PT106302A - HYBRID COATINGS FOR THE OPTIMIZATION OF ANTI-CORROSIVE PROTECTION OF MAGNESIUM ALLOYS - Google Patents
HYBRID COATINGS FOR THE OPTIMIZATION OF ANTI-CORROSIVE PROTECTION OF MAGNESIUM ALLOYS Download PDFInfo
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- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
- C09D5/00—Coating compositions, e.g. paints, varnishes or lacquers, characterised by their physical nature or the effects produced; Filling pastes
- C09D5/08—Anti-corrosive paints
- C09D5/082—Anti-corrosive paints characterised by the anti-corrosive pigment
- C09D5/086—Organic or non-macromolecular compounds
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- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
- C09D163/00—Coating compositions based on epoxy resins; Coating compositions based on derivatives of epoxy resins
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- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C22/00—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
- C23C22/73—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals characterised by the process
- C23C22/74—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals characterised by the process for obtaining burned-in conversion coatings
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- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
- C08K5/00—Use of organic ingredients
- C08K5/54—Silicon-containing compounds
- C08K5/544—Silicon-containing compounds containing nitrogen
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- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C2222/00—Aspects relating to chemical surface treatment of metallic material by reaction of the surface with a reactive medium
- C23C2222/20—Use of solutions containing silanes
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Abstract
A PRESENTE INVENÇÃO REFERE-SE A REVESTIMENTOS DE PROTEÇÃO ANTI-CORROSÃO PARA LIGAS DE MAGNÉSIO, UTILIZADOS NA INDÚSTRIA AUTOMÓVEL E AERONÁUTICA. DE UM MODO PARTICULAR, REFERE-SE À COMPOSIÇÃO DE REVESTIMENTOS, FILMES FORMADOS SOBRE O SUBSTRATO E AS PROPRIEDADES ANTI-CORROSIVAS DO SISTEMA EM GERAL, QUANDO IMERSO NUM ELETRÓLITO AGRESSIVO. A SUA COMPOSIÇÃO COMPREENDE UM COMPONENTE EPÓXI (EX. POLI(BISFENOL A-CO-EPICLORIDRINA), COM TERMINAÇÃO GLICIDILO), UM COMPONENTE SILANO (EX. AMINOPROPILTRIETOXISILANO, APTES) E UMA AMINA (EX. DIETILENOTRIAMINA, DETA), DISSOLVIDOS EM SOLVENTES ORGÂNICOS. ESTES REVESTIMENTOS PODEM SER APLICADOS SOBRE OS SUBSTRATOS DE LIGAS DE MAGNÉSIO POR SPRAY OU IMERSÃO (SPRAY OU DIP-COATING), SEGUIDOS DE UMA CURA TÉRMICA NUMA GAMA ESPECÍFICA DE CONDIÇÕES. A ESPESSURA DO REVESTIMENTO VARIA DE 5 A 20 MICRÓMETROS. AS LIGAS DE MAGNÉSIO ASSIM REVESTIDAS TÊM UMA RESISTÊNCIA À CORROSÃO EXCELENTE E APÓS UM MÊS DE IMERSÃO EM CLORETO DE SÓDIO O SEU DESEMPENHO É SIGNIFICATIVAMENTE MELHOR QUANDO COMPARADO COM REVESTIMENTOS CONVENCIONAIS, COMO DESCRITOS NO ESTADO DA ARTE.The present invention relates to anti-corrosion protection coatings for magnesium alloys, used in the automotive and aero-aviation industries. In a particular way, it refers to the composition of coatings, films formed on the substructure and the anti-corrosive properties of the system in general, when immersed in an aggressive electrolyte. Its composition comprises an EPOXY COMPONENT (EX-POLY (BISPHENOL A-CO-EPICLORIDRINE), WITH A GLYCIDYL TERMINATION), A SILANE COMPONENT (EX-AMINOPROPYLETHETHOXYSOLANE, APTES) AND AN AMINE (EXE DIETILENOTRHYMINE, DETA), DISSOLVED IN ORGANIC SOLVENTS . These coatings may be applied to the substrates of sputtering or spray-coating, following a thermal cure in a specific range of conditions. THE COATING THICKNESS WILL BE VARY FROM 5 TO 20 MICROMETERS. THE MAGNESIUM ALLOYS SO COATED HAVE AN EXCELLENT CORROSION RESISTANCE AND AFTER A MONTH OF IMMERSION IN SODIUM CHLORIDE ITS PERFORMANCE IS SIGNIFICANTLY BETTER WHEN COMPARED WITH CONVENTIONAL COATINGS, AS DESCRIBED IN THE STATE OF ART.
Description
DESCRIÇÃO "Revestimentos híbridos para otimização da proteção anti-corrosiva de ligas de Magnésio"DESCRIPTION " Hybrid coatings for optimization of the corrosion protection of magnesium alloys "
Campo da invençãoField of the Invention
Campo técnico em que a invenção se insere A presente invenção refere-se a revestimentos para ligas à base de magnésio utilizadas na indústria automóvel e aeronáutica para melhorar a sua resistência à corrosão. Os três principais componentes do revestimento são: um silano, um epóxi e uma amina. Verificou-se que o revestimento é capaz de tolerar a imersão numa solução de 0,05M de cloreto de sódio (NaCl) durante um mês sem ser destruído. 0 desempenho do revestimento foi avaliado através de medições de espectroscopia de impedância eletroquímica.TECHNICAL FIELD OF THE INVENTION The present invention relates to coatings for magnesium based alloys used in the automotive and aeronautical industries to improve their corrosion resistance. The three main components of the coating are: a silane, an epoxy and an amine. It has been found that the coating is capable of tolerating immersion in a 0.05M solution of sodium chloride (NaCl) for a month without being destroyed. Coating performance was assessed by electrochemical impedance spectroscopy measurements.
Estado da técnicaState of the art
As ligas de magnésio (Mg) são caracterizadas por um conjunto único de propriedades (leveza, elevada condutividade térmica, estabilidade dimensional e características de dissipação, reciclabilidade, ...) [1-5] que as tornam em materiais de valor para diversas aplicações industriais, tais como componentes automóveis e aeroespaciais, material desportivo, material eletrónico e implantes biocompatíveis.Magnesium alloys (Mg) are characterized by a unique set of properties (lightness, high thermal conductivity, dimensional stability and dissipation characteristics, recyclability, ...) [1-5] that make them valuable materials for various applications such as automotive and aerospace components, sports equipment, electronics and biocompatible implants.
