Novel Coatings to Minimize Corrosion of Titanium in Oral Biofilm

The aim of this work is to investigate the effects produced by polymicrobial biofilm (Porphyromonas gingivalis, Streptococcus mutans, Streptococcus sanguinis, and Streptococcus salivarius) on the corrosion behavior of titanium dental implants. Pure titanium disks were polished and coated with titanium nitride (TiN) and silicon carbide (SiC) along with their quarternized versions. Next, the disks were cultivated in culture medium (BHI) with P. gingivalis, S. mutans, S. sanguinis, and S. salivarius and incubated anaerobically at 37 °C for 30 days. Titanium corrosion was evaluated through surface observation using Scanning Electron Microscope (SEM) and Atomic Force Microscopy (AFM). Furthermore, the Ti release in the medium was evaluated by Inductively Coupled Plasma Mass Spectrometry (ICP-MS). SEM images showed that coated Ti disks exhibited lower corrosion compared to non-coated disks, except for the quartenized TiN. This was confirmed by AFM, where the roughness was higher in non-coated Ti disks. ICP showed that Ti levels were low in all coating disks. These results indicate that these SiC and TiN-based coatings could be a useful tool to reduce surface corrosion on titanium implant surfaces.     

The Effect of the Corrosion Medium on Silane Coatings Deposited on Titanium Grade 2 and Titanium Alloy Ti13Nb13Zr

The present paper focuses on the fabrication of coatings based on vinyltrimethoxysilane and the influence of various corrosion media on the coatings produced. Coatings were deposited on two substrate materials, namely, titanium Grade 2 and titanium alloy Ti13Nb13Zr, by immersion in a solution containing vinyltrimethoxysilane, anhydrous ethyl alcohol, acetic acid and distilled water. The obtained coatings were characterized in terms of surface morphology, adhesion to the substrate and corrosion resistance. As corrosion solutions, four different simulated physiological fluids, which differed in the contents of individual ions, and a 1 mol dm⁻³ NaBr solution were used. The chloride ions contained in the simulated physiological fluids did not lead to pitting corrosion of titanium Grade 2 and titanium alloy Ti13Nb13Zr. This investigation shows that titanium undergoes pitting corrosion in a bromide ion medium. It is demonstrated that the investigated coatings slow down corrosion processes in all corrosion media examined.     

In Vivo Degradation Behavior of the Magnesium Alloy LANd442 in Rabbit Tibiae

In former studies the magnesium alloy LAE442 showed promising in vivo degradation behavior and biocompatibility. However, reproducibility might be enhanced by replacement of the rare earth composition metal “E” by only a single rare earth element. Therefore, it was the aim of this study to examine whether the substitution of “E” by neodymium (“Nd”) had an influence on the in vivo degradation rate. LANd442 implants were inserted into rabbit tibiae and rabbits were euthanized after 4, 8, 13 and 26 weeks postoperatively. In vivo µCT was performed to evaluate the in vivo implant degradation behaviour by calculation of implant volume, density true 3-D thickness and corrosion rates. Additionally, weight loss, type of corrosion and mechanical stability were appraised by SEM/EDS-analysis and three-point bending tests. Implant volume, density and true 3-D thickness decreased over time, whereas the variance of the maximum diameters within an implant as well as the corrosion rate and weight loss increased. SEM examination revealed mainly pitting corrosion after 26 weeks. The maximum bending forces decreased over time. In comparison to LAE442, the new alloy showed a slower, but more uneven degradation behavior and less mechanical stability. To summarize, LANd442 appeared suitable for low weight bearing bones but is inferior to LAE442 regarding its degradation morphology and strength.     

Improvement of Corrosion Resistance of TiO2 Layers in Strong Acidic Solutions by Anodizing and Thermal Oxidation Treatment

By anodization and thermal oxidation at 600 °C, an oxide layer on Ti with excellent corrosion resistance in strong acid solutions was prepared. The structural properties of TiO₂ films before and after thermal oxidation were investigated with methods of Scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD). The electrochemical characterization was recorded via electrochemical impedance spectroscopy, potentiodynamic polarization and Mott–Schottky methods. XRD results show that a duplex rutile/anatase structure formed after oxidation, and the amount of anatase phase increased as the treatment time was prolonged from 3 to 9 h. XPS analysis indicates that as the thermal oxidation time increased, more Ti vacancies were present in the titanium oxide films, with decreased donor concentration. Longer thermal oxidation promoted the formation of hydroxides of titanium on the surface, which is helpful to improve the passive ability of the film. The anodized and thermally oxidized Ti samples showed relatively high corrosion resistance in 4 M HCl and 4 M H₂SO₄ solutions at 100 ± 5 °C. The passive current density values of the thermally oxidized samples were five orders of magnitude under the testing condition compared with that of the anodized sample. With the oxidation time prolonged, the passive current density decreased further to some extent.     

