Electroplating industry term
Common nouns
This standard includes terms and explanations commonly used in electroplating professions, and is applicable to electroplating and electroplating-related processes.
1. Chemical corrosion--chemical corrosion
The corrosion (oxidation) process of metals under non-electrochemical effects. Usually refers to corrosion caused by pure chemical action in non-electrolyte solutions and dry gases.
2. Electric double layer--electric double layer
There are charge layers of equal size and opposite sign on the interface between the electrode and the electrolyte solution.
3. Bipolar electrode--bipolar electrode
A conductor that is not connected to an external power source and is immersed in the electrolyte between the anode and the cathode. The part of the conductor near the anode functions as the cathode, and the part near the cathode functions as the anode.
4. Dispersion ability--throwing power even plating ability
Under certain conditions, the ability of a certain solution to make the coating distribution on the electrode (usually the cathode) more uniform than the result obtained by the initial current distribution.
This term can also be used for the anode process, and its definition is similar to the above.
5. Decomposition voltage --decomposition voltage
The definition is similar to the above.
The minimum voltage at which the electrochemical reaction can continue at a significant speed (the ohmic voltage drop of the solution is not included).
6. Insoluble anode (inert anode)--inert anode / insoluble anode
When the current is passed, the anode dissolution reaction does not occur.
7. Electrochemistry--electrochemistry
The science of studying the properties of the contact interface between electronic conductors and ion conductors and their changes.
8. Electrochemical polarization (activation polarization)--activation polarization
Polarization caused by difficulties encountered in the progress of electrochemical reactions.
9. Electrochemical corrosion--electrochemical corrosion
The metal corrosion (oxidation) process that is subject to the law of electrochemical reaction in the liquid film on the surface of the base hydrolysate
10. Electrochemical equivalent--electrochemical equivalent
Pass a unit of electricity on the electrode (for example, 1 Ampere hour, 1 Coulomb or 1 Faraday hour), and the electrode reacts to form the theoretical weight of the product. It is usually expressed in grams/coulomb or grams/amp-hour.
11 Conductivity (specific conductivity) --conductivity
The conductance of a conductor per unit cross-sectional area and unit length is usually expressed in S/m.
12 Electrophoresis--electrophoresis cataphoresis
The migration phenomenon of the charged colloidal particles in the liquid medium relative to the liquid under the action of an external electric field.
13 electromotive force--electromotive force
The potential difference between the two poles when the primary battery is open.
14 passivation potential--passivation potential
The electric potential at which the dissolution rate of the metal anode suddenly drops when the metal electrode is polarized. Usually the corrosion current experiences a maximum value before reaching the passivation potential.
15 Corrosion potential--corrosion potential
A stable electrode potential is established spontaneously for metal materials in a specific corrosive environment.
16 current density--current density
The intensity of the current passing through the electrode per unit area is usually expressed in A/dm2.
17 current efficiency--current efficiency
When a unit of electricity passes through the electrode, the ratio of the actual mass of the electrode reaction product to the electrochemical equivalent, usually expressed in %.
18 Corrosion rate, corrosion current --corrosion rate (vcor), corrosion current (Icor)
The corrosion rate is the amount of material transformation per unit time on a specific surface of a material. Or according to Faraday's law, the corrosion rate is the current under the corrosion potential.
The corrosion current is: Icor = nFvcor;
Where: the number of electrons reacted by the n-electrode;
F-Faraday constant;
vcor-corrosion rate.
19 Electrode--electrode
A conductor placed in a conductive medium (such as electrolyte, melt, solid, or gas). Electric current flows into or out of the conductive medium through it.
20 electrode potential--electrode potential
In the standard state, a certain electrode and a standard hydrogen electrode (as the negative electrode) form a galvanic cell, and the measured electromotive force is called the hydrogen standard electrode potential of the electrode, or simply the electrode potential. The hydrogen standard electrode potential of various electrodes can indicate the relative magnitude of the potential difference between the electrode and the solution interface.
21 Electrolyte--electrolyte
It is a substance that has ionic conductivity by itself or can exhibit ionic conductivity under certain conditions (such as high temperature melting or dissolving in a solvent to form a solution).
22 Electrolyte--electrolytic solution
Solution with ion conductivity.
23 Ionization degree --degree of ionization
The ratio of the number of moles of free ions to the total number of moles of the electrolyte in the solution. Usually expressed in %.
24 Depolarization--depolarization
A phenomenon in which a certain depolarizer is added to the electrolyte solution or electrode to reduce the polarization of the electrode.
25 Balance electrode potential --equilibrium electrode potential
The electrode potential is at which the electrode reaction is in a thermodynamic equilibrium state.