Em aeronáutica e indústria automóvel há uma utilização crescente de ligas de magnésio, com origem na crescente importância da economia de combustível e da redução de emissões de dióxido de carbono (C02) que implicam a redução 1 do peso da aeronave [6,7] . Nesta perspetiva, as ligas de Mg representam um excelente candidato devido à sua elevada razão resistência mecânica-massa.In aeronautics and the automotive industry there is a growing use of magnesium alloys, due to the increasing importance of fuel economy and the reduction of carbon dioxide emissions (C02), which imply the reduction of aircraft weight [6,7]. In this perspective, the Mg alloys represent an excellent candidate because of their high mechanical strength-mass ratio.
No entanto, uma grande desvantagem na utilização de ligas de magnésio é a sua elevada suscetibilidade à corrosão, originada pela presença de pares galvânicos internos provenientes da presença de outras fases ou impurezas e à natureza do filme de hidróxidos na superfície que é poroso e pouco protetor [5]. A literatura sobre revestimentos anti-corrosão para ligas de magnésio ainda é escassa, quando comparada com a referente ao alumínio e aço. A anodização de magnésio é a técnica mais usada para melhorar a resistência contra a corrosão das ligas de Mg sujeitas a ambientes agressivos, uma vez que a oxidação anódica produz um filme de óxidos com uma melhor proteção contra a corrosão e razoáveis propriedades de aderência [8-13]. No entanto, os revestimentos obtidos por anodização são porosos e por isto precisam de uma camada extra de isolante, ex. um revestimento sol-gel à base de silanos. Além disso, a anodização possui um custo elevado, uma vez que requer uma elevada intensidade de corrente e ainda um sistema de arrefecimento muito eficiente para evitar sobreaquecimento dos sistemas. Este facto traduz-se num elevado consumo de energia. Para mais, a camada de anodizado muitas vezes é defeituosa, especialmente quando o material de base (as ligas de magnésio) possui uma geometria mais complexa.However, a major drawback in the use of magnesium alloys is their high susceptibility to corrosion, caused by the presence of internal galvanic pairs from the presence of other phases or impurities and the nature of the hydroxyl film on the surface which is porous and poorly protective [5]. The literature on anti-corrosion coatings for magnesium alloys is still scarce compared to aluminum and steel. Magnesium anodization is the most commonly used technique to improve the corrosion resistance of Mg alloys subject to aggressive environments, since anodic oxidation produces a film of oxides with a better protection against corrosion and reasonable adhesion properties [8]. -13]. However, coatings obtained by anodizing are porous and therefore need an extra layer of insulation, eg. a sol-gel coating based on silanes. In addition, anodising has a high cost as it requires a high current intensity and a very efficient cooling system to prevent overheating of the systems. This results in high energy consumption. Furthermore, the anodized layer is often defective, especially when the base material (the magnesium alloys) has a more complex geometry.
Tratamentos de conversão comerciais como MagPass [14] e GardoBond [15], providenciam uma proteção anti-corrosão muito mais fraca que as anodizações e requerem ainda a aplicação de um sistema de proteção adicional, selanes, 2 baseados em filmes de sol gel ou de silanos. Mais uma vez, o processo de anodização encarece o processo de proteção.Commercial conversion treatments such as MagPass [14] and GardoBond [15], provide a much weaker anti-corrosion protection than anodisations and require the application of an additional protection system, selanes, 2 based on sol gel films or silanes. Once again, the process of anodization makes the process of protection more expensive.
Revestimentos à base de cromatos também são um método eficiente anti-corrosão [16]. No entanto, tratamento e revestimentos à base de cromatos foram proibidos e estão em processo de eliminação de ciclos de produção devido aos seus efeitos nocivos para a saúde e ambiente.Chromate-based coatings are also an efficient anti-corrosion method [16]. However, treatment and coatings based on chromates have been banned and are in the process of eliminating production cycles due to their harmful effects on health and the environment.
Tendo isto em conta, os revestimentos à base de silanos feitos por processo sol-gel, têm despertado bastante interesse por serem materiais de revestimento fáceis de processar e com potencial para substituírem tratamentos de superfície à base de cromatos para ligas de Mg [1-3, 17-24] . 0 desempenho daqueles tratamentos de superfície depende essencialmente de uma barreira contra a penetração de água e iniciadores de corrosão, e nas suas forças de adesão ao substrato, que pode ser obtida através da introdução de diversos grupos funcionais orgânicos na matriz de silanos, ajustando assim a sua composição química. Daí que os revestimentos obtidos por sol-gel representem uma via eficaz e ecológica para preparar filmes sobre substratos metálicos a baixo custo.With this in mind, silane based coatings made by the sol-gel process have attracted considerable interest because they are easy-to-process coating materials and have the potential to replace surface treatments based on chromates for Mg alloys [1-3 , 17-24]. The performance of such surface treatments essentially depends on a barrier against the penetration of water and corrosion initiators, and on their adhesion forces to the substrate, which can be obtained by introducing various organic functional groups into the silane matrix, thereby adjusting the their chemical composition. Hence sol-gel coatings represent an efficient and environmentally friendly way to prepare films on metal substrates at low cost.
Para além disso têm um método de aplicação facilmente adaptável na indústria. Os revestimentos sol-gel são assim, na perspetiva da síntese, vias versáteis para sintetizar revestimentos com propriedades específicas. A funcionalidade pode ser otimizada através da variação de parâmetros experimentais tais como estrutura química, composição e proporção de precursores e agentes de complexação, velocidade e condições de hidrólise, meio de 3 síntese, inclusão de espécies ativas adicionais, condições de cura e envelhecimento, método de deposição, etc [3].In addition they have an easily adaptable application method in the industry. Sol-gel coatings are thus, from the synthetic perspective, versatile ways of synthesizing coatings with specific properties. The functionality can be optimized by varying experimental parameters such as chemical structure, composition and proportion of precursors and complexing agents, rate and hydrolysis conditions, synthesis medium, inclusion of additional active species, conditions of cure and aging, method deposition, etc. [3].
Revestimentos sol-gel híbridos orgânico-inorgânicos revelam uma flexibilidade e espessura acrescidas quando comparados com os seus análogos exclusivamente inorgânicos. De uma forma geral estes revestimentos derivados de sol-gel têm revelado uma boa resistência à corrosão para substratos metálicos devido às suas propriedades barreira, forte adesão, inércia química, versatilidade da formulação do revestimento e facilidade de aplicação a temperatura ambiente [4,25].Organic-inorganic hybrid sol-gel coatings exhibit increased flexibility and thickness when compared to their exclusively inorganic analogues. In general, these sol-gel-derived coatings have shown good corrosion resistance for metallic substrates due to their barrier properties, strong adhesion, chemical inertia, versatility of the coating formulation and ease of application at room temperature [4,25] .
