In this study, a superhydrophobic surface is constructed on an LAZ933 magnesium-lithium (Mg-Li) alloy surface by regulating laser etching power combined with chemical post-treatment. The work focuses on clarifying how laser power affects surface microstructure evolution, wetting behaviors, and corrosion-related performance, providing a controllable strategy for tailoring the surface properties of Mg-Li alloys.
Rolled LAZ933 Mg-Li alloy plates are cut into 20 mm × 20 mm × 2 mm samples, mechanically polished, and cleaned prior to laser processing. Surface microstructures are fabricated with an infrared nanosecond laser system (DL-TG-IRF-30, Delphilaser, China) with a wavelength of 1 064 nm. During laser texturing, the scanning speed (100 mm/s), scanning interval (100 μm), and pulse frequency (20 kHz) are kept constant, while the laser etching power is varied from 6 to 12 W to investigate its influence on surface morphology and wettability. After laser processing, the samples are ultrasonically cleaned in anhydrous ethanol, dried, and subsequently etched in hydrochloric acid under fixed concentration and time conditions to further refine the surface structures. The etched samples are then modified in a 0.25 mol/L stearic acid ethanol solution at room temperature for 1 h to reduce surface energy. Surface morphology and three-dimensional topography are characterized by field-emission scanning electron microscopy (FESEM) and laser scanning confocal microscopy (LSCM), providing detailed microstructural features and surface roughness information. Wettability is evaluated by contact angle (CA) and sliding angle (SA) measurements, with 8 μL water droplets tested at five different positions on each sample. Surface chemical composition and functional groups are analyzed by energy-dispersive spectroscopy (EDS) and Fourier transform infrared spectroscopy (FTIR). Electrochemical performance is assessed by potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) in a 3.5wt.% NaCl solution with a standard three-electrode system. Corrosion parameters, including corrosion potential and corrosion current density, are determined by Tafel extrapolation and impedance fitting.
The results show that laser etching power plays a decisive role in determining surface microstructure and wetting behaviors. At low laser powers, insufficient surface roughness results in limited hydrophobicity, whereas excessive laser power causes partial melting and structural damage, deteriorating surface performance. An optimal laser etching power of 9 W enables the formation of uniform microstructures, which evolve into hierarchical micro-nano features after acid etching. Following stearic acid modification, the surface exhibits a stable superhydrophobic state with a maximum contact angle of 159.4° and a sliding angle of 4.6°. Chemical analyses confirm that the wetting transition from hydrophilicity to superhydrophobicity is resulted from the combined effects of laser-induced hierarchical structures and low-surface-energy modification. Electrochemical measurements indicate that the superhydrophobic surface prepared at 9 W conforms to the Cassie-Baxter wetting model and exhibits significantly enhanced corrosion resistance. Compared with the smooth Mg-Li alloy substrate, the corrosion potential shifts positively by 0.29 V, the corrosion current density decreases by approximately two orders of magnitude, and the corrosion inhibition efficiency reaches 98.8%. Durability tests, including ultrasonic vibration wear, thermal annealing, and long-term atmospheric exposure, demonstrate that the superhydrophobic surface maintains stable wettability and functional performance. This study confirms that laser power modulation is an effective and reliable approach for controlling surface wettability and improving the comprehensive performance of superhydrophobic Mg-Li alloy surfaces, offering practical guidance for surface engineering and corrosion protection of lightweight metallic materials.
Key words
Mg-Li alloy /
superhydrophobic surface /
laser power /
durability /
thermal stability /
wear resistance
{{custom_sec.title}}
{{custom_sec.title}}
{{custom_sec.content}}
References
[1] KHAN M A, USMAN M, ZHAO Y H.First Principles Calculations for Corrosion in Mg-Li-Al Alloys with Focus on Corrosion Resistance: A Comprehensive Review[J]. Computers, Materials & Continua, 2024, 81(2): 1905-1952.
[2] ZHENG H, LIU X M, HAO X M, et al.Effects of Friction Surfacing on Microstructure and Properties of LA103Z Magnesium-Lithium Alloys[J]. Advanced Engineering Materials, 2025, 27(21): e202501342.
