2113 results about "Micro arc oxidation" patented technology

The present invention relates to a nanoporous configuration for drug release used in a drug-eluting device and its preparation, employing acid corrosion or anode oxidation to prepare pores, or employing acid corrosion to prepare pores firstly, then employing anode oxidation or micro-arc oxidation combined with micro-arc nitridation to prepare single sized or two sized or multiple sized nanopores, as well as a uniform size distributed or two or more nonuniform size distributed in pore diameter or pore depth h nanopores on the raw material of device body directly. The preparation process includes: ① Pre-treating the surface of the device body, ② Preparing pore, ③ Post-treating the surface of the device body, ④preparing drug, ⑤ Spraying drug etc. The nanoporous configuration lowers the risk of forming thrombus after the drug-delivery device with polymer carrier is implanted into the tissue. The device also controls the release rate of drug efficiently and lowers the incidence of restenosis significantly.

The invention discloses a ceramic membrane layer on a metal surface and a preparation method thereof. The preparation method comprises the following step of carrying out preset type laser cladding or synchronous laser cladding on the ceramic membrane layer and ceramic powder obtained in a micro-arc oxidation process, so as to prepare the ceramic membrane layer. The invention further discloses the ceramic membrane layer prepared by using the preparation method. By utilizing the method, the thickness of the micro-arc oxidation ceramic membrane layer is increased, so that the purposes of increasing the abrasion resistance and corrosion resistance are reached, and the problem that a micro-arc oxidation ceramic membrane layer at present is too thin to meet application to a brake disc and the like with high requirements on the abrasion resistance is solved.

The invention provides a method for processing the surface of magnesium-lithium alloy. The technique of micro-arc oxidation is successfully applied to processing the surface of the magnesium-lithium alloy. Direct current/ DC pulse/alternating current pulse multiplex power supply is used and the magnesium-lithium alloy with different lithium contents in a compound electrolyte system of sodium polyphosphate, sodium silicate, calgon and sodium hydroxide is carried out by micro-arc oxidation for 2-120min. A ceramic oxide film of 10-100Mum with a rigidity higher than 200Hv is formed in situ on the surface of the magnesium-lithium alloy, thus remarkably improving corrosion resistant property compared with an alloy matrix, solving the problem known at home and abroad concerning processing the surface of the magnesium-lithium alloy and broadening the application in the fields of aviation, aerospace, car, electronic, etc.

The invention discloses a method for preparing an antisepsis and antiwear ceramics coating layer on the surface of alloy through microarc oxidation. The method includes three steps of collocating electrolyte, arranging power electric parameters and microarc oxidation treatment; wherein, the component concentrations of the electrolyte are sodium silicate of 20 to 100g/L, sodium hydroxide of 5 to 10g/L and organic amine additive of 5 to 15ml/L; the current density of unit area is 50 to 100A/centiare; the pulse frequency is 100 to 700Hz; the pulse dutyfactor is 20 to 90 percent; the temperature of the electrolyte in the microarc oxidation treatment is not higher than 45 DEG C. The method needs lower unit power density and has fast film forming speed to prepare the ceramics coating layer on the surface of aluminum and magnesium alloys; the method adopts 100KVA power which can treat at least 2 centiares of the surface area of the aluminum alloy for one time; the growing speed of the ceramics coating layer can reach 1 to 1.5 micron/min. The formed ceramics coating layer is uniform and compact; the rigidity of the aluminum alloy can reach 1200 to 1300Hv.