Frequentemente, inibidores de corrosão são adicionados ao sistema de forma a melhorar o desempenho e durabilidade e com capacidade de auto-reparação para reparar danos. A presença de aditivos deverá contribuir para uma redução da velocidade de corrosão. Este conceito assenta na recuperação de danos de corrosão através da libertação controlada de inibidores de corrosão contidos no revestimento orgânico com uma determinada organização ou apenas dispersos na matriz polimérica [2-4, 18-21, 26, 27].Often, corrosion inhibitors are added to the system in order to improve performance and durability and with self-repair capability to repair damages. The presence of additives should contribute to a reduction in the corrosion rate. This concept relies on the recovery of corrosion damage through the controlled release of corrosion inhibitors contained in the organic coating with a given organization or only dispersed in the polymer matrix [2-4,18-21,26,27].
Patentes dos EUA de Ostrovsky [28, 29] apresentam um tratamento para uma maior resistência à corrosão superficial para Mg e suas ligas. As patentes descrevem as soluções de decapagem ácida para pré-tratamento de superfície e as composições das soluções aquosas/orgânicas de silanos hidrolisados. As ligas de magnésio assim tratadas, revelaram a presença de picadas provocadas por corrosão após um período de 8 - 24 h, isto porque os revestimentos obtidos somente a partir de silanos (sem aditivos) não conseguem proteger eficazmente as ligas de 4 magnésio. Os tratamentos descritos nas patentes [28,29] visam essencialmente a aderência de sistemas de pintura ou a colmatagem de anodizados, não sendo eficazes na proteção anti-corrosiva por si mesmos.US patents by Ostrovsky [28, 29] present a treatment for increased surface corrosion resistance for Mg and its alloys. The patents describe acid pickling solutions for surface pretreatment and compositions of the aqueous / organic solutions of hydrolysed silanes. The magnesium alloys thus treated revealed the presence of bites caused by corrosion after a period of 8 - 24 h, because coatings obtained only from silanes (without additives) can not effectively protect the magnesium alloys. The treatments described in the patents [28,29] essentially aim at the adherence of painting systems or the sealing of anodized ones, not being effective in the anticorrosive protection by themselves.
Khramov et al. desenvolveram revestimentos sol-gel híbridos orgânico-inorgânicos com funcionalidades fosfonato [18, 19]. Dada a interação química entre grupos fosfonato e a superfície do substrato magnésio, estes revestimentos barreira de organo-silicatos especialmente desenvolvidos deverão resultar em revestimentos protetores com uma melhor adesão e resistência à corrosão para materiais de Magnésio. Os revestimentos organo-silicatos foram preparados através da hidrólise com catálise ácida e a condensação de uma mistura de TetraEtOxiSilano (TEOS) e dietilfosfonatoetil-trietoxisilano (PHS) numa solução de etanol/água numa baixa proporção água-silano.Khramov et al. have developed organic-inorganic hybrid sol-gel coatings with phosphonate functionalities [18,19]. Given the chemical interaction between phosphonate groups and the surface of the magnesium substrate, these specially developed organo-silicate barrier coatings should result in protective coatings with improved adhesion and corrosion resistance for magnesium materials. Organosilicate coatings were prepared by hydrolysis with acid catalysis and condensation of a mixture of TetraEtOxSilane (TEOS) and diethylphosphonate-triethoxysilane (PHS) in a water / silane solution in a low water-silane ratio.
Zhang et al. criaram um novo processo sol-gel, em que os aditivos adequados eram usados para estabilizar e dispersar homogeneamente os sais inorgânicos dos precursores (tais como o ião cério) ; a solução com o pH adequado podia ser aplicada directamente sobre as ligas de magnésio [17]. Montemor et al. [24] investigaram o comportamento protetor do tetrasulfeto de bis(trietoxisilispropilo) (BTESPT) modificado pela adição de nitrato de cério ou nitrato de lantânio por forma a incluir uma proteção ativa contra a corrosão no filme de silano.Zhang et al. created a novel sol-gel process, where suitable additives were used to homogeneously stabilize and disperse the inorganic salts of the precursors (such as the cerium ion); the solution with the appropriate pH could be applied directly on the magnesium alloys [17]. Montemor et al. [24] investigated the protective behavior of bis (triethoxysilispropyl) tetrasulfide (BTESPT) modified by the addition of cerium nitrate or lanthanum nitrate in order to include an active protection against corrosion in the silane film.
Lamaka et al. [3] desenvolveram revestimentos sol-gel híbridos orgânico-inorgânicos sintetizados por copolimerização de siloxano epóxi e alcóxidos de titânio ou 5 zircónio. A adição de fosfato de tris(trimetilsililo) melhorou significativamente a proteção contra a corrosão da liga de magnésio.Lamaka et al. [3] have developed organic-inorganic hybrid sol-gel coatings synthesized by copolymerization of epoxy siloxane and titanium or zirconium alkoxides. The addition of tris (trimethylsilyl) phosphate significantly improved the corrosion protection of the magnesium alloy.
Apesar de todos estes revestimentos contra a corrosão de ligas de magnésio serem mais ecológicos, ainda revelam algumas limitações dado gue apresentam uma baixa durabilidade e fraca resistência à corrosão mesmo contendo aditivos ativos. Alguns destes revestimentos foram testados apenas em soluções diluídas - 0, 005 M de NaCl e/ou por um curto período de tempo (30 minutos de imersão) [17-19]. Montemor [24] e Lamaka [3] conseguiram bons resultados em termos de resistência à corrosão, mas o desempenho foi apenas avaliado durante um período de imersão de uma e duas semanas respetivamente. Além disso, o eletrólito usado foi 0,05M de NaCl, que ainda é considerado diluído, quando comparado com a tendência atual da indústria e o que foi usado com o propósito da presente invenção.Although all these corrosion coatings of magnesium alloys are more environmentally friendly, they still show some limitations as they exhibit low durability and poor corrosion resistance even with active additives. Some of these coatings were tested only in dilute solutions - 0.005 M NaCl and / or for a short time (30 minutes immersion) [17-19]. Montemor [24] and Lamaka [3] achieved good results in terms of corrosion resistance, but performance was only assessed during a one and two-week immersion period respectively. In addition, the electrolyte used was 0.05M NaCl, which is still considered diluted, as compared to the current industry trend and what was used for the purpose of the present invention.