[3] MA Y L, LIU L, ZHANG X X, et al.Effect of Air- Formed Film on Corrosion Behavior of Magnesium-Lithium Alloys[J]. Journal of Magnesium and Alloys, 2023, 11(11): 4325-4337.
[4] WANG Y C, LIU B Y, ZHAO X A, et al.Turning a Native or Corroded Mg Alloy Surface into an Anti-Corrosion Coating in Excited CO2[J]. Nature Communications, 2018, 9: 4058.
[5] WANG X J, XU D K, WU R Z, et al.What Is Going on in Magnesium Alloys[J]. Journal of Materials Science & Technology, 2018, 34(2): 245-247.
[6] WANG Y F, LIU C M, LI H Z, et al.Corrosion Behavior of ZrO2-Incorporated PEO Coatings on Magnesium-Lithium Alloy: Parameter Optimization and Stress-Induced Phase Transformation[J]. Journal of Materials Research and Technology, 2025, 39: 2704-2717.
[7] OUYANG Y B, GUO E Y, CHEN X B, et al.Recent Progress in Protective Coatings Against Corrosion Upon Magnesium-Lithium Alloys: A Critical Review[J]. Journal of Magnesium and Alloys, 2024, 12(10): 3967-3995.
[8] ZHANG Y, ZHANG Z T, YANG J L, et al.A Review of Recent Advances in Superhydrophobic Surfaces and Their Applications in Drag Reduction and Heat Transfer[J]. Nanomaterials, 2022, 12(1): 44.
[9] KUMAR V, BHAUMIK S, MAJUMDER A.Synergistic Effect of Thermal Annealing and Metal-Fatty Acid Coordination on the Formation of Superhydrophobic, Corrosion- Resistant Surfaces[J]. Surface and Coatings Technology, 2025, 518: 132916.
[10] LUO J Y.Preparation of Superhydrophobic Corrosion- Resistant Surface by Etching Method[J]. Journal of Materials Engineering and Performance, 2026, 35(14): 13633-13645.
[11] WEI J F, LI B C, JING L Y, et al.Efficient Protection of Mg Alloy Enabled by Combination of a Conventional Anti-Corrosion Coating and a Superamphiphobic Coating[J]. Chemical Engineering Journal, 2020, 390: 124562.
[12] LI W Y, YANG H M, XUE S, et al.A Simple Strategy towards Construction of Fluorine-Free Superhydrophobic Aluminum Alloy Surfaces: Self-Cleaning, Anti-Corrosion and Anti-Frost[J]. Applied Physics A, 2022, 128(7): 626.
[13] ZHENG W W, TENG L, LAI Y K, et al.Magnetic Responsive and Flexible Composite Superhydrophobic Photothermal Film for Passive Anti-Icing/Active Deicing[J]. Chemical Engineering Journal, 2022, 427: 130922.
[14] JISHNU A, S JAYAN J, SARITHA A, et al. Superhydrophobic Graphene-Based Materials with Self- Cleaning and Anticorrosion Performance: An Appraisal of Neoteric Advancement and Future Perspectives[J]. Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2020, 606: 125395.
[15] YONG J L, YANG Q, GUO C L, et al.A Review of Femtosecond Laser-Structured Superhydrophobic or Underwater Superoleophobic Porous Surfaces/Materials for Efficient Oil/Water Separation[J]. RSC Advances, 2019, 9(22): 12470-12495.
[16] GAO S W, HUANG J Y, LI S H, et al.Facile Construction of Robust Fluorine-Free Superhydrophobic TiO2@fabrics with Excellent Anti-Fouling, Water-Oil Separation and UV-Protective Properties[J]. Materials & Design, 2017, 128: 1-8.
[17] WEI D S, WANG J G, LIU Y, et al.Controllable Superhydrophobic Surfaces with Tunable Adhesion on Mg Alloys by a Simple Etching Method and Its Corrosion Inhibition Performance[J]. Chemical Engineering Journal, 2021, 404: 126444.
[18] BARTHWAL S, BARTHWAL S.Engineering a Robust, Multifunctional Superhydrophobic/Oleophobic Microporous Aluminum Surface via a Two-Step Chemical Etching Process[J]. Surfaces and Interfaces, 2024, 46: 103933.
