Focusing on clarifying the role of Sm-doping in regulating the micro-arc oxidation (MAO) coating formation process on TC11 Ti alloy and enhancing its anti-corrosion performance, the present work conducts a series of systematic experiments. SmCl3 was used as the Sm3+ source, and MAO treatment was performed on the alloy in an electrolyte of sodium phosphate. The coatings’ characteristics during their formation, such as surface topography and phase composition, the cross-sectional morphology, and corrosion resistance, were featured by SEM, EDS, XPS, XRD, and an electrochemical workstation. Discoveries suggest that the MAO voltage of the Sm-containing coating exhibited a tendency of initial decrease followed by a subsequent increase, and the coating-forming process of the coating was related to the voltage variation during the oxidation process. Rare-earth Sm-doping not only improved the coating's micro-structure but also contributed to an increase in coating thickness; meanwhile, phase composition analysis revealed the presence of Ti, anatase, rutile, and Sm2O3. Relative to the TC11 substrate, the Sm-containing coating showed a 54.81% reduction in the Icorr value and also a 53.88% decrease in corrosion rate. Electrochemical impedance measurement indicated that rare-earth Sm-doping could significantly improve the Cl− anti-corrosion performance of the TC11 alloy.
DongZHHuangZQTangL, et al.Surface modification of biomedical titanium alloy for hard tissue repair and reconstruction. Surf Eng2024; 40: 847–862.
2.
PradeepRCKarthik BabuNBRajeshKA, et al.Progress in the optimization of compositional design and thermomechanical processing of metastable β ti alloys for biomedical applications. ACS Biomater Sci Eng2024; 10: 3528–3547.
3.
BonettiSPTorrento JhulieneEMGrandiniCR, et al.Surface engineering of non-equiatomic TiZrNbTaMo HEA by MAO treatment in a cu-rich electrolyte for biomedical applications. Materials2026; 19: 174.
4.
PernaASCampatelliGCaneschiA, et al.Surface modification of WAAM Ti6Al4V via organic chemical machining for improved gold PVD coating adhesion. Surf Eng2025; 41: 1055–1068.
5.
LiGQMaFCLiuP, et al.Review of micro-arc oxidation of titanium alloys: mechanism, properties and applications. J Alloys Compd2023; 948: 169773.
6.
JiangHsuCHLinCYChenJX. Wear and corrosion performance of Ti-6Al-4V alloy arc-coated TiN/CrN nano-multilayer film. Metals (Basel) 2023; 13: 907.
7.
GopalLSudarshanT. High-temperature coatings for titanium alloys. Surf Eng2024; 40: 139–141.
8.
OuyanZJ. Study on the wear resistance of micro-arc-oxidised ceramic films on the surface of TC4 titanium alloy oil well tubing in the ordos basin. Surf Eng2024; 40: 758–771.
9.
WangCJiangBSongRG. The SCC behavior of MAO/EPD biocomposite coatings on Ti-6Al-4V alloy. Surf Eng2024; 40: 873–882.
10.
Majkowska-MarzecBSypniewskaJJażdżewskaM, et al.Influence of the micro-arc oxidation (MAO) parameters on surface properties of the hydroxyapatite and hydroxyapatite - carbon nanotube coatings formed on the Ti13Nb13Zr alloy. Adv Mater Sci2025; 25: 38–52.
11.
WangYShenJWuGL, et al.Growth characteristics of scanning micro-arc oxidation coating on Ti6Al4V alloy. Volume2022; 38: 218–228.
12.
WangYFuBYChenSL, et al.Thermophysical properties of Ln2(Zr0.7Ce0.3)2O7 (Ln=La, Nd, Sm, Gd) nanomaterials for thermal barrier coatings. Cailiao Yanjiu Xuebao/Chin J Mater Res2023; 37: 855–861.
13.
SiYCLiLFWangRD, et al.Preparation, thermophysical properties and corrosion resistance of high-entropy rare earth tantalates (5RE0.2)TaO4 (RE=Y, Gd, Dy, Ce, Sm, La, Yb) ceramics as promising thermal barrier coating materials. Ceram Int2025; 51: 10783–10793.
14.
Sabhya DhananjayaKRaoKM. Capacitance enhancement of Sm-doped hafnia MoS capacitors via cubic phase mediation. Phys Biol2025; 712: 417332.
15.
KompaAKekudaDMohan RaoK. Influence of low concentration Sm doping on optical and catalytic performance of titania. Ceram Int2023; 49: 4230–4239.
16.
GaoZXFuSZhangXY, et al.Investigation of the mechanical and thermal properties of RE2Ti2O7 (RE = Y, Dy, Sm) ceramics with a pyrochlore structure. J Eur Ceram Soc2025; 45: 117661.
17.
