly Laser-Directed Energy Deposition (LDED), holds great promise for producing high-strength aluminum alloy components used in industries such as automotive manufacturing, aerospace, and biomedicine. However, achieving defect-free and superior mechanical strength in high-strength aluminum alloys, especially 7XXX series Al alloys, through LDED remains challenging. In this study, the LDED of ZrH2 particles reinforced Al7075 alloy was investigated. Results indicated that the addition of ZrH2 particles to the Al7075 alloy facilitated the columnar-to-equiaxed transition and effectively prevented hot-crack formation during the solidification process, leading to a crack-free and fine equiaxed-grain microstructure. The as-deposited Zr-modified Al7075 alloy demonstrated a favorable combination of strength and ductility, a yield strength of 266 MPa, a strength of 321 MPa, and an elongation of 21.0% in the Al7075–3%ZrH2 sample, which represents promising performance among the reported LDED-fabricated Al alloys. Contributions of four different strengthening mechanisms to yield strength were calculated, showing that the introduction of ZrH2 particles highlighted the effects of grain refinement and geometrically necessary dislocation strengthening. Moreover, the grain reinforcement mechanism in the Al7075 alloy with ZrH2 particles reinforced was elucidated after adequate material characterizations including SEM, EDS, TEM, and XRD. Needle-like Al3Zr and angular-like Al3Zr were observed in the equiaxed and ultrafine grain regions of the LDED-fabricated Al7075–3%ZrH2 samples, corroborating the truth that Al3Zr serves as heterogeneous nucleation sites during the solidification and plays a significant role in grain refinement. The successful manufacturing of crack-free, equiaxed high-strength 7XXX series Al alloys lays the foundation for LDED production of high-strength aluminum engineering components.

Assessment of self-lubricating coated cutting tools fabricated by laser additive manufacturing technology for friction-reduction

Dry cutting acting as a green machining technology is a promising manufacturing process in industrial applications; however, severe friction under dry cutting conditions aggravates tool wear and reduces tool life. Self-lubricating cutting tools exhibit excellent benefits in improving cutting properties and that can be used in sustainable machining. The complex process, low efficiency and thin coating thickness limit the production and use of present self-lubricating cutting tools with traditional methods. To enhance the lubricating effect and motivate the development of fabrication methods for self-lubricating cutting tools, Ni-based powders dispersed with MoS2 and Al2O3 particles were preset on the tool substrate; afterward, the self-lubricating coatings were deposited by laser powder-bed fusion additive manufacturing (AM) with a nanosecond fiber laser for cutting application. The self-lubricating coatings were characterized, and the friction and cutting performances of the AM self-lubricating coated tools (SLCs) were evaluated by sliding friction and dry machining tests. The results show that the developed SLC tools reduced the friction coefficient by 8.8–11.7%, cutting forces by 17.6–29.6%, and cutting power by 17.3–22.0% compared to conventional high-speed steel cutting tools (HSS). Built-up edge formation and tool wear were also significantly reduced. The observed mechanisms were attributed to the release of MoS2 particles from the coatings forming a lubricating film at the tool-chip interface, while the Al2O3 particles enhanced surface hardness. The results revealed the practicability of self-lubricating coated cutting tools fabricated by laser-based AM for friction-reduction, and that provide a cleaner process for dry cutting applications.

Laser additively manufactured crack-free aluminum-bearing high entropy alloys: alloy design, synthesis, cracking inhibition and microstructure evolution effects on their tensile properties

ABSTRACT Developing high-performance high-entropy alloys (HEAs) fabricated by laser additive manufacturing (LAM) is the pursuit of the metallic community. In the present work, we designed a series of [(Al6-xNbx)-(FeCoNi)12]Cr3 HEA compositions using a high-entropy alloying strategy based on a cluster-plus-glue-atom model. And their thin-wall-sharped bulks were fabricated by LAM and post-aging treatment. The effects of cracking inhibition and microstructure evolution on the tensile properties were researched in detail. The results show that as the Nb substitutes for Al atoms, the cracking behaviour is ameliorated, ascribed to the tiny Laves phase refined the dendrite spacings and back-filled in the inter-dendritic liquid film. Also, introducing Nb atoms improves the strength but deteriorates the ductility. Significantly, the Nb4 HEA possesses the best tensile-property combination (i.e. σs ∼ 419.2 MPa, σb ∼ 787.4 MPa, and δ ∼ 15.5%) with a strain mechanism of dislocation slip mode. After post-aging for 72 h, the microstructure comprises fully recrystallized equiaxed FCC grains and many tiny needle-like D019 precipitates, leading to high strength and sufficient ductility (i.e. σ0.2 ∼ 535.9 MPa, σb ∼820 MPa and δ value of 8.9%). These findings provide a new paradigm for the LAM of crack-free HEAs with excellent mechanical properties.