Muito bons resultados foram obtidos recentemente por Wang et al [22]. O revestimento híbrido sol-gel/polianilina aplicado sobre a liga AZ31 suportou imersão em 3,5% NaCl, com um valor de impedância a baixa frequência superior a IMOhm.cm2 após 27 dias de imersão. A espessura do revestimento era de cerca de 53 micrómetros. A preparação da superfície do substrato também tem um papel muito importante no desempenho geral da organização do revestimento, uma vez que a presença de impurezas em ligas de Mg tem efeito crucial no seu comportamento corrosivo [27, 30, 31] . Daí que as aplicações dos revestimentos sejam sempre precedidas por um procedimento de limpeza que pode consistir num simples lixamento e polimento ou num processo químico como a decapagem ácida. 6Very good results were recently obtained by Wang et al [22]. The sol-gel / polyaniline hybrid coating applied on the AZ31 alloy supported immersion in 3.5% NaCl, with a low frequency impedance value greater than IMOhm.cm2 after 27 days of immersion. The thickness of the coating was about 53 micrometers. The preparation of the substrate surface also plays a very important role in the overall performance of the coating organization, since the presence of impurities in Mg alloys has a crucial effect on its corrosive behavior [27, 30, 31]. Hence, the coating applications are always preceded by a cleaning procedure which can consist of a simple sanding and polishing or a chemical process such as acid etching. 6
Entre os ácidos usados para limpeza, o ácido fluoridrico (HF) tem sido alvo de uma atenção particular, por levar à formação de uma fina camada protetora na superfície do metal, melhorando a sua resistência à corrosão [32, 33] . Todos os revestimentos constituem uma barreira protetora contra a corrosão; no entanto uma vez que a água atinge a interface metal/revestimento, pode ocorrer delaminação do filme, acompanhada pela formação de um defeito devido à entrada de gás, o que diminui significativamente as propriedades de proteção. Daí que, seja necessário um pré-tratamento que remova impurezas, aumente a hidrofobicidade da superfície do metal e melhore a adesão. 0 HF é um bom candidato a este propósito, uma vez que cria estas características.Among the acids used for cleaning, hydrofluoric acid (HF) has been the subject of particular attention because it leads to the formation of a thin protective layer on the surface of the metal, improving its corrosion resistance [32,33]. All coatings provide a protective barrier against corrosion; however, once the water reaches the metal / coating interface, film delamination may occur, accompanied by the formation of a defect due to the gas inlet, which significantly decreases the protective properties. Hence, pretreatment is required to remove impurities, increase the hydrophobicity of the metal surface and improve adhesion. 0 HF is a good candidate in this regard as it creates these characteristics.
Resumo da invenção A presente invenção refere-se a revestimentos de proteção anti-corrosão para ligas de magnésio e respetivo método de preparação, de um modo particular, refere-se à composição de revestimentos, filmes formados sobre o substrato e as propriedades anti-corrosivas do sistema em geral, quando imerso num eletrólito agressivo. A sua composição compreende um silano (ex. aminopropiletoxisilano, APTES ou aminopropiltrimetoxisilano, APTMS), um componente epóxi (i. e. poli(bisfenol A-co-epicloridrina), com terminação glicidilo) e uma amina (i. e. dietilenotriamina), dissolvidos em solventes orgânicos.SUMMARY OF THE INVENTION The present invention relates to anti-corrosion protective coatings for magnesium alloys and their method of preparation, in particular, relates to the composition of coatings, films formed on the substrate and the anti-corrosive properties of the system in general, when immersed in an aggressive electrolyte. Its composition comprises a silane (eg, aminopropylethoxysilane, APTES or aminopropyltrimethoxysilane, APTMS), an epoxy component (i.e., glycidyl terminated poly (bisphenol A-co-epichlorhydrin)) and an amine (i.e., diethylenetriamine) dissolved in organic solvents.
Uma vasta gama de ligas de magnésio utilizadas na indústria aeronáutica e automóvel podem ser protegidas de uma forma eficaz utilizando o revestimento proposto nesta 7 invenção. As ligas de magnésio que podem ser protegidas incluem, mas não se limitam a, ligas com adição de alumínio como AZ31, AZ91 e AM60, ligas com adição de Zinco como a ZK30, ZK60 e ainda as ligas modificadas com terras raras como WE43, WE45, Elektron 21 e ZE41.A wide range of magnesium alloys used in the aeronautics and automotive industry can be effectively protected using the coating proposed in this invention. Magnesium alloys which may be protected include, but are not limited to, aluminum addition alloys such as AZ31, AZ91 and AM60, Zinc addition alloys such as ZK30, ZK60 and also rare earth modified alloys such as WE43, WE45 , Elektron 21 and ZE41.
Estes revestimentos podem ser aplicados sobre os substratos de ligas de Magnésio por imersão ou por spray, seguidos de uma cura térmica numa gama específica de condições. A espessura do revestimento varia de 5 a 20 micrómetros. O desempenho anti-corrosão deste revestimento é avaliado submergindo o produto final num ambiente agressivo, como NaCl, por um longo período de tempo e avaliando o efeito através de inspeção ótica e métodos eletroquímicos. Em particular, a espetroscopia de impedância eletroquímica (EIS) é usada para a análise, uma vez que permite que se estime a eficácia na proteção contra a corrosão dos revestimentos. A presente invenção pode ser utilizada em componentes automóveis e aeroespaciais, material desportivo, material eletrónico e em implantes biocompatíveis.These coatings may be applied to the substrate of magnesium alloys by immersion or spray, followed by a thermal cure in a specific range of conditions. The thickness of the coating ranges from 5 to 20 micrometers. The anti-corrosion performance of this coating is evaluated by submerging the final product in an aggressive environment, such as NaCl, over a long period of time and evaluating the effect through optical inspection and electrochemical methods. In particular, electrochemical impedance spectroscopy (EIS) is used for analysis as it allows the corrosion protection effectiveness of the coatings to be estimated. The present invention can be used in automotive and aerospace components, sports equipment, electronic material and biocompatible implants.