26 positive electrode--positive electrode
The positive electrode of the two electrodes of the galvanic cell.
27 negative electrode--negative electrode
The electrode with the more negative potential of the two electrodes of the galvanic cell.
28 Cathode--cathode
The electrode on which the reduction reaction occurs, that is, the electrode on which the reactant obtains electrons.
29 Cathodic polarization--cathodic polarization
When a current flows, the electrode potential of the cathode shifts in a negative direction.
30 Cathodic coating--cathodic coating
A metal coating that is more positive than the electrode potential of the base metal.
31 anode--anode
The electrode on which the oxidation reaction occurs is the electrode that can accept the electrons given by the reactant.
32 anode slime--anode slime
Under the action of electric current, the insoluble residue produced in the process of anode dissolution.
33 anodic polarization--anodic polarization
When a current flows, the anode electrode potential shifts in the positive direction.
34 anodic coating--anodic coating
A metal coating that is more negative than the electrode potential of the base metal.
35 migration number --transport number
When current passes through the electrolyte solution, the ratio of the current carried by a certain ion in the solution to the total current passed is called the migration number of the ion.
36 Overpotential--overpotential
The difference between the electrode potential when the current passes through the electrode and the thermodynamic equilibrium electrode potential.
37 diffusion layer--diffusion layer
There is a thin layer of solution with a concentration gradient near the surface of the electrode when the current passes.
38 Stray current--stray current
Current flowing in other circuits (such as plating tanks or heaters) other than the circuits that need to pass current.
39 Conducting salt--conducting salt
Salt substances that can be added to the electrolyte to increase the conductivity of the solution.
40 volume current density--volume current density
The intensity of current passing through a unit volume of electrolyte solution. Usually expressed in A/L.
41 deposition rate--deposition rate
The thickness of the metal deposited on the surface of the plated part in a unit time. Usually expressed in μm/h.
42 Primary current distribution--primary current distribution
When there is no electrode polarization, the current distribution on the electrode surface.
43 local corrosion --local corrosion
Corrosion damage is mainly concentrated in local areas of the surface, while other parts are almost uncorroded.
44 Polarization--polarization
The phenomenon that the electrode potential deviates from its equilibrium value when there is current passing through the electrode.
45 Polarizability--polarizability
The rate of change of electrode potential with current density, which is equivalent to the change of electrode potential caused by changing unit current density.
46 Polarization curve--polarization curve
A curve describing the relationship between the electrode potential and the current density through the electrode.
47 Interelectrode distance--Interelectrode distance
The distance between two electrodes (positive and negative or negative and anode) in a primary cell or electrolytic cell.
48 emulsification--emulsification
A phenomenon in which a liquid is uniformly dispersed in a liquid that is immiscible with each other as tiny droplets.
49 Stress corrosion--stress corrosion
The cracking phenomenon of metal materials under the combined action of stress and corrosive environment.
50 Gassing--gassing
During the electrolysis process, there are obvious gas evolution phenomena on the electrodes.
51 activation--activation
Adjust the effective ion concentration to achieve the desired behavior to eliminate the passivation state of the electrode surface.
52 Activity--activity
In the standard state, the thermodynamic concentration of the components in the solution is the effective concentration used to correct the deviation of the properties of the real solution and the ideal solution.
53 Standard electrode potential --standard electrode potential
In the standard state, the activity (or fugacity) of all reactants and products in the electrode reaction is equal to the equilibrium electrode potential of 1.
54 Concentration polarization--concentration polarization
Polarization caused by changes in the concentration of reactants or products near the electrode surface when current flows through the electrode.
55 passivation--passivation
After the metal anode polarization exceeds a certain value in a certain solution, the metal dissolution rate not only does not increase, but drastically decreases. This process of changing the metal surface from the "active state" to the "passive state" is called passivation. The passivation caused by anodic polarization is electrochemical passivation, and the passivation caused by the action of some passivators in the solution is called chemical passivation.
56 point corrosion--spot corrosion
Pitting corrosion on the metal surface.
57 coordination compound--complex compound
Metal ions or atoms form a compound with coordination bonds with a certain number of negatively charged groups or neutral polar molecules.
58 double salt--double salt
A compound formed by two kinds of salts crystallized together in a certain proportion. It is essentially a coordination compound in the form of crystals.
59 Hydrogen embrittlement--hydrogen embrittlement
Brittleness caused by the absorption of hydrogen atoms and the presence of stress in metals or alloys.
60 Seepage hydrogen--seepage hydrogen
Metal parts often have this phenomenon of adsorption of hydrogen atoms in the process of etching, degreasing or electroplating.