Biomimetic Calcium Phosphate Coatings for Bioactivation of Titanium Implant Surfaces: Methodological Approach and In Vitro Evaluation of Biocompatibility

Ti6Al4V as a common implant material features good mechanical properties and corrosion resistance. However, untreated, it lacks bioactivity. In contrast, coatings with calcium phosphates (CaP) were shown to improve cell–material interactions in bone tissue engineering. Therefore, this work aimed to investigate how to tailor biomimetic CaP coatings on Ti6Al4V substrates using modified biomimetic calcium phosphate (BCP) coating solutions. Furthermore, the impact of substrate immersion in a 1 M alkaline CaCl₂ solution (pH = 10) on subsequent CaP coating formation was examined. CaP coatings were characterized via scanning electron microscopy, x-ray diffraction, energy-dispersive x-ray spectroscopy, and laser-scanning microscope. Biocompatibility of coatings was carried out with primary human osteoblasts analyzing cell morphology, proliferation, collagen type 1, and interleukin 6 and 8 release. Results indicate a successful formation of low crystalline hydroxyapatite (HA) on top of every sample after immersion in each BCP coating solution after 14 days. Furthermore, HA coating promoted cell proliferation and reduced the concentration of interleukins compared to the uncoated surface, assuming increased biocompatibility.     

Effect of Al Concentration on Microstructure and Properties of AlNbTiZr Medium-Entropy Alloy Coatings

The AlNbTiZr medium-entropy alloy (MEA) coatings with different Al contents were prepared on N36 zirconium alloy substrates by RF magnetron co-sputtering. The morphology, microstructure, mechanical properties, surface wettability and corrosion resistance of the AlNbTiZr MEA coatings were studied to evaluate the surface protection behavior of zirconium alloy cladding under operation conditions of a pressurized water reactor. The results showed that all the coatings were composite structures with amorphous and bcc-structured nanocrystals. With the increase of Al content, both the elastic modulus and hardness decreased first and then increased. The hydrophobicity of the coatings was enhanced compared with that of the substrate. The 10.2 at.% Al AlNbTiZr coating had the best corrosion resistance and the minimum oxygen penetration depth, which originated from the formation of a denser oxide layer consisting of Nb₂Zr₆O₁₇ and ZrO₂. This study provides an improved idea for the design and development of Al-containing MEA coating materials for accident tolerant fuel.     

Effect of γ′ Phase Elements on Oxidation Behavior of Nanocrystalline Coatings at 1050 °C

To study the effect of γ′ phase elements on the oxidation behavior of nanocrystalline coatings, two comparable nanocrystalline coating systems were established and prepared by magnetron sputtering. The oxidation experiments of the nanocrystalline coatings on the K38G and N5 superalloys were carried at 1050 °C for 100 h, respectively. The chemical composition of the above coatings is the same as the substrate alloy, including the γ′ elements, such as Al, Ta, and Ti. After serving at a high temperature for certain periods, their oxides participated and then affected the oxidation behavior of the coatings. The Al₂O₃ scale can be formed on the N5 coating, which cannot be formed on the K38G coating. Tantalum and titanium oxides can be detected on the oxide scale, which ruin its purity and integrity.     

The Effect of Zn and Zn–WO3 Composites Nano-Coatings Deposition on Hardness and Corrosion Resistance in Steel Substrate

Pure Zn (Zinc) and its Zn–WO₃ (Zinc–Tungsten trioxide) composite coatings were deposited on mild steel specimens by applying the electrodeposition technique. Zn–WO₃ composites were prepared for the concentration of 0.5 and 1.0 g/L of particles. The influence of WO₃ particles on Zn deposition, the surface morphology of composite, and texture co-efficient were analyzed using a variety of techniques, such as X-ray diffraction (XRD) and scanning electron microscopy (SEM) with Energy Dispersive X-ray analysis (EDX). Higher corrosion resistance and microhardness were observed on the Zn–WO₃ composite (concentration of 1.0 g/L). The higher corrosion resistance and microhardness of 1.0 g/L Zn–WO₃ nanocomposite coatings effectively protect the steel used for the manufacture of products, parts, or systems from chemical or electrochemical deterioration in industrial and marine ambient environments.     