Descrição detalhada da invenção A presente invenção refere-se a revestimentos de proteção anti-corrosão para ligas de magnésio e respetivo método de preparação, de um modo particular, refere-se à composição de revestimentos, filmes formados sobre o substrato e as propriedades anti-corrosivas do sistema em geral, quando imerso num eletrólito agressivo. A composição do revestimento desta invenção compreende três ingredientes principais: um silano (aminopropiltrietoxisilano, APTES ou um componente epóxi aminopropiltrimetoxisilano, APTMS), (poli(bisfenol A-co-epicloridrina), com terminação glicidilo) e uma amina (dietilenotriamina, DETA) como reticulador (cross-linker). Os componentes epóxi e silano são inicialmente preparados em separado diluindo-os em solventes orgânicos, etanol e acetona, e deixando em agitação durante uma hora. Em seguida as duas soluções são misturadas e a amina adicionada. A concentração final dos componentes principais está compreendida entre 1 a 10 % (m/m) de silano, preferencialmente entre 3 a 5%, entre 5 a 50% (m/m) de epóxi, preferencialmente entre 30 a 40% e entre 0,5 a 10 % (m/m) de amina, preferencialmente entre 2 e 4%. A solução é agitada durante 1 a 6 horas antes da deposição do substrato, que pode ser efetuada por spray ou por imersão. A preparação das ligas de magnésio, aqui designadas a titulo de exemplo, por substratos consiste no polimento mecânico com papel de carbeto de silicio, seguido de decapagem química em ácido fluorídrico 12% durante 15 minutos. Este tratamento de decapagem é muito eficiente uma vez que ajuda a remover impurezas da superfície da liga e a formação de hidróxidos, óxidos e fluoretos de Mg na superfície metálica [25]. Isto é crucial para a formação de um revestimento anti-corrosão eficiente. 0 revestimento é aplicado nas ligas de magnésio mergulhando o substrato na solução do revestimento (dip-coating). O substrato é mergulhado 3 vezes, durante 5 segundos cada. Após a imersão, as ligas de magnésio tratadas, aqui designadas a título de exemplo por amostras, são curadas num forno a diversas temperaturas compreendidas entre 120°C e 180°C, durante um período de tempo 9 compreendido entre 0,5 a 5 horas, preferencialmente compreendido entre 1 e 2 horas. As espessuras dos revestimentos obtidas pelo procedimento descrito variam de 5 a 20 micrómetros, dependendo das condições específicas.DETAILED DESCRIPTION OF THE INVENTION The present invention relates to anti-corrosion coatings for magnesium alloys and their method of preparation, in particular, relates to the composition of coatings, films formed on the substrate and the anti- corrosive properties of the system when immersed in an aggressive electrolyte. The coating composition of this invention comprises three main ingredients: a silane (aminopropyltriethoxysilane, APTES or an epoxy aminopropyltrimethoxysilane component, APTMS), (glycidyl terminated poly (bisphenol A-co-epichlorhydrin)) and an amine (diethylenetriamine, DETA) as cross-linker. The epoxy and silane components are initially prepared separately by diluting them in organic solvents, ethanol and acetone, and allowing to stir for one hour. Then the two solutions are mixed and the amine added. The final concentration of the principal components is from 1 to 10% (m / m) silane, preferably from 3 to 5%, from 5 to 50% (m / m) epoxy, preferably from 30 to 40%, and from 0 , 5 to 10% (w / w) amine, preferably 2 to 4%. The solution is stirred for 1 to 6 hours prior to substrate deposition, which can be sprayed or immersed. The preparation of the magnesium alloys, designated by way of example, by substrates consists of mechanical polishing with silicon carbide paper, followed by chemical etching in 12% hydrofluoric acid for 15 minutes. This pickling treatment is very efficient as it helps remove impurities from the alloy surface and the formation of hydroxides, oxides and fluorides of Mg on the metal surface [25]. This is crucial for the formation of an efficient anti-corrosion coating. The coating is applied to the magnesium alloys by immersing the substrate in the coating solution (dip-coating). The substrate is dipped 3 times, for 5 seconds each. After immersion, the treated magnesium alloys, designated here by example as samples, are cured in a furnace at various temperatures of from 120øC to 180øC for a period of time ranging from 0.5 to 5 hours , preferably from 1 to 2 hours. The thicknesses of coatings obtained by the described procedure range from 5 to 20 micrometers, depending on the specific conditions.
As propriedades anti-corrosivas do produto final, ligas de magnésio revestidas, são avaliadas através de medições de espetroscopia de impedância eletroquímica (EIS) . Estas são feitas a potencial de circuito aberto (OCP) do sistema em estudo, na gama de frequências de 100kHz a lOmHz, através de um potenciostato no modo potenciostático. A amplitude da perturbação é de lOmV rms. A célula eletroquímica consiste numa montagem com três elétrodos: um elétrodo saturado de calomelanos (SCE) como referência, uma espiral de platina como contra-elétrodo, e o elétrodo de trabalho, que é o magnésio revestido. Os testes são efetuados no eletrólito 0,05M de cloreto de sódio. Por inspeção visual e ótica verifica-se que a superfície da amostra revestida está intacta e sem sinais de danos por corrosão, após um mês de imersão.The anti-corrosive properties of the final product, coated magnesium alloys, are evaluated by electrochemical impedance spectroscopy (EIS) measurements. These are made the open circuit potential (OCP) of the system under study, in the frequency range of 100kHz to 10mHz, through a potentiostat in the potentiostatic mode. The disturbance amplitude is 10 mV rms. The electrochemical cell consists of a three-electrode assembly: a calomel-saturated electrode (SCE) as a reference, a platinum coil as a counter-electrode, and the working electrode, which is the coated magnesium. The tests are performed on 0.05M sodium chloride electrolyte. By optical and visual inspection, the surface of the coated sample is intact and without signs of corrosion damage after one month of immersion.
Pelo contrário, as amostras não revestidas apresentam fortes sinais de corrosão e acumulação de produtos de corrosão na sua superfície. Este desempenho superior na proteção contra a corrosão é confirmado pelos resultados obtidos pelos testes de espectroscopia de impedância eletroquímica exibidos na Figura 1. Amostras da liga de magnésio AZ31 revestidas com um revestimento de espessura 12 ± 2pm, apresentam valores de impedância muito elevados e estáveis para tempos de imersão até 31 dias. Para estas amostras a resistência à corrosão não mostrou qualquer redução significativa. O facto da impedância não se alterar durante todo o período de imersão revela a ausência de 10 picadas ou outros fenómenos de corrosão. Os valores da impedância situam-se acima de 1 Gohm· cm2 após 31 dias de imersão, valores que são muitíssimo superiores aos reportados na literatura [1-3, 17-24, 26-33]. Estes resultados revelam que os revestimentos propostos têm um desempenho consideravelmente superior aos descritos na literatura. A presente invenção pode ser utilizada em componentes automóveis e aeroespaciais, material desportivo, material eletrónico e em implantes biocompatíveis.On the contrary, uncoated samples show strong signs of corrosion and accumulation of corrosion products on their surface. This superior performance in corrosion protection is confirmed by the results obtained by the electrochemical impedance spectroscopy tests shown in Figure 1. Samples of the AZ31 magnesium alloy coated with a coating thickness 12 ± 2pm have very high and stable impedance values for immersion times up to 31 days. For these samples the corrosion resistance showed no significant reduction. The fact that the impedance does not change throughout the immersion period reveals the absence of 10 bites or other corrosion phenomena. Impedance values are above 1 Gohm · cm2 after 31 days of immersion, values that are much higher than those reported in the literature [1-3, 17-24, 26-33]. These results show that the coatings proposed perform considerably better than those described in the literature. The present invention can be used in automotive and aerospace components, sports equipment, electronic material and biocompatible implants.