61 Interracial tension--interracial tension
The force that exists between the two-phase interface to shrink the interface is called interfacial tension. If one of the phases is a gas, it is called surface tension.
62 critical current density--critical current density
Within the potential range of the electrode reaction required for electroplating, the highest or lowest current density of the reaction can be maintained. When the current density is higher than the highest current density, the potential will move beyond the required range, and new side reactions will occur. When the current density is lower than the minimum current density, the electrode reaction rate will decrease and fail to meet production requirements.
63 Half-cell--half-cell
A system composed of a single electrode and an electrolyte solution.
64 galvanic cell--galvanic cell
A device that can directly convert chemical energy into electrical energy. A primary battery can be seen as composed of two half-cells.
65 salt bridge--salt bridge
The device used to connect two half-cells to reduce the liquid junction potential is usually a glass tube containing a higher concentration of electrolyte solution (for example, a saturated KCL solution).
66 pH value--pH value
The negative value of the common logarithm of the hydrogen ion activity αH+ (or approximately the concentration), that is, pH=-logaH+.
67 base material--basis material(substrate)
A material that can deposit metal or form a film on it.
68 auxiliary anode--auxiliary anode
An additional anode used to improve the current distribution on the surface of the article to be plated.
69 auxiliary cathode--auxiliary cathode
A cathode of a certain shape is added to some parts where the current is too concentrated on the part to avoid defects such as burrs and scorching. This additional cathode is an auxiliary cathode.
70 Contact potential --contact potential
When two different conductive materials are in contact, the potential difference generated at the interface.
71 Intercrystalline corrosion--intercrystalline corrosion
Selective corrosion that occurs along the grain boundaries.
72 solubility product--solubility product
The product of the concentration of the corresponding ion in the saturated solution of the insoluble electrolyte at a certain temperature, where the power of each ion concentration is the same as its coefficient in the electrolyte ionization equation.
73 solubility--solubility
Under a certain temperature and pressure, the maximum number of grams of solute that can be dissolved in 100g of solvent.
74 micro-covering power--microcovering power
The ability of metal ions in the electroplating bath to be electrodeposited in pores or scratches under certain conditions.
75 tank voltage--tank voltage
The total potential difference between the two poles of the unit cell during electrolysis.
76 static electrode potential --static electrode potential
The electrode potential of the metal electrode in the electrolyte when no external current passes.
77 Chelate--chelate compound
A coordination compound with a cyclic structure formed by multi-position coordination between a central ion and a ligand.
78 Leveling action--1eveling action
The ability of the plating solution to make the surface of the plating layer smoother than the surface of the substrate.
79 Covering power--covering power
Under certain electroplating conditions, the ability of the bath to deposit metal to cover the entire surface of the plated part.
80 main surface--signiflcant surface
The specified surface before and after electroplating on the part. The coating on the surface is extremely important for the appearance and (or) performance of the part.
81 impulse current--striking current
The instantaneous large current passed during the electroplating process.
Material equipment
1 Softening of water--softening of water
The process of removing Ca2+ and Mg2+ plasma in water to reduce its hardness.
2 Busbar--busbar
Connect the rectifier (or DC generator) and the copper or aluminum row of the plating tank for conducting electricity.
3 Anode bag--anode bag
A cotton or chemical fiber bag that is put on the anode to prevent anode sludge from entering the solution.
4 Brightening agent (brightener)
Adding to the plating solution can obtain bright plating additives.
5 filter aid--filter aid
In order to prevent the filter residue from accumulating too densely and to make the filtration proceed smoothly, insoluble inert materials with different degrees of fineness are used.
6 Inhibitor--an inhibitor
Substances that can reduce the rate of chemical or electrochemical reactions, such as corrosion inhibitors used in strong etching.
7 Surfactant--surface active agent(surfactant)
Substances that can significantly reduce interfacial tension are often used as detergents, wetting agents, emulsifiers, dispersants, foaming agents, etc.
8 Emulsifier--emulsifying agent(emulsifier)
A substance that can reduce the interfacial tension between immiscible liquids and make them form emulsions.
9 Complexing agent--complexant
A substance that can combine with metal ions or atoms to form coordination compounds.
10 Insulation layer--insulated layer(resist)
A coating is applied to a certain part of the electrode or hanger to make the surface of the part non-conductive.
11 Hanger (fixture) --plating rack
A tool is used to mount parts so that they can be placed in a tank for electroplating or other processing.
12 Wetting agent--wetting agent
A substance that can reduce the interfacial tension between the part and the solution, and make the surface of the part easy to be wetted by the solution.
