44results about How to "Lessen the tendency to corrode" patented technology

The invention provides a preparation method of a superhydrophobic hydroxyapatite film layer on the surface of magnesium alloy. The preparation method comprises the following steps: performing surfacepretreatment, preparing a nano-structured hydroxyapatite layer by a hydrothermal method and performing hydrophobization treatment to the hydroxyapatite layer. The hydrothermal method is designed, andby the hydrothermal method, a rod-shaped hydroxyapatite crystal layer adopting micron-scale length and nano-scale diameter is prepared on the surface of the magnesium alloy, then a stearic acid film is prepared on the surface of the nano-structured hydroxyapatite film layer to form a superhydrophobic film layer with the contact angle of 153 degrees under a static droplet, the film layer can reducethe corrosion current density of the magnesium alloy by 2 orders of magnitude and the impedance modulus of coating is increased from 2029 Omega.cm2 to 117674 Omega.cm2. The preparation method of thenano-structured hydrophobic coating is simple, equipment is simple and easy to control, the cost is low, and the controllability is good; the preparation method is suitable for large-scale production.

The invention discloses a preparation method of a magnesium alloy surface super-hydrophobic fluorine conversion coating. The super-hydrophobic fluorine conversion coating of a micro / nano structure isprepared on the surface of a magnesium alloy by the adoption of a liquid-phase growth and hydro-thermal treatment combined method. Through cleaning, polishing, preparation of a fluorine conversion layer and hydrophobization treatment, a porous hydrophobic coating of a micro / nano structure is formed on the film layer. The contact angle of the coating in simulated body fluid reaches 150 degrees, thecontact area between a magnesium alloy sample and the liquid can be reduced, the corrosion current density of the magnesium alloy can be lowered by 3 grades, and the impedance magnitude is increasedfrom 12000 omega.cm<2> to 1400000 Omega.cm<2> and is increased by 100 times. The preparation method of the hydrophobic coating of the nano-structure is simple, equipment is simple and easy to control,cost is low, and the controllability is good.

An arrangement in a motor vehicle includes a support structure which is made of magnesium or of a magnesium alloy and includes at least one solid portion. Further, the arrangement includes an electronic component which is supported or held by the support structure, and a connection arrangement having a connection element which is at a prespecified electrical potential. At least one self-tapping screw is self-tapped into the solid portion of the support structure and thereby mechanically connects the support structure to the connection arrangement.

The invention discloses a fuel-cell bipolar plate with a nitrified and enhanced surface and a preparation method thereof and belongs to the technical field of fuel cells. The bipolar plate is prepared by the following steps of: preparing a nitrified layer, a chromium-nitride thin film and a carbon-based nano composite conductive thin film on the two side surfaces of a matrix of a stainless-steel plate or a titanium-alloy plate in sequence, cleaning and drying the matrix of the stainless-steel plate or the titanium-alloy plate, then putting the matrix in vacuum-arc ion-plating equipment, introducing nitrogen and hydrogen under the vacuum condition, starting bias voltage and hot wires, and preparing the nitrified layer; and introducing argon-nitrogen mixed gas, preparing the chromium-nitride thin film, opening a carbon target and preparing the carbon-based nano composite conductive thin film. The fuel-cell bipolar plate disclosed by the invention has the advantages that an ion nitrification technology is introduced into the field of surface modification of the fuel-cell bipolar plate, and the nitrified layer is prepared on the surface, so that the passivation of the matrix can be avoided, the condition that a coating fails due to corrosion can be effectively prevented; and a stepped transition method is adopted for multi-element composition of the chromium-nitride thin film and the nano composite conductive thin film, so that the peeling of the coating in the use process due to overlarge internal stress and oversmall bonding force is prevented.