Microstructure and Performance Research on Ceramic-Enhanced Inconel 718 Matrix Composite Using Laser Additive Manufacturing

This article presents a 95% IN718 + 5% (75% Cr2O3 + TiO2) ceramic coating on the SS316L substrate surface with laser additives. The macro shape, phase, microstructure, interface, wear resistance and tensile resistance of metal base composite materials are analyzed. The results show that metal matrix composite (MMC) laminated composite materials have good microscopic hardness and wear resistance compared to single materials. Comparative analyses with single IN718 materials indicate that the laminated composite materials exhibit superior microscopic hardness and wear resistance. Additionally, the study reveals a positive correlation between material hardness and wear resistance, characterized by reduced wear coefficient and average abrasion with increased material hardness. The findings of this research offer a cost-effective and practical method for producing high-resistance coating layer composite materials.

Shock-compression microstructure transformation of the additive manufactured FeCoNiAlTi high-entropy alloy

Investigation into the microstructural deformation mechanisms of a high-entropy alloy (Fe28.0Co29.5Ni27.5Al8.5Ti6.5 (at%)) prepared by laser additive manufacturing and aging treatment, with a three-phase nanocomposite structure, is carried out via shock compression experiments using plate impact. Microstructural characteristics and compositions are inspected using X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. The microstructure of the high-entropy alloy is comprised of high-density dislocation structures, high-volume-fraction L12 nano-precipitates, a small amount of L21 nano-precipitates, and face-centered cubic (FCC) matrix phases. The lattice arrangement of the FCC matrix phase is disordered, with strong segregation of Fe and Co atoms, while Ni, Al, and Ti atoms are predominantly present in the ordered L12 and L21 nano-precipitates. The FCC matrix or the FCC matrix with high-density stacking faults are bounded by a 9R-phase between two phase boundaries. The mechanisms of microstructural transformation of the high-entropy alloy are discussed in detail.

Enhanced strength-ductility synergy of laser additive manufactured stainless steel/Ni-based superalloy dissimilar materials characterized by bionic mechanical interlocking structures

The unique mechanism of toughness enhancement found in natural materials has served as inspiration for the development of a new generation of dissimilar metal materials (DMMs). Here we present a bionic mechanical interlocking structure strategy that stainless steel 316L and Inconel 625 DMMs with an enhanced strength-conductivity trade-off processed by laser additive manufacturing (AM), possessing an ultimate tensile strength of 675.64 MPa, and a uniform elongation of 33.6%. The incompatible deformation between SS316L (plastic deformation) and IN625 (non-deformation) contributes to overcoming the strength-ductility trade-off. The integration of alternating soft and hard non-uniform structures plays a pivotal role in effectively absorbing and dissipating the energy introduced by external loads during crack propagation. This geometric arrangement and multilevel structure at the interface notably reduces the effective stress intensity factor along the crack path, leading to added resistance against loading. The multi-strengthening mechanism coupled with the heterogeneous deformability gives the material excellent strength-ductility synergy, especially the bionic mechanical interlocking structure extending the crack expansion path, which helps to avoid premature failure of weak interface layers. These findings will provide new insights into the controlled design of high-performance DMMs, which highlights the potential to inherit merits from constitutive materials for better strength-ductility combinations.

Optimization of Process Parameters and Mechanical Properties of 316L Stainless Steel Block via Arc Additive Manufacturing

_ A study was conducted on the influence of current, spacing, current mode, and arc length on the formation of adjacent weld overlays in the 316L stainless steel block melting process using an extremely inert gas-shielded arc additive manufacturing method. The main defect observed during the formation of adjacent weld overlays was the incomplete fusion at the bottom. When using direct current, low current and short arc length could ensure the flatness of the overlay surface, and the fusion at the bottom of the adjacent weld overlays was improved, but the problem of incomplete fusion remained unresolved. When using pulse current, low current, short arc length, and continuous welding method could solve the problem of bottom fusion of adjacent weld overlays. Due to the thermal influence during the accumulation of adjacent weld overlays, the microstructure inside the weld overlay was uneven, and the crystallographic texture in the entire weld overlay was not formed. With a pulse current of 80 A, adjacent weld overlay spacing of 4.5 mm, travel speed of 200 mm/min, dry elongation of 10 mm, and arc length of 2 mm, the tensile strengths of the block in the X, Y, and Z directions were 568.5, 570.3, and 550.7 MPa, respectively, and the fracture elongations were 46%, 48%, and 43.3%, respectively. The strength and plasticity in the Z-direction were lower than those in the X and Y directions. Keywords 316L stainless steel; arc additive manufacturing; incomplete fusion; pulse current