Amorphous–Crystalline Calcium Phosphate Coating Promotes In Vitro Growth of Tumor-Derived Jurkat T Cells Activated by Anti-CD2/CD3/CD28 Antibodies

A modern trend in traumatology, orthopedics, and implantology is the development of materials and coatings with an amorphous–crystalline structure that exhibits excellent biocopatibility. The structure and physico–chemical and biological properties of calcium phosphate (CaP) coatings deposited on Ti plates using the micro-arc oxidation (MAO) method under different voltages (200, 250, and 300 V) were studied. Amorphous, nanocrystalline, and microcrystalline statesof CaHPO₄ and β-Ca₂P₂O₇ were observed in the coatings using TEM and XRD. The increase in MAO voltage resulted in augmentation of the surface roughness R_a from 2.5 to 6.5 µm, mass from 10 to 25 mg, thickness from 50 to 105 µm, and Ca/P ratio from 0.3 to 0.6. The electrical potential (EP) of the CaP coatings changed from −456 to −535 mV, while the zeta potential (ZP) decreased from −53 to −40 mV following an increase in the values of the MAO voltage. Numerous correlations of physical and chemical indices of CaP coatings were estimated. A decrease in the ZP magnitudes of CaP coatings deposited at 200–250 V was strongly associated with elevated hTERT expression in tumor-derived Jurkat T cells preliminarily activated with anti-CD2/CD3/CD28 antibodies and then contacted in vitro with CaP-coated samples for 14 days. In turn, in vitro survival of CD4⁺ subsets was enhanced, with proinflammatory cytokine secretion of activated Jurkat T cells. Thus, the applied MAO voltage allowed the regulation of the physicochemical properties of amorphous–crystalline CaP-coatings on Ti substrates to a certain extent. This method may be used as a technological mechanism to trigger the behavior of cells through contact with micro-arc CaP coatings. The possible role of negative ZP and Ca²⁺ as effectors of the biological effects of amorphous–crystalline CaP coatings is discussed. Micro-arc CaP coatings should be carefully tested to determine their suitability for use in patients with chronic lymphoid malignancies.     

Performance of Sprayed PVDF-Al2O3 Composite Coating for Industrial and Civil Applications

Because of their great water repellency, Superhydrophobic coatings have a major impact on a variety of industrial applications. The current study’s key originality is the development of low-cost, stable, superhydrophobic, and corrosion-resistant composite coatings. In the present work, polyvinylidene fluoride (PVDF)/Al₂O₃ composite coatings were produced using the spray technique to investigate the wettability and corrosion behavior of the coated materials for industrial and civil applications. PVDF was mixed with various concentrations of Al₂O₃ nanoparticles, and the mixture was sprayed onto steel, aluminum, and glass substrates. The wettability and morphology of the coated surfaces were investigated using the sessile droplet method and scanning electron microscopy, respectively. The corrosion resistance of bare substrates was compared to that of those coated with PVDF alone and those coated with PVDF/Al₂O₃ nanoparticles using Tafel polarization techniques. The force of adhesion between the coat and the substrates was measured in pounds per square inch. A nanoindentation test was also used to measure the hardness of the coating layer. The PVDF/Al₂O₃ coated steel showed a significantly higher water contact angle and lower contact angle hysteresis, reaching 157 ± 2° and 7 ± 1°, respectively, compared to the coated aluminum and glass substrates. Corrosion test results showed that the superhydrophobic PVDF/Al₂O₃ coatings had a much higher corrosion protection efficiency for steel and aluminum than that of the PVDF ones. The PVDF/Al₂O₃ coated substrates showed moderate but still acceptable adhesion between the coating layer and the substrates. Moreover, the PVDF/Al₂O₃ coatings had much better mechanical properties than the PVDF only coatings. Such type of coating could be a promising candidate for possible industrial and civil applications.     