Descrição das figuras A Figura 1 representa graficamente a evolução da impedância eletroquímica, em função do tempo da amostra revestida imersa em 0,05M de cloreto de sódio.Description of the Figures Figure 1 graphically shows the evolution of the electrochemical impedance as a function of the time of the coated sample immersed in 0.05M sodium chloride.
Na Figura 1 (A) o eixo das ordenadas, identificado por Z, refere-se à impedância eletroquímica, expressa em Ω cm2 e o eixo das abcissas refere-se à Frequência, expressa em Hz .In Figure 1 (A), the ordinate axis, identified by Z, refers to the electrochemical impedance, expressed in Ω cm2 and the abscissa axis refers to the Frequency, expressed in Hz.
Na Figura 1(B) o eixo das ordenadas, identificado por Ângulo de Fase refere-se à fase, expressa em graus e o eixo das abcissas refere-se à Frequência, expressa em Hz.In Figure 1 (B) the ordinate axis, identified by Phase Angle, refers to the phase, expressed in degrees, and the abscissa axis refers to the Frequency, expressed in Hz.
Referências Bibliográficas 1. V. Barranco, N. Carmona, J. C. Galvan, M. Grobelny, L. Kwiatkowski, Μ. A. Villegas. Electrochemical study of tailored sol-gel thin films as pre-treatment prior to organic coating for AZ91 magnesium alloy. Prog. Org. Coat., 68 (4) : 347-355, 2010. 11 2. A. F. Galio, S. V. Lamaka, M. L. Zheludkevich, L. F. P. Dick, I. L. Muller, M. G. S. Ferreira. Inhibitor-doped sol-gel coatings for corrosion protection of magnesium alloy AZ31. Surf. Coat . Technol., 204 (9-10): 1479-1486, 2010. 3. S. V. Lamaka, M. F. Montemor, A. F. Galio, M. L.Bibliographical References 1. V. Barranco, N. Carmona, J. C. Galvan, M. Grobelny, L. Kwiatkowski, Μ. A. Villegas. Electrochemical study of tailored sol-gel thin films as pre-treatment prior to organic coating for AZ91 magnesium alloy. Prog. Org. Coat., 68 (4): 347-355, 2010. 11 2. A. F. Gallio, S. V. Lamaka, M. L. Zheludkevich, L. F. P. Dick, I. L. Muller, M. G. S. Ferreira. Inhibitor-doped sol-gel coatings for corrosion protection of magnesium alloy AZ31. Surf. Coat. Technol., 204 (9-10): 1479-1486, 2010. 3. S. V. Lamaka, M. F. Montemor, A. F. Galio, M. L.
Zheludkevich, C. Trindade, L. F. Dick, M. G. S. Ferreira. Novel hybrid sol-gel coatings for corrosion protection of AZ31B magnesium alloy. Electrochim. Acta, 53 (14): 4773- 4783, 2008. 4. R.G.Hu, S.Zhang, J.F. Bu, C.J. Lin, G.L. Song. Recent progress in corrosion of magnesium alloys by organic coatings. Prog. Org. Coat., 73: 129- 141, 2012. 5. G. L. Song and A. Atrens. Corrosion mechanisms of magnesium alloys. Advanced Engineering Materials, 1 (1): 11-33, 1999. 6. I. Ostrovsky, Y. Henn, Present State and future of magnesium application in aerospace industry, in: New Challenges in Aeronautics, ASTEC '07, Moscow, 2007. 7. R. Kar, P.A. Bonnefoy, R. J.Hansman. Dynamics of implementation of mitigating measures to reduce CO2 emissions from commercial aviation. Technical Report No. ICAT-2010-01, MIT International Center for Air Transportation (ICAT), June 2010 2010. 8. S.J. Xia, R. Yue, R.G. Rateick, V.I. Birss,Zheludkevich, C. Trindade, L. F. Dick, M. G. S. Ferreira. Novel hybrid sol-gel coatings for corrosion protection of AZ31B magnesium alloy. Electrochim. Acta, 53 (14): 4773-4783, 2008. 4. R.G.Hu, S.Zhang, J. F. Bu, C.J. Lin, G.L. Song. Recent progress in corrosion of magnesium alloys by organic coatings. Prog. Org. Coat., 73: 129-141, 2012. 5. G. L. Song and A. Atrens. Corrosion mechanisms of magnesium alloys. Advanced Engineering Materials, 1 (1): 11-33, 1999. 6. I. Ostrovsky, Y. Henn, Present State and future of magnesium application in aerospace industry, in: New Challenges in Aeronautics, ASTEC '07, Moscow, 2007 7. R. Kar, PA Bonnefoy, RJHansman. Dynamics of implementation of mitigating measures to reduce CO2 emissions from commercial aviation. Technical Report No. ICAT-2010-01, MIT International Center for Air Transportation (ICAT), June 2010 2010. 8. S.J. Xia, R. Yue, R.G. Rateick, V.I. Birss,