Influence of intrinsic manufacturing defects on corrosion behavior of AISI 420 stainless steel fabricated by laser powder bed fusion

In this study, 420 stainless steel (SS) was fabricated by L-PBF with specific processing parameters: 140 W laser power, 550 mm/s scanning speed, 80 μm spot size, and 50 μm layer thickness. The resulting specimens exhibited 0.42% porosity and an average size of 18 μm for Lack-of-fusion (LOF) pores, with elemental C and Cr ablation at approximately 35.9% and 18.0%, respectively. A comparative analysis between the corrosion resistance of L-PBF specimens and cast 420 SS was conducted. Despite exhibiting extraordinary mechanical properties, L-PBF specimen displayed lower corrosion resistance and failed to produce a passive region. LOF pores and elemental ablation from intrinsic laser additive manufacturing process were the primary reasons for this outcome. Two distinct corrosion mechanisms were observed in the study. The LOF pores exhibited a higher susceptibility to pitting corrosion, leading to the formation of larger pitting pits with an approximate size of 100 μm. Conversely, the LOF-free areas displayed the presence of smaller pitting nucleation, measuring < 2 μm. This observation was attributed to the ablation of C element, leading to a 28% increase in the Cr/C content. The higher Cr/C in the LOF-free areas offered enhanced protection, thus preventing the formation of larger pitting pits in these regions.

A state-of-the-art digital factory integrating digital twin for laser additive and subtractive manufacturing processes

PurposeThis study aims to discuss the state-of-the-art digital factory (DF) development combining digital twins (DTs), sensing devices, laser additive manufacturing (LAM) and subtractive manufacturing (SM) processes. The current shortcomings and outlook of the DF also have been highlighted. A DF is a state-of-the-art manufacturing facility that uses innovative technologies, including automation, artificial intelligence (AI), the Internet of Things, additive manufacturing (AM), SM, hybrid manufacturing (HM), sensors for real-time feedback and control, and a DT, to streamline and improve manufacturing operations.Design/methodology/approachThis study presents a novel perspective on DF development using laser-based AM, SM, sensors and DTs. Recent developments in laser-based AM, SM, sensors and DTs have been compiled. This study has been developed using systematic reviews and meta-analyses (PRISMA) guidelines, discussing literature on the DTs for laser-based AM, particularly laser powder bed fusion and direct energy deposition, in-situ monitoring and control equipment, SM and HM. The principal goal of this study is to highlight the aspects of DF and its development using existing techniques.FindingsA comprehensive literature review finds a substantial lack of complete techniques that incorporate cyber-physical systems, advanced data analytics, AI, standardized interoperability, human–machine cooperation and scalable adaptability. The suggested DF effectively fills this void by integrating cyber-physical system components, including DT, AM, SM and sensors into the manufacturing process. Using sophisticated data analytics and AI algorithms, the DF facilitates real-time data analysis, predictive maintenance, quality control and optimal resource allocation. In addition, the suggested DF ensures interoperability between diverse devices and systems by emphasizing standardized communication protocols and interfaces. The modular and adaptable architecture of the DF enables scalability and adaptation, allowing for rapid reaction to market conditions.Originality/valueBased on the need of DF, this review presents a comprehensive approach to DF development using DTs, sensing devices, LAM and SM processes and provides current progress in this domain.

Crevice corrosion behavior and mechanism of laser additive manufacturing nickel-based alloy under wedge-shaped crevice by using wire beam electrode

PurposeThe purpose of this study is to investigate the crevice corrosion behavior and mechanism of laser additive manufacturing (LAM) nickel-based alloy under wedge-shaped crevice.Design/methodology/approachFirst, the opening size of the wedge-shaped crevice was designed to 0.1, 0.3 and 0.5 mm by controlling the thickness of silicon rubber and the double-side adhesive tape. Then, one side of the glass sheet was stuck on the silicon strip and keep the electrodes of Rows 1 and 2 outside the crevice as a reference, and the opposite side was stuck to the wire beam electrode by silica gel.FindingsThe current density with a maximum value of 5.7 × 10−6 A/cm2 was observed at the crevice opening of 0.5 mm, while the lowest value of 9.2 × 10−7 A/cm2 was found at the crevice opening of 0.1 mm. In addition, the corrosion resistance at the inside of the crevice is higher than that at the outside and the middle of the crevice. It means that the internal width of the wedge-shaped crevice tends toward 0, which hinders the migration of ions in the corrosive medium. The generation of corrosive products further reduce the crevice size to cause the inhibition of corrosion at the inside of the crevice as well.Originality/valueThe multilayer and multipath LAM component is prepared to show the complex microstructure, which made the corrosion behavior and mechanism at wedge-shaped crevice nondeterminacy.