In Vivo Corrosion of Two Novel Magnesium Alloys ZEK100 and AX30 and Their Mechanical Suitability as Biodegradable Implants

In magnesium alloys, the components used modify the alloy properties. For magnesium implants in contact with bone, rare earths alloys are commonly examined. These were shown to have a higher corrosion resistance than other alloys and a high mechanical strength, but their exact composition is hard to predict. Therefore a reduction of their content could be favorable. The alloys ZEK100 and AX30 have a reduced content or contain no rare earths at all. The aim of the study was to investigate their in vivo degradation and to assess the suitability of the in vivo µCT for the examination of their corrosion. Implants were inserted in rabbit tibiae. Clinical examinations, X-rays and in vivo µCT scans were done regularly. Afterwards implants were analyzed with REM, electron dispersive X-ray (EDX), weighing and mechanical testing. The in vivo µCT is of great advantage, because it allows a quantification of the corrosion rate and qualitative 3D assessment of the corrosion morphology. The location of the implant has a remarkable effect on the corrosion rate. Due to its mechanical characteristics and its corrosion behavior, ZEK100 was judged to be suitable, while AX30, which displays favorable degradation behavior, has too little mechanical strength for applications in weight bearing bones.     

Ti-Ions and/or Particles in Saliva Potentially Aggravate Dental Implant Corrosion

The corrosive titanium products in peri-implant tissues are a potential risk factor for peri-implantitis. There is very limited information available on the effect of the corrosion and wear products on the dental implant corrosion. Therefore, we determined the influence of Ti-ions and Ti-particles on Ti corrosion. Eighteen commercially pure-Ti-grade-2 discs were polished to mirror-shine. Samples were divided into six groups (n = 3) as a function of electrolytes; (A) Artificial saliva (AS), (B) AS with Ti-ions (the electrolyte from group A, after corrosion), (C) AS with Ti-particles 10 ppm (D) AS with Ti-particles 20 ppm, (E) AS with Ti-ions 10 ppm, and (F) AS with Ti-ions 20 ppm. Using Tafel’s method, corrosion potential (E_corr) and current density (I_corr) were estimated from potentiodynamic curves. Electrochemical Impedance Spectroscopy (EIS) data were used to construct Nyquist and Bode plots, and an equivalent electrical circuit was used to assess the corrosion kinetics. The corroded surfaces were examined through a 3D-white-light microscope and scanning electronic microscopy. The data demonstrated that the concentration of Ti-ions and corrosion rate (I_corr) are strongly correlated (r = 0.997, p = 0.046). This study indicated that high Ti-ion concentration potentially aggravates corrosion. Under such a severe corrosion environment, there is a potential risk of increased implant associated adverse tissue reactions.     

Potentiodynamic Polarization Studies and Surface Chemical Composition of Bismuth Titanate (BixTiyOz) Films Produced through Radiofrequency Magnetron Sputtering

The applications of Bismuth Titanate (Bi_xTi_yO_z) materials have been focused on their electronic and optical properties, but with respect to the use of these compounds in applications like corrosion resistance, have been very few or nonexistent. For this reason, in the present investigation Bi_xTi_yO_z thin films were deposited using RF magnetron sputtering onto silicon wafers, stainless steel 316L, and titanium alloy (Ti₆Al₄V) substrates, in order to carry out a study of the corrosion behavior of this compound. The structural properties of the coatings were studied through X-ray diffraction (XRD), the morphology was determined using Scanning Electron Microscopy (SEM), the corrosion resistance behavior of the coated and uncoated substrates was evaluated via the Potentiodynamic Polarization technique, and surface chemical composition was evaluated through X-ray photoelectron spectroscopy (XPS). The XRD results indicated that the films were amorphous. The SEM micrographs showed that the deposited films were homogeneous, but in some cases there were cracks. The potentiodynamic polarization technique showed that the corrosion current in the coated substrates decreased by an order of two magnitudes with respect to the uncoated substrates, but in both cases the corrosion mechanism was pitting due to the pores in the film. The XPS analysis shows that the deposited films contain both Bi³⁺ and Ti⁴⁺.     