13 Centrifugal dryer--centrifuge
Equipment that uses centrifugal force to dehydrate and dry parts.
14 additives--addition agent(additive)
A small number of additives added to the plating solution can improve the electrochemical performance of the plating solution and improve the quality of the coating.
15 Buffer--buffer
A substance capable of maintaining a substantially constant pH of the solution within a certain range.
16 Mobile cathode--swept cathode
The part to be plated and the pole bar is connected together to make a cathode that periodically reciprocates.
17 Diaphragm--diaphragm
A porous membrane or semi-permeable membrane that separates the anode and cathode regions of an electrolytic cell from each other.
18 Integrating agent--chelating agent
A substance that can combine with metal ions to form a chelate.
19 leveling agent--leveling agent
In the electroplating process, the micro-flatness of the surface of the substrate can be improved to obtain an additive for a flat and smooth coating.
20 rectifier--rectifier
A device that directly converts alternating current to direct current.
Plating method
1 chemical vapor deposition chemical vapor deposition
The process of using heat to induce a chemical reaction or vapor phase reduction to condense on the substrate to produce a deposited layer.
2 physical vapor deposition physical vapor deposition
The overlayer of the cover layer is usually deposited in a high vacuum by evaporation and subsequent condensation of elemental substances or compounds.
3 chemical passivation chemical passivation
The process of treating metal parts with a solution containing an oxidant to form a thin passive protective film on the surface.
4 chemical oxidation
The process of forming an oxide film on the metal surface through chemical treatment.
5 anodizing
Metal parts are used as anodes to electrolyze in a certain electrolyte to form a layer of an oxide film with a certain function (such as protective, decorative, or other functions) on the surface.
6 electroless plating (autocatalytic plating) autocatalytic plating
A process in which metal ions in the plating solution are catalytically reduced on the surface of the activated substrate to form a metal plating layer.
7 Laser electroplating 1aser electroplating
Electroplating under the action of the laser.
8 flash (flash plate)
Very short energizing time produces electroplating of thin coatings.
9 electroplating
The process of using electrolysis to form a uniform, dense, and well-bonded metal or alloy deposited layer on the surface of the part.
10 mechanical plating
In the presence of fine metal powder and suitable chemical reagents, a hard small ball is used to hit the metal surface so that the fine metal powder covers the surface.
11 immersion plate
Metal deposits produced by the substitution reaction of one metal for another metal from a solution, such as:
Fe+Cu2+→Cu+Fe2+
12 electroforming electroforming
The process of making or replicating metal products by depositing metal on a mold through electrolysis (the mold can be separated from the metal deposit).
13 superimposed current electroplating superimposed current electroplating
Electroplating that superimposes pulse current or alternating current on direct current.
14 bright plating bright plating
Under appropriate conditions, a shiny plating layer can be obtained directly from the plating tank.
15 alloy plating alloy plating
The process of co-deposition of two or more metals (including non-metal elements) under the action of electric current.
16 multiplayer plating
Electroplating in which several metal layers of different properties or materials are deposited successively on the same substrate.
17 strike plating strike plating
A method of electrodepositing a thin metal layer in a specific solution with a high current density in a short time to improve the bonding force between the subsequently deposited plating layer and the substrate.
18 metal electrodeposition metal electrodeposition
The process of reducing the metal ions in the solution on the electrode and forming a metal phase by means of electrolysis. Including electroplating, electroforming, electrolytic refining, etc.
19 brush plating
Use an electrode or brush that is connected to the anode and can provide the electrolyte needed for electroplating, and moves on the workpiece as the cathode for selective electroplating.
20 periodic reverse plating periodic reverse plating
Electroplating in which the direction of the current changes periodically.
21 conversion coating
A surface film layer containing the metal compound formed by chemical or electrochemical treatment of a metal, such as a chromate film on zinc or cadmium or an oxide film on steel.
22 rack plating
Electroplating using hangers to hang parts.
23 composite plating (dispersion plating) composite plating
The process of simultaneously depositing metal ions and insoluble non-metal or other metal particles uniformly suspended in the solution by electrochemical or chemical methods to obtain a composite coating.
24 pulse plating pulse plating
Use pulse power instead of DC power for electroplating.
25 blueing (chemical oxide)
The process of heating steel parts in the air or immersing them in an oxidizing solution to form a blue (black) oxide film on the surface.
26 high-speed electroplating high-speed electrodeposition
In order to obtain a high deposition rate, special measures are adopted to carry out the electroplating process at a very high cathode current density.
27 barrel plating
The parts are electroplated in a rotating container. Suitable for small parts.
28 plating on plastics
The process of electrodepositing metal coatings on plastic parts.