The invention discloses a method for preparing biomedical titanium and titanium alloy surface antibacterial coatings. The method comprises steps of firstly, processing the surface of a biomedical titanium or titanium alloy sample to be processed, immersing the biomedical titanium or titanium alloy sample in a glycol aqueous solution containing soluble fluoride and performing an anode oxidation treatment; secondly, immersing the biomedical titanium or titanium alloy sample after being subjected to the anode oxidation treatment in a silver nitrate solution, taking out the biomedical titanium or titanium alloy sample, using ultraviolet light radiation to process the biomedical titanium or titanium alloy sample and obtaining the silver-carrying biomedical titanium or titanium alloy sample; and performing a micro-arc oxidation treatment for the silver-carrying biomedical titanium or titanium alloy sample, performing ultrasonic cleaning and vacuum drying and obtaining the antibacterial coatings. The nano precoating layer preparation, the silver-carrying treatment and a micro-arc oxidation technology are combined, then a large amount of silver can be fixed on the biomedical titanium and titanium alloy sample surfaces and can be released slowly for a long time, the antibacterial performance of titanium and titanium alloys is greatly improved, the antibacterial effect can be kept for a long time, and the bacterial infection caused by the fact that a titanium and titanium alloy apparatus is embedded in a human body is greatly reduced or avoided.

This invention discloses a surface treatment method for Mg-based material. The method comprises: (1) performing micro-arc oxidation treatment on Mg or Mg alloy work piece as the anode in a Cl--free alkaline micro-arc oxidation electrolyte; (2) activating; (3) performing preliminary chemical plating of Ni; (4) performing chemical plating of Ni; (5) performing thermal treatment. The micro-arc oxidation treatment comprises: (1) applying a positive pulse with an average current density of 5-20 A/dm2 until the voltage is automatically elevated to a critical value, and applying a constant working voltage of 50-80 V (total time = 5-30 min); (2) applying a positive pulse of 30-300 V and a negative pulse of 0-200 V with an average current density of 0.5-15 A/dm2 (total time = 10-60 min). The activation comprises: (1) performing anode alkaline coarsening treatment for 3-10 min; (2) performing surface activation treatment; (3) performing cathode alkaline electrification reduction activation treatment; (4) performing cathode acidic electrification dispergation activation treatment. The treated Mg alloy work piece has high corrosion resistance of ceramic materials and the properties and touch sense of metal materials.

The invention provides a preparation method of a magnesium alloy surface micro-arc oxidation/spray coating compound film, which relates to a preparation method of a magnesium alloy surface compound film. The invention solves the problems that film layers obtained by chemical composition coating, anodic oxidation and vapor deposition in the existing magnesium alloy surface treatment method are thin and have poor corrosion resistance performance, the ion injection has high cost and is difficult to realize large-area processing, the combining force between coating layers and the magnesium alloy is poor, and organic coating layers has the defect of easy aging. The preparation method has the following steps: firstly, using micro-arc oxidation for preparing ceramic films on the surface of the magnesium alloy; then, adopting air spray coating for spraying and coating inorganic paint onto the ceramic films; and then, carrying out heat treatment to obtain the micro-arc oxidation/spray coating compound film. The method is simple, and the cost is low. The air spray coating uses porous structures of the micro-arc oxidation ceramic films, so the combination of the inorganic coating layers and the ceramic films is firm, the thickness of the compound films is between 20 and 40 mum, the self corrosion electric potential is positively moved to -1.02 V, the corrosion current density is lowered by 5 orders through being compared with that of the magnesium alloy, the magnesium alloy surface micro-arc oxidation/spray coating compound film has no damage after 72 to 144h of salt spray tests, and the corrosion resistance performance is good.

The invention discloses a micro-arc oxidation electrolyte and a micro-arc oxidation method. The micro-arc oxidation electrolyte comprises the following components: a basic solution, a wear-resisting agent, a pore sealing agent and a dispersing agent, wherein the basic solution is phosphate and silicate aqueous solution of pH 8-12, the wear-resisting agent is graphite powder, the pore sealing agent is silica powder or alumina powder, and the dispersing agent is polyoxyethylenealkylphenol ether. The micro-arc oxidation electrolyte of the invention is simple in composition, and easy in control. Light metal parts to be plated are subjected to micro-arc oxidation using the micro-arc oxidation electrolyte of the invention, and are directly subjected to pore sealing treatment in the micro-arc oxidation process without after-treatment. The process of the invention is simple, and obtained micro-arc oxide film layer is high in hardness, and is good in abrasion resistance and corrosion resistance.