Electrochemical studies of AC/DC anodized Mg alloy in a NaCl Solution. J. Electrochem. Soc., 151 (3): B179-B187, 2004. 9. E.L. Schmeling, B. Roschenbleck, Μ. H. Weidemann, Method of producing protective coatings that are resistant 12 to corrosion and wear on magnesium and magnesium alloys, US Patent 4 978 432, 12/18/1990. 10. H. von Campe, D. Liedtke, B. Schum, Method and device for forming a layer by plasma-chemical process, US Patent 4915978, 04/10/1990. 11. D. E. Bartak, B.E. Lemieux, E.R. Woolsey, Hard anodic coating for magnesium alloys, US Patent 5 470 664, 11/28/1995. 12. H. Ardelean, P. Marcus, PCT/FR03/00313, WO 03/069026 Al, 2003, US Patent 7094327, 2006. 13. T.F. Barton, Anodization of magnesium and magnesium based alloys, US Patent 5 792 335, 08/11/1998. 14. Aalberts Industries Material Technologies. MAGPASS-COAT®: Chrome-free passivation of magnesium-based materiais. No web site da Mamesta: http://www.mamesta.nl/files/magpass-coat_engl.puf 15. AeroMagnesium. AeroMagnesium: Lightweight Solutions for aeronautics and defense. No web site da Aero-Magnesium Limited: http : //wwvj.magnesium--· technologies.com/var/249/469488-Aer o % 2 0Mg% 2 OFolder.pdf 16. Magnesium Elektron. Surface treatments for magnesium alloys in aerospace and defence - Datasheet: 256. No web site da Magnesium Elektron: ht tp://www.magnes i um-Electrochemical studies of AC / DC anodized Mg alloy in NaCl Solution. J. Electrochem. Soc., 151 (3): B179-B187, 2004. 9. E.L. Schmeling, B. Roschenbleck, Μ. H. Weidemann, Method of producing protective coatings that are resistant to corrosion and wear on magnesium and magnesium alloys, US Patent 4,978,432, 12/18/1990. 10. H. von Campe, D. Liedtke, B. Schum, Method and device for forming a layer by plasma-chemical process, US Patent 4915978, 04/10/1990. 11. D. E. Bartak, B. E. Lemieux, E. R. Woolsey, Hard anodic coating for magnesium alloys, US Patent 5,470,664, 11/28/1995. 12. H. Ardelean, P. Marcus, PCT / FR03 / 00313, WO 03/069026 A1, 2003, US Patent 7094327, 2006. 13. TF Barton, Anodization of magnesium and magnesium based alloys, US Patent 5, 792,335, 08 / 11/1998. 14. Aalberts Industries Material Technologies. MAGPASS-COAT®: Chrome-free passivation of magnesium-based materials. On the Mamesta website: http://www.mamesta.nl/files/magpass-coat_engl.puf 15. AeroMagnesium. AeroMagnesium: Lightweight Solutions for aeronautics and defense. On the Aero-Magnesium Limited website: http://wwvj.magnesium-e technologies.com/var/249/469488-Aer the% 2 0Mg% 2 OFolder.pdf 16. Magnesium Elektron. Surface treatments for magnesium alloys in aerospace and defense - Datasheet: 256. On the website of Magnesium Elektron: ht tp: //www.magnes i um-
elektron . com/data/downloads/'DS2 56SU0 . PDF 17. S. Y. Zhang, Q. Li, J. M. Fan, W. Kang, W. Hu, X. K. Yang. Novel composite films prepared by sol-gel technology for the corrosion protection of AZ91D magnesium alloy. Prog. Org. Coat., 66 (3): 328-335, 2009. 18. A.N. Khramov, V.N. Balbyshev, L.S. Kasten, R.A. Mantz. Sol-gel coatings with phosphonate functionalities 13 for surface modification of magnesium alloys. Thin Solid Films, 514 (1-2): 174 - 181, 2006. 19. A.N. Khramov, J.A. Johnson. Phosphonate-functionalized ormosil coatings for magnesium alloys. Prog. Org. Coat., 65 (3): 381 - 385, 2009. 20. J. Hu, Q. Li, X. Zhong, L. Zhang, B. Chen, Composite anticorrosion coatings for AZ91D magnesium alloy with molybdate conversion coating and Silicon sol-gel coatings, Prog. Org. Coat., 66 (3): 199-205, 2009. 21. S.V. Lamaka, G. Knõrnschild, D.V. Snihirova, M.G. Taryba, M.L. Zheludkevich, M.G.S. Ferreira, Complex anticorrosion coating for ZK30 magnesium alloy, Electrochim. Acta, 55 (1): 131-141, 2009. 22. H. Wang, R. Akid, M. Gobara. Scratch-resistant anticorrosion sol-gel coating for the protection of AZ31 magnesium alloy via a low temperature sol-gel route.elektron. com / data / downloads / 'DS2 56SU0. PDF 17. S. Y. Zhang, Q. Li, J. M. Fan, W. Kang, W. Hu, X. K. Yang. Novel composite films prepared by sol-gel technology for the corrosion protection of AZ91D magnesium alloy. Prog. Org. Coat., 66 (3): 328-335, 2009. 18. A.N. Khramov, V.N. Balbyshev, L.S. Kasten, R. A. Mantz. Sol-gel coatings with phosphonate functionalities 13 for surface modification of magnesium alloys. Thin Solid Films, 514 (1-2): 174-181, 2006. 19. A.N. Khramov, J.A. Johnson. Phosphonate-functionalized ormosil coatings for magnesium alloys. Prog. Org. Coat, 65 (3): 381-385, 2009. 20. J. Hu, Q. Li, X. Zhong, L. Zhang, B. Chen, Composite anticorrosion coatings for AZ91D magnesium alloy with molybdate conversion coating and Silicon sol-gel coatings, Prog. Org. Coat., 66 (3): 199-205, 2009. 21. S.V. Lamaka, G. Knõrnschild, D.V. Snihirova, M.G. Taryba, M.L. Zheludkevich, M.G.S. Ferreira, Complex anticorrosion coating for ZK30 magnesium alloy, Electrochim. Acta, 55 (1): 131-141, 2009. 22. H. Wang, R. Akid, M. Gobara. Scratch-resistant anticorrosion sol-gel coating for the protection of AZ31 magnesium alloy via a low temperature sol-gel route.