Nano-TiO2 Coating Layers with Improved Anticorrosive Properties by Aerosol Flame Synthesis and Thermophoretic Deposition on Aluminium Surfaces

TiO₂ in the form of nanoparticles is characterized by high photocatalytic activity and high resistance to oxidation, making it an excellent candidate to realize coatings for improving the corrosion resistance of aluminium surfaces. Different coating technologies have been proposed over the years, which often involve the use of toxic compounds and very high temperatures. In this work, an alternative and novel one-step method for the coating of aluminium alloy surfaces with titania nanoparticles is presented. The method is based on the combination of aerosol flame synthesis and direct thermophoretic deposition and allows to produce nanostructured thin coating layers of titania with different features. Specifically, 3.5 nm anatase nanoparticles were synthesized and deposited onto aluminium alloy AA2024 samples. The thickness of the coating was changed by modifying the total deposition time. A thermal annealing treatment was developed to improve the adhesion of nano-titania on the substrates, and the morphology and structures of the coatings were characterized using (ultra violet) UV-vis absorption, scanning electron microscopy, transmission electron microscopy and Raman spectroscopy. The corrosion resistance behavior of the coatings was evaluated by means of electrochemical polarization measurements, coupled with a numerical analysis using COMSOL software. Both the experimental and numerical electrochemical polarization curves showed a significant increase in the corrosion potential of coated substrates with respect to the bare aluminium and a decrease in the current density. The coatings obtained with higher deposition time and greater thickness showed the best performances in terms of the resistance of the aluminium surfaces to corrosion.     

Hydrothermal Corrosion of Double Layer Glass/Ceramic Coatings Obtained from Preceramic Polymers

Polysilazane-based double layer composite coatings consisting of a polymer-derived ceramic (PDC) bond-coat and a PDC top-coat that contains ceramic passive and glass fillers were developed. To investigate the environmental protection ability of the prepared coatings, quasi-dynamic corrosion tests under hydrothermal conditions were conducted at 200 °C for 48–192 h. The tested PDC coatings exhibited significant mass loss of up to 2.25 mg/cm² after 192 h of corrosion tests, which was attributed to the leaching of elements from the PDC coatings to the corrosion medium. Analysis of corrosion solutions by inductively coupled plasma optical emission spectrometry (ICP-OES) confirmed the presence of Ba, Al, Si, Y, Zr, and Cr, the main component of the steel substrate, in the corrosion medium. Scanning electron microscopy (SEM) of the corroded surfaces revealed randomly distributed globular crystallites approximately 3.5 µm in diameter. Energy-dispersive X-ray spectroscopy (EDXS) of the precipitates showed the presence of Ba, Al, Si, and O. The predominant phases detected after corrosion tests by X-ray powder diffraction analysis (XRD) were monoclinic and cubic ZrO₂, originating from the used passive fillers. In addition, the crystalline phase of BaAl₂Si₂O₈ was also identified, which is in accordance with the results of EDXS analysis of the precipitates formed on the coating surface.     

Effect of pH on the Corrosion and Repassivation Behavior of TA2 in Simulated Seawater

The effect of pH on the corrosion and repassivation behavior of TA2 in simulated seawater was studied using electrochemical tests, immersion experiments, and surface morphology topology analysis. The results show that E_corr and R_f increased while i_pass and weight loss rate decreased as the pH of simulated seawater increased. The TA2 passive film was determined to be mainly composed of a large amount of TiO₂ and a small amount of TiO. The repassivation function of TA2 can be expressed as E = −0.1375 + 0.0532ln(t − 1.241) for a simulated seawater pH of 8.2. The parameter b, which represents the slope of the potential–time curve during the friction electrode test, was used to evaluate the repassivation behavior of TA2. The increase in pH value was observed to promote the repassivation speed of the passive film, which is beneficial to the corrosion resistance of TA2.     

The Effect of Heat Treatment on the Corrosion Resistance of Fe-Based Amorphous Alloy Coating Prepared by High Velocity Oxygen Fuel Method