The present invention relates to a process for preparing hydroxylapatite bio-ceramic membranes at titanium or titanium alloy surfaces by utilizing differential arc oxidation process. Firstly, preparing electrolytic solution A by using calcium ion salts and phosphate radical ion-containing salts, or preparing electrolytic solution B by adding metal silver ions to the electrolytic solution A; or preparing electrolytic solution C by adding metal silicon ions to the electrolytic solution A; and then, selecting titanium or titanium alloy as anodes and putting them respectively into the electrolytic solution A, B and C, selecting the non-corrodible steel container for containing the electrolytic solutions as cathodes, controlling conditions such as impulse electrical source positive phase voltage, frequency for differential arc oxidation of titanium or titanium alloy, then hydroxylapatite bio-ceramic membrane layers possessing different performances are prepared. Said titanium based bio-ceramic compound material prepared according to said process possesses not only intensity and toughness of metals but also biological activity of hydroxylapatites, and is capable of being applied in the fields such as jackstraw chirurgery implantation body and tooth planting body.

The invention discloses a method for preparing magnesium alloy super-hydrophobic surface. The method comprises: cleaning the magnesium alloy after conventional pretreatment, adopting the micro-arc oxidation technique to form a roughening micro/nano porous surface on the surface of a sample in a phosphate electrolyte, treating the surface in an acrylic acid solution, performing spin coating of ethylene dimethyl silicone polymer on the surface, and drying the processed sample to prepare the magnesium alloy super-hydrophobic surface.

The invention relates to an environmentally-friendly magnesium alloy chemical conversion film, microarc oxide film hole sealing solution and a hole sealing method. The hole sealing solution comprises phytate or phytic acid and one or more following substances of alkali metal hydroxide, silicate, phosphoric acid or phosphate. The hole sealing method is operated according to the following steps: preliminary treatment; chemical conversion or micro-arc oxidation; post treatment: in phytate, one of or several kinds of silicate, phosphoric acid or phosphate are added, the pH value of solution is adjusted by the alkali metal hydroxide or ammonia water, solution temperature is controlled at 30-100 DEG C, and hole sealing treatment is carried out. The hole sealing solution used by the invention does not contain Cr6 and F-, thus causing no pollution to environment. After sealing holes, the size of the crack or the micropore of the chemical conversion film or oxide film is obviously decreased, and corrosion resisting property is improved; meanwhile, the film layer and the organic coating obtained by next-step painting have favourable adhesive force.

An exemplary housing includes a light metal base and a ceramic film. The light metal base has an outer surface. The ceramic film is formed on the outer surface of the light metal base by micro-arc oxidation process. A method for making the present housing is also provided.

The invention discloses a corrosion-resistant magnesium alloy bracket and a preparation method thereof, which relate to a magnesium alloy bracket with a corrosion-resistant coating and the preparation method thereof. The bracket and the method solve the problems of low bonding strength between the coating and a substrate, poor corrosion-resistant lasting stability, low mechanical bearing capacity and poor bracket coordination and deformation ability of the traditional magnesium alloy bracket. The corrosion-resistant magnesium alloy bracket is prepared by growing a ceramic coating in situ on the surface of the magnesium alloy by a micro-arc oxidation process. The method of the invention comprises the following steps: 1, processing the magnesium alloy to make a net-like bracket and removing oil to obtain the magnesium alloy bracket; 2, performing the micro-arc oxidation reaction; and 3, cleaning and drying the bracket to obtain the corrosion-resistant magnesium alloy bracket. The product of the invention is high in hardness and relatively high in tenacity and can coordinate with a substrate bracket to deform; and the ceramic coating is insusceptible to falling off and is high in body fluid corrosion resistance, so life cycle of the embedded bracket can be prolonged to a maximum extent. The method is simple and low in cost and can realize mass production. The product of the invention is suitable for implants with complex shapes, such as brackets, and is convenient to promote and use.

A surface treatment method of a light metal material comprises the following steps of forming a micro-arc oxide film on the surface of the light metal material, and sequentially subjecting the surface of the light metal material with the micro-arc oxide film to laser etching and anode oxidization. The light metal material obtained by the method in the invention has the advantages of very high hardness, abrasion resistance, corrosion resistance and electrical insulation, strong appearance decoration, bright and diversified color and three-dimensional pattern, thus greatly improving the additional value of the light metal material.