Corros. Sei., 52 (11): 2565 - 2570, 2010 . 23. X. Guo, M. An, P. Yang, C. Su, Y. Zhou, Property characterization and formation mechanism of anticorrosion film coated on AZ31B Mg alloy by SNAP technology, J. Sol-Gel Sei. Technol., 52 (3) 335-347, 2009. 24. M.F. Montemor, M.G.S. Ferreira. Electrochemical study of modified bis-[triethoxysilylpropyl] tetrasulfide silane films applied on the AZ31 Mg alloy. Electrochim. Acta, 52 (27): 7486 - 7495, 2007. 25. J. E. Gray and B. Luan. Protective coatings on magnesium and its alloys - a criticai review. J. Alloys Compd., 336 (1-2): 88-113, 2002. 26. S. Zhang, Q. Li, B. Chen, X. Yang, Preparation and corrosion resistance studies of nanometric sol-gel-based 14Corros. Sci., 52 (11): 2565-2570, 2010. 23. X. Guo, M. An, P. Yang, C. Su, Y. Zhou, Property characterization and formation mechanism of anticorrosion film coated on AZ31B Mg alloy by SNAP technology, J. Sol-Gel Sci. Technol., 52 (3) 335-347, 2009. 24. M.F. Montemor, M.G.S. Ferreira. Electrochemical study of modified bis- [triethoxysilylpropyl] tetrasulfide silane films applied on the AZ31 Mg alloy. Electrochim. Acta, 52 (27): 7486-7495, 2007. 25. J. E. Gray and B. Luan. Protective coatings on magnesium and its alloys - a review review. J. Alloys Compd., 336 (1-2): 88-113, 2002. 26. S. Zhang, Q. Li, B. Chen, X. Yang, Preparation and corrosion resistance studies of nanometric sol-gel-based 14
Ce02 film with a chromium-free pretreatment on AZ91D magnesium alloy, Electrochim. Acta, 55 (3): 870-877, 2010. 27. N. Scharnagl, C. Blawert, W. Dietzel. Corrosion protection of magnesium alloy AZ31 by coating with poly(ether imides) (PEI). Surf. Coat. Technol. , 203 (10 — 11) : 1423-1428, 2009. 28. I. Ostrovsky. Treatment for improved magnesium surface corrosion-resistance, US patent 7 011 719, 03/14/2006. 29. I. Ostrovsky. Treatment for improved magnesium surface corrosion-resistance, US patent 6 777 094, 08/17//2004. 30. U.C. Nwaogu, C. Blawert, N. Scharnagl, W. Dietzel, K.U. Kainer, Influence of inorganic acid pickling on the corrosion resistance of magnesium alloy AZ31 sheet. Corros. Sei., 51 (11): 2544-2556, 2009. 31. U.C. Nwaogu, C. Blawert, N. Scharnagl, W. Dietzel, K.U. Kainer, Effects of organic acid pickling on the corrosion resistance of magnesium alloy AZ31 sheet. Corros. Sei., 52 (6) : 2143-2154, 2010. 32. T. F. da Conceicao, N. Scharnagl, C. Blawert, W. Dietzel, K. U. Kainer. Surface modification of magnesium alloy AZ31 by hydrofluoric acid treatment and its effect on the corrosion behaviour. Thin Solid Films, 518 (18): 5209- 5218, 2010. 33. R.Supplit, T.Koch, Ulrich Schubert. Evaluation of the anti-corrosive effect of acid pickling and sol-gel coating on magnesium AZ31 alloy. Corros. Sei., 49 (7): 3015-3023, 2007.Ce02 film with a chromium-free pretreatment on AZ91D magnesium alloy, Electrochim. Acta, 55 (3): 870-877, 2010. 27. N. Scharnagl, C. Blawert, W. Dietzel. Corrosion protection of magnesium alloy AZ31 by coating with poly (ether imides) (PEI). Surf. Coat. Technol. , 203 (10-11): 1423-1428, 2009. 28. I. Ostrovsky. Treatment for improved magnesium surface corrosion-resistance, US patent 7 011 719, 03/14/2006. 29. I. Ostrovsky. Treatment for improved magnesium surface corrosion-resistance, US patent 6,777,094, 08/17/2004. 30. U.C. Nwaogu, C. Blawert, N. Scharnagl, W. Dietzel, K.U. Kainer, Influence of inorganic acid pickling on the corrosion resistance of magnesium alloy AZ31 sheet. Corros. Sci., 51 (11): 2544-2556, 2009. 31. U.C. Nwaogu, C. Blawert, N. Scharnagl, W. Dietzel, K.U. Kainer, Effects of organic acid pickling on the corrosion resistance of magnesium alloy AZ31 sheet. Corros. Sci., 52 (6): 2143-2154, 2010. 32. T. F. da Conceicao, N. Scharnagl, C. Blawert, W. Dietzel, K. U. Kainer. Surface modification of magnesium alloy AZ31 by hydrofluoric acid treatment and its effect on corrosion behavior. Thin Solid Films, 518 (18): 5209-5228, 2010. 33. R.Supplit, T.Koch, Ulrich Schubert. Evaluation of the anti-corrosive effect of acid pickling and sol-gel coating on magnesium AZ31 alloy. Corros. Sci., 49 (7): 3015-3023, 2007.
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US11530362B2 (en) | 2020-04-23 | 2022-12-20 | The Boeing Company | Organosiloxane-based surface treatments for enhancing the adhesion and lubricity of metal surfaces |
CN113913803B (en) * | 2021-09-28 | 2023-07-11 | 中国人民解放军空军工程大学 | Magnesium alloy chemical conversion composite film and preparation method thereof |
CN116694183B (en) * | 2023-06-07 | 2024-07-23 | 四川轻化工大学 | Magnesium alloy double-layer organic composite coating and preparation method thereof |
Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2006137861A (en) * | 2004-11-12 | 2006-06-01 | Origin Electric Co Ltd | Anticorrosive coating material composition for magnesium alloy and article having coating film made from the same |
CN101885940A (en) * | 2009-05-15 | 2010-11-17 | 北京化工大学 | Magnesium alloy anticorrosion coating and preparation method thereof |
Family Cites Families (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE3629000C1 (en) | 1986-08-27 | 1987-10-29 | Nukem Gmbh | Method and device for forming a layer by a plasma chemical process |
DE3808609A1 (en) | 1988-03-15 | 1989-09-28 | Electro Chem Eng Gmbh | METHOD OF GENERATING CORROSION AND WEAR RESISTANT PROTECTION LAYERS ON MAGNESIUM AND MAGNESIUM ALLOYS |
US5470664A (en) | 1991-02-26 | 1995-11-28 | Technology Applications Group | Hard anodic coating for magnesium alloys |
DE4205819A1 (en) * | 1992-02-26 | 1993-09-02 | Henkel Kgaa | Stable water free compsn. for anticorrosion layer on metal esp. aluminium@ or alloy - prepd. by reacting titanium alkoxide or zirconium alkoxide, silane contg. epoxy gps. and silane contg. amino gps. |
US5792335A (en) | 1995-03-13 | 1998-08-11 | Magnesium Technology Limited | Anodization of magnesium and magnesium based alloys |
DE60230420D1 (en) | 2001-06-28 | 2009-01-29 | Alonim Holding Agricultural Co | TREATMENT FOR IMPROVED SURFACE CORROSION RESISTANCE BY MAGNESIUM |
FR2835851B1 (en) | 2002-02-13 | 2004-04-23 | Univ Paris Curie | COMPOSITION FOR THE TREATMENT OF MAGNESIUM ALLOYS |
WO2008150568A2 (en) * | 2007-03-30 | 2008-12-11 | Ndsu Research Foundation | Hybrid coatings prepared from glycidyl carbamate resins |
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Patent Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2006137861A (en) * | 2004-11-12 | 2006-06-01 | Origin Electric Co Ltd | Anticorrosive coating material composition for magnesium alloy and article having coating film made from the same |
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