1, depending on what metal is passivated, iron is ferric oxide after passivation, aluminum after passivation alumina. Passivation is the gain of electrons by the strongly oxidizing elements of various concentrated acids, and the loss of electrons by the metal to form the corresponding dense oxides.
2, after iron passivation, Fe3O4 is generally generated by default, but in fact, FexOy is generated, the composition of the substance is generally very complex (not only the ratio of x and y, but also the structure of the crystal, may be very complex), and according to the different acid, concentration, temperature and so onAnd change (i.e. x and y will be different).
3, about the common passivation reaction is as follows: iron, aluminum and other active metals in dilute nitric acid or dilute sulfuric acid can be quickly dissolved, but in concentrated nitric acid or concentrated sulfuric acid dissolution phenomenon almost completely stopped, carbon steel is usually easy to rust, if the appropriate amount of nickel, chromium added to the steel, it will become stainless steel.
4, read, here is not much to say, if only to say proton acid, that is, the ability to protonate the substance, not to say how many free hydrogen ions. Even though they are both oxide films, they have different structures. Like metal, aluminum is formed on the surfaceHow does passivation work?
Common aluminum and iron are passivated in concentrated sulfuric acid and concentrated nitric acid. Passivation refers to the process by which the metal is oxidized by a strong oxidizer or electrochemical method to make the surface become inactive or blunt, which is a method to convert the metal surface into a state that is not easy to be oxidized and delay the corrosion rate of the metal.
Similar to aluminum, they are passivated because of the strong oxidation of concentrated sulfuric acid and concentrated nitric acid, generating an oxide film to wrap the metal and prevent the reaction from continuing to occur, that is, passivation. The reaction in the chemical equation above is only a small fraction of the real reaction and is quickly wrapped in an oxide film. If heatedI can continue to react.
The basic principle of passivation is that the strong oxidizing acid encounters the steel to produce an oxide film, which prevents the metal from further reacting with the acid.
The main function of the passivation layer is to reduce the surface recombination rate of the battery, so as to improve the photoelectric conversion efficiency of the battery. Reduced surface recombination rate In semiconductor materials, electron-hole pairs are created when photons strike the surface of the cell.
The role of the passivation layer in the battery is to strengthen the batteryWafer stability and improved photoelectric conversion efficiency. First, let's look at the basic structure of the battery. The cell, especially in the photovoltaic field, usually refers to the solar cell, which is the core part of the solar photovoltaic system, responsible for converting solar energy into electricity.
The main function of the passivation layer is to reduce the surface recombination rate of the battery, so as to improve the photoelectric conversion efficiency of the battery. In detail, the role of the passivation layer in the battery is crucial. As the core part of photovoltaic cells, the main function of the cell is to convert light energy into electricity.
The chip passivation layer is a protective layerThe function is to prevent the surface of the chip from being eroded by oxygen in the air. The PI layer of the chip is an electrical insulation layer, which is used to isolate the current leakage between the circuit in the chip and the external circuit.
1, such aluminum oxide passivation layer can prevent the metallized layer from being scratched, and has been practically applied in industrial production.
2, after the study of a variety of surface passivation film growth processes, including phosphorus silicon glass (PSG), lowWarm deposition silicon dioxide, chemical vapor deposition silicon nitride (Si3N4), aluminum oxide (Al2O3) and polyimide are the most suitable. The dielectric film in direct contact with the semiconductor is usually called the first passivation layer. 3. The principle of the process flow (as shown in the figure) is as follows: the essence is that under different conditions, the control reaction is carried out in different directions.
Stabilization of heavy metals in sludge Add some passivating agents, such as quicklime, fly ash and clay, etc., to increase pH. To convert heavy metals into hydroxidesLake, to achieve the effect of passivation of heavy metals and kill pathogenic bacteria.
For the production of active lime, passivation lime. Calcination of limestone produces active lime, and passivated lime can be produced after processing. Passivated lime has the advantages of moisture absorption and good blowing performance.
Passivated white ash powder and passivated magnesium powder in loading are used in the desulfurization production of steel. The product spherical magnesium powder has the advantages of small resting Angle, good fluidity, small amount in desulfurization, short treatment time, fast reaction speed, hot metal cooling bottom, small slag amount, and good desulfurization effect.
should not be the passivation film is not firm, is the phenomenon of white ash. This isSince passivation is caused by corrosion while coating, the reaction is too intense and excessive. To adjust the passivation solution formula can be improved.
White ash is the zinc on the surface of the galvanized layer has been corroded by oxidation, and the white ash will be removed by re-polishing, but the white ash will soon appear again. Coating or waxing the surface will delay the time of corrosion. The surface of the galvanized layer is generally passivated, anti-corrosion, and can not be damaged, otherwise it will be easy to generate white ash (corrosion).
Both sea blue and white gray refer to the color after galvanized treatment, and different colors can be obtained through different formulations of passivation fluids.
1, the main principle of passivation agent is to form a film on the metal surface through soaking or coating treatment to improve its corrosion resistance to the external environment.
2, metal passivation is to form a dense oxide film on the surface of the metal, so as to block the metal and the oxidizer to achieve the purpose of inhibiting metal corrosion.
3, the effect of passivation is to convert the metal surface into a state that is not easy to be oxidized, thusDelay the corrosion rate of metal.
4, the passivation mechanism can be explained by the film theory, that is, the passivation is due to the action of metal and oxidizing substances, and a very thin, dense, good covering performance is generated on the metal surface when the passivation film is firmly adsorbed on the metal surface. This film exists as an independent phase, usually a compound of oxidized metals.
5, passivation treatment The principle of passivation treatment we can use the film theory to explain, that is, passivation is due to the metal and the oxidizing medium, the action will generate a very thin (about 1nm) on the metal surface,A dense, well-coated passivated film that adheres firmly to a metal surface.
6, the principle of passivation agent under certain conditions, through its effect on the metal surface to form a dense oxide film (passivation film), in order to enhance the corrosion resistance of the metal. The passivating agent used by different metals should be different, such as concentrated nitric acid can passivate iron and aluminum.