The present invention features that the composite ceramic film consists of two layers, the inner layer film of silicon-containing composite Mg-Al oxide and the outer layer film of Mg-Al silico-oxide of 5-70 micron thickness each. The composite ceramic film is formed through surface treatment, degreasing, neutralizing, water washing, micro-arc anodizing, water washing, drying, closing treatment or painting. The composite ceramic film has no holes and cracks, high corrosion resistance, high wear resistance and smooth surface.

The present invention relates to a magnesium alloy surface microarc oxidation method. Said method includes the following steps: (1), pretreatment; (2), preparing alkaline silicate electrolyte or alkaline aluminate electrolyte; and (3), placing the pretreated magnesium alloy in the alkaline silicate electrolyte or alkaline aluminate electrolyte and making microarc oxidation; applying DC current, continuously rising voltage, constant current, current density is 1-15 A/sq.dm, galvanization time is 5-90 min and electrolyte temperature is less than 40 deg.C.

The invention discloses pure-titanium metal surface micro-arc oxidation treatment electrolyte and an antimicrobial bioactive coating preparation method thereof, belongs to a medical titanium metal surface modification technology, and aims to provide a micro-arc oxidation treatment electrolyte which can remarkably improve pure-titanium metal surface bioactivity and coating bonding strength and a coating preparation method thereof. The electrolyte comprises a compound system including the components of calcium acetate, sodium phosphate and a zinc oxide precursor, wherein the phosphorous ion concentration is 0.5 to 1.0 M, the molar ratio of Ca to P is 0.2 to 1.0, and the designed Zn<2+> concentration accounts for 10 to 20 percent of the total concentration. A biological composite coating is directly generated on the surface of a titanium metal surface in-situ by adopting the electrolyte and a micro-arc oxidation technology. The coating has high bonding strength with a substrate, dense inner layer, coarse and porous outer layer, high bioactivity and high antibacterial property; moreover, the used raw materials are easy to obtain; the process is simple and easy to operate; and the electrolyte has stability, reusability, and low production cost and is suitable for industrial production.

The invention discloses a method for preparing a dense enhancement type ceramic membrane based on micro-arc oxidizing and laser remelting, and relates to a method for preparing a dense enhancement type ceramic membrane on the surfaces of light metals such as magnesium, aluminium and titanium and other alloys. The method is used for solving the problems that a micro-arc oxidizing surface treatment technology for preparing the dense enhancement type ceramic membrane on the surfaces of light metals such as magnesium, aluminium and titanium and other alloys cannot have low energy consumption and high membrane performance at the same time. The method comprises steps of: 1, pretreatment of basic materials; 2, working liquid preparation treatment; 3, micro-arc oxidation; and 4, laser remelting treatment of the micro-arc oxidation (MAO) membrane, and thus obtaining a sample piece of the dense enhancement type ceramic membrane. The prepared membrane has good binding force with a base body, dense tissues, low porosity, high hardness and good corrosion resistance and wear resistance; and the porosity of the membrane can be reduced to below 3%, the harness number can be improved by double times of the original MAO membrane which is not subjected to laser remelting treatment. The method can be used for preparing the dense enhancement type ceramic membrane on the surfaces of light metals such as magnesium, aluminium and titanium and other alloys.

The invention relates to a method for preparing a titanium-alloy surface micro-arc oxidation antifriction compound film layer, which is characterized by comprising the following steps of: (1) micro-arc oxidation of an electrolyte; and (2) preparation of a compound film. The invention has the technical effects that: 1. the method provided by the invention is used for preparing the micro-arc oxidation compound film layer with an antifriction effect by introducing a solid lubricant and experimenting on a one-step method in the titanium-alloy micro-arc oxidation process on the premise of not destroying a micro-arc oxidation film layer, and the antifriction effect is remarkable; and 2. the composition raw materials of a sodium-silicate system electrolyte adopted by the invention are simply and easily obtained, a solution is neutral or weakly alkaline, the solution does not contain heavy metal ions, such as chromium ions and the like or environment-friendly constraint elements and does not contain substances harmful to human bodies and environments, the environmental pollution is small, and the requirements of high-quality clean production are satisfied.