The invention discloses a method for using a strong electrolyte solution to inhibit the corrosion of a hydraulic steel structure. The specific steps are as follows: (1) Add a strong electrolyte to the solution where the hydraulic steel structure is located until the conductivity of the aqueous solution is greater than 20000µS / cm, and then connect the protected hydraulic steel structure with the titanium anode to form a closed loop; (2) polarize for a period of time, measure the potential of the hydraulic steel structure; (3) if the hydraulic steel structure If the surface potential is lower than ‑0.85V, it indicates that the corrosion of the hydraulic steel structure is inhibited; if the surface potential is higher than ‑0.85V, repeat steps (1)‑(2) until the surface potential is lower than ‑0.85V ; Strong electrolytes are salts of strong acids and strong bases. Adopting the method for inhibiting the corrosion of hydraulic steel structural parts provided by the present invention can prevent the metal from being continuously oxidized and corroded, and can further change the corrosion characteristics of the solution by adjusting the conductivity of the reaction solution in which the metal is located, so as to slow down the tendency of metal corrosion .

The invention discloses a stirring and friction welding device which mainly comprises a high-speed motor, a stirring head connected onto the output shaft of the high-speed motor, as well as a stirring pin and two shaft shoulders, and the contacting surface between the two shaft shoulders and the weld assembly is of an arc supporting sector. According to the stirring, friction and welding device provided by the invention, the welding seam height is increased, and the welding seam intensity is improved as well.

A high-potential Mg alloy used as consumable anode for the underground oil or gas pipeline, storage tank and water pipe is prepared through micro-alloying the Mg-Mn alloy by Mg-Ca and Mg-RE intermediate alloys, and refining by use of special refining agent to obtain Mg MnRECa alloy, which contains proportionally Mn, Ce, Ca, Si, Cu, Ni, Fe and Mg. Its advantages are high open-circuit potential 1.7-1.8 (-V) and high current efficiency (55-60%).

The invention discloses an aluminum and aluminum alloy spiral tube molding welding device. The aluminum and aluminum alloy spiral tube molding welding device is characterized by mainly comprising a spiral tube molding device fixedly installed at one end of a machine frame and a stirring friction welding device fixedly installed at the other end of the machine frame. The stirring friction welding device mainly comprises a high-speed motor, a stirring head connected to an output shaft of the high-speed motor and comprising a stirring needle and two shaft shoulders and at least two sets of rotary rollers arranged on the stirring friction welding device in a rotary mode. The aluminum and aluminum alloy spiral tube molding welding device is wide in adaptation, high in efficiency and capable of satisfying welding production of aluminum and aluminum alloy spiral welding tubes of various types.

The invention provides a brazing material alloy, a brazing material, a preparation method and application thereof, and a prepared brazing product, and relates to the technical field of welding materials. The above-mentioned solder alloy is prepared on the basis of traditional Zn-Al-based solder by adding Mg, Ni, Cr, Ga and rare earth elements in a specific composition ratio. Among them, Ni in the above-mentioned solder alloy can increase the strength of the solder; Mg can increase the electrode potential of the solder; Cr can form a dense oxide film to reduce the corrosion rate; Ga can improve the adhesion of corrosion products, making it evenly covered on the solder On the surface, the exposed area of ​​solder is reduced; rare earth elements can refine the grains and purify the interface, reducing the tendency of intergranular corrosion. The present invention can realize synergistic effects through the reasonable proportioning of the above-mentioned components, while improving the brazing strength of the brazing filler metal, it can also ensure that the brazing filler metal has good corrosion resistance, and can fully meet the requirements of existing aluminum- Process requirements for brazing connections of copper materials.

The invention discloses an Mg-Mn-Ca-Zn-Sr sacrificial anode with high current efficiency, which belongs to the technical field of sacrificial anodes and is characterized by comprising the following elements in percentage by weight: 0.93 percent of Mn, 0.13 percent of Ca, 0.05 percent of Zn, 0.07 percent of Sr, less than 0.045 percent of Si, less than 0.018 percent of Cu, less than 0.001 percent of Ni, less than 0.030 percent of Fe, and the balance of Mg. Aiming at the defect that the conventional magnesium anode has low current efficiency, by adding trace elements, the dissolution evenness and corrosion resistance of the magnesium anode are increased, and the current efficiency of the magnesium anode is improved.