29 phosphating
The process of forming a layer of insoluble phosphate protective film on the surface of steel parts.
Test inspection
1 Atmospheric corrosion test atmospheric corrosion test
It is a test to check the atmospheric corrosion resistance of the coating according to the specified method in the exposure field of different climatic zones.
2 Neutral salt spray test (NSS test) neutral salt spray test (NSS-test)
Use the specified neutral salt spray to test the corrosion resistance of the coating.
3 Discontinuous water film water break
The phenomenon of discontinuous water film on the surface of the part due to uneven wettability is caused by contamination. This is a way to check the degree of cleaning.
4 pH meter pH meter
An instrument for measuring the pH of a solution.
5 porosity
The number of pinholes per unit area.
6 internal stress
During the electroplating process, the crystal structure of the coating is changed due to various reasons, so that the coating is stretched or compressed, but the coating has been fixed on the substrate, so the coating is in a stressed state. This internal force acting on the coating is called internal stress.
7 conductivity gauge
An instrument for measuring the conductivity of an electrolyte solution.
8 coulomb meter (coulomb meter) coulomb meter
An instrument that measures the amount of electricity passed according to the mass or volume (for gas) of the precipitate on the electrode during the electrolysis process.
9 rotating disk electrode rotating disk electrode
An electrode for measuring the diffusion coefficient and electrochemical parameters of the solution system. It embeds a metal rod in a concentric plastic cylinder. The bottom surface of the metal rod is the working surface of the electrode. The electrode is connected with the rotating shaft of the rotating motor. Axis. In this way, the liquid phase close to the working surface of the electrode when the electrode rotates establishes a uniform and stable diffusion layer whose thickness is related to the rotation speed.
10 rotating ring disk electrode rotating ring disk electrode
The ring disk electrode is an electrode with a concentric ring on the working surface of the disk electrode, and the ring and the disk are separated by a thin layer of insulating material. The ring electrode is used to detect the soluble reaction products on the disk electrode, and the ring disk electrode is also a commonly used electrode for electrochemical testing.
11 pores
From the surface of the coating to the bottom of the coating or the tiny holes of the base metal.
12 copper accelerated salt spray (CASS test) copper accelerated salt spray (CASS test).
An accelerated corrosion test with a specified sodium chloride aqueous solution containing copper salt and acetic acid as a spray.
13 reference electrode reference electrode
The balanced electrode potential is very stable and highly reversible half-cell, which can form a galvanic cell with the other half-cell to determine the electrode potential of the latter.
14 calomel electrode
A half-cell composed of mercury, mercurous chloride, and potassium chloride solution of a certain concentration (such as a saturated solution).
15 Solderability solderability
The ability of the coating surface to be wetted by molten solder.
16 hardness
The ability of the coating to resist other objects being scratched or pressed into its surface is an important mechanical property of the coating. According to different measurement methods, different values can be used to express hardness, such as Brinell hardness, Rockwell hardness, Vickers hardness, Shore hardness, and Knoop hardness. Hardness is usually measured by a microhardness tester.
17 Metal discoloration tarnish
Changes in the color of the metal or plating surface due to corrosion, such as darkening, loss of color, etc.
18 dropping corrosion test dropping corrosion test
A test method for testing the corrosion resistance of the protective layer on the surface of the sample by dropping a specific corrosive liquid on the surface of the sample in a controlled manner.
19 glass electrode
An electrode that uses a thin glass membrane to separate two solutions to produce a potential difference is often used to measure the pH of the solution.
20 adhesion
The measurement of the bonding strength between the coating and the base material can be expressed by the force required to separate the coating from the base.
21 Haring cell
A rectangular tank made of insulating material. The anode in the tank corresponds to the two cathodes far and near. It is a device used to estimate the dispersion capacity of the plating solution and the polarization of the electrode.
22 potentiostatic method
In order to obtain the relationship curve between electrode potential and current density, the electrode potential of the research electrode can be controlled to change according to a certain law, and the corresponding current density can be measured at the same time.
23 galvanostatic method
In order to obtain the relationship curve between the current density and the electrode potential, the current density of the research electrode can be controlled to change according to a certain law, and the corresponding electrode potential can be measured at the same time.
24 AC current method a.c method
It is a method to excite the electrode with a small amplitude sine wave alternating current, and from the response of its electrode potential, some parameters of the electrode process can be obtained.
25 dendritic trees
Rough, loose dendritic, or irregularly raised deposits formed on the cathode (especially the edges and other high current density areas) during electroplating.
26 brittleness
The ability of the coating to withstand the degree of deformation is mainly determined by the coating material