The invention discloses a method for preparing a magnesium-based ceramic coating by micro-arc oxidation-electrophoretic deposition. The method comprises the following steps of: immersing preheated magnesium alloy taken as an anode in an electrolyte, taking a micro-arc oxidation stainless steel electrolytic cell as a cathode, adopting a direct-current pulsed micro-arc oxidation device, carrying out micro-arc oxidation for 10-25 minutes under the conditions that the electric current is 10-20A/dm<2>, the duty ratio is 37.5-50%, and the temperature of the electrolyte is 20-30 DEG C, taking out the anode, naturally drying, thus obtaining magnesium alloy subjected to micro-arc oxidation; immersing the magnesium alloy subjected to micro-arc oxidation and taken as the anode in electrophoretic deposition liquid, taking the stainless steel electrolytic cell as the cathode, adopting a pulsed power supply, carrying out electrophoretic deposition treatment for 10-30 minutes under the conditions that the voltage is 250-350V, and the duty ratio is 37.5-50%, naturally cooling, thus obtaining the magnesium-based ceramic coating. The adhesive force of the biological nanometer coating is obviously enhanced, the toughness and the corrosion resistance of the coating are improved, and the coating has certain biological activity.

The invention discloses a micro-arc oxidation-electrodeposition preparation method of a magnesium-based bioactive coating. The preparation method comprises the following steps: putting a magnesium-based base material in micro-arc oxidation electrolyte after pretreatment to perform micro-arc oxidation reaction to obtain a micro-arc oxidation coating sample; then, putting the micro-arc oxidation coating sample in electrodeposition electrolyte to perform electrodeposition reaction; and after electrodeposition, taking the sample out, and washing and drying the sample. The micro-arc oxidation-electrodeposition preparation method has the advantages that a biologic coating prepared by the method has high binding property with a base material; and the entire biologic coating has excellent corrosion resistance, bioactivity and compatibility; moreover, the formed bioactive coating is a composite coating (comprising HA, OCP, Mg3(PO3)2 and MgO); and because the composite coating comprises OCP, problems that the degradation of pure HA is difficult are avoided and only an HA crust is left after the degradation of formed magnesium alloy can be avoided.

The invention relates to a magnesium alloy micro-arc oxidation electrolyte and a micro-arc oxidation method. The electrolyte comprises phytate (or phytic acid), a calcic electrolyte, and further one or more added electrolytes as follows: carbonate, silicate, boric acid or borate, and aluminate or aluminum hydroxide. The micro-arc oxidation method comprises the following steps of: pre-treatment; micro-arc oxidation; and post-treatment. The micro-arc oxidation electrolyte provided by the invention does not contain Cr<6+>, F<-> and PO4<3->, and even if strong base used is less, so that the environment is not polluted. The film obtained by the micro-arc oxidation method is smooth in surface, good in corrosion resistance and better in antibacterial performance and biological activity. According to the method, raw materials are easily available, and the method is suitable for industrialized production.

The invention belongs to the technical field of surface treatment, and relates to a preparation method of a ceramic film through chemical conversion and micro-arc oxidation of aluminum and aluminum alloy. The preparation method comprises: cleaning aluminum and aluminum alloy, and then carrying out chemical conversion treatment on the cleaned aluminum and aluminum alloy to generate chemical conversion film containing metal ions; and then placing the chemical conversion film in a micro-arc oxidation electrolyte and carrying out micro-arc oxidation treatment on the chemical conversion film to obtain dark micro-arc oxidized ceramic film. In the preparation method provided by the invention, different metal cations such as Mn<7+>, Mo<6+>, Ni<2+>, Ce<2+>, Co<2+> and Zr<2+> are introduced to formthe chemical conversion film containing the corresponding metal ion on the surfaces of the aluminum and aluminum alloy, then the chemical conversion film is placed in different micro-arc oxidation electrolytes, the micro-arc oxidized ceramic film with improved corrosion resistance is obtained by virtue of micro-arc oxidation treatment, and simultaneously the film is colored.