[19] ZHOU D S, CHEN Y F, BAI Z H, et al.Study on the Preparation and Properties of Superhydrophobic Mg-Li Alloy Surface via Composite Etching Method[J]. Materials Today Communications, 2026, 51: 114687.
[20] JIANG C, ZHANG W, WANG M Y, et al.Attaining Superhydrophobic and Superoleophilic Bronze Surface by Picosecond Laser Texturing and Post-Heat Treatment[J]. Optics & Laser Technology, 2024, 177: 111139.
[21] ZHANG Z H, SRIDHAR S, WEI G Y, et al.A Highly Controlled Fabrication of Porous Anodic Aluminium Oxide Surface with Versatile Features by Spatial Thermo- Anodization[J]. Surface and Coatings Technology, 2021, 408: 126809.
[22] KANG Y X, LI Z L, YAN S F, et al.Optimization of Anodizing Conditions and Hole Sealing Treatments for Enhanced Anti-Corrosion Properties of Magnesium Alloys[J]. Ceramics International, 2024, 50(14): 25667-25678.
[23] ZHANG S J, CAO D L, XU L K, et al.Corrosion Resistance of a Superhydrophobic Dodecyltrimethoxysilane Coating on Magnesium Hydroxide-Pretreated Magnesium Alloy AZ31 by Electrodeposition[J]. Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2021, 625: 126914.
[24] WU Z, LIU Y L, ZHANG Y, et al.The Effect of Micro/ Nanostructures Formed by Laser Ablation on the Superhydrophobicity of AZ31B Magnesium Alloy[J]. Journal of Materials Research, 2024, 39(5): 850-863.
[25] LI D W, WANG H Y, LUO D, et al.Corrosion Resistance Controllable of Biomimetic Superhydrophobic Microstructured Magnesium Alloy by Controlled Adhesion[J]. Surface and Coatings Technology, 2018, 347: 173-180.
[26] YAN P C, HOU Y Y, ZHENG H Y, et al.Ultrafast Laser-Assisted Hybrid Fabrication of Biomimetic Superhydrophobic Surfaces: Strategies, Mechanisms, and Applications[J]. Nanoscale, 2025, 17(37): 21400-21422.
[27] TANG Y P, CAI Y K, WANG L, et al.Formation Mechanism of Superhydrophobicity of Stainless Steel by Laser-Assisted Decomposition of Stearic Acid and Its Corrosion Resistance[J]. Optics & Laser Technology, 2022, 153: 108190.
[28] WENZEL R N.Resistance of Solid Surfaces to Wetting by Water[J]. Industrial & Engineering Chemistry, 1936, 28(8): 988-994.
[29] CASSIE A B D, BAXTER S. Wettability of Porous Surfaces[J]. Transactions of the Faraday Society, 1944, 40: 546-551.
[30] LIU X, ZHANG T C, HE H Q, et al.A Stearic Acid/CeO2 Bilayer Coating on AZ31B Magnesium Alloy with Superhydrophobic and Self-Cleaning Properties for Corrosion Inhibition[J]. Journal of Alloys and Compounds, 2020, 834: 155210.
[31] DING J H, ZHAO H R, JI D, et al.Achieving Long-Term Anticorrosion via the Inhibition of Graphene’s Electrical Activity[J]. Journal of Materials Chemistry A, 2019, 7(6): 2864-2874.
[32] ZHU Y J, SUN F L, QIAN H J, et al.A Biomimetic Spherical Cactus Superhydrophobic Coating with Durable and Multiple Anti-Corrosion Effects[J]. Chemical Engineering Journal, 2018, 338: 670-679.
[33] ZHAO X, WEI J F, LI B C, et al.A Self-Healing Superamphiphobic Coating for Efficient Corrosion Protection of Magnesium Alloy[J]. Journal of Colloid and Interface Science, 2020, 575: 140-149.
[34] BOINOVICH L B, EMELYANENKO A M, MODESTOV A D, et al.Not Simply Repel Water: The Diversified Nature of Corrosion Protection by Superhydrophobic Coatings[J]. Mendeleev Communications, 2017, 27(3): 254-256.
Funding
The National Natural Science Foundation of China (52401150)
PDF(11135 KB)