In this study, Fe₄₀Cr₁₉Mo₁₈C₁₅B₈ amorphous coatings were prepared using high velocity oxygen fuel (HVOF) technology. Different temperatures were used in the heat treatment (600 °C, 650 °C, and 700 °C) and the annealed coatings were analyzed by DSC, SEM, TEM, and XRD. XRD and DSC results showed that the coating started to form a crystalline structure after annealing at 650 °C. From the SEM observation, it can be found that when the annealing temperature of the Fe-based amorphous alloy coating reached 700 °C, the surface morphology of the coating became relatively flat. TEM observation showed that when the annealing temperature of the Fe-based amorphous alloy coating was 700 °C, crystal grains in the coating recrystallized with a grain size of 5–20 nm. SAED analysis showed that the precipitated carbide phase was M₂₃C₆ phase with different crystal orientations (M = Fe, Cr, Mo). Finally, the corrosion polarization curve showed that the corrosion current density of the coating after annealing only increased by 9.13 μA/cm², which indicated that the coating after annealing treatment still had excellent corrosion resistance. It also proved that the Fe-based amorphous alloy coating can be used in high-temperature environments. XPS analysis showed that after annealing FeO and Fe₂O₃ oxide components increased, and the formation of a large number of crystals in the coating resulted in a decrease in corrosion resistance.     

Wear and Corrosion Resistance of Plasma Electrolytic Oxidation Coatings on 6061 Al Alloy in Electrolytes with Aluminate and Phosphate

Phosphate and aluminate electrolytes were used to prepare plasma electrolytic oxidation (PEO) coatings on 6061 aluminum alloy. The surface and cross-section microstructure, element distribution, and phase composition of the PEO coatings were characterized by SEM, EDS, XPS, and XRD. The friction and wear properties were evaluated by pin-on-disk sliding tests under dry conditions. The corrosion resistance of PEO coatings was investigated by electrochemical corrosion and salt spray tests in acidic environments. It was found that the PEO coatings prepared from both phosphate and aluminate electrolytes were mainly composed of α-Al₂O₃ and γ-Al₂O₃. The results demonstrate that a bi-layer coating is formed in the phosphate electrolyte, and a single-layered dense alumina coating with a hardness of 1300 HV is realizable in the aluminate electrolyte. The aluminate PEO coating had a lower wear rate than the phosphate PEO coating. However, the phosphate PEO coating showed a better corrosion resistance in acidic environment, which is mainly attributed to the presence of an amorphous P element at the substrate/coating interface.     

The Effect of Electrophoretic Deposition Parameters on the Microstructure and Adhesion of Zein Coatings to Titanium Substrates

Zein coatings were obtained by electrophoretic deposition (EPD) on commercially pure titanium substrates in an as-received state and after various chemical treatments. The properties of the zein solution, zeta potential and conductivity, at varying pH values were investigated. It was found that the zein content and the ratio of water to ethanol of the solution used for EPD, as well as the process voltage value and time, significantly influence the morphology of coatings. The deposits obtained from the solution containing 150 g/L and 200 g/L of zein and 10 vol % of water and 90 vol % of ethanol, about 4–5 μm thick, were dense and homogeneous. The effect of chemical treatment of the Ti substrate surface prior to EPD on coating adhesion to the substrate was determined. The coatings showed the highest adhesion to the as-received and anodized substrates due to the presence of a thick TiO₂ layer on their surfaces and the presence of specific surface features. Coated titanium substrates showed slightly lower electrochemical corrosion resistance than the uncoated one in Ringer’s solution. The coatings showed a well-developed surface topography compared to the as-received substrate, and they demonstrated hydrophilic nature. The present results provide new insights for the further development of zein-based composite coatings for biomedical engineering applications.     

Inhibition of Mild Steel Corrosion in Hydrochloric Acid Solution by New Coumarin

A new coumarin derivative, N,N′-((2E,2′E)-2,2′-(1,4-phenylenebis(methanylylidene))bis(hydrazinecarbonothioyl))bis(2-oxo-2H-chromene-3-carboxamide) PMBH, was synthesized and its chemical structure was elucidated and confirmed using spectroscopic techniques (Infrared spectroscopy IR, Proton nuclear magnetic resonance, ¹H-NMR and carbon-13 nuclear magnetic resonance ¹³C-NMR). The corrosion inhibition effect of PMBH on mild steel in 1.0 M HCl was investigated using corrosion potential (E_CORR), potentiodynamic polarization, electrochemical impedance spectroscopy (EIS), and electrochemical frequency modulation (EFM) measurements. The obtained results indicated that PMBH has promising inhibitive effects on the corrosion of mild steel in 1.0 M HCl across all of the conditions examined. Scanning electron microscopy (SEM) was used to investigate the morphology of the mild steel before and after immersion in 1.0 M HCl solution containing 0.5 mM of PMBH. Surface analysis revealed improvement of corrosion resistance in presence of PMBH.