BučkoMStuparSJelenaBB. The influence of Sm content on the surface morphology and corrosion behavior of Zn-Co-Sm composite coatings. Metals (Basel)2023; 13: 481.
18.
LanXYXiongDWangP, et al.Smcl3's effect on plasma electrolytic oxidation coating's corrosion characteristics on AZ91D. Mater Sci Technol2022; 38: 1585–1596.
19.
MathisARoccaEVeys-RenauxD, et al.Electrochemical behaviour of titanium in KOH at high potential. Electrochim Acta2016; 202: 253–261.
20.
ZhaiDJQiuTShenJ, et al.Growth kinetics and mechanism of microarc oxidation coating on Ti-6Al-4V alloy in phosphate/silicate electrolyte. Int J Miner Metall Mater2022; 29: 1991–1999.
21.
KangJHuYSunW, et al.Utilization of sodium hexametaphosphate for separating scheelite from calcite and fluorite using an anionic-nonionic collector. Minerals2019; 9: 705.
22.
NiAOLiuDXZhangXH, et al.Microstructural characteristics of PEO coating: effect of surface nanocrystallization. J Alloys Compd2020; 823: 153823.
23.
YaoZPJiangYLJiaFZ, et al.Growth characteristics of plasma electrolytic oxidation ceramic coatings on Ti-6Al-4V alloy. Appl Surf Sci2008; 254: 4084–4091.
24.
LiQYangWLiuC, et al.Correlations between the growth mechanism and properties of micro-arc oxidation coatings on titanium alloy: effects of electrolytes. Surf Coat Technol2017; 316: 162–170.
25.
OnodaHIinumaA. Selective preparation of samarium phosphates from transition metal mixed solution by two-step precipitation. Environ Technol2023; 44: 3459–3465.
26.
AndrewCDhivyaMJayakumarM. Electrochemical and spectroscopic investigation of samarium in a neutral ligand based-ionic liquid. J Electroanal Chem2021; 895: 115398.
27.
KangJGMinBKSohnYK. Synthesis and characterization of Sm(OH)3 and Sm2O3 nanoroll sticks. J Mater Sci2015; 50: 1958–1964.
28.
MosséALPechkovskiiVVMenkhVA, et al.The possibility of thermal phosphate decomposition in a low-temperature plasma jet. J Eng Phys Thermophys1968; 15: 1200–1203.
29.
YangSLWangP, et al.Influences of Sc(NO3)3 on characteristics of micro-arc oxidation coatings. Surf Eng2023; 39: 307–314.
30.
YamamotoOTakedaYKannoR, et al.Thermal decomposition and electrical conductivity of M(OH)3 and MOOH (M=Y, lanthanide). Solid State Ionics1985; 17: 107–114.
31.
WongYHLeeCYGohKH. Influence of applied voltage on the physical and electrical properties of anodic Sm2O3 thin films on Si in 0.01 M NaOH solution. Micro Nano Lett2017; 12: 347–351.
32.
DamasPRJunqueiraRMRDornelasSJ, et al.Comparative study of nanostructured titania grown by electrochemical anodization of α-Ti and β-TiNi substrates in organic electrolytes. J Mater Res Technol2020; 9: 10121–10129.
33.
YangSLDuanYFWangP, et al.Effect of NdCl3 on characteristics of micro-arc oxidation coating formed on TC4 alloy. J Mater Sci2024; 59: 7931–7944.
34.
EL-DesokyMMMoradIWasfyMH, et al.Synthesis, structural and electrical properties of PVA/TiO2 nanocomposite films with different TiO2 phases prepared by sol-gel technique. J Mater Sci Mater Electron2020; 31: 17574–17584.
35.
PascariuPHomocianuMTudoracheF, et al.Enhancing humidity sensitivity properties through RE (Er, La, and Sm) dopants in TiO2 nanofiber composites. J Mater Sci2024; 59: 2712–2727.
36.
LiYJCaoTPSunDW. Preparation of Bi/TiO2∶ Sm3+ composite fibers and visible light photocatalytic degradation of antibiotic lomofloxacin. Bullet Chin Ceram Soc2025; 44: 1918–1926.
37.
GülerSHÖmerGKavazE, et al.Fabrication and structural, physical, and nuclear radiation shielding properties for oxide dispersion-strengthened (ODS) alloys through erbium (III) oxide, samarium (III) oxide, and praseodymium (III) oxide into 316L matrix. Ceram Int2024; 50: 5443–5452.
38.
XueHSLiXYZhangWN, et al.Microwave-assisted hydrothermal synthesis of Sm2O3 nanoparticles and their optical properties. J Nano Res2017; 46: 100–110.
39.
HienTVHungNVRijndersG, et al.Sm-doping driven state-phase transition and energy storage capability in lead-free Ba(Zr0.35Ti0.65)O3 films. J Alloys Compd2023; 968: